CN117794609A

CN117794609A - Expandable sheath for introducing an intravascular delivery device into a body

Info

Publication number: CN117794609A
Application number: CN202280055037.7A
Authority: CN
Inventors: D·迈蒙; E·布尔曼; S·特兰; I·塔米尔; J·S·李; M·H·法恩; N·W·萨利赫; S·马克; T·T·阮
Original assignee: Edwards Lifesciences Corp
Current assignee: Edwards Lifesciences Corp
Priority date: 2021-06-10
Filing date: 2022-06-09
Publication date: 2024-03-29

Abstract

Aspects of the expandable sheath may be used in conjunction with a catheter assembly to introduce a prosthetic device, such as a heart valve, into a patient. These aspects may minimize damage to the vessel by allowing a portion of the introducer sheath to temporarily expand to accommodate the delivery device, and then return to the original diameter once the prosthetic device is passed. Some aspects may include a sheath having a tubular liner wound in a helical spool slidable configuration. The disclosed sheath is configured to expand from a predetermined resting diameter dT to an expanded diameter de during application of a radially outward force through the sheath by a medical device.

Description

Expandable sheath for introducing an intravascular delivery device into a body

Cross reference to related applications

The present application claims the benefit of U.S. provisional application Ser. No. 63/209,337, filed on 6-month 10 of 2021, U.S. provisional application Ser. No. 63/214,605, filed on 6-month 24 of 2021, U.S. provisional application Ser. No. 63/214,349, and U.S. provisional application Ser. No. 63/323,429, filed on 3-month 24 of 2022, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present application relates to aspects of sheaths for use with catheter-based techniques for repairing and/or replacing heart valves, and for delivering prosthetic devices, such as prosthetic valves, to the heart via the vasculature of a patient.

Background

Endovascular delivery catheter assemblies are used to implant prosthetic devices, such as prosthetic valves, at locations inside the body that are not readily accessible for surgery or where access is desired without invasive surgery. For example, aortic, mitral, tricuspid and/or pulmonary prosthetic valves can be delivered to a treatment site using minimally invasive surgical techniques.

The introducer sheath may be used to safely introduce the delivery device into the vasculature (e.g., femoral artery) of a patient. The introducer sheath typically has an elongated cannula inserted into the vasculature, and a housing that receives one or more sealing valves that allow the delivery device to be in fluid communication with the vasculature with minimal blood loss. Conventional introducer sheaths typically require that a tubular loader be inserted through a seal in the housing to provide an unobstructed path through the housing for a valve mounted on the balloon catheter. Conventional loaders extend from the proximal end of the introducer sheath, thus reducing the usable working length of the delivery device that can be inserted into the body through the sheath.

Conventional methods of accessing a vessel, such as the femoral artery, prior to introducing a delivery system involve dilating the vessel using multiple dilators or sheaths of progressively larger diameter. Such repeated insertion and vessel dilation can increase the time spent in the procedure, as well as the risk of damaging the vessel.

Radially expanded intravascular sheaths have been disclosed. Such sheaths often have complex mechanisms, such as a ratchet mechanism, which maintains the shaft or sheath in the expanded configuration once a device having a diameter greater than the initial diameter of the sheath is introduced.

However, delivery to and/or removal of prosthetic devices and other materials from a patient still poses significant risks to the patient. Furthermore, access to the vessel remains a challenge due to the relatively large profile of the delivery system, which can lead to longitudinal and radial tearing of the vessel during insertion. The delivery system may also remove calcified plaque within the vessel, thereby posing a risk of clotting blocks caused by the removed plaque.

Accordingly, there remains a need in the art for an improved introducer sheath for an intravascular system for implantation of valves and other prosthetic devices.

Disclosure of Invention

In certain aspects, disclosed herein is an expandable sheath that can minimize damage to a vessel by allowing a portion of an introducer sheath to temporarily expand to accommodate a delivery system, and then return to an original diameter once the delivery system is passed through. Aspects of the present disclosure relate to a sheath having a smaller profile than prior art introducer sheaths. It should be appreciated that in certain aspects, the use of the sheaths disclosed herein may reduce the length of time spent in surgery, as well as reduce the risk of longitudinal or radial vessel tearing or plaque displacement, as only one sheath is required, rather than several sheaths of different sizes. In a further aspect, the guidance of the expandable sheath disclosed herein requires only one vessel insertion, rather than multiple insertions to expand the vessel.

Aspects of the present disclosure relate to a sheath for guiding a prosthetic device, wherein the sheath may include an inner liner and an outer layer. At least a portion of the sheath may be designed or configured to locally expand from a first diameter (resting diameter) to a second diameter (expanded diameter) as the prosthetic device is pushed through the lumen of the sheath, and then return at least partially to the first diameter once the prosthetic device has passed through.

Also disclosed herein is a sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end, and comprises: a tubular liner having a longitudinal slit extending along a length of the tubular liner such that the tubular liner is wound in a helical reel configuration; wherein the longitudinal slit forms a first longitudinal edge and a second longitudinal edge of the tubular liner; wherein in the spiral reel configuration at least a portion of the inner surface of the liner helically covers at least a portion of the outer surface of the liner, and wherein theThe first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner; wherein the inner surface of the tubular liner defines a lumen of the sheath; and wherein the tubular liner is configured to move from a resting diameter d during application of a radially outward force by a medical device through the lumen of the liner by sliding the first edge of the liner in a spiral along at least a portion of the inner surface and sliding the second edge of the liner in a spiral along at least a portion of the outer surface of the liner _r Expanded to an expanded diameter d _e 。

In a further aspect, the tubular liner of the disclosed sheath is configured to expand without substantially forming a gap between the first and second longitudinal edges of the tubular liner. In yet further aspects, the tubular liner of the disclosed sheath is further configured to bend as it passes through the natural anatomy of the patient without forming a gap between the first and second longitudinal edges of the tubular liner.

In a further aspect, the longitudinal slit in the tubular liner extends from a proximal end of the tubular liner to a distal end of the tubular liner in a direction offset from a longitudinal axis of the tubular liner. In a further aspect, the helical configuration of the tubular liner may have a predetermined pitch.

In further aspects, the sheaths disclosed herein can further comprise an outer layer. In such exemplary and non-limiting aspects, the outer layer may comprise one or more layers.

Also disclosed herein are aspects including a method of manufacturing a sheath having a proximal end and a distal end, the method comprising: the tubular liner is formed by: i) By cutting the circumference of an elongate single lumen tube between its proximal and distal ends in a direction offset from the longitudinal axis of the elongate single lumen tube to form a first longitudinal edge and a second longitudinal edge A longitudinal slit; ii) winding the elongated single lumen tube having the longitudinal slit into a tubular liner having a helical spool configuration such that at least a portion of an inner surface of the liner helically covers at least a portion of an outer surface of the liner, and wherein the first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner, wherein an inner surface of the tubular liner defines a lumen of the sheath; and wherein the tubular liner is configured to move from a resting diameter d during application of a radially outward force by a medical device through the lumen of the liner by sliding the first edge of the liner in a spiral along at least a portion of the inner surface and sliding the second edge of the liner in a spiral along at least a portion of the outer surface of the liner _r Expanded to an expanded diameter d _e 。

In a further aspect, the winding step includes positioning the elongated single lumen tube having the longitudinal slit over a mandrel having a predetermined diameter to form the helical configuration, wherein the predetermined diameter of the mandrel and a rest d of the liner _r Substantially the same. In a further aspect, the formed tubular liner is configured to expand without substantially forming a gap between the first and second longitudinal edges of the tubular liner. In yet a further aspect, the formed tubular liner is configured to bend when passing through the natural anatomy of a patient without forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

In a further aspect, the methods disclosed herein further comprise disposing an outer layer over at least a portion of the outer surface of the liner. In yet further exemplary aspects, the methods disclosed herein may include disposing a braid at least a portion of the outer surface of the tubular inner layer prior to disposing the outer layer. In further aspects, the method may further include disposing the outer layer over the braid and at least partially embedding the braid within the outer layer. In further aspects, the method may further include disposing a lubricant on at least a portion of the outer surface of the liner prior to disposing the outer layer. In such exemplary aspects, the method may include disposing a lubricant on at least a portion of the outer surface of the liner prior to disposing the braid or after disposing the braid.

Also disclosed herein is a method of delivering a prosthetic device to a surgical site, the method comprising at least partially inserting an expandable sheath into the vasculature of the patient, the expandable sheath being in accordance with any of the examples herein; locally expanding the tubular liner by sliding the first longitudinal edge and the second longitudinal edge during passage of the prosthetic device; and locally collapsing the sheath from a locally expanded state to an unexpanded state after passage of the prosthetic device.

Additionally or alternatively, the medical device may be a prosthetic heart valve mounted on the delivery apparatus in a radially crimped state, and the act of advancing the medical device through the sheath includes advancing the delivery apparatus and the prosthetic heart valve into the vasculature of the patient.

The foregoing and other features and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

Drawings

Fig. 1 is an elevation view of a sheath according to the present disclosure and an intravascular delivery device for implanting a prosthetic valve.

Fig. 2A and 2B are cross-sectional views of aspects of a sheath for introducing a prosthetic device into a patient, and fig. 2C is a perspective view of one component of the sheath.

Fig. 3A, 3B and 3C are front views of three aspects of a sheath according to the present disclosure having a uniform and varying resting diameter d _r 。

Fig. 4A-4D illustrate partial elevation views of various exemplary aspects of braid structures with various PICs in accordance with the present disclosure.

Fig. 5A and 5B illustrate cross-sectional views of one aspect of an exemplary liner. Fig. 5A depicts an unexpanded configuration, while fig. 5B depicts an expanded configuration.

Fig. 6A-6E and 6H illustrate cross-sectional views of various aspects of an exemplary sheath. Fig. 6F, 6G, and 6I illustrate perspective views of various aspects of an exemplary sheath.

Fig. 7 illustrates a block diagram of one aspect of a method of manufacturing a sheath in accordance with the present disclosure.

Fig. 8 illustrates a block diagram of another aspect of a method of manufacturing a sheath according to the present disclosure.

Fig. 9A-9K show cross-sectional or side views of various method steps of the method shown in fig. 7-8.

Fig. 10 is a front view of an expandable sheath and representative housing according to the present disclosure.

Fig. 11 is an enlarged cross-sectional view of the distal end of the sheath of fig. 10.

Fig. 12A-12D are cross-sectional views of the distal end of the example sheath of fig. 14, taken along line 37-37 in fig. 11.

Fig. 13A-13D are cross-sectional views of the proximal section of the sheath of fig. 10 taken along line 38-38 in fig. 11.

Fig. 14 is a cross-sectional view of the sheath of fig. 10 in a resting (unexpanded) configuration, taken along line 39-39 in fig. 11.

Fig. 15 shows a cross-sectional view of the sheath of fig. 14 in an expanded configuration.

Fig. 16 shows experimental data for an exemplary sheath of one aspect.

Fig. 17 shows experimental data for an exemplary sheath of another aspect.

Fig. 18 depicts the inner liner of an exemplary sheath in one aspect of a collapsed and unexpanded configuration.

Fig. 19 depicts a cross-sectional view of an exemplary sheath of one aspect, showing the inner liner and outer layer as shown in fig. 18.

Fig. 20A-20C depict exemplary manufacturing steps of the liner as shown in fig. 18.

21A-21B depict an exemplary sheath of one aspect showing the inner and outer layers in collapsed and unexpanded configurations. Fig. 21A shows a schematic cross-sectional view of the sheath, and fig. 21B depicts a schematic side view of the sheath.

Fig. 22A-22B depict an exemplary sheath of one aspect. FIG. 22A shows a schematic diagram of a cross-sectional view of the sheath in a collapsed configuration (left side) and an expanded configuration (right side); fig. 22B shows a snapshot of an exemplary sheath expanded during passage of a medical device.

Fig. 23 depicts a schematic cross-sectional view of an exemplary sheath of an aspect.

24A-24B depict cross-sectional schematic views of an exemplary sheath of one aspect.

Figures 25A-25H depict various liner combinations of the exemplary sheath. FIGS. 25A-25D illustrate cross-sectional views of various liners prior to formation of an exemplary liner; figures 25E-25H illustrate various cross-sectional views of an exemplary liner in a spiral configuration.

FIG. 26 depicts a side view of an exemplary lubricant pattern disposed on an exemplary liner, in accordance with an aspect.

27A-27B depict cross-sectional views of an exemplary sheath in a collapsed configuration (FIG. 27A) and an expanded configuration (FIG. 27B) with bonding between an inner liner and an outer liner.

Fig. 28A-28C depict various methods of forming a bond between the inner liner and the outer layer of an exemplary sheath.

Fig. 29A-29F depict schematic views of the stiffening sheath effect (fig. 25A-25D) and the bulge shield effect (fig. 25A-25B and 25E-25F) on the anatomy of a patient.

30A-30B depict schematic diagrams of an aspect of a reinforcement sheath present in an exemplary sheath.

Fig. 31 depicts a method of making an exemplary sheath in one aspect.

Fig. 32 depicts an exemplary sheath of an aspect.

Fig. 33 depicts an exemplary sheath of an aspect.

Fig. 34 depicts an exemplary sheath of an aspect.

Fig. 35 is a cross-sectional view of an exemplary sheath according to another aspect.

Fig. 36 is a cross-sectional view of an exemplary sheath according to another aspect.

Fig. 37 is a front view of an exemplary outer layer according to another aspect.

Fig. 38 is a cross-sectional view of an exemplary elongate tube taken along section line A-A of fig. 37.

FIG. 39 is a cross-sectional view of an exemplary outer layer in a resting (unexpanded) configuration, taken along section line B-B of FIG. 37.

FIG. 40 is a partial cross-sectional view of an exemplary outer layer of an aspect.

FIG. 41 is a cross-sectional view of another exemplary outer layer in a resting (unexpanded) configuration containing a single reinforcing member, taken along section line B-B of FIG. 37.

Fig. 42A-42C illustrate an exemplary sheath having a two-layer construction in one aspect.

43A-43B illustrate an exemplary sheath having at least one bond site on an inner surface of an outer layer in one aspect.

FIG. 44 is a side elevation view of an exemplary sheath having a proximal section and a tip section in an unexpanded configuration.

Fig. 45 is a perspective view of the tip section of the sheath of fig. 44 in an unexpanded configuration.

FIG. 46 is another perspective view of the example sheath of FIG. 44 with the tip section in an expanded configuration.

Fig. 47 is a side elevational view of the tip section of the sheath of fig. 44 in a separated configuration.

Fig. 48 is a perspective view of the tip section of the sheath of fig. 44 in a separated configuration.

Fig. 49 is a plan view of an inner liner having a cutout for forming a tip section.

Fig. 50 is a perspective view of the inner liner of fig. 49 in a rolled configuration.

Fig. 51 is a top plan view of the inner liner of fig. 50.

Fig. 52 is an enlarged view of a portion of the inner liner of fig. 51.

Fig. 53 is a plan view of the liner with the additional section removed to shape the tip section.

Fig. 54 is a side elevation view of a rolled liner having another aspect of a partially formed distal tip section.

Fig. 55 is a perspective view of the distal tip section of fig. 54.

Fig. 56 is a top plan view of the distal tip section of fig. 54.

Fig. 57 is an enlarged view of a portion of fig. 56.

FIG. 58 is a side elevational view of the distal tip section of FIG. 54 receiving an intermediate layer for further shaping the distal tip section.

Fig. 59 is a side elevational view of the distal tip section of fig. 58 further assembled.

Fig. 60 is a perspective view of the distal tip section of fig. 59 with an intermediate layer formed, for example, by flow melt.

Fig. 61 is a side elevational view of the distal tip section of fig. 60.

Fig. 62 is a top plan view of the distal tip section of fig. 60.

Fig. 63 is a schematic view of an assembly process of a distal tip section of an expandable delivery sheath of another aspect of the present invention, including rolling and scoring an inner liner.

FIG. 64 is a schematic view of an assembly process, including placement of an intermediate tie layer on a formed liner and incorporation of a radiopaque marker into the distal tip section.

Fig. 65 is a schematic view of an assembly process, including further shaping an intermediate layer of the distal tip section.

Fig. 66 is a side elevation view of a distal tip section of another aspect of an expandable delivery sheath.

FIG. 67 is a side elevation view of an inner layer in which an intermediate layer is at least partially formed into a distal tip section.

Fig. 68 is a cross-sectional view of a tube for forming an intermediate layer of another aspect.

FIG. 69 is a cross-sectional view of a tube for forming another aspect of an intermediate layer having three sublayers.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description, examples, figures and claims, and their previous and following description. However, before the articles, systems, and/or methods of the present disclosure are disclosed and described, it is to be understood that this disclosure is not limited to specific or exemplary aspects of the disclosed articles, systems, and/or methods, unless otherwise specified, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing various aspects only and is not intended to be limiting.

The following description of the present disclosure is provided as an enabling teaching of the present disclosure in its best, presently known aspects. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the disclosure described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, one of ordinary skill in the relevant art will recognize that many modifications and variations to the present disclosure are possible, and in some cases may even be desirable, and are part of the present disclosure. The following description is, therefore, again provided as illustrative of the principles of the present disclosure, and not in limitation thereof.

Definition of the definition

As used in this application and the claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a polymer" includes aspects having two or more such polymers unless the context clearly indicates otherwise.

It is also to be understood that the terminology used herein is for the purpose of describing various aspects only and is not intended to be limiting. As used in the specification and claims, the term "comprising" may include aspects consisting of … … and consisting essentially of … …. In addition, the term "comprising" means "including".

For the terms "e.g." and grammatical equivalents thereof, the phrase "and not limited to" is to be construed as conforming, unless specifically stated otherwise.

References in the specification and conclusive claims to parts by weight of a particular element or component in a composition or article denote the relationship by weight between that element or component and any other element or component in the composition or article, expressed in parts by weight. Thus, in a composition or selected portion of a composition comprising 2 parts by weight of component X and 5 parts by weight of component Y, X and Y are present in a weight ratio of 2:5, and are present in that ratio whether or not additional components are included in the composition.

Unless specifically stated to the contrary, the weight percentages of the components are based on the total weight of the formulation or composition in which the components are included.

Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will also be understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

Throughout this disclosure, various aspects of the invention may be presented in a range format. It should be understood that the description of the range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all possible sub-ranges as well as individual values within the range. For example, a description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual values within the range such as 1, 2, 2.7, 3, 4, 5, 5.3, 6, and any whole and partial increments therein. This applies regardless of the width of the range.

As used herein, the term "substantially" when used in reference to a composition means at least about 80 wt%, at least about 85 wt%, at least about 90 wt%, at least about 91 wt%, at least about 92 wt%, at least about 93 wt%, at least about 94 wt%, at least about 95 wt%, at least about 96 wt%, at least about 97 wt%, at least about 98 wt%, at least about 99 wt%, or about 100 wt%, of the particular feature or component, based on the total weight of the composition.

As used herein, the term "substantially", e.g., in the context of "substantially free of, means that the composition has less than about 1 wt%, e.g., less than about 0.5 wt%, less than about 0.1 wt%, less than about 0.05 wt%, or less than about 0.01 wt% of the material, based on the total weight of the composition.

As used herein, the term "substantially identical reference composition" or "substantially identical reference article" refers to a reference composition or article that includes substantially identical components but in the absence of the components of the present invention. In another exemplary aspect, the term "substantially", e.g., in the context of "substantially identical reference compositions", refers to reference compositions that include substantially identical components, and in which the components of the present invention are replaced by components common in the art.

Furthermore, the terms "coupled" and "associated" generally mean an electrical, electromagnetic, and/or physical (e.g., mechanical or chemical) coupling or linkage, and do not exclude the presence of intermediate elements between the coupled or associated items.

As used herein, the term "atraumatic" is well known in the art and refers to a device or procedure that minimizes tissue damage.

As used herein, the term or phrase "effective," "effective amount," or "condition effective for … …" refers to such an amount or condition that is capable of achieving the function or property indicated by the effective amount or condition. As will be noted below, the exact amount or particular conditions required will vary from aspect to aspect, depending on recognized variables such as the materials used and the processing conditions observed. Thus, it is not always possible to specify an exact "effective amount" or "condition effective for … …". However, one of ordinary skill in the art will readily determine a suitable effective amount using only routine experimentation.

Although the operations of the exemplary aspects of the disclosed methods may be described in a particular sequential order for ease of presentation, it should be understood that the disclosed aspects may encompass an order of operations other than the particular sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Furthermore, the description and disclosure provided in connection with a particular aspect is not limited in this regard and may be applied to any aspect disclosed.

Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed systems, methods, and apparatus can be used in conjunction with other systems, methods, and apparatus (as would be readily recognized by one of ordinary skill in the art based on the present disclosure). In addition, the present specification sometimes uses terms such as "generate" and "provide" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that may be performed. The actual operations corresponding to these terms may vary depending on the particular embodiment and are readily discernable to one of ordinary skill in the art based on this disclosure.

Sheath sleeve

Disclosed herein is one aspect of a sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end, and comprises: a) An inner liner defining a first diameter d at rest _r And a second expanded diameter d _e Wherein the lumen is configured to receive and pass through a medical device, wherein the liner comprises a sheet comprising a first portion having a first surface and an opposing second surface, wherein a first end portion of the first portion is divided into a first segment having the first surface and the opposing second surface, and a third segment having the first surface and the opposing second surface, and wherein a second end portion of the first portion extends into the second segment having the first surface and the opposing second surface, wherein the sheet is wound into a spiral configuration such that at least a portion of the first surface of the second segment overlaps at least a portion of the second surface of the first segment, wherein at least a portion of the first surface of the third segment overlaps with at least a portion of the second surface of the second segmentAt least a portion of the second surface overlaps, and wherein at least a portion of the first surface of the third segment overlaps at least a portion of the second surface of the first segment, wherein the first surface of the first segment extends into the first surfaces of the first segment, the second segment, and the third segment, and wherein the second surface of the first segment extends into the second surfaces of the second segment and the third segment; wherein each segment is configured to slidably move along each other as the medical device passes through the lumen; wherein the sheet comprises a polymer layer; and an outer layer.

In certain aspects, the resting diameter d may be substantially uniform along the longitudinal axis of the lumen. In other aspects, the resting diameter d _r Along the longitudinal axis of the lumen, and wherein the resting diameter d at the proximal end _r Greater than the resting diameter d at the distal end _r . In one disclosed aspect, the expanded diameter d _e Configured to accommodate passage of a medical device through the lumen. In yet another aspect, the sheath is collapsible to a predetermined resting diameter d after the medical device has been passed through the lumen _r 。

In one disclosed aspect, the sheet of the sheath comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In yet another aspect, the sheet may have a multi-layer structure. In a further aspect, the inner surface of the sheet is at least partially ribbed.

In one exemplary aspect, the sheet is smooth and has a coefficient of friction of less than about 0.5.

In yet another aspect, an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer. In other disclosed aspects, an amount of a second lubricant may be disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portion of the sheet.

In other disclosed aspects, the outer surface of the elastomeric polymer layer can define at least a portion of the outer surface of the outer layer. In some disclosed aspects, at least a portion of the inner surface of the elastomeric polymer layer is at least partially bonded to at least a portion of the outer surface of the sheet of the liner. In further aspects, at least a portion of the inner surface of the elastomeric polymer layer can define at least a portion of the inner surface of the outer layer. In yet other aspects, at least a portion of the braid or coil may define at least a portion of the inner surface of the outer layer.

In one disclosed aspect, the sheath can further include a first strip of elastomeric polymer disposed along at least a portion of the longitudinal axis of the lumen between at least a portion of the outer surface of the sheet excluding the covered portion of the sheet and the inner surface of the outer layer. In other aspects, the sheath may further comprise a second strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the proximal end of the sheath and the inner surface of the outer layer. In yet other aspects, the sheath may further comprise a third strip of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the distal end of the sheath and the inner surface of the outer layer.

In a further aspect, the braid or coil is an expandable braid or coil. In further aspects, the braid or coil may include at least one filament comprising stainless steel, nitinol, a polymeric material, or a composite material. In certain aspects, at least one filament may be a round filament or a flat filament. In aspects wherein at least one filament comprises a polymeric material, the polymeric material may be polyester or nylon. In aspects wherein at least one filament is round, the round filament may have a diameter of less than about 0.015 ". While in aspects where at least one filament is flat, the flat filament may have a height of less than about 0.006 "and a width of greater than about 0.003" to about 0.015 ". In further aspects, the braid may have a number of crossovers Per Inch (PIC) of less than 50. In further aspects, the PIC of the braid may vary along the longitudinal axis of the lumen.

In a further aspect, where at least one of the filaments is nitinol, nitinol is d _e And (5) heat setting. In other aspects, where the at least one filament comprises stainless steel or nitinol, the filament may be configured to be atraumatic at least at the distal end of the sheath.

In other aspects, the elastomeric polymer present in the outer layer comprises a styrene-based elastomer, polyurethane, latex, copolymers thereof, blends thereof, or co-extrudates thereof. In one aspect, the elastomeric polymer exhibits a shore a hardness of less than 90. In certain aspects, the braid or coil may be at least partially embedded within at least a portion of the elastomeric polymer layer. However, in other aspects, a hydrophilic coating may be disposed on the outer surface of the outer layer.

Also disclosed herein is one aspect including a method of making a sheath having a proximal end and a distal end. In certain aspects, a method of making such a sheath comprises: forming a variable diameter liner by rolling up a sheet having a first edge and a second edge, and wherein the sheet is defined by an inner surface and an outer surface, is of a helical configuration such that at least a portion of the inner surface of the sheet overlies at least a portion of the outer surface of the sheet, thereby forming an overlying portion, and wherein the first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the sheath, the lumen having a longitudinal axis; forming an outer layer having an inner surface and an outer surface and extending around at least a portion of the variable diameter liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the liner, wherein the outer layer comprises: a braid or coil; and an elastomeric polymer layer having a predetermined thickness and having an inner surface and an outer surface; wherein the variable diameter liner is configured to move from a predetermined resting diameter d during application of a radially outward force by the medical device through the lumen of the liner by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface _r Expanded to an expanded diameter d _e 。

In some exemplary aspects, the step of forming the variable liner includes winding a sheet material on a mandrel having a predetermined diameter to form a helical configuration, the predetermined diameter of the mandrel and the predetermined diameter d of the liner _r Substantially the same. In a further aspect, the resting diameter d _r Is substantially uniform along the longitudinal axis of the lumen. WhileIn other aspects, the resting diameter d _r Along the longitudinal axis of the lumen, and wherein the resting diameter d at the proximal end _r Greater than the resting diameter d at the distal end _r . In a further aspect, the expanded diameter d of the sheath _e Configured to accommodate passage of a medical device through the lumen. In yet other aspects, the sheath formed by the methods disclosed herein may be contracted to a predetermined resting diameter d after the medical device is passed through the lumen _r 。

In a further aspect, the step of forming the outer layer includes installing a braid or coil over the inner liner. In a further aspect, the step of forming the outer layer further comprises mounting the elastomeric polymer on a woven fabric or coil. In some exemplary aspects, the methods disclosed herein may further comprise at least partially embedding the braid or coil within at least a portion of the elastomeric polymer layer. In other exemplary aspects, the step of forming the outer layer may include installing the elastomeric polymer layer on a braid or coil, and then installing the elastomeric polymer layer and braid or coil on a liner positioned over the mandrel. In such exemplary aspects, the method may further comprise at least partially embedding the braid or coil within at least a portion of the elastomeric polymer layer prior to installing the elastomeric polymer layer and the braid or coil on the liner. In yet other aspects, the method may further comprise at least partially embedding the braid or coil within at least a portion of the elastomeric polymer layer prior to installing the elastomeric polymer layer and the braid or coil on the liner. In a further aspect, the sheath is removed from the mandrel after the outer layer is installed on the liner and the bonding is complete.

In other aspects, in the methods disclosed herein, the outer surface of the elastomeric polymer layer can define at least a portion of the outer surface of the outer layer. However, in other aspects, in the methods disclosed herein, at least a portion of the inner surface of the elastomeric polymer layer can define at least a portion of the inner surface of the outer layer. Aspects are further disclosed herein in which at least a portion of the braid or coil may define at least a portion of an inner surface of the outer layer.

In certain aspects, the methods disclosed herein further comprise bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. In one aspect, bonding is performed by heating at a temperature of about 350°f to about 550°f for a period of time effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner.

In one aspect, a method as described herein includes applying a first strip of elastomeric polymer to at least a portion of an outer surface of a sheet that does not include a cover portion along at least a portion of a longitudinal axis of a lumen before or during the step of bonding at least a portion of an inner surface of an elastomeric polymer layer to at least a portion of an outer surface of a sheet of a liner. In other aspects, a second strip of elastomeric polymer may be applied to at least a portion of the outer surface of the sheet at the proximal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. In a further aspect, a third strip of elastomeric polymer may be applied to at least a portion of the outer surface of the sheet at the distal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner.

In a further aspect and as described herein, prior to the step of forming the outer layer, an amount of a first lubricant may be applied to at least a portion of the inner liner such that the amount of the first lubricant is disposed in the sheath between at least a portion of the inner liner and at least a portion of the outer liner. In yet other aspects, an amount of a second lubricant is applied to at least a portion of the overlying portion and the sliding portion of the sheet prior to the step of forming the outer layer.

In other aspects, in the methods described herein, the sheet material can comprise high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In other aspects, the sheet may have a multi-layer structure. In a further aspect, the inner surface of the sheet may be at least partially ribbed. In other aspects, the sheet may be smooth and have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, or less than about 0.1.

In further aspects, the methods disclosed herein comprise a braid or coil, wherein the braid or coil is an expandable braid or coil. In further aspects, the braid or coil of the disclosed method can include at least one filament comprising stainless steel, nitinol, polymeric material, or composite material. In certain aspects, at least one filament may be a round filament or a flat filament. In certain aspects, the polymeric material present in the braid may be polyester or nylon. In aspects where at least one filament is a round filament, such a filament may have a diameter of less than about 0.015 ". In other aspects, wherein at least one filament is a flat filament, such a filament can have a height of less than about 0.006 "and a width of greater than about 0.003" to about 0.015", including exemplary values of about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.010", about 0.011", about 0.012", about 0.013", and about 0.014". In aspects of the methods disclosed herein, the braid may have a number of crossovers Per Inch (PIC) of less than 50, less than 45, less than 40, or even less than 35. In further exemplary aspects, the PIC may vary along the longitudinal axis of the lumen.

In aspects wherein at least one of the filaments comprises nitinol, nitinol is d _e And (5) heat setting. In aspects wherein at least one filament comprises stainless steel or nitinol, the filament is configured to be atraumatic at least at the distal end of the sheath.

In a further aspect, the methods disclosed herein include elastomeric polymers including styrene-based elastomers, polyurethanes, latexes, copolymers thereof, blends thereof, or co-extrudates thereof. In further aspects, the elastomeric polymer may exhibit a shore a hardness of less than 90. In further aspects, the method can further include disposing a hydrophilic coating on an outer surface of the elastomeric polymer layer.

In some methods, a soft tip portion may be coupled to a distal end of the expandable sheath to facilitate passage of the expandable sheath through the vasculature of the patient.

The disclosed aspects of the expandable sheath may minimize damage to the vessel by allowing a portion of the introducer sheath to temporarily expand to accommodate the delivery system, and then return to the original diameter once the device is passed. Some aspects may include a sheath having a smaller profile (e.g., having a smaller diameter in a resting configuration) than prior art introducer sheaths. Furthermore, aspects of the present invention may reduce the length of time spent in surgery, as well as reduce the risk of longitudinal or radial vessel tearing or plaque displacement, since only one sheath is needed instead of several sheaths of different sizes. In aspects of the invention, the expandable sheath may avoid the need for multiple insertions to dilate the vessel. Such an expandable sheath may be used in many types of minimally invasive procedures, such as any procedure requiring the introduction of a device into a subject's vessel. For example, the sheath may be used to introduce other types of delivery devices for placement of various types of intraluminal devices (e.g., stents, prosthetic heart valves, stent grafts, etc.) into many types of vascular and non-vascular body lumens (e.g., veins, arteries, esophagus, bile ducts, intestines, urethra, fallopian tubes, other endocrine or exocrine tubes, etc.).

Fig. 1 illustrates a sheath 8 according to the present disclosure for use with a representative delivery apparatus 10 for delivering a prosthetic device 12, such as a tissue heart valve, to a patient. The apparatus 10 may include a steerable guide catheter 14 (also referred to as a curved catheter), a balloon catheter 16 extending through the guide catheter 14, and a nasal catheter 18 extending through the balloon catheter 16. The guide catheter 14, balloon catheter 16, and nasal catheter 18 in the illustrated aspects are adapted to slide longitudinally relative to one another to facilitate delivery and positioning of the valve 12 at an implantation site within a patient, as described in detail below. Typically, the sheath 8 is inserted through the skin of the patient into a vessel (e.g., a trans-femoral vessel) such that the distal end of the sheath 8 is inserted into the vessel. The sheath 8 may contain a hemostatic valve at the opposite proximal end of the sheath. The delivery apparatus 10 may be inserted into the sheath 8 and the prosthetic device 12 may then be delivered and implanted in the patient.

Fig. 2A and 2B illustrate cross-sectional views of aspects of two exemplary sheaths disclosed herein for use with a delivery device such as that shown in fig. 1. Fig. 2C illustrates a perspective view of one aspect of a liner 202 for use with the disclosed sheath. As shown in fig. 2A-2C, in some aspects, the disclosed sheath includes an inner liner 202 that is wound in a helical configuration such that at least a portion of an inner surface of the sheet covers at least a portion of an outer surface of the sheet, thereby forming a covered portion 202C, and wherein a first edge 202A of the sheet is slidable along at least a portion of the inner surface of the sheet and a second edge 202b is slidable along at least a portion of the outer surface of the sheet. The sheath as shown in fig. 2A and 2B may also include an outer layer comprising a braid (or coil) 204 and an elastomeric polymer layer 206. In one aspect, and as shown in fig. 2A, the outer layer may include a braid (or coil) 204 that is not embedded in an elastomeric polymer layer 206. While in another aspect, and as shown in fig. 2B, the outer layer may include a braid (or coil) 204 embedded in an elastomeric polymer layer 206.

The liner 202 defines a lumen 201 through which a delivery device may be advanced into a vessel of a patient for delivery, removal, repair, and/or replacement of a prosthetic device. The disclosed sheath may also be used in other types of minimally invasive procedures, such as any procedure requiring the introduction of a device into a subject's vessel. For example, the disclosed sheaths may also be used to introduce other types of delivery devices for placement of various types of intraluminal devices (e.g., stents, stent grafts, etc.) into many types of vascular and non-vascular body lumens (e.g., veins, arteries, esophagus, bile ducts, intestines, urethra, fallopian tubes, other endocrine or exocrine tubes, etc.).

In further aspects, the sheet material used to make the liner 202 may include high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In further aspects, the sheet may include one or more layers. In some aspects, if one or more layers are present, each layer may comprise the same or different polymers. In further aspects, the sheet material may have a predetermined thickness, wherein the predetermined thickness may be defined by one of ordinary skill in the art depending on the particular application. In certain aspects, the predetermined thickness of the liner may be about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.01 inches, about 0.015 inches, and about 0.02 inches. It should also be appreciated that the predetermined thickness of the sheet material forming liner 202 may vary depending on the amount of radial expansion desired as well as the strength desired.

In a further aspect, the inner surface of the sheet may be at least partially ribbed. In further aspects, the sheet may also be smooth. In some exemplary aspects, the sheet forming the liner may have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. It should also be appreciated that the coefficient of friction of the sheet material may be any value between any two of the values described above. Such a liner may facilitate passage of the delivery device through the lumen 201 of the disclosed sheath. In some further exemplary aspects, materials that may be used to form a suitable smooth liner include materials that may reduce the coefficient of friction of liner 202, such as PTFE, polyethylene, polyvinylidene fluoride, and combinations thereof. Suitable materials for the lubricious liner also include other materials that desirably have a coefficient of friction of about 0.1 or less, about 0.09 or less, about 0.08 or less, about 0.07 or less, about 0.05 or less, about 0.04 or less, about 0.03 or less, about 0.02 or less, or about 0.01 or less.

In further aspects, the outer layer comprising the braid or coil and the elastomeric polymer layer may have any predetermined thickness. It will be appreciated that the predetermined thickness of the outer layer may depend on the particular application of the sheath. For example, but not limited to, the thickness of the inner liner 202 and the outer layer comprising the braid (or coil) 204 and the layer of elastomeric material 206 may also vary depending on the particular application of the sheath disclosed. In some aspects, the thickness of the liner 202 ranges from about 0.0005 inches to about 0.010 inches, including exemplary values of about 0.0006 inches, about 0.0007 inches, about 0.0008 inches, about 0.0009 inches, about 0.001 inches, about 0.002 inches, about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, and in one particular aspect, the thickness may be about 0.002 inches. The outer layer comprising braid (or coil) 204 and elastomeric material layer 206 may have a thickness of about 0.002 inch to about 0.015 inch, including exemplary values of about 0.003 inch, about 0.004 inch, about 0.005 inch, about 0.006 inch, about 0.007 inch, about 0.008 inch, about 0.009 inch, and about 0.01 inch.

It should be appreciated that the liner may have any shape or configuration depending on the desired application and the size of the delivery apparatus and prosthetic device. It should also be understood that the liner is not limited to a particular shape or configuration. In further aspects, the outer layer comprising the braid or coil and the elastomeric polymer layer may conform to the shape or configuration of the inner liner. In certain aspects, the sheath disclosed herein consists of a resting diameter d _r And an outer diameter d _o-limit . Diameter at rest d, as disclosed herein _r Is defined by the inner liner and the outer diameter may be defined by the inner liner and the outer layer, wherein the outer layer comprises a braid or coil and an elastomeric polymer layer.

Resting diameter d of liner 202 _r May vary depending on the application and size of the delivery device and prosthetic apparatus. Figures 3A-3C illustrate various configurations and shapes of liners. It should be appreciated that in some aspects, and as shown in FIG. 3B, the resting diameter d _r Is substantially uniform along the longitudinal axis of the lumen, with no change from the proximal end 308 to the distal end 306. In other aspects, and as shown in FIGS. 3A and 3C, the resting diameter d _r Can vary along the longitudinal axis of the lumen (e.g., d of FIG. 3A _r1 And d _r2 Or d as shown in FIG. 3C _r1 、d _r2 、d _r3 And d _r4 ). In certain aspects, the resting diameter d at the proximal end 304 or 312 _r1 Greater than the resting diameter d as shown in FIG. 3A _r2 Or distal end 302 or 310d as shown in fig. 3C _r D at _r4 . In a further aspect, wherein the outer layer conforms to the shape of the liner, an outer diameter d _o (not shown) includes the overall diameter of the inner liner and outer layer. In such an aspect, an outer diameter d _o Defined by the specific application of the sheath. Similar to the resting diameter d _r The outer diameter d of the unexpanded sheath disclosed herein _o Can be substantially uniform (constant) There is no change from the proximal end to the distal end (not shown). In an alternative aspect, with a resting diameter d _o Similarly, the initial unexpanded outer diameter d of the disclosed sheath _r May decrease from the proximal end to the distal end. In some aspects, similar to the resting diameter d _r The initial unexpanded outer diameter may decrease along a gradient from the proximal end to the distal end; or it may taper along the length of the sheath with a maximum initial unexpanded outer diameter d near the proximal end _o With a minimum initial unexpanded outer diameter d near the distal end _o 。

In some aspects, a resting diameter d _r May range from about 0.005 inch to about 0.400 inch, including exemplary values of about 0.01 inch, about 0.02 inch, about 0.03 inch, about 0.04 inch, about 0.05 inch, about 0.06 inch, about 0.07 inch, about 0.08 inch, about 0.09 inch, about 0.1 inch, about 0.2 inch, and about 0.3 inch. As described above, in certain aspects, the sheath may include a sheath having a different d _r Is provided. In such aspects, d _r May have any value between any two of the foregoing values, and may depend on the particular application and the size and shape of the delivery device and prosthetic apparatus. Different sheaths may have different expanded and unexpanded rest diameters d _r And an outer diameter d _o Depending on the size requirements of the delivery device for various applications. In addition, some aspects may provide more or less expansion depending on the particular design parameters, materials, and/or configuration used.

As disclosed herein, the outer layer of the sheath has an inner surface and an outer surface. The outer layer of the disclosed sheath extends around at least a portion of the variable diameter liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the liner. As disclosed herein, the outer layer includes a braid (or coil) 204 and an elastomeric polymer layer 206 (shown in fig. 2A and 2B) having a predetermined thickness and having an inner surface and an outer surface. In certain aspects, the braid or coil may be an expandable braid or coil. In further aspects, the braid or coil may include at least one filament comprising stainless steel, nitinol, a polymeric material, or a composite material. In certain non-limiting aspects, the braid or coil comprises filaments comprising nitinol and/or other shape memory alloys. In other non-limiting aspects, the braid may have filaments comprising polyester or nylon. In other exemplary aspects, the braid may include filaments comprising spectroscopic fibers, polyethylene fibers, aramid fibers, or combinations thereof.

It should be appreciated that the braid or coil may have any configuration known in the art. In certain aspects, the braid (or coil) 204 is generally a thin, hollow, substantially cylindrical tube, including an arrangement, pattern, structure, or configuration of filaments or struts, although other geometries may be used. Suitable filaments may be round with a diameter of less than about 0.015", less than about 0.01", less than about 0.008", less than about 0.005", less than about 0.002", less than about 0.001", less than about 0.0008", or less than about 0.0005". In other aspects, suitable filaments may be round with diameters ranging from about 0.0005 "inches thick to about 0.015" thick, comprising exemplary values of about 0.0006", about 0.0007", about 0.0008", about 0.0009", about 0.001", about 0.002", about 0.003", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014 ". In other aspects, suitable filaments can be flat filaments having a height of less than about 0.006", less than about 0.005", less than about 0.004", less than about 0.003", less than about 0.001", less than about 0.0009", less than about 0.0008", less than about 0.0007", less than about 0.0006", and about 0.0005". In other aspects, the flat filaments can have a width of greater than about 0.003 "to about 0.015", including exemplary values of about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". However, other geometries and sizes are also suitable for use in particular aspects.

In further aspects, the braid may have a crossover Per Inch (PIC) of less than 50, less than 40, less than 30, less than 20, or less than 10. In other aspects, the braid may have a PIC number from 10 to 2, including exemplary values 9, 8, 7, 6, 5, 4, and 3. In a further aspect, the PIC may vary along the longitudinal axis of the lumenAnd (5) melting. In other aspects, the weave pattern may vary along the longitudinal axis of the lumen. In aspects where the braid or coil comprises nitinol filaments, the nitinol expands in diameter d _e And (5) heat setting. In a further aspect, wherein the filament comprises stainless steel or nitinol, the filament is configured to be atraumatic at least at the distal end of the sheath. Fig. 4A-4D show partial elevation views of various structures of braid 28. It should be understood that the configuration of braid 28 may vary between different sections, varying along the length of the sheath. It should also be appreciated that the structures shown in fig. 4A-4D are not necessarily drawn to scale and are merely illustrative and non-limiting in nature. It should also be appreciated that the braid is configured to provide the ability of the sheath to twist during insertion of the prosthetic device.

In a further aspect, the outer layer includes an elastomeric polymer layer 206, as shown in fig. 2A and 2B. In certain aspects, the elastomeric polymer may include styrene-based elastomers, polyurethanes, latexes, copolymers thereof, blends thereof, or co-extrudates thereof. In certain and non-limiting aspects, the elastomeric polymer may include polyether block ester copolymers, polyesters, polyvinylchloride, thermoset silicones, polyisoprene rubber, polyolefins, other medical grade polymers, or combinations thereof. In further aspects, the elastomeric polymers described herein can have any useful additive. In certain aspects, the elastomeric polymer may include at least one friction reducing additive. In some exemplary aspects, the friction reducing additive may include, for example, baSO ₄ 、ProPell ^TM PTFE, any combination thereof, and the like. It should be understood that this list of friction reducing additives is not limiting and that any friction reducing additive known in the art may be utilized.

It should be understood that the hardness of each layer of the disclosed sheath may also vary depending on the particular application and desired properties of the sheath. In some aspects, the elastomeric polymer layer 206 has a shore hardness of less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, or less than 20. In further exemplary aspects, the elastomeric polymer layer 206 has a shore hardness of about 25 to about 75, including exemplary values of about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, and about 70.

Alternative aspects of a sheath for introducing a prosthetic device are also described. For example, fig. 5A-5B illustrate cross-sectional views of the liners 500A and 500B of the disclosed sheath in an unexpanded and expanded configuration (fig. 5A and 5B, respectively). As the prosthetic device is introduced into the liner, the first edge 502 and the second edge 504 slide along the liner and cause the liner to move from the resting diameter d _r Expanded to an expanded diameter d _e Thereby shortening the covered portion 506 of the liner. It should be appreciated that the expanded diameter d _e Configured to receive a medical device through the lumen. In a further aspect, the sheath is contracted to a predetermined resting diameter d after the medical device has passed through the lumen _r 。

In certain aspects, an amount of a first lubricant is disposed between at least a portion of the inner liner and at least a portion of the outer layer. In other aspects, an amount of the second lubricant is disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portion of the sheet. It should be appreciated that the first lubricant and the second lubricant may be the same or different. In certain and non-limiting aspects, the first lubricant and/or the second lubricant may include Christo Lube provided by ECL or MED10/6670 provided by Nusil. In further aspects, it should be appreciated that one of ordinary skill in the art can readily determine the amount of the first lubricant and/or the second lubricant

In further aspects, the outer surface of the elastomeric polymer layer can define at least a portion of the outer surface of the outer layer. In other aspects, at least a portion of the inner surface of the elastomeric polymer layer is at least partially bonded to at least a portion of the outer surface of the sheet of the liner. In one aspect, wherein at least a portion of the inner surface of the elastomeric polymer layer defines at least a portion of the inner surface of the outer layer. In yet another aspect, at least a portion of the braid defines at least a portion of the inner surface of the outer layer. It should be appreciated that the outer layer of the disclosed sheath is configured to provide hemostasis and prevent bleeding in a patient during a surgical procedure.

Fig. 6A-6D illustrate additional alternative aspects of a sheath for introducing a prosthetic device. Fig. 6A shows a sheath 600A that includes a liner 602 having first and second edges 602a, 602b and a cover portion 602c, wherein an inner surface and an outer surface of the liner cover each other. Sheath 600A also includes an amount of a second lubricant 608, as disclosed herein, disposed between the sliding portion and the cover portion of the inner sheath. The sheath also includes a braid 604 and an elastomeric polymer layer 606. In this exemplary aspect, the braid 604 is not embedded in the elastomeric polymer layer 606. Fig. 6B depicts an alternative aspect of sheath 600B in which an amount of a first lubricant 610 is applied between the inner liner and the outer layer comprising braid 604 and elastomeric polymer layer 606. Fig. 6C illustrates another aspect of a sheath 600C. In this aspect, sheath 600C includes a liner 602 having first and second edges 602a and 602b and a cover portion 602C, wherein an inner surface and an outer surface of the liner cover each other. The sheath also includes a braid 604 and an elastomeric polymer layer 606 that together form the outer layer of the sheath. Sheath 600C also includes an amount of a first lubricant 610, as disclosed herein, disposed between the outer layer and the inner liner of the inner sheath. In this exemplary aspect, the braid 604 is not embedded in the elastomeric polymer layer 606. In the exemplary aspect shown in fig. 6D, the exemplary sheath 600D includes a braid 604 embedded within an elastomeric polymer layer 606.

In further aspects, the sheath of the present disclosure may include a hemostatic valve inside the lumen of the sheath, at or near the proximal end of the sheath. Additionally, the example sheaths disclosed herein may include a soft tip at the distal end of the sheath. Such a soft tip may have a lower hardness than the rest of the sheath. In some aspects, the soft tip may have a shore hardness of about 25D to about 40D, including exemplary values of about 26D, about 27D, about 28D, about 29D, about 30D, about 31D, about 32D, about 33D, about 34D, about 35D, about 36D, about 37D, about 38D, and about 39D. In still other aspects, the soft tip may have a shore hardness of about 25A to about 40A, including exemplary values of about 26A, about 27A, about 28A, about 29A, about 30A, about 31A, about 32A, about 33A, about 34A, about 35A, about 36A, about 37A, about 38A, and about 39A.

In certain aspects, the outer layer and the inner liner may be bonded together or otherwise physically bonded to one another. It should be appreciated that the amount of adhesion between liner 602 and the polymeric outer layer comprising braid 604 and elastomeric polymer layer 606 is variable over the surface of the layer. Bonding between the layers may be produced by, for example, thermal bonding. In certain aspects, the presence of additional portions of elastomeric polymer may promote bonding. For example, in certain aspects, the sheath as described herein and shown in fig. 6H-6I can further include a first strip 611 of elastomeric polymer disposed along at least a portion of the longitudinal axis of the lumen between at least a portion of the outer surface of the sheet excluding the covered portion 602c of the sheet and the inner surface of the outer layer. In such aspects, the bond between the outer layer and the inner liner may be facilitated by the first strip of elastomeric polymer. In other aspects, the sheath can further include a second strip 611 (fig. 6E-6F) of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the proximal end of the sheath and the inner surface of the outer layer. In a further aspect, the sheath may further comprise a third strip 611 of elastomeric polymer disposed between at least a portion of the outer surface of the sheet at the distal end of the sheath and the inner surface of the outer layer (fig. 6E and 6G). Also, in such aspects, the bond between the outer layer and the inner liner may be facilitated by the second and/or third strips of elastomeric polymer.

Applications may utilize the sheath of the present disclosure having a resting diameter d of the lumen formed by the inner liner 602 _r Which can be expanded to an expanded diameter d of about 3Fr to about 26Fr _e Exemplary values of about 5Fr, about 8Fr, about 10Fr, about 12Fr, about 15Fr, about 18Fr, about 20Fr, about 22Fr, about 25Fr are included. The expanded diameter may vary along the length of the disclosed sheath. For example, the expanded outer diameter at the sheath proximal end may range from about 3Fr to about 28Fr, inclusive of exemplary values of about 5Fr, about 8Fr, about 10Fr, about 12Fr, about 15Fr, about 18Fr, about 20Fr, about 22Fr, about 25Fr, while the expanded outer diameter at the sheath distal end may range from about 3Fr to about 25Fr, inclusive of exemplary values of about 8Fr, about 10Fr, about 12Fr, about 15Fr, about 18Fr, about 20Fr, and about 22 Fr. All sides of the sheath are disclosedThe faces may expand to an expanded outer diameter ranging from about 10% to about 100% of the initial unexpanded outer diameter, including exemplary values of about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, and about 95% of the initial unexpanded outer diameter.

It should be appreciated that the disclosed sheath may be expanded from its rest position, as described above. The expansion of the sheath disclosed may result in a resting diameter d _r Expansion is about 10% or less to about 430% or more. In certain aspects, expansion of the sheath may result in a resting diameter d _r Expansion to about 10% or less, about 9% or less, about 8% or less, about 7% or less, about 6% or less, about 5% or less, about 4% or less, about 3% or less, about 2% or less, about 1% or less. In other aspects, expansion of the disclosed sheath can result in a resting diameter d _r Expansion to about 10% or more, about 20% or more, about 30% or more, about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 100% or more, about 125% or more, about 150% or more, about 175% or more, about 200% or more, about 225% or more, or about 250% or more.

As with the previously disclosed aspects, the aspects shown in fig. 6A-6D are applicable to a variety of static diameters D _r And an outer diameter d _o Is provided. In some aspects, the sheath has an outer diameter d _o Gradually decreasing from the proximal end of the sheath to the distal end of the sheath. For example, in one aspect, the outer diameter d _o May taper from about 26Fr at the proximal end to about 18Fr at the distal end. Diameter d of sheath _o The transition may be gradual over substantially the entire length of the sheath. In other aspects, the transition or decrease in sheath diameter may occur along only a portion of the length of the sheath. For example, the transition may occur along a length from the proximal end to the distal end, where the length may range from about 0.5 inches to about the entire length of the sheathDegree, including any value between any two of the foregoing values. In a further aspect, d along a sheath segment passing through the vasculature _o Minimum and constant. In such aspects, the tapered section is about 4 "or less proximal to the sheath.

In some aspects, the outer layer comprising the braid and elastomeric polymer layers may comprise the same material or combination of materials along the entire length. In alternative aspects, the material composition of the outer layer may vary along the length of the sheath. For example, the outer layer may have one or more segments, wherein the composition varies from segment to segment. For example, in one segment, the braid may include nitinol with a different PIC number than another segment. In yet another exemplary aspect, the elastomeric material layer in one segment may be different from the elastomeric material layer in another segment. In further exemplary aspects, one segment of the sheath may include a braid or coil embedded within the elastomeric polymeric material layer, while another segment may include a braid or coil not embedded within the elastomeric polymeric material layer. It should be understood that the exemplary sheath disclosed herein is not limiting. In certain exemplary aspects, the sheath can comprise n segments, wherein each segment can be the same or different. In further exemplary aspects, the hardness level of the outer layer composition may also vary along the length of the sheath such that the section near the proximal end comprises a stiffer material or combination of materials and the section near the distal end comprises a softer material or combination of materials. This may allow the sheath to have a relatively stiff proximal end when introduced into the delivery device, while still having a relatively soft distal tip when entering the patient's vasculature.

Fig. 10 and 11 illustrate an expandable sheath 100 according to the present disclosure that may be used with a delivery apparatus for delivering a prosthetic device (e.g., a tissue heart valve) into a patient. In general, the delivery apparatus may include a steerable guide catheter (also referred to as a curved catheter), a balloon catheter extending through the guide catheter (e.g., as depicted in fig. 1). The guide catheter, balloon catheter, and nasal catheter may be adapted to slide longitudinally relative to one another to facilitate delivery and positioning of the valve at the implantation site within the patient. However, it should be noted that the sheath 100 may be used with any type of elongate delivery apparatus for implanting balloon-expanded prosthetic valves, self-expanding prosthetic valves, and other prosthetic devices. In general, the sheath 100 may be inserted into a vessel (e.g., a femoral artery or an iliac artery) by passing through the skin of a patient such that the soft tip portion 102 at the distal end 104 of the sheath 100 is inserted into the vessel. The sheath 100 may also include a proximal flared end portion 114 to facilitate mating with the introducer housing 101 and the catheter described above (e.g., the proximal flared end portion 114 may provide a press fit over the housing tip, and/or the proximal flared end portion 114 may be secured to the housing 101 by a nut or other fastening device or by bonding the proximal end of the sheath to the housing). The introducer housing 101 may house one or more valves that, once inserted through the housing, form a seal around the outer surface of the delivery device. The delivery device may be inserted through the sheath 100, allowing the prosthetic apparatus to be advanced through the vasculature of the patient and implanted within the patient.

In an exemplary aspect, the sheath 100 includes an inner liner 108 and an outer layer 110 disposed about the inner liner 108. The outer layer 110 includes a braid (or coil) 111 and an elastomeric polymer layer 113. Fig. 11 depicts one non-limiting aspect of embedding braid (or coil) 111 into elastomeric polymer layer 113. The liner 108 defines a diameter d having a rest diameter _r Through which the delivery apparatus may be advanced into a vessel of a patient for delivering, removing, repairing and/or replacing the prosthetic device, moving in a direction along the longitudinal axis X. As the prosthetic device passes through the sheath 100, the sheath has a diameter d from rest _r Locally expanded to an expanded diameter d _e To accommodate the prosthetic device. After the prosthetic device passes through a particular location of the sheath 100, each successive expanded portion or segment of the sheath 100 at least partially returns to the resting diameter d _r . In this way, the sheath 100 may be considered self-expanding in that it does not require the use of a balloon, dilator, and/or occluder to expand.

As shown herein, inner layer 108 and outer layer 110 may comprise any of the materials disclosed above.

Additionally, some aspects of the sheath 100 may include an outer layer110 on the outer surface thereof. Such a hydrophilic coating may facilitate insertion of the sheath 100 into a patient's vasculature. Examples of suitable hydrophilic coatings include Harmony ^TM Advanced lubricious coatings, and other advanced hydrophilic coatings available from SurModics, inc. Of Eden Prairie, MN. The DSM medical coating (available from Koninklijke DSM N.V of herlen, netherlands) and other hydrophilic coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheath 100.

As best seen in fig. 11, in some aspects, the soft tip portion 102 may comprise Low Density Polyethylene (LDPE) and may be configured to minimize trauma or injury to a patient's vasculature as the sheath passes through the vasculature. For example, in some aspects, the soft tip portion 102 may be slightly tapered to facilitate passage through a vessel. The soft tip portion 102 may be secured to the distal end 104 of the sheath 100, for example, by thermally bonding the soft tip portion 102 to the inner and outer layers of the sheath 100. Such a soft tip portion 102 may have a lower hardness than other portions of the sheath 100. In some aspects, the soft tip 102 may have a shore hardness of about 25A to about 40A, including exemplary values of about 28A, about 30A, about 32A, about 35A, and about 38A. It should also be appreciated that the shore hardness may have any value between any two of the foregoing values. In other aspects, the soft tip 102 may have a shore hardness of about 25D to about 40D, including exemplary values of about 28D, about 30D, about 32D, about 35D, and about 38D. The tip portion 102 is configured to be radially expandable to allow the prosthetic device to pass through the distal opening of the sheath 100.

As shown in fig. 11, the sheath 100 may optionally contain at least one radiopaque filler or marker, such as a discontinuous or C-shaped band 112 located near the distal end 104 of the sheath 100. The indicia 112 may be associated with the inner and/or outer layers 108, 110 of the sheath 100. Such radiopaque tip markers may include, for example, materials suitable for use with radiopaque fillers, platinum, iridium, platinum/iridium alloys, stainless steel, other biocompatible metals, or combinations thereof. Suitable materials for use as the radiopaque filler or marker include, for example, barium sulfite, bismuth trioxide, titanium dioxide, bismuth subcarbonate, or combinations thereof. The radiopaque filler may be mixed with or embedded in the elastomeric polymer layer used to form the outer layer and may comprise about 5 wt% to about 45 wt% of the outer layer, including exemplary values of about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, and about 40 wt% of the polymeric tubular outer layer. Depending on the particular application, more or less radiopaque materials may be used in some aspects.

Fig. 12A-12B illustrate cross-sectional views of the sheath 100 taken near the distal end 104 of the sheath 100.

Fig. 12A shows a cross-sectional view of an exemplary sheath in which a lubricant is disposed between the sliding portion and the cover portion of the sheet and the braid is not embedded in the elastomeric polymer layer. More specifically, fig. 12A shows a sheath 1200A that includes a liner 1202 having first and second edges 1202A, 1202b and a cover portion 1202c, wherein the inner and outer surfaces of the liner cover each other. The sheath 1200A also includes an amount of a second lubricant 1208, as disclosed herein, disposed between the sliding portion and the cover portion of the inner sheath. The sheath also includes a braid (or coil) 1204 and an elastomeric polymer layer 1206. In this exemplary aspect, braid (or coil) 1204 is not embedded in elastomeric polymer layer 1206.

Fig. 12B shows a cross-sectional view of an exemplary sheath with lubricant disposed between the sliding portion and the cover portion of the sheet and lubricant disposed between the inner liner and the outer layer, wherein the braid is not embedded in the elastomeric polymer layer. More specifically, fig. 12B depicts an alternative aspect of the sheath 1200B in which an amount of a first lubricant 1210 is applied between the inner liner and the outer layer comprising the braid (or coil) 1204 and the elastomeric polymer layer 1206.

Fig. 12C shows another aspect of sheath 1200C. Fig. 12C shows a cross-sectional view of an exemplary sheath with lubricant disposed between the inner liner and the outer layer, wherein the braid is not embedded in the elastomeric polymer layer with and without the lubricant. More specifically, in this aspect, the sheath 1200C includes an inner liner 1202 having first and second edges 1202a, 1202b and a cover portion 1202C, wherein the inner and outer surfaces of the inner liner cover each other. The sheath also includes a braid (or coil) 1204 and an elastomeric polymer layer 1206, which together form the outer layer of the sheath. The sheath 1200C also includes an amount of a first lubricant 1210, as disclosed herein, disposed between the outer layer and the inner liner of the inner sheath. In this exemplary aspect, braid (or coil) 1204 is not embedded in elastomeric polymer layer 1206. Fig. 12D shows a cross-sectional view of an exemplary sheath with lubricant disposed between the sliding portion and the cover portion of the sheet and lubricant disposed between the inner liner and the outer layer, wherein the braid is at least partially embedded in the elastomeric polymer layer. More specifically, in this exemplary aspect shown in fig. 12D, the exemplary sheath 1200D includes a braid (or coil) 1204 embedded within an elastomeric polymer layer 1206.

Fig. 13A-D illustrate a cross-sectional view of the proximal section of the sheath of fig. 10 taken along line 38-38.

Fig. 13A shows a cross-sectional view of an exemplary sheath in which a lubricant is disposed between the sliding portion and the cover portion of the sheet, and the braid is not embedded in the elastomeric polymer layer. More specifically, fig. 13A shows a sheath 1300A comprising a liner 1302 having first and second edges 1302a, 1302b and a cover portion 1302c, wherein an inner surface and an outer surface of the liner cover each other. Sheath 1300A also includes an amount of a second lubricant 1308, as disclosed herein, disposed between the sliding portion and the cover portion of the inner sheath. The sheath also includes a braid (or coil) 1304 and an elastomeric polymer layer 1306. In this exemplary aspect, the braid (or coil) 1304 is not embedded in the elastomeric polymer layer 1306.

Fig. 13B shows a cross-sectional view of an exemplary sheath with lubricant disposed between the sliding portion and the cover portion of the sheet and lubricant disposed between the inner liner and the outer layer, wherein the braid is not embedded in the elastomeric polymer layer. More specifically, fig. 13B depicts an alternative aspect of sheath 1300B in which an amount of a first lubricant 1310 is applied between the inner liner and the outer layer comprising braid (or coil) 1304 and elastomeric polymer layer 1306. Fig. 13C shows another aspect of sheath 1300C. Fig. 13C shows a cross-sectional view of an exemplary sheath with lubricant disposed between the inner liner and the outer layer, wherein the braid is not embedded in the elastomeric polymer layer with and without the lubricant. More specifically, in this aspect, sheath 1300C includes a liner 1302 having first and second edges 1302a, 1302b and a cover portion 1302C, wherein an inner surface and an outer surface of the liner cover each other. The sheath also includes a braid (or coil) 1304 and an elastomeric polymer layer 1306 that together form the outer layer of the sheath. Sheath 1300C also includes an amount of a first lubricant 1310, as disclosed herein, disposed between the outer layer and the inner liner of the inner sheath. In this exemplary aspect, the braid (or coil) 1304 is not embedded in the elastomeric polymer layer 1306.

Fig. 13D shows a cross-sectional view of an exemplary sheath with lubricant disposed between the sliding portion and the cover portion of the sheet and lubricant disposed between the inner liner and the outer layer, wherein the braid is at least partially embedded in the elastomeric polymer layer. In this exemplary aspect, sheath 1300D includes a braid (or coil) 1304 embedded within an elastomeric polymer layer 1306.

In a further aspect, as shown in fig. 14, the sheath 1400, whether having a braid or coil embedded within an elastomeric polymer layer (as shown in fig. 14) or having a braid or coil not embedded within an elastomeric polymer layer, is configured to expand from a resting configuration to an expanded configuration shown in fig. 15. In such aspects, the first and second edges (1502 a and 1502 b) of the liner slide such that the length of the covered portion is shortened. In some exemplary aspects, as disclosed above, the presence of the first lubricant and/or the second lubricant may facilitate such movement.

The sheath disclosed herein may be configured such that it locally expands along the length of the lumen at a particular location corresponding to the location of the medical device, and then locally contracts when the medical device has passed the particular location. Thus, as the medical device is guided through the sheath, ridges running longitudinally along the length of the sheath can be seen, which represent continuous local expansion and contraction as the device travels along the length of the sheath. In some aspects, each of the sheaths after removal of any radially outward (insertion) force The segment may be locally contracted such that it resumes the initial resting diameter d of the lumen _r 。

In some aspects, upon removal of any radially outward force, each segment of the sheath may locally collapse such that it at least partially returns to the initial resting diameter d of the lumen _r 。

Additional sheath 8 configurations are also disclosed that may be used with the delivery apparatus 10 shown in fig. 1 to deliver a prosthetic device 12.

For example, and without limitation, figures 21A-21B illustrate one exemplary aspect of the sheath disclosed herein. In such aspects, the sheath includes a proximal end and a distal end. Sheath 2100 can include a variable diameter liner 2102 comprising a sheet having a first edge 2104 and a second edge 2106 and defined by an inner surface 2102a and an outer surface 2102 b. When the sheet is wound in a spiral configuration, at least a portion of the inner surface 2102a of the sheet overlies at least a portion of the outer surface 2102b of the sheet. As can be seen in fig. 21A-B, the first edge 2104 of the sheet can slide along at least a portion of the inner surface 2102a of the sheet, and the second edge 2106 can slide along at least a portion of the outer surface 2102B of the sheet. The sheath also includes an outer layer 2108 having an inner surface 2108a and an outer surface 2108 b.

The inner surface 2102a of the sheet also defines a lumen of a sheath through which a delivery device can be advanced into a vessel of a patient for delivery, removal, repair, and/or replacement of a prosthetic device. The disclosed sheath may also be used in other types of minimally invasive procedures, such as any procedure requiring the introduction of a device into a subject's vessel. For example, the disclosed sheaths may also be used to introduce other types of delivery devices for placement of various types of intraluminal devices (e.g., stents, stent grafts, etc.) into many types of vascular and non-vascular body lumens (e.g., veins, arteries, esophagus, bile ducts, intestines, urethra, fallopian tubes, other endocrine or exocrine tubes, etc.).

It should also be appreciated that the sheath may also include additional layers. Some of these additional layers are disclosed in detail below or above. For example, as disclosed in some exemplary aspects above, the sheath may further include a braid or coil disposed between the inner liner and the outer layer and/or a braid or coil embedded in the outer layer.

In the exemplary aspect shown in fig. 21A-21B, the sheath does not include a braid or coil disposed along the length of the sheath between the inner liner and the outer layer or embedded in the outer layer.

Similar to other aspects of the sheath, the example sheath of fig. 21A-21B may have an inner liner with various depending on the desired application and size of the delivery apparatus and prosthetic device. It should also be understood that the liner is not limited to a particular shape or configuration. In certain aspects, the sheath disclosed herein consists of a resting diameter d _r And an outer diameter d _{o is defined.} Diameter at rest d, as disclosed herein _r Is defined by the inner liner and the outer diameter may be defined by the inner liner and the outer layer.

Resting diameter d of inner liner 2102 _r May vary depending on the application and size of the delivery device and prosthetic apparatus. The sheath disclosed herein may have a similar configuration as depicted in fig. 3A-3C and described above. It should be appreciated that in some aspects, and as shown in FIG. 3B, the resting diameter d _r1 Is substantially uniform along the longitudinal axis of the lumen, with no change from the proximal end 308 to the distal end 306. In other aspects, and as shown in FIGS. 3A and 3C, the resting diameter d _r Can vary along the longitudinal axis of the lumen (e.g., d of FIG. 3A _r1 And d _r2 Or d as shown in FIG. 3C _r1 、d _r2 、d _r3 And d _r4 ). In certain aspects, the resting diameter d at the proximal end 304 or 312 _r1 Greater than the resting diameter d as shown in FIG. 3A _r2 Or distal end 302 or 310d as shown in fig. 3C _r D at _r4 . In a further aspect, wherein the outer layer conforms to the shape of the liner, an outer diameter d _o (not shown) includes the overall diameter of the inner liner and outer layer. In such an aspect, an outer diameter d _o Defined by the specific application of the sheath. Similar to the resting diameter d _r The outer diameter d of the unexpanded sheath disclosed herein _o May be substantially uniform (constant) along the longitudinal axis of the lumen, with no change from the proximal end to the distal end. In an alternative aspect, with a resting diameter d _o Similarly, the initial unexpanded outer diameter d of the disclosed sheath _r May decrease from the proximal end to the distal end. In some aspects, similar to the resting diameter d _r The initial unexpanded outer diameter may decrease along a gradient from the proximal end to the distal end; or it may taper along the length of the sheath with a maximum initial unexpanded outer diameter d near the proximal end _o With a minimum initial unexpanded outer diameter d near the distal end _o 。

In some aspects, and similar to other sheath configurations disclosed herein, the resting diameter d of the sheath, as shown in fig. 21A-21B _r May range from about 0.005 inch to about 0.400 inch, including exemplary values of about 0.01 inch, about 0.02 inch, about 0.03 inch, about 0.04 inch, about 0.05 inch, about 0.06 inch, about 0.07 inch, about 0.08 inch, about 0.09 inch, about 0.1 inch, about 0.2 inch, and about 0.3 inch. As described above, in certain aspects, the sheath may include a sheath having a different d _r Is provided. In such aspects, d _r May have any value between any two of the foregoing values, and may depend on the particular application and the size and shape of the delivery device and prosthetic apparatus. Different sheaths may have different expanded and unexpanded rest diameters d _r And an outer diameter d _o Depending on the size requirements of the delivery device for various applications. In addition, some aspects may provide more or less expansion depending on the particular design parameters, materials, and/or configuration used.

Fig. 22A-22B depict an exemplary sheath expansion process, such as that shown in fig. 21-21B. Sheath 2202, as shown in fig. 22A, may be expanded from a collapsed configuration to an expanded configuration 2204 by sliding the first and second longitudinal edges along each other and reducing the overlap of the helical configuration during passage of the medical device. Also, the expansion diameter d _e May depend on the diameter of the medical device being passed through. In a further aspect and as discussed in detail below, the outer layer is configured to apply an inward radial force to the liner to collapse the sheath into engagement with d after the medical device passes through the lumen _r Substantially the same diameter. It should also be understood that as described hereinCan locally expand and collapse as the medical device is passed. Fig. 22B shows images of sheath expansion at successive times during the passage of an exemplary medical device.

Fig. 24A-24B disclose additional aspects of the sheath. For example, fig. 24A illustrates an inner liner of a sheath similar in construction to the sheath disclosed in fig. 22, wherein first end 2404 and second end 2406 are substantially aligned in spaced apart relation along a vertical axis 2420 through the thickness of the sheath. In this configuration, a portion of sheet 2403 is positioned along a vertical axis between the first edge and the second edge. As can be seen in fig. 24A, when the inner liner 2402 is in an unexpanded, rest state, the inner liner includes at least two layers of sheet material that overlie one another along at least a portion of the circumference of the sheath. However, and as can be seen in fig. 24, the liner may comprise at least two layers of sheet material that are overlaid on each other along the entire circumference of the sheath.

Fig. 24B shows a different configuration of the liner in an expanded state. For example, when the liner 2402 is in an unexpanded, rest state, the liner may include a portion along the circumference of the sheath that may have three layers of sheets 2430.

Referring to fig. 22A, for example, there is also a liner configuration in which the first edge 2204 is substantially aligned with a vertical axis 2420 through the thickness of the sheath and the second edge 2406 is circumferentially offset from the vertical axis. In this aspect, the liner comprises a layer of sheet material along at least a portion of the circumference of the sheath without any cover portions.

Fig. 31-32 also illustrate additional configurations of the sheath. Some of the sheath configurations disclosed above are formed by providing an elongate tube and cutting the tube along the length of the tube to form a sheet having a first longitudinal edge and a second longitudinal edge. The sheet is formed by forming a slit. In various constructions, a particular type of slit may be formed depending on the end desired application. For example, for the various sheath configurations disclosed above, for example, the slit 905 as shown in fig. 9A is substantially straight along the length of the tube forming the liner. In such exemplary aspects, the slit formed during cutting is substantially straight from the proximal end of the liner to the distal end of the liner. In such aspects, the helical configuration formed when the sheet is wound into a spool is substantially straight along the length of the sheath.

However, aspects of the liner being wound in a spiral reel configuration are also disclosed herein. Fig. 32 shows an exemplary view of such a configuration. In such aspects, the elongate tube that will form the liner 915 is disposed and cut (fig. 31) such that a longitudinal slit 911 is formed between the proximal and distal ends of the tube, thereby forming a first longitudinal edge and a second longitudinal edge of the tubular liner 915. For example, as shown in fig. 31, the slits are not formed along the longitudinal axis of the liner in these aspects, but are at least somewhat offset from the longitudinal axis. The slit is formed such that the liner is wound in a spiral reel configuration such that in the spiral reel configuration, at least a portion of the inner surface of the liner 915b covers at least a portion of the outer surface 915a of the liner in a spiral fashion (overlapping is not shown in fig. 31). Overlapping portion 913 is visible in fig. 32. In a further aspect, in the helical sheath configuration, the first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner.

In such exemplary aspects, the tubular liner is further configured to move from the resting diameter d during application of the radially outward force by the medical device through the lumen of the liner by sliding the first edge of the liner in a helical fashion along at least a portion of the inner surface and sliding the second edge of the liner in a helical fashion along at least a portion of the outer surface of the liner _r Expanded to an expanded diameter d _e 。

When the sheath is inserted into a patient, for example, through the femoral artery and passed along an arterial path, the arterial path may generally be a tortuous and tortuous path, forcing the sheath to assume a curved configuration therealong. In addition, when a larger diameter prosthetic valve (or any other prosthetic device that may be advanced through the sheath) passes through the sheath, the combination of the expansion force and the curved configuration of the sheath may cause the layers of the sheath to potentially separate the longitudinal edges, possibly resulting in an undesirable gap being formed between the two longitudinal edges. A sheath having a helical configuration may avoid this potentially undesirable effect. In some aspects, the exemplary helical configuration of the sheath may allow the liner to expand with substantially no gaps formed between longitudinal edges of the liner defined by the slits. Even further in these exemplary aspects, the tubular liner of the disclosed sheath is configured to bend as it passes through the natural anatomy of the patient without forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

It will be appreciated that the separation may be formed in any orientation that achieves a helical configuration of the spool. For example, but not limiting of, in some aspects, the longitudinal slit may extend from a proximal end of the tubular liner to a distal end of the tubular liner in a direction offset from a longitudinal axis of the tubular liner. In another aspect, the direction is diagonal from a direction from a proximal end of the tubular liner to a distal end of the tubular liner. In further aspects, the longitudinal slit extends from the proximal end of the tubular liner to the distal end of the tubular liner at an angle greater than about 90 degrees (e.g., about 100 degrees, about 110 degrees, about 120 degrees, about 130 degrees, about 140 degrees, about 150 degrees, about 160 degrees, and about 170 degrees) or less than about 90 degrees (e.g., about 80 degrees, about 70 degrees, about 60 degrees, about 50 degrees, about 40 degrees, about 30 degrees, about 20 degrees, and about 10 degrees) across the length of the tubular liner.

In further aspects, the longitudinal slit may be formed between the proximal end of the tubular liner and the distal end of the tubular liner in a pattern other than a straight line. For example, but not limited to, the slit may be formed as a sheet such that a specific pattern may be formed. For example, in such aspects, the first longitudinal edge and the second longitudinal edge have substantially no straight lines. In some aspects, the slit may be formed such that each of the first and second longitudinal edges may have a zig-zag form, or may have an angle greater than or less than 180 degrees or 0 degrees. For example, depending on the orientation of the slit, each edge may have a convex shape and a corresponding concave shape, or a concave shape and a corresponding convex shape, a curved shape, etc. Also, it should be understood that any orientation of the slots that may form the helical spool configuration of the liner is contemplated and described.

In a further aspect, the slits may be formed such that the helical configuration of the liner has a predetermined pitch. In certain aspects, the pitch may be at least about 2, at least about 3, at least about 4, at least about 5, or at least about 6 turns per 10cm on the sheath.

In a further aspect, the resting diameter d of the exemplary sheath _r And an expanded diameter d _e May be similar to any of the previous aspects described.

In further aspects, and similar to other sheath constructions, the tubular liner having a helical reel construction may comprise high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. In further aspects, and as disclosed in other constructions, the liner may have a multi-layer structure. In some aspects, the inner surface of the liner may be substantially smooth. While in other aspects, the inner surface of the tubular liner may be at least partially ribbed. In further aspects, the tubular liner is smooth and may have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1.

Fig. 33 also shows another configuration of the sheath. In this aspect, the variable diameter liner 3300 includes a sheet 3302 having a first longitudinal edge 3302a and a second longitudinal edge 3302 b. As shown in fig. 33, the sheet is wound in a spiral configuration such that at least a portion of the inner surface of the sheet covers at least a portion of the outer surface of the sheet, thereby forming an overlapping portion; wherein at least a portion of the outer surface of the sheet adjacent the first longitudinal edge 3302a includes a first plurality of projections 3320. In a further aspect, at least a portion of the first plurality of protrusions is disposed within the overlapping portion, thereby reducing a contact area between the inner surface and the outer surface of the sheet within the overlapping portion.

In a further aspect, in the spiral configuration of the disclosed liner, the first longitudinal edge 3302a of the sheet can slide along at least a portion of the inner surface of the sheet, and the second longitudinal edge 3302b can slide along at least a portion of the outer surface of the sheet.

However, it should be understood that a plurality of protrusions may be present on the inner surface of the sheet material in addition to or instead of the outer surface. In such aspects (not shown), the second plurality of protrusions 3320 may also be disposed on the inner surface, at least adjacent the second longitudinal edge 3302b. It should also be appreciated that the first plurality of protrusions and the second plurality of protrusions may be the same or different. In such exemplary aspects, for example, the composition of the first plurality of protrusions and the second plurality of protrusions may be the same, but different in shape. Other exemplary aspects are also contemplated, including a first plurality of protrusions and a second plurality of protrusions that differ in both composition and shape or both composition and shape.

In a further aspect, the inner surface of the sheet defines a lumen of the sheath, the lumen having a longitudinal axis.

In a further aspect, the variable diameter liner is configured to move from the first resting diameter d during application of a radially outward force by the medical device through the lumen of the liner by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface _r Expanded to a second expanded diameter d _e 。

In a further aspect, the sheet is rolled to form a spiral wherein all sections have more than three predetermined thicknesses in the radial direction and a small portion has only one predetermined thickness in the radial direction. In certain aspects, the radial force applied is high when the medical device passes through the expandable variable diameter liner, and any friction or tackiness between the sliding portions undesirably increases the thrust force.

In a further aspect, the sheet has a predetermined thickness. In such aspects, the sheet can have any thickness from about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.01 inches, about 0.015 inches, and about 0.02 inches. It should also be appreciated that the predetermined thickness of the sheet forming the liner having any of the configurations disclosed herein may vary depending on the amount of radial expansion desired as well as the strength desired.

In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may be adapted for any possible arrangement or pattern arrangement of desired application on the inner and/or outer surfaces of the sheet material. In some aspects, the first plurality of protrusions and/or the second plurality of protrusions may be arranged in a predetermined pattern to reduce the contact area between the inner surface and the outer surface of the sheet in the overlapping portion. It will be appreciated that reducing contact may be useful during the dilation procedure because the two portions do not adhere to each other, thus reducing the thrust required to pass the medical device through the sheath.

In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may have any shape that allows for the desired result to be achieved. In certain aspects, the first plurality of protrusions and/or the second plurality of protrusions may comprise a regular shape, such as a continuous stripe shape along the length of the liner or a discontinuous pattern, such as discontinuous circular shape protrusions, rectangles, diamonds, trapezoids, and so forth. In other aspects, the shape may be irregular, such as a star or any other shape. In other aspects, the plurality of protrusions may have a combination of various shapes.

In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may have an average height of at most about 1%, about 5%, about 10%, about 15%, or at most about 20% of the predetermined thickness of the sheet itself. It should be appreciated that in some aspects, it is not required that each of the first plurality of protrusions and/or the second plurality of protrusions have the same height. In other aspects, the first plurality of protrusions and/or the second plurality of protrusions may have substantially the same height.

In a further aspect, the sheet comprises a first polymer composition. In such aspects, the first polymer composition may comprise high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof. While in further aspects, the sheet may comprise a multi-layer structure. In aspects where there is more than one layer, each layer may comprise the same material or different materials.

In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may comprise a second polymer composition. Also, it should be understood that the second polymer composition may be the same as or different from the first polymer composition, depending on the particular application. Also, it should be appreciated that the first plurality of protrusions and/or the second plurality of protrusions may be disposed on an outer surface and/or an inner surface of the sheet material, respectively. In terms of the presence of the first plurality of protrusions and the second plurality of protrusions, the second plurality of protrusions present on the inner surface may be the same as or different from the first plurality of protrusions present on the outer surface of the sheet. It will be appreciated that in terms of the second polymer composition being different from the first polymer composition, the two compositions are compatible with each other and are capable of bonding together.

In further aspects, it should be appreciated that the portion of the sheet comprising the first plurality of protrusions and/or the second plurality of protrusions is not limited to the overlapping portion.

In some aspects, at least a portion of the sheet having the first plurality of protrusions and/or the second plurality of protrusions may be greater than the overlapping portion. In a further aspect, at least a portion of the sheet having the first plurality of protrusions and/or the second plurality of protrusions is substantially the same circumference as the sheet in the spiral configuration. It will be appreciated that in such aspects, the first plurality of protrusions and/or the second plurality of protrusions are disposed on the entire outer and/or inner surface of the sheet material, respectively.

In other aspects, the first plurality of protrusions and/or the second plurality of protrusions may be disposed on an outer surface and/or an inner surface of the sheet material, respectively, along at least a portion of the length of the sheath. In yet other aspects, the first plurality of protrusions and/or the second plurality of protrusions may be disposed on an outer surface and/or an inner surface of the sheet material, respectively, adjacent the distal end of the sheath. In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may be disposed on an outer surface and/or an inner surface of the sheet material, respectively, adjacent the proximal end of the sheath. In yet further aspects, the first plurality of protrusions and/or the second plurality of protrusions may be disposed on the outer and/or inner surfaces of the sheet material along the entire length of the sheath, respectively.

It should also be appreciated that in some exemplary aspects, the first plurality of protrusions and/or the second plurality of protrusions may have various shapes as disclosed above, and that these shapes may be continuous along at least a portion of the length of the inner member or they may be entirely discontinuous. The size of each of the first plurality of protrusions and/or the second plurality of protrusions may vary depending on the desired application. In further aspects, the average size of the first plurality of protrusions and/or the second plurality of protrusions may be about 50% less, about 40% less, about 30% less, about 20% less, about 10% less, or even about 5% less than the predetermined thickness of the sheet.

Similar to other sheath configurations, in this sheath configuration, the resting diameter d _r May be substantially uniform along the longitudinal axis of the lumen or may vary along the longitudinal axis of the lumen.

In some aspects, the inner surface of the liner may be substantially smooth. While in other aspects, the inner surface of the tubular liner may be at least partially ribbed. In further aspects, the tubular liner is smooth and may have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1.

Fig. 34 also shows another configuration of the sheath. In this aspect, the variable diameter liner 3400 includes a sheet 3402 having a first longitudinal edge 3402a and a second longitudinal edge 3402 b. The sheath liner 3400 has an inner surface 3403a and an outer surface 3405a. As shown in fig. 34, the sheet is wound in a spiral configuration such that at least a portion of the inner surface 3403b of the sheet overlies at least a portion of the outer surface 3405b of the sheet, thereby forming an overlap. As further shown in fig. 34, at least a portion of the outer surface 3405a of the sheet may include a plurality of bond sites 3420 at least partially embedded within the sheet. As illustrated in fig. 34, the plurality of bond sites 3420 are disposed such that the outer surface 3405b of the sheet in the overlap portion is substantially free of the bond sites.

In a further aspect, in the spiral configuration of the disclosed liner, the first longitudinal edge 3402a of the sheet may slide along at least a portion of the inner surface of the sheet and the second longitudinal edge 3402b may slide along at least a portion of the outer surface of the sheet.

In a further aspect, the sheet has a predetermined thickness. In such aspects, the sheet can have any thickness from about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.01 inches, about 0.015 inches, and about 0.02 inches. It should also be appreciated that the predetermined thickness of the sheet forming the liner having any of the configurations disclosed herein may vary depending on the amount of radial expansion desired as well as the strength desired. In such aspects, the plurality of bond sites as shown in the exemplary sheath of fig. 34 may have a depth (depth of bond sites embedded within the sheet itself) of no more than about 50% of any predetermined value of the sheet thickness disclosed above. For example, the depth of the plurality of bond sites may be no more than about 50%, no more than about 45%, no more than about 40%, no more than about 35%, no more than about 30%, no more than about 25%, no more than about 20%, no more than about 15%, no more than about 10%, or no more than about 5% of the predetermined thickness disclosed above.

In a further aspect, the bond sites are provided at the outer surface and are not embedded or only partially embedded within the sheet. In such aspects, the plurality of bond sites may also extend at least partially from the outer surface of the sheet. In such exemplary aspects, the extended portion of the plurality of bond sites may have a height of no more than about 50%, no more than about 45%, no more than about 40%, no more than about 35%, no more than about 30%, no more than about 25%, no more than about 20%, no more than about 15%, no more than about 10%, or no more than about 5% of the predetermined thickness disclosed above. In further aspects, wherein the plurality of bond sites each extend from an outer surface of the sheet and are at least partially embedded within the sheet, the plurality of bond sites have a height and depth of no more than about 50%, no more than about 45%, no more than about 40%, no more than about 35%, no more than about 30%, no more than about 25%, no more than about 20%, no more than about 15%, no more than about 10%, or no more than about 5% of the disclosed predetermined thickness.

In further aspects, the plurality of bond sites may have an average depth of at most about 1%, at most about 5%, at most about 10%, at most about 15%, at most about 20%, at most about 25%, at most about 30%, at most about 35%, at most about 40%, at most about 45%, or at most about 50% of the predetermined thickness of the sheet itself. In further aspects, a plurality of bond sites may have an average depth and an average height if at least a portion of such bond sites extends above the outer surface by up to about 1%, up to about 5%, up to about 10%, up to about 15%, up to about 20%, up to about 25%, up to about 30%, up to about 35%, up to about 40%, up to about 45%, or up to about 50% of the predetermined thickness of the sheet itself.

To the extent that multiple bond sites are embedded in the sheet and extend above the outer surface, the depth and height of such bond sites may be the same or different depending on the particular application. In further aspects, the depth and/or height of each of the plurality of bond sites may also be the same or different.

In further aspects, the plurality of bond sites may include a second polymer composition. In such aspects, the second polymer composition is different from the first polymer composition. However, it should be understood that the first and second polymer compositions may also be substantially identical if desired and depending on the particular application. In a further aspect, the second polymer composition comprises polyethylene, polypropylene, graft modified polyethylene or polypropylene, or a combination thereof. In some exemplary aspects, the second polymer composition may include grafted Low Density Polyethylene (LDPE), grafted medium density polyethylene, grafted Ultra Low Density Polyethylene (ULDPE), grafted High Density Polyethylene (HDPE), grafted heterogeneously branched Linear Low Density Polyethylene (LLDPE), grafted homogeneously branched linear ethylene polymer, and substantially linear ethylene polymer, grafted polypropylene, or Ethylene Vinyl Acetate (EVA), or any combination thereof.

For example, but not limited to, the sheet may include HDPE and the bond site may include LDPE, or a terpolymer, such as: such as but not limited toMaleic anhydride modified polyolefins (commercially available from Arkema), e.g., DOW Chemical +.>Ethylene acrylic acid copolymers of (2), e.g. +.>Vinyl acrylate copolymers, ethylene glycidyl methacrylate copolymers, commercially available from Arkema, for example +.>Ethylene acrylate glycidyl methacrylate terpolymers (commercially available from Arkema), e.g.>Or->Ethylene acrylate maleic anhydride terpolymers (commercially available from Arkema), or combinations thereof.

In further aspects, the first polymer composition and the second polymer composition may be co-extruded together to form the liner. It will be appreciated that in terms of the second polymer composition being different from the first polymer composition, the two compositions are compatible with each other and do not create delamination.

In further aspects, a plurality of bond sites may be provided along at least a portion of the length of the liner. In further aspects, a plurality of bond sites may be provided along the entire length of the liner. In yet other aspects, a plurality of bond sites may be provided on the outer surface of the sheet (i.e., not in the overlapping portion) adjacent the distal end of the sheath. In further aspects, a plurality of bond sites may be provided on the outer surface of the sheet (i.e., not in the overlapping portion) adjacent the proximal end of the sheath.

In such aspects, the plurality of bond sites are arranged in a predetermined pattern, thereby allowing coupling with the outer layer and preventing axial movement of the outer layer during passage of the medical device through the lumen of the liner. In further aspects, the pattern may be any pattern desired for a particular application and that allows bonding with the outer layer.

In some aspects, the plurality of bond sites are arranged in a predetermined pattern to bond the liner to the outer layer without compromising expansion of the liner as the medical device is passed. It will be appreciated that since the expansion can be achieved by sliding the first and second longitudinal edges and reducing the overlap, no bond sites are provided within the overlap to avoid undesirable bonding and restriction in sliding.

In further aspects, the plurality of bond sites may have any desired shape. For example, but not limited to, the plurality of bond sites may have a regular shape, an irregular shape, or any combination thereof. In certain aspects, the plurality of bond sites may include a regular shape, such as a continuous stripe shape along the length of the liner, or a discontinuous pattern, such as a discontinuous circular shape, a rectangle, a diamond, a trapezoid shape, and so forth. Also, it should be understood that the plurality of bond sites may be at least partially embedded within the sheet, or fully embedded within the sheet, or extend at least partially above the outer surface of the sheet. In any of these aspects, the shape of each of the plurality of bond sites may be the same or different, or may be any variation of shape.

In further aspects, each of the plurality of bond sites has a width of no more than about 50%, no more than about 45%, no more than about 40%, no more than about 35%, no more than about 30%, no more than about 25%, no more than about 20%, no more than about 15%, no more than about 10%, or no more than about 5% of the predetermined thickness disclosed above. In yet other aspects, each of the plurality of bond sites has a width of up to about 1%, up to about 5%, up to about 10%, up to about 15%, up to about 20%, up to about 25%, up to about 30%, up to about 35%, up to about 40%, up to about 45%, or up to about 50% of the predetermined thickness disclosed above.

In other aspects, each of the plurality of bond sites has a width of about 1 x to about 10 x of a thickness of the plurality of bond sites, including exemplary values of about 2 x, about 3 x, about 4 x, about 5 x, about 6 x, about 7 x, about 8 x, and about 9 x of the thickness of the plurality of bond sites.

In further aspects, each of the plurality of bond sites has a width of about 0.01 "to about 0.15", including exemplary values of about 0.015", about 0.02", about 0.025", about 0.03", about 0.035", about 0.04", about 0.045", about 0.05", about 0.055", about 0.06", about 0.065", about 0.07", about 0.075", about 0.08", about 0.085", about 0.09", about 0.095", about 0.1", about 0.11", about 0.12", about 0.13", and about 0.14".

In further aspects, the plurality of bond sites may include one bond site. While in other aspects, the plurality of bond sites includes at least two bond sites. It should be appreciated that the number of bond sites may be specifically selected depending on the desired application. It should also be appreciated that each of the plurality of bond sites may be disposed at a predetermined distance from each other, wherein the predetermined distance may be selected depending on the desired application. In further aspects, the number and location of the bond sites may be selected to allow the section of the outer sheath to expand as the inner member expands, but to provide sufficient anchoring strength to substantially prevent axial movement of the outer sheath (elastomeric outer member) relative to the inner member during insertion and withdrawal of the sheath into the body and during passage of the medical device.

In further aspects, instead of being disposed on the outer surface of the inner layer (liner) of the sheath, any of the disclosed plurality of bond sites may be disposed on the inner surface of the outer layer (outer jacket) of the sheath. In such exemplary aspects, such as shown in fig. 43A-43B, the inner liner does not include any bond sites, and the inner surface of the outer layer may include one or more bond sites. For example, the liner in this aspect may have any thickness as disclosed above. The outer layer may also have a predetermined thickness, as disclosed below. For example, the predetermined thickness of the outer layer may vary along the length of the sheath. In yet other aspects, the predetermined thickness of the outer layer is the same along the length of the sheath. However, in a further aspect, the predetermined thickness of the outer layer is greater at the proximal end. In further aspects, the predetermined thickness of the outer layer is up to 0.015", such as, but not limited to, about 0.001" to about 0.015", including exemplary values of about 0.0015", about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", 0.0095", about 0.01", about 0.0105", about 0.011", about 0.01105", about 0.012", about 0.01205", about 0.013", about 0.01305", about 0.014", and about 0.01405.

Fig. 43B shows a close-up 4300 of the bonding site. It can be seen that the outer layer may include one or more bond sites having a width w. In such aspects, the width may have any value from about 0.01 "to about 0.15", including exemplary values of about 0.015", about 0.02", about 0.025", about 0.03", 0.035", about 0.04", 0.045", about 0.05", about 0.055", about 0.06", about 0.065", about 0.07", about 0.075", about 0.08", about 0.085", about 0.09", about 0.095", about 0.1", about 0.11", about 0.12", about 0.13", and about 0.14".

In further aspects, the bond site may include a thickness having any value between 0.0001 "to about 0.005", including exemplary values of about 0.0002", about 0.0003", about 0.0004", about 0.0005", about 0.0006", about 0.0007", about 0.0008", about 0.0009", about 0.001", about 0.0015", about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", and about 0.0045".

Any of the inner liner, outer layer (outer jacket), and materials used to form the bond sites disclosed herein may be used without limitation. It should also be appreciated that the plurality of bond sites disposed on the inner surface of the outer layer (outer jacket) may have the same shape as the plurality of bond sites disposed on the outer surface of the liner, as disclosed above. Any characteristic or feature of the bond sites provided on the outer surface of the liner is applicable to the plurality of bond sites provided on the inner surface of the outer jacket.

For example, but not limited to, the bond site is disposed at the inner surface of the outer sheath and may not be embedded or only partially embedded within the outer sheath. It should be appreciated that if the outer sheath is comprised of more than one polymer layer, the bond sites may be embedded in any or all of the polymer layers present in the outer sheath. In other aspects, the plurality of bond sites may include a polymer that may replace at least a portion of at least one polymer layer at a predetermined location.

In the sense that a plurality of bond sites are embedded in the outer jacket and extend above the inner surface thereof, the depth and height of such bond sites may be the same or different depending on the particular application. In further aspects, the depth and/or height of each of the plurality of bond sites may also be the same or different.

In further aspects, a sheath having examples of liners disclosed herein may further include any of the outer layers, braids, tie layers, lubricants, etc. disclosed herein.

Fig. 18 depicts yet another configuration of the liner. Fig. 18 shows a liner 1800 comprising a sheet wound into a spiral configuration, wherein the sheet comprises a first portion 1802 having a first surface 1802a and an opposing second surface 1802, wherein a first end 1804 of the first portion 1802 is divided into a first segment 1806 having a first surface 1806a and an opposing second surface 1806b and a third segment 1808 having a first surface 1808a and an opposing second surface 1808b, and wherein a second end of the first portion extends into a second segment 1810 having a first surface 1810a and an opposing second surface 1810 b.

As can be seen in fig. 18, in the spiral configuration, at least a portion of the first surface 1810a of the second segment 1810 overlaps at least a portion of the second surface 1806b of the first segment 1806, wherein at least a portion of the first surface 1808a of the third segment 1808 overlaps at least a portion of the second surface 1810b of the second segment 1810, and wherein at least a portion of the first surface 1808a of the third segment overlaps at least a portion of the second surface 1806b of the first segment 1806. It can also be seen that the first surface 1804a of the first portion 1804 extends into the first surface 1806a of the first segment 1806, the first surface 1810a of the second segment 1810, and the first surface 1808a of the third segment 1808. It can also be seen that the second surface 1804b of the first portion 1804 extends into the second surface 1810b of the second segment 1810 and into the second surface 1808b of the third segment 1808. Each of these segments may slide along each other and expand the sheath during passage of the medical device.

Fig. 19 shows an exemplary sheath having an inner liner 1800 and an outer layer 1900 as depicted in fig. 18.

Referring back to fig. 18, when at least a portion of the first surface 1810a of the second segment 1810 overlaps at least a portion of the second surface 1806b of the first segment 1806, a first gap 1812 is formed between at least a portion of the first surface 1810a of the second segment 1810 and at least a portion of the second surface 1804b of the first segment 1806.

In addition, a second gap 1814 may be formed when at least a portion of the first surface 1808a of the third segment 1808 overlaps at least a portion of the second surface 1810b of the second segment 1810. In addition, a third gap 1816 may be formed when at least a portion of the first surface 1808a of the third segment 1808 overlaps at least a portion of the second surface 1806b of the first segment 1806.

It should be appreciated that the first gap may have a substantially uniform width along the overlap portion, or the width thereof may vary. Similarly, the second gap may have a substantially uniform width along the overlap portion, or the width of the second gap may vary along the overlap portion. In addition, the third gap may have a substantially uniform or variable width along the overlapping portion. In further aspects, the width between gaps can be any width as desired. It should be appreciated that the width of each of the three gaps may be the same, or may be different, for example. In some aspects, the widths of some of the gaps are the same, while the widths of other gaps are different.

When utilizing the sheath as disclosed in fig. 18 and 19, the first segment 1806, the second segment 1810, and the third segment 1808 are configured to slidably move along each other as the medical device passes through the lumen such that the overlap between the first segment and the second segment and between the second segment and the third segment decreases and the overlap between the first segment and the third segment increases.

Similar to any of the sheath configurations disclosed herein, the diameter of the lumen of the sheath shown in fig. 19 is from a first resting diameter d _r Increase to a second expanded diameter d _e . After the medical device passes through the lumen, the first, second, and third segments 1806, 1808, 1810 are configured to slidably move in opposite directions along each other such that the overlap between the first and second segments, between the second and third segments, and between the first and third segments increases. After the device has been passed, the diameter of the lumen is increased from the second expanded diameter d _e Reduced to a first resting diameter d _r Substantially the same diameter.

It should also be appreciated that d, as disclosed above _r May be uniform along the length of the sheath or may vary from the proximal end of the sheath to the distal end of the sheath, as shown in fig. 3A-3C. It is also to be understood that d disclosed herein _r Any value of (c) is also applicable to the sheath configuration, as shown in fig. 18 and 19.

During Transcatheter Aortic Valve Replacement (TAVR) procedures, a sheath as disclosed herein is used to provide access to the vasculature without trauma to the patient, thereby functioning to maintain hemostasis and facilitate delivery of interventional devices and guidewire and catheter exchanges. In order for the sheath to be as minimally invasive as possible, the sheath must have a low profile or small Outer Diameter (OD) when accessed. Once inside the body, however, the sheath must be expanded to a larger diameter in order to allow passage of a catheter that is larger than the original diameter of the sheath. The force that propels these devices through the sheath is commonly referred to as thrust. For larger devices, such as crimped valves on Delivery Systems (DS), and challenging vascular anatomy, such as small, tortuous or stenotic vessels, the thrust during surgery is very important. High thrust may lead to delays in surgery, dissatisfaction by the physician, and even failure to complete the surgery.

An important function of the sheath is to have clinically acceptable thrust to advance the delivery system and valve throughout the sheath for all patient anatomy. In some aspects, a lubricant is used to help reduce thrust. The lubricious is placed between the layers that slide relative to each other to reduce the friction that needs to be overcome to expand the sheath, thereby making DS easier to pass through the sheath. Recent studies have shown that lubricants are required in order to reduce thrust to acceptable levels.

Additionally, the sheath construction as disclosed herein may include a lubricant. Fig. 23 illustrates one exemplary aspect of the sheath 2300. In this configuration, for example, lubricant 2306 may be disposed between inner liner 2302 and outer layer 2304.

For sheaths having the configuration shown in fig. 18 and 19, lubricant may be provided between any portion and segment in any amount and in any combination. In certain exemplary and non-limiting aspects, the lubricant may be disposed between the first segment and the second segment, or between the second segment and the third segment, or between the first segment and the third segment, or any combination thereof. In other aspects, the lubricant may be disposed such that it is positioned on an innermost surface of the sheath or an outermost surface of the sheath, or a combination thereof.

In further aspects, the lubricant is disposed along the entire circumference of the liner, or it may be disposed between at least a portion of the overlying portion of the sheet and at least a portion of the sliding portion of the sheet.

In addition, the lubricant may be disposed along at least a portion of the inner surface of the sheet or at least a portion of the outer surface of the sheet, or a combination thereof.

Lubricants known in the art may be utilized. In further aspects, the lubricant may comprise a PTFE-based lubricant or a silicone-based lubricant. In certain and non-limiting aspects, the lubricant may comprise Christo lubricating oil supplied by ECL or MED10/6670 or PRO-3499 supplied by Nusil, or PRO-3595 also supplied by Nusil. In further aspects, it should be appreciated that one of ordinary skill in the art can readily determine the amount of the first lubricant and/or the second lubricant

In certain aspects, the lubricant may be disposed in a predetermined pattern, such as shown in fig. 26. In such aspects, the lubricant is disposed in a pattern 2609, for example, on the liner 2602. It should be appreciated that the pattern 2609 is merely exemplary and that any desired pattern for any particular application may be applied.

The lubricant may be applied in any manner. For example, the lubricant may be applied manually. The lubricant is manually brushed onto the sheath, which makes it difficult to precisely control how much lubricant is added to the sheath and the exact location where the lubricant is applied to the sheath.

Thus, lubricants as disclosed herein may also be applied by pad printing or spraying, such that the materials are applied in a precisely controlled and repeatable manner, suitable for large-scale manufacturing. The detailed method of lubricant application is discussed below.

However, it should be understood that in terms of applying the lubricant by pad printing, the lubricant has a viscosity of about 600 to about 1,200cP prior to its application, including exemplary values of about 650cP, about 700cP, about 750cP, about 800cP, about 850cP, about 900cP, about 950cP, about 1,000cP, about 1,050cP, about 1,100cP, and about 1150 cP.

While in terms of spraying the lubricant, the lubricant may have a viscosity equal to or less than about 600cP, or about 550cP, about 500cP, about 450cP, about 400cP, about 350cP, or equal to or less than about 350 cP.

In a further aspect, the outer layer is then positioned over the inner liner of the sheath as the lubricant cures.

The lubricant may also form a film. When formed, such films may have a thickness equal to or less than about 20 μm, about 15 μm, about 10 μm, about 5 μm, about 1 μm, or even equal to or less than about 0.5 μm.

In further aspects, any of the constructions disclosed herein can include a polyolefin, a polyamide, a fluoropolymer, copolymers thereof, or blends thereof. In further aspects, the polyolefin may comprise high density polyethylene, polypropylene, or blends thereof.

In further aspects, the sheet may include one or more layers. In further aspects, the sheet may have a multi-layer structure. In some aspects, if one or more layers are present, each layer may comprise the same or different polymers. In further aspects, the sheet material may have a predetermined thickness, wherein the predetermined thickness may be defined by one of ordinary skill in the art depending on the particular application. In certain aspects, the predetermined thickness of the liner may be about 0.002 inches to about 0.025 inches, including exemplary values of about 0.003 inches, about 0.004 inches, about 0.005 inches, about 0.006 inches, about 0.007 inches, about 0.008 inches, about 0.009 inches, about 0.01 inches, about 0.015 inches, and about 0.02 inches. It should also be appreciated that the predetermined thickness of the sheet forming the liner having any of the configurations disclosed herein may vary depending on the amount of radial expansion desired as well as the strength desired.

In certain aspects, the liner of any of the sheath constructions described herein can comprise a compound material. For example, the polymer layer of the sheet used to form the liner may include a compound material including a polyolefin and a lubricating filler. It should be understood that any of the polyolefins described above may be used. In some exemplary aspects, the polyolefin used in the compound material is a high density polyethylene. In other aspects, the lubricating filler may be any filler that can improve the lubricity of the polymer layer and reduce the overall coefficient of friction of its liner. In some exemplary and non-limiting aspects, the lubricating filler may include any additive known to reduce friction and function as a lubricant. In such exemplary and non-limiting aspects, the lubricating filler may include one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicone, talc, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene, and the like. In a further aspect, the lubricating filler comprises a PTFE filler. In a further aspect, the PTFE filler is a powder.

In further aspects, the lubricating filler may be present in any amount. In some exemplary and non-limiting aspects, the lubricating filler may be present in an amount of about 5 wt% to about 20 wt% of the total weight of the compound material used to prepare the polymeric layer of the liner. In further aspects, the lubricating filler may be present in an exemplary amount of about 5 wt.%, about 6 wt.%, about 7 wt.%, about 8 wt.%, about 9 wt.%, about 10 wt.%, about 11 wt.%, about 12 wt.%, about 13 wt.%, about 14 wt.%, about 15 wt.%, about 16 wt.%, about 17 wt.%, about 18 wt.%, about 19 wt.%, or about 20 wt.%.

In further aspects, sheets comprising such compound materials are smooth and may have a coefficient of friction of less than about 0.5, less than about 0.4, less than about 0.3, less than about 0.2, less than about 0.1, or less than about 0.05, or even less than about 0.01. It should also be appreciated that the coefficient of friction of the sheet material may be any value between any two of the values described above.

It should also be appreciated that when the polymer layer of the sheet used to form the liner includes the compound material disclosed herein, the sheath may be substantially free of a separately disposed lubricant. For example, if the liner itself includes a lubricating filler, there may be no need for a lubricant as disclosed above to be applied between the overlapping portions of the liner or between the outermost surface of the liner and the innermost surface of the outer layer. However, aspects of the sheath are also disclosed herein, wherein the liner includes a lubricating compound in its composition, and a separate lubricant as disclosed above is still applied between the various portions of the sheath. In such exemplary aspects, such additional lubricant applied manually, pad printing, or spray may be applied between some portion of the liner and the outer layer or all portions of the liner and the outer layer, as disclosed above. It should also be appreciated that this additional lubricant may be applied in any desired pattern. It may also be applied along all the length of the sheath or only along some portion of the sheath. The lubricant may also be applied in different patterns in different portions of the sheath. However, in other aspects, the lubricant may be applied in the same pattern along various portions of the sheath.

In a further aspect, the inner surface of the sheet may be at least partially ribbed. In such exemplary aspects, the inner surface of the sheet may be at least partially ribbed prior to winding the sheet into a spiral configuration to form the liner.

In some aspects, the sheath described herein including a lubricating material in the liner may exhibit a thrust force required to move the prosthetic device through the sheath that is comparable to or even less than a thrust force of a substantially identical reference sheath rolled into a spiral configuration, wherein the liner of the substantially identical reference sheath includes a polymer layer that is substantially free of lubricating filler and includes an amount of lubricant disposed between overlapping portions of the spiral configuration and/or an outermost surface of the liner. In other words, in some aspects, when comparing the performance of any of the sheath constructions disclosed herein, in such exemplary and non-limiting aspects, a sheath having a lubricating material in the liner and no additional lubricant present may exhibit similar or even better performance than a similar sheath having no lubricating material in the liner but additional lubricant dispersed between the various portions of the sheath.

In further aspects and as described herein, the sheath can further comprise a tie layer. In such aspects, the tie layer may be disposed on an inner surface of the liner or an outer surface of the liner, for example, with reference to fig. 25A-B. Fig. 25A-B illustrate an exemplary coextruded tube that may be used to form a sheet, which is then wound into a spiral configuration. Details of the method of forming the liner are discussed in more detail below. Here, fig. 25A-B illustrate a co-extruded tube 2502 comprising a polymer layer 2505 and a tie layer 2503. Fig. 25A shows the tie layer 2503 being coextruded with the polymer layer 2505 such that the tie layer is positioned on an outer surface of the polymer layer. It will be appreciated that when the liner is in a helical configuration, the outer surface of the polymer layer will define at least a portion of the outer surface of the liner. Fig. 25B shows the tie layer 2503 being coextruded with the polymer layer 2505 such that the tie layer 2503 is positioned on the inner surface of the polymer layer. It will be appreciated that when the liner is in a helical configuration, the inner surface of the polymer layer will define at least a portion of the inner surface of the liner.

It is to be understood that the polymer layer 2505 can be any of the polymer layers described above and used to make a sheet. In certain aspects, the polymer layer may be a high density polyethylene.

In further aspects, the connection layer 2503 can comprise any material suitable for a desired application. It should be appreciated that the tie layer may have adhesive or cohesive properties. In certain aspects, the tie layer may comprise a polyurethane material, such as Tecoflex, or a polymer, copolymer, or terpolymer, such as: such as but not limited toMaleic anhydride modified polyolefins (commercially available from Arkema), e.g., DOW Chemical +.>Ethylene acrylic acid copolymers of (2), e.g. +.>Vinyl acrylate copolymers, ethylene glycidyl methacrylate copolymers (commercially available from Arkema), for exampleEthylene acrylate glycidyl methacrylate terpolymers (commercially available from Arkema), e.g.>Or->Ethylene acrylate maleic anhydride terpolymers (commercially available from Arkema).

In certain aspects, the total thickness of the sheet having the polymer layer and the tie layer can be about 0.002 inch to about 0.025 inch, including exemplary values of about 0.003 inch, about 0.004 inch, about 0.005 inch, about 0.006 inch, about 0.007 inch, about 0.008 inch, about 0.009 inch, about 0.01 inch, about 0.015 inch, and about 0.02 inch. It should also be appreciated that the total thickness of the sheet material forming the liner of any of the configurations disclosed herein may vary depending on the amount of radial expansion desired as well as the strength desired.

In further aspects, the tie layer can have a thickness of about 0.001 "to about 0.003", including exemplary values of about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", and about 0.0029 ".

In further aspects, any of the sheath configurations disclosed herein can have at least one lubricious liner, such as shown in fig. 25C-D.

Fig. 25C-D illustrate an exemplary co-extruded tube comprising a tie layer 2503 and a polymer layer 2505, and a smooth liner 2507 as disclosed above. This tube may be used to form a sheet that is then wound into a helical configuration. Details of the method of forming the liner are discussed in more detail below. As can be seen herein, a lubricious liner 2507 is disposed on the tie layer 2503. It should be appreciated that in one configuration, the tie layer and the lubricious liner are disposed on the outer surface of the polymer layer (fig. 25C) or the inner surface of the polymer layer (fig. 25D). In a further aspect, the lubricious liner is bonded to the polymer layer of the sheet with a tie layer.

Figures 25E-H illustrate various configurations of the sheet 2502 in a spiral configuration when the sheet includes a polymer layer 2505, a tie layer 2503, and a smooth liner 2507.

The lubricious liner may comprise any material that reduces the coefficient of friction of the sheath. In some exemplary and non-limiting aspects, the lubricious liner may comprise PTFE, polyether block amide, silicone based liners, perfluoroalkoxyalkane based liners, e-PTFE, ethylene tetrafluoroethylene, and the like. In a further aspect, the lubricious liner comprises PTFE.

In another aspect, the total thickness of the sheath can be any thickness, as disclosed above.

However, in other aspects, the at least one lubricious lining has a thickness of about 0.001 "to about 0.005", including about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", about 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", about 0.0029", about 0.0030", about 0.0031", about 0.0032", about 0.0033", about 0.0034", about 0.0035", about 0.0036", about 0.0037", about 0.0038", about 0.0039", about 0.0040.0040", about 0.0041", about 0.0042, about 0.0043", about 0.0044", about 0.0045", about 0.0046", about 0.0048", and the exemplary values of about 0.0049 ".

In further aspects, the lubricious liner can further be ribbed. It should also be appreciated that aspects are also disclosed that include additional lubricant added separately from the smooth liner. In such aspects, the additional lubricant may be provided by any of the methods disclosed herein. It can be set manually, pad printed or sprayed. It should also be appreciated that when present, this additional lubricant may be disposed in any of the predetermined patterns disclosed herein along a portion of the length of the sheath or along the entire length of the sheath. In other aspects, when a lubricant layer as described herein is present, no additional lubricant is present.

In further aspects, the outer layer of any of the sheath constructions can include styrene-based elastomers, polyurethanes, latexes, copolymers thereof, blends thereof, or co-extrudates thereof. In certain and non-limiting aspects, the polymer may include polyether block ester copolymers, polyesters, polyvinylchlorides, thermoset silicones, polyisoprene rubber, polyolefins, other medical grade polymers, or combinations thereof.

In further aspects, the outer layer may include one or more layers. In some aspects, at least one layer comprises a styrene-based elastomer. In other aspects, at least one layer may comprise polyurethane. While in other aspects at least one layer comprises a blend of a styrene-based elastomer and a polyurethane.

It should be understood that the hardness of each layer of the disclosed sheath may also vary depending on the particular application and desired properties of the sheath. In some aspects, the layer of the outer layer has a shore a hardness between 20A and 50A, including exemplary values of about 25A, about 30A, about 35A, about 40A, and about 45A.

In further aspects, the polymer layer of the outer layer may have a shore hardness of less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, or less than 20. In further exemplary aspects, the polymer layer of the outer layer can have a shore hardness of about 25 to about 75, including exemplary values of about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, and about 70.

The sheath as shown in any of the foregoing constructions may further comprise an outer layer comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt% to less than 100 wt% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof, based on the total weight of the first compound composition; less than about 65 weight percent of an inorganic filler, based on the total weight of the first compound composition; and up to about 20% by weight of a solid lubricant filler, based on the total weight of the first compound composition. However, it should be understood that there are aspects of the disclosed sheath that may include additional components. These exemplary aspects are disclosed herein, as shown in detail below.

In certain aspects, the outer layer comprises a first polymer layer. In these exemplary aspects, the first polymer layer can include a first compound composition that includes from greater than 0 wt% to less than 100 wt%, including exemplary values of about 0.01 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, and about 99.9 wt% of a polymer that includes a polyether block amide, polyurethane, or any combination thereof.

In further aspects, the first compound composition can include from greater than about 35 wt% to less than about 80 wt%, including exemplary values of about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, and about 75 wt% of a polymer including a polyether block amide, a polyurethane, or any combination thereof.

In certain aspects, the polymer in the first compound composition comprises a polyether block amide. In such exemplary aspects, the polyether block amide may include PEBAX from armema. In a further aspect, the polymer may comprise polyurethane, e.gIn yet further aspects, the polymer may comprise a combination of polyether block amide (e.g., PEBAX) and polyurethane. It should also be understood that if a mixture of polymers is present, such mixture may include any amount of each component relative to the other component to provide the desired polymer that falls within the disclosed ranges above.

In further aspects, the first compound composition can include less than about 65 wt% inorganic filler, including exemplary values of less than about 60 wt%, less than about 55 wt%, less than about 50 wt%, less than about 45 wt%, less than about 40 wt%, less than about 35 wt%, less than about 30 wt%, less than about 25 wt%, less than about 20 wt%, less than about 15 wt%, less than about 10 wt%, less than about 5 wt%, and less than about 1 wt% inorganic filler, based on the total weight of the first compound composition.

In further aspects, the inorganic filler may be present in an amount of at least about 1 wt%, at least about 2 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 45 wt%, at least about 50 wt%, or at least about 55 wt%.

In further aspects, the inorganic filler may include any inorganic material that can be used as a filler and is acceptable for the desired application. In certain exemplary and non-limiting aspects, the inorganic filler may include bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin, limestone, or any combination thereof. Also, it should be understood that the inorganic filler may include a combination of various fillers. In these exemplary aspects, the amount of each filler in the combination can be in any range to provide a final combination that falls within the disclosed ranges described above.

In further aspects, the first compound composition can include up to about 20 wt.% of the solid lubricant filler, including exemplary values of about 0.01 wt.%, about 0.1 wt.%, about 0.5 wt.%, about 1 wt.%, about 2 wt.%, about 3 wt.%, about 4 wt.%, about 5 wt.%, about 6 wt.%, about 7 wt.%, about 8 wt.%, about 9 wt.%, about 10 wt.%, about 11 wt.%, about 12 wt.%, about 13 wt.%, about 14 wt.%, about 15 wt.%, about 16 wt.%, about 17 wt.%, about 18 wt.%, about 19 wt.%, and about 19.9 wt.% of the solid lubricant filler, based on the total weight of the first compound composition. In further aspects, the solid lubricant filler may be present up to about 20 wt%, up to about 15 wt%, or up to about 10 wt%, based on the total weight of the first compound composition.

In further aspects, the solid lubricant filler may include any additive known to reduce friction and function as a lubricant. In such exemplary and non-limiting aspects, the solid lubricant filler may include one or more of graphene, reduced graphene oxide, carbon black, boron nitride, silicone, talc, polytetrafluoroethylene (PTFE), fluorinated ethylene propylene, and the like. In a further aspect, the solid lubricant comprises a PTFE filler. In a further aspect, the PTFE filler is a powder.

In further aspects, the first compound composition may further comprise at least one viscosity-reducing compound. Any compound known in the art capable of reducing the tackiness of a polymer composition is contemplated and used for the purposes of this disclosure. In further exemplary and non-limiting aspects, the at least one viscosity-reducing compound comprises ProPell from Foster Corp ^TM 。

In certain aspects, the at least one viscosity-reducing compound is present in an amount of from 0 wt% to about 20 wt%, including exemplary values of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, and about 19 wt%, based on the total weight of the first compound composition. In a further aspect, the at least one viscosity-reducing compound is present in any amount having a value between any two of the foregoing values. For example, but not limited to, the at least one viscosity-reducing compound may be present in an amount of about 1% to about 5% by weight or about 5% to about 10% by weight, based on the total weight of the first compound composition.

In a further aspect and as disclosed herein, the polymers in the first polymer layer composition have substantially the same hardness along the total length of the outer layer. However, it should be understood that the hardness of the polymer in the first polymer layer composition of the outer layer may also vary along the length of the outer layer. For example, and without limitation, aspects are disclosed herein in which the hardness of the polymer in the first polymer layer composition at the proximal end of the outer layer is different than the hardness of the polymer in the first polymer layer composition at the distal end of the outer layer.

In a further aspect, the polymer in the first polymer layer composition has a shore D of about 20D to about 72D, comprising exemplary values of about 25D, about 30D, about 35D, about 40D, about 45D, about 50D, about 55D, about 60D, about 65D, and about 70D. In a further aspect, the polymer in the first polymer layer composition has a shore D of about 20D to about 35D. In a further aspect, the polymer in the first polymer layer composition has a shore D of about 30D. In a further aspect, however, the polymer in the first polymer layer composition has a shore D of about 25D.

It should be understood that the outer layer as disclosed herein may include aspects where only one polymer layer is present. However, in other aspects, two or more polymer layers may be present in the outer layer. In such exemplary aspects, the outer layer can include a second polymer layer including a second compound composition including greater than 0 wt% to 100 wt% of a second polymer including polyether block amide, polyurethane, or a combination thereof. Similar to the first compound composition, the second polymer may be present in any amount falling within the disclosed ranges. For example, the second polymer may be present in the second compound composition in greater than 0 wt%, about 0.01 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, about 45 wt%, about 50 wt%, about 55 wt%, about 60 wt%, about 65 wt%, about 70 wt%, about 75 wt%, about 80 wt%, about 85 wt%, about 90 wt%, about 95 wt%, and about 99.9 wt% of the polymer comprising the polyether block amide, the polyurethane, or any combination thereof. In further aspects, the second polymer may be present in the second compound composition from greater than about 95 wt% to less than about 99 wt%, including exemplary values of about 95.5 wt%, about 96 wt%, 96.5 wt%, about 97 wt%, about 97.5 wt%, about 98 wt%, and about 98.5 wt%.

In further aspects, the second compound composition can further comprise up to 20 wt%, based on the total weight of the second compound composition, comprising exemplary values of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, and about 19 wt% of the viscosity-reducing additive. In a further aspect, the at least one viscosity-reducing compound is present in any amount having a value between any two of the foregoing values. For example, but not limited to, the at least one viscosity-reducing compound may be present in an amount of about 1% to about 5% by weight or about 5% to about 10% by weight, based on the total weight of the second compound composition. In further aspects and as disclosed herein, the second compound composition may be substantially free of solid lubricant filler.

It is also understood that in certain aspects, the first polymer in the first compound composition may be the same as the second polymer in the second compound composition. However, in other aspects, the first polymer in the first compound composition is different from the second polymer in the second compound composition. In a further aspect, the second polymer layer composition comprises While in a further aspect the second polymer layer composition may comprise polyurethane, e.g. from PolyOne +.>

In a further aspect, the second polymer has a shore D of about 20D to about 35D. In a further aspect, however, the second polymer has a shore D of about 25D or about 35D.

In a further aspect, the second compound composition may be substantially free of inorganic filler. In certain aspects, the inorganic filler may be present in the second compound composition in any amount from greater than 0 wt% to less than 100 wt%, including exemplary values of about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.5 wt%, about 1 wt%, about 5 wt%, about 10 wt%, about 20 wt%, about 30 wt%, about 40 wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, about 90 wt%, and about 95 wt%. In the aspect that an inorganic filler is present in the second compound composition, such inorganic filler may include any of the fillers disclosed above.

In a further aspect and as disclosed herein, the outer layer has a predetermined thickness, and wherein at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100% of the predetermined thickness comprises a first compound composition and/or a second compound composition comprising a first polymer and/or a second polymer having a shore D of equal to or less than about 30D.

In further aspects, the predetermined thickness of the outer layer may vary along the length of the sheath. In yet other aspects, the predetermined thickness of the outer layer is the same along the length of the sheath. However, in a further aspect, the predetermined thickness of the outer layer is greater at the proximal end. In a further aspect, the predetermined thickness of the outer layer is up to 0.006", such as, but not limited to, about 0.001" to about 0.006", including exemplary values of about 0.0015", about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", and about 0.006 ".

In further aspects, the first polymer layer and the second polymer layer may have the same thickness. While in other aspects, the first polymer layer and the second polymer layer have different thicknesses. For example, in some aspects, the thickness of the first polymer layer is about 001 "to about 0.003", including exemplary values of about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", about 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", and about 0.0029 ". However, in further aspects, the thickness of the second polymer layer can be about 0.002 "to about 0.004", including exemplary values of about 0.0011", about 0.0012", about 0.0013", about 0.0014", about 0.0015", about 0.0016", about 0.0017", about 0.0018", about 0.0019", about 0.0020", about 0.0021", about 0.0022", about 0.0023", about 0.0024", about 0.0025", about 0.0026", about 0.0027", about 0.0028", about 0.0029", 0.0030", about 0.0031", about 0.0032", about 0.0033", about 0.0034", about 0.0035", about 0.0036", about 0.0037", about 0.0038", and 0.0039 ".

In a further aspect, the predetermined thickness of the outer layer is greater at the proximal end. In yet other aspects, the predetermined thickness of the outer layer at the distal end is less than the predetermined thickness of the outer layer at the proximal end.

In further aspects where there are two or more layers in the outer layer, the first polymer layer may define an inner surface of the outer layer and the second polymer layer may define an outer surface of the outer layer. However, there are also aspects in which the first polymer layer defines the outer surface of the outer layer and the second polymer layer defines the inner surface of the outer layer. It should also be understood that other aspects are also included in which one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.

In a further aspect, the outer layer is extruded as a tube and then can be slipped over the inner liner of the sheath. Such polymer layers may be co-extruded in the presence of the first and second polymer layers. In further aspects, the first polymer layer can be substantially bonded to the second polymer layer. In such an exemplary aspect, the first polymer layer does not substantially detach from the second polymer layer. It should be appreciated that in some aspects, the bond may be a physical bond or a chemical bond or any other type known in the art.

In further aspects, any sheath including the outer layers disclosed herein can exhibit an insertion force of less than about 55N, less than about 50N, less than about 45N, less than about 40N, less than about 35N, or less than about 35N as the medical device is pushed through the sheath.

In further aspects, the outer layer may also exhibit a friction force of less than about 10N, or less than about 9N, or less than about 8N, or less than about 7N, or less than about 6N, or even less than about 5N, against a substrate surface comprising one or more of polytetrafluoroethylene, fluorinated ethylene propylene, or high density polyethylene having a diameter of about 0.300 "in a dry state.

In further aspects, the outer layer extruded into a tube may exhibit a hoop force of less than about 10N, or less than about 9N, or less than about 8N, or less than about 7N, or less than about 6N, or even less than about 5N at 10mm extension (about 85% strain). In such exemplary aspects, the extruded tube that will form the outer layer of the sheath can have a diameter of about 0.290 "(7.4 mm) and a wall thickness as disclosed herein. In aspects where the outer layer has a diameter of about 0.290 "(7.4 mm) and a total wall thickness of about 0.0045", the sample length is about 0.25 "(6.4 mm), the hoop force at 10mm extension may be less than about 8N. It should be appreciated that in some exemplary and non-limiting aspects, a lower force at 10mm extension is desirable for a lower sheath expansion force.

In further aspects, the outer layer may exhibit an elongation at break ranging between about 650% and about 800%, including exemplary values of about 680%, about 700%, about 710%, about 750%, and about 780%. It should be appreciated that in some exemplary and non-limiting aspects, a high elongation is preferred for expanding to a larger diameter before the outer layer breaks.

In certain aspects, the outer layer extends along a portion of the length of the sheath. In such exemplary aspects, the outer layer may be positioned at a proximal end of the sheath, or a middle of the sheath, or a distal portion of the sheath. While in other aspects the outer layer extends along the entire length of the sheath. In such exemplary aspects, the outer layer may be positioned at the proximal end of the sheath and extend to the distal end of the sheath.

In further aspects, the outer layer of any of the sheath constructions disclosed herein can include one or more polymer layers. In some aspects, the first polymer layer can be the first polymer layer disclosed above. However, in other aspects, the outer layer may also include a second polymer layer, wherein the second polymer layer may be any of the second polymer layers disclosed above. In some exemplary and non-limiting aspects, the second polymer layer can include polyurethane. In some exemplary and non-limiting aspects, the first polymer layer can include PEBAX alone or PEBAX in combination with an inorganic filler and a solid lubricant filler, as disclosed above. In other exemplary and non-limiting aspects, the second polymer layer can include polyurethane, such as Neusoft.

In certain aspects, as described above, the first polymer layer and the second polymer can be co-extruded to form a bumped tube. It should be appreciated that a bump tube or tapered tube is commonly used in a variety of applications.

It should be appreciated that in some aspects, a bump tube or tapered tube may be particularly useful for certain catheter applications. Neurovascular and microcatheters generally rely on a larger proximal diameter to increase pushability of the device, while smaller distal ends provide improved performance and deliverability.

In some aspects disclosed herein, the bump tube forming the outer layer of the sheath may have a predetermined length substantially similar to the length of the sheath. However, in other aspects, the bump tube forming the outer layer of the sheath may have a predetermined length shorter than the length of the sheath.

In certain aspects, the first polymer layer may define an inner surface of the outer layer (bump tube). In such aspects, the second polymer layer will define an outer surface of the outer layer.

However, in other aspects, the second polymer layer may define the outer surface of the outer layer (bump tube). In such aspects, the second polymer layer will define the inner surface of the outer layer.

In further aspects, where the outer layer has the above-described configuration, the first polymer layer can have a thickness of about 0.001 "to about 0.010", including exemplary values of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009', and about 0.0095 ". It should be appreciated that the thickness of the first polymer layer in the outer layer may be uniform along the length of the sheath. However, in other aspects, the thickness of the first polymer layer in the outer layer may vary along the length of the sheath. In some aspects, the thickness of the first polymer layer at the proximal end of the sheath is greater than the thickness of the first polymer layer along other portions of the sheath. However, in other aspects, the thickness of the first polymer layer at the distal end of the sheath may be less than the thickness of the first polymer layer at the proximal end of the sheath.

In some aspects, if present in the outer layer, the second polymer layer can have a thickness of about 0.001 "to about 0.010", including exemplary values of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", about 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009', and about 0.0095 ". It will be appreciated that the thickness of the second polymer layer in the outer layer may be uniform along the length of the sheath. However, in other aspects, the thickness of the outer polymer layer in the outer layer may vary along the length of the sheath. In some aspects, the thickness of the second polymer layer at the proximal end of the sheath is greater than the thickness of the second polymer layer along other portions of the sheath. However, in other aspects, the thickness of the second polymer layer at the distal end of the sheath may be less than the thickness of the second polymer layer at the proximal end of the sheath.

In further aspects, the first polymer layer can have a shore D of about 20D to about 72D, including exemplary values of about 25D, about 30D, about 35D, about 40D, about 45D, about 50D, about 55D, about 60D, about 65D, and about 70D. In a further aspect, the polymer in the first polymer layer composition has a shore D of about 20D to about 35D. In a further aspect, the polymer in the first polymer layer composition has a shore D of about 30D. In a further aspect, however, the polymer in the first polymer layer composition has a shore D of about 25D.

However, in other aspects, the second polymer layer can have a shore a of about 30A to about 80A, including exemplary values of about 40A, about 45A, about 50A, about 55A, about 60A, about 65A, about 70A, and about 75A.

In a further aspect and as disclosed herein, the outer layer has a total predetermined thickness, and wherein at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100% of the total predetermined thickness comprises a first compound composition comprising a first polymer having a shore D of from about 20D to about 35D. In further aspects, the total predetermined thickness of the outer layer is at most about 0.02", or at most about 0.015", or at most about 0.01", or at most about 0.009", or at most about 0.008", or at most about 0.007", or at most about 0.006'.

In further aspects, the total predetermined thickness of the outer layer may be uniform along the length of the sheath, or may vary along the length of the sheath. In some exemplary and non-limiting aspects, the total predetermined thickness of the outer layer is greater at the proximal end of the sheath. However, in other aspects, the total predetermined thickness of the outer layer at the distal end of the sheath is less than the total predetermined thickness of the outer layer at the proximal end of the sheath.

Also disclosed herein are sheath aspects wherein the outer layer has one or more layers, and where the layers are formed separately. For example, as described above, the first polymer layer and the second polymer layer are formed separately rather than being co-extruded. In such aspects, the outer layer is formed by disposing one polymer layer over another polymer layer.

In some exemplary and non-limiting aspects, the second polymer layer can be at least partially disposed over the first polymer layer. Aspects are also disclosed in which a first polymer layer at least partially covers a second polymer layer.

In certain aspects, when the two polymers are formed separately and disposed over one another, each of the polymer layers may have a different length.

In some exemplary and non-limiting aspects, the first polymer layer can have a length that is shorter than a length of the second polymer layer. In some aspects, the first polymer layer may be disposed on the liner at the proximal end of the sheath and have a length of about 5cm to about 15cm, including exemplary values of about 6cm, about 7cm, about 8cm, about 9cm, about 10cm, about 11cm, about 12cm, about 13cm, and about 14 cm. In yet another aspect, the second polymer layer is then disposed on the first polymer layer. In such aspects, the second polymer layer can have any length suitable for the desired application. In certain aspects, the second polymer layer may have a length that is substantially the same as a length of the sheath.

However, it should be understood that the relative configuration of the outer layers is also disclosed. In this aspect, the second polymer layer may be disposed on the liner first and have a length that is shorter than the length of the sheath. In addition, a second polymer layer may be disposed on the second polymer layer. In this exemplary aspect, the first polymer layer can have any length. In some aspects, the length of the first polymer layer may be substantially the same as the length of the sheath.

In addition, the first polymer layer as disclosed in these aspects may have a thickness that is uniform along the length of the first polymer layer or may vary along the length of the first polymer layer. For example, the thickness of the first polymer layer (d 2, e.g., as shown at 4200 of fig. 42B) can be any thickness, as disclosed above. In some aspects, the thickness can be any value between about 0.001 "to about 0.006", including exemplary values of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", and about 0.0055".

In addition, the second polymer layer as disclosed in these aspects may have a thickness that is uniform along the length of the second polymer layer or may vary along the length of the second polymer layer. As disclosed above, the thickness of the second polymer layer may be any thickness. In some aspects, the thickness d1 of the second polymer, such as shown in 4200 of fig. 42C, can be any value between about 0.001 "and about 0.010", including exemplary values of about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009', and about 0.0095 ".

In further aspects, the total thickness of the outer layer can be any value between about 0.001 "and about 0.015", including exemplary values of about 0.0015", about 0.002", about 0.0025", about 0.003", about 0.0035", about 0.004", about 0.0045", about 0.005", about 0.0055", about 0.006", 0.0065", about 0.007", about 0.0075", about 0.008", about 0.0085", about 0.009", 0.0095", about 0.01", about 0.0105", about 0.011", about 0.01105", about 0.012", about 0.01205", about 0.013", about 0.01305", about 0.014", and about 0.01405.

In further aspects, the outer layers disclosed herein can include at least two polymer layers. In further aspects, the outer layers disclosed herein can include at least one intermediate reinforcing layer disposed between the first polymer layer and the second polymer layer. In a further aspect, the at least one intermediate reinforcing layer is a polymeric layer.

In some aspects, at least one intermediate layer may extend along the entire circumference of the outer layer. In a further aspect, the first polymer layer forms an inner surface of the outer layer and the second polymer layer forms an outer surface of the outer layer, the intermediate layer is disposed between the outer surface of the first polymer and the inner surface of the second polymer layer. However, in other aspects and as disclosed above, if the second polymer layer forms the inner surface of the outer layer and the first polymer layer forms the outer surface of the outer layer, the intermediate layer is disposed between the outer surface of the second polymer layer and the inner surface of the first polymer layer. In further aspects, the intermediate reinforcing layer may bond the first and second polymer layers, and may also help bond the outer layer as a whole to the inner member of the sheath.

In a further aspect, at least one intermediate layer has a finite width less than the circumference of the outer layer. In such aspects, at least one intermediate layer may be interposed as a strip between the first polymer layer and the second polymer layer. In some exemplary and non-limiting aspects, if the outer layer has a distal outer diameter of about 0.200", the strips can have a width (w, e.g., as shown in 4200 of fig. 42B) of between about 0.010" and about 0.150", including exemplary values of about 0.03", about 0.035", about 0.04", about 0.045", about 0.05", about 0.055", about 0.06", about 0.065", about 0.07", about 0.075", about 0.08", about 0.085", about 0.09", about 0.095", about 0.10", about 0.105", about 0.110", about 0.115", about 0.120", about 0.125", about 0.130", about 0.135", about 0.140", and about 0.145 ". It should be understood that the widths shown above are exemplary and that the strip widths may be adjusted at the same or different ratios if the outer distal diameter of the outer layer has a dimension other than 0.200 ".

In a further aspect, at least one intermediate layer has a finite width less than the circumference of the outer layer. In such aspects, at least one intermediate layer may be interposed as a strip between the first polymer layer and the second polymer layer. In some exemplary and non-limiting aspects, if the outer layer has a distal outer diameter of about 0.200", the width of the strip may be about 5% to about 50% of the circumference of the outer layer. In further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the outer layer. It should be appreciated that the widths shown above are exemplary and that the strap widths may be adjusted at the same or different ratios if the distal outer diameter of the elongate sheath has a size other than 0.200 ".

In further aspects, the outer layer may include two or more intermediate layers. In such aspects, two or more intermediate layers may be disposed circumferentially as separate strips between the first and second polymer layers at a predetermined distance from each other. In aspects where two or more intermediate layers are disposed between the first and second polymer layers of the outer layer, the total combined width of all the strips is from about 5% to about 50% of the circumference of the outer layer. In further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the outer layer.

In a further aspect, the at least one intermediate layer is configured to provide axial reinforcement to the outer layer, and thus to the sheath in which the outer layer may be used. In such exemplary aspects, the at least one intermediate layer may be disposed along the length of the outer layer or along a portion of the length of the outer layer.

In some aspects, a portion of the length of the outer layer in which the at least one intermediate layer is disposed is positioned at the distal end and/or the proximal end of the outer layer. In other aspects, at least one intermediate layer may also be positioned anywhere along the length of the outer layer.

It will also be appreciated that where the intermediate layer is present as one or more strips circumferentially arranged along the length of the sheath, the width of the strips may be the same along the length, or may vary along the length. Such a strip may have any of the width values disclosed above in terms of the width of the strip varying along the length of the outer layer.

In further aspects, the first polymer layer used in this exemplary outer layer can be any of the first polymer layers described above. In further exemplary and non-limiting aspects, the first polymer layer forms an inner surface of the outer layer and includes a first compound composition comprising: from greater than 0 wt% to less than 100 wt% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof, based on the total weight of the first compound composition; less than about 65% inorganic filler, based on the total weight of the first compound composition; and up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition.

Any of the above-disclosed inorganic fillers and solid lubricant fillers may be present in any of the amounts disclosed. For example, the inorganic filler may include bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin, limestone, or any combination thereof. In other aspects, the inorganic filler may be present at least 10 wt%. In further aspects, the inorganic filler may be present in an amount of less than about 50 weight percent based on the total weight of the first compound composition.

In further aspects, the solid lubricant filler may comprise a PTFE filler.

The first compound may also include any of the additives disclosed above. For example, the compound may include at least one viscosity reducing compound in an amount of about 1% to about 20% by weight.

In further exemplary aspects, the polymer present in the first compound can have a shore D of about 20D to about 35D, including exemplary values of about 22D, about 25D, about 27D, about 30D, and about 32D.

In further aspects, the hardness of the polymer in the first polymer layer composition at the proximal end of the outer layer may be different than the hardness of the polymer in the first polymer layer composition at the distal end of the outer layer.

In a further aspect, the polymer in the first compound may comprise a polyether block amide, e.gIn yet other aspects, the polymer in the first compound may comprise polyurethane. In further aspects, the first compound may further comprise a polyamide.

In further aspects, the thickness of the first polymeric layer can be from about 1 mil to about 5 mils, including exemplary values of about 1.1 mil, about 1.2 mil, about 1.3 mil, about 1.4 mil, about 1.5 mil, about 1.6 mil, about 1.7 mil, about 1.8 mil, about 1.9 mil, about 2.0 mil, 2.1 mil, about 2.2 mil, about 2.3 mil, about 2.4 mil, about 2.5 mil, about 2.6 mil, about 2.7 mil, about 2.8 mil, about 2.9 mil, about 3.0 mil, about 3.1 mil, about 3.2 mil, about 3.3 mil, about 3.4 mil, about 3.5 mil, about 3.6 mil, about 3.7 mil, about 3.8 mil, about 3.9 mil, about 4.1 mil, about 4.2 mil, about 4.3 mil, about 4.4 mil, about 4.5 mil, about 4.6 mil, about 4.7 mil, and about 4.8 mil.

In further aspects, the second polymer layer can comprise any of the polymers disclosed above. In some aspects, the second polymer layer may include a second compound composition including greater than 0 wt% to 100 wt% of a second polymer including polyether block amide, polyurethane, or a combination thereof. In further aspects, the second polymer layer may comprise polyamide. In other aspects, the second compound may also include any of the fillers or additives disclosed above. And in some aspects, the second compound does not include the solid lubricant filler disclosed herein. While in a further aspect, the second compound may include the viscosity-reducing additives described in the present disclosure. In some aspects, the second polymer may be a polyurethane. In a further aspect, the polyurethane is a thermoplastic polyurethane.

While in a further aspect, the second polymer may be a blend comprising polyurethane and styrene block copolymers. In further aspects, the blend may also include additional polymers and copolymers. For example, an ether-based polymer may be present in the blend. In some exemplary and non-limiting aspects, the second polymer may be selected from the group consisting of Neusoft under the trade name Neusoft ^TM Commercial polymers are sold. In further aspects, the second polymer can have a shore a hardness of about 20A to about 75A, including exemplary values of about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, about 60A, about 65A, and about 70A. In further aspects, the second polymer may have a shore a hardness of less than 60A. In some exemplary aspects, the second polymer may be Neusoft ^TM 597-50A。

In further aspects, the thickness of the second polymeric layer can be from about 1 mil to about 6 mils, including exemplary values of about 1.1 mil, about 1.2 mil, about 1.3 mil, about 1.4 mil, about 1.5 mil, about 1.6 mil, about 1.7 mil, about 1.8 mil, about 1.9 mil, about 2.0 mil, 2.1 mil, about 2.2 mil, about 2.3 mil, about 2.4 mil, about 2.5 mil, about 2.6 mil, about 2.7 mil, about 2.8 mil, about 2.9 mil, about 3.0 mil, about 3.1 mil, about 3.2 mil, about 3.3 mil, about 3.4 mil, about 3.5 mil, about 3.6 mil, about 3.7 mil, about 3.8 mil, about 3.9 mil, about 4.1 mil, about 4.2 mil, about 4.3 mil, about 4.4 mil, about 4.5 mil, about 4.6 mil, about 4.5 mil, about 4.7 mil, about 4.5 mil, about 5 mil, about 3.5 mil, about 5 mil. In further aspects, the thickness of the at least one intermediate reinforcing layer may be any value between about 1 mil and about 6 mils, including about 1.1 mil, about 1.2 mil, about 1.3 mil, about 1.4 mil, about 1.5 mil, about 1.6 mil, about 1.7 mil, about 1.8 mil, about 1.9 mil, about 2.0 mil, about 2.1 mil, about 2.2 mil, about 2.3 mil, about 2.4 mil, about 2.5 mil, about 2.6 mil, about 2.7 mil, about 2.8 mil, about 2.9 mil, about 3.0 mil, about 3.1 mil, about 3.2 mil, about 3.3 mil, about 3.4 mil, about 3.5 mil, about 3.6 mil, about 3.7 mil, about 3.8 mil, about 3.9 mil, about 4.1 mil, about 4.2 mil, about 4.3 mil, about 4.4.4 mil, about 4.6 mil, about 4.7 mil, about 4.8 mil, about 4.9 mil, about 5.1 mil, about 5.5 mil, about 5 mil, and about 5 mil values of examples thereof.

In further aspects, the at least one intermediate layer can comprise any of the polymers disclosed herein. In some aspects, at least one intermediate layer can include the first compound disclosed above. However, in other aspects, at least one intermediate layer may comprise the second compound disclosed above. In yet further aspects, the at least one intermediate layer may comprise a first compound. However, in further aspects, the at least one intermediate layer may comprise any polymer known in the art and suitable for the desired application. In some aspects, the at least one intermediate layer may comprise polyether block amide, polyurethane, or a combination thereof. In yet further aspects, at least one intermediate layer is a polyether block amide, such as PEBAX. While in a further aspect, the intermediate layer is polyurethane. In such exemplary aspects, the at least one intermediate layer does not include a solid lubricant filler, such as PTFE. In other aspects, at least one intermediate layer does not include an inorganic filler. In a further aspect, at least one intermediate layer may comprise a polymer (which comprisesOr polyurethane) having a shore D (or shore a) hardness of about 45D (85A) to about 90D, including exemplary values of about 50D, about 55D, about 60D, about 65D, about 70D, about 72D, about 75D, about 80D, and about 85D.

In further aspects, the at least one intermediate reinforcing layer may comprise a polyolefin. In further aspects, the at least one intermediate reinforcing layer may comprise polyethylene, polypropylene, graft modified polyethylene, or polypropylene. In further aspects, the at least one intermediate reinforcing layer may comprise grafted Low Density Polyethylene (LDPE), grafted medium density polyethylene, grafted Ultra Low Density Polyethylene (ULDPE), grafted High Density Polyethylene (HDPE), grafted heterogeneously branched Linear Low Density Polyethylene (LLDPE), grafted homogeneously branched linear ethylene polymer and substantially linear ethylene polymer, grafted polypropylene or Ethylene Vinyl Acetate (EVA), or any combination thereof. In these exemplary aspects, maleic anhydride or acrylic acid may be used to graft the polymers disclosed above. In further aspects, the at least one intermediate reinforcing layer may comprise maleic anhydride or acrylic acid grafted low density polyethylene. In further aspects, the at least one intermediate reinforcing layer may comprise maleic anhydride or acrylic acid grafted polypropylene. In further aspects, the at least one intermediate reinforcing layer may comprise maleic anhydride or acrylic acid grafted ethylene vinyl acetate. In a further aspect, the at least one intermediate reinforcing layer may include a laminate Maleic anhydride grafted polyolefins are sold.

In a further aspect, any of the at least one intermediate reinforcing layers disclosed above may thermally bond the outer layer to the variable liner of the sheath. In further aspects, an intermediate reinforcing layer may be extruded to be positioned between the first polymer layer and the second polymer layer. In further aspects, the at least one intermediate reinforcing layer may be fused with the first polymer layer and the second polymer layer by at least one of heat or compression.

In further aspects, an outer layer including at least one intermediate reinforcing layer as disclosed herein may exhibit an expansion force of less than about 50N, less than about 49N, less than about 48N, less than about 47N, less than about 46N, less than about 45N, less than about 44N, less than about 43N, less than about 42N, less than about 41N, or even less than about 40N. However, it should also be appreciated that the expansion force is dependent on the size of the medical device passing through the sheath. The exemplary values shown above apply to a medical cardiac implant of about 26 mm. It should be appreciated that the force values are not limited to the values disclosed above and are adjusted according to the device dimensions.

In further aspects, an outer layer including at least one intermediate reinforcing layer as disclosed herein may exhibit a burst pressure of greater than about 4.5psi, greater than about 5psi, greater than about 5.5psi, greater than about 6psi, greater than about 6.5psi, greater than about 7psi, greater than about 7.5psi, greater than about 8psi, greater than about 8.5psi, greater than about 9psi, greater than about 9.5psi, greater than about 10psi, greater than about 10.5psi, greater than about 11psi, greater than about 11.5psi, greater than about 12psi, greater than about 12.5psi, greater than about 13psi, greater than about 13.5psi, greater than about 14psi, greater than about 14.5psi, or greater than about 15 psi.

As shown in fig. 35-36, the outer layer 140 may include one or more axial stiffening members 145 extending longitudinally along all or a portion of the outer layer 140. The stiffening members 145 help prevent the outer layer 140 from axial aggregation during insertion into the patient's vasculature, while not sacrificing the low radial expansion force of the outer layer 140.

As shown in fig. 10, the sheath 100 may include a tapered section at the proximal end of the sheath 100 adjacent the flared end portion 114. The tapered section and flared end portion 114 are referred to as strain relief sections, helping to mitigate the transition between the smaller diameter portion of the sheath 100 and the housing 101. As disclosed above, when the outer layer 140 is present, the thickness and/or composition of the outer layer may be adjusted to improve the performance of the strain relief section and reduce the thrust.

For example, in certain aspects, the outer layer 140 may be bonded at the proximal and/or distal ends of the liner. At the proximal and distal ends, the outer layer 140 may be bonded to the liner around the entire circumference of the outer layer.

As disclosed herein, the outer layer may have the same diameter over the length of the sheath, or may have a varying diameter over the length of the sheath. Fig. 37 is a front view of the outer layer 140, showing the tapered section adjacent the flared end portion at the sheath proximal end. Fig. 38 is a cross-sectional view of an exemplary elongate tube taken along section line A-A of fig. 37. Fig. 39 is a cross-sectional view of outer layer 140 taken along section B-B of fig. 37. As described above, the tapered portion is referred to as a strain relief section, and the tapered section and flared proximal end help mitigate the transition between the smaller diameter portion of the sheath 100 and the housing 101. The proximal end (L1) may range in length from 1.600 inches to 2.400 inches. In some aspects, the proximal end has a length of about 2.000 inches. The length of the tapered section (L2) may range from 2.000 inches to 3.000 inches. In some aspects, the length (L2) of the tapered section is about 2.500 inches. The overall length (L3) of the outer layer 140/sheath 100 may be in the range of 17.600 inches to 26.400 inches. In some aspects, the overall length (L3) of the outer layer 140/sheath 100 is about 22.000 inches.

As provided in fig. 38, the diameter of the outer layer 140 at the proximal end is greater than the diameter of the outer layer 140 at the distal end. This allows the outer layer 140 to slide over the inner liner 108 without having to expand. For example, the diameter (D1) of the outer liner 140 at the proximal end may range from 0.264 inches to 0.396 inches. In some examples, the diameter (D1) of the outer liner 140 at the proximal end is about 0.330 inches. The diameter (D2) of the outer layer 140 at the distal end may range from 0.176 inches to 0.264 inches. In some examples, the diameter (D2) of the outer layer at the distal end is about 0.220 inches.

In further aspects, the outer layer 140 may include two or more reinforcing members 145. In such aspects, two or more reinforcing members 145 may be provided as separate strips circumferentially disposed in the first polymer layer, in the second polymer layer, or between the first and second layers, a predetermined distance from each other. Fig. 39 is a detailed view of the outer layer 140 taken along section line B-B of fig. 37. As provided in fig. 39, the outer layer 140 includes three reinforcing members 145. In some examples, outer layer 140 contains only one stiffening member 145 (fig. 40). In other examples, the outer layer includes at most eight reinforcing members 145. When more than one stiffening member 145 is used, the stiffening members are evenly spaced around the circumference of the outer layer 140. As further shown in fig. 39, the reinforcing member 145 may have a straight line shape (e.g., rectangular) in cross section. However, any other regular or irregular shape is contemplated. For example, the stiffening member may also be circular in cross-section.

In a further aspect, the stiffening member 145 has a limited width less than the circumference of the outer layer 140. The total combined width (w) of the reinforcement members 145 may be in the range of 5% to 50% of the circumference of the outer layer 140. In further aspects, the total combined width of the strips is about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% of the circumference of the outer layer.

Fig. 40 contains a partial view of the outer layer 140 of fig. 39. As provided in fig. 40, the circumferential width of the stiffening member 145 may range from 0.010 inch to 0.150 inch. In some examples, the distal end of the outer layer 140 has a diameter of 0.200 inches, and the circumferential width of the stiffening member 145 may be in the range of 0.010 inches to 0.150 inches. In some exemplary and non-limiting aspects, the outer layer can have a diameter of about 0.200 "at the distal end, and the reinforcement member can have a width of about 0.010" to about 0.150", including exemplary values of about 0.03", about 0.035", about 0.04", about 0.045", about 0.05", about 0.055", about 0.06", about 0.065", about 0.07", about 0.075", about 0.08", about 0.085", about 0.09", about 0.095", about 0.10", about 0.105", about 0.110", about 0.115", about 0.120", about 0.125", about 0.130", about 0.135", about 0.140", and about 0.145 ". It should be appreciated that the widths shown above are exemplary and that the strap widths may be adjusted at the same or different ratios if the distal outer diameter of the elongate sheath has a size other than 0.200 ". In a further aspect, as described above, the width of the stiffening member may be measured as a percentage of the circumference of the outer layer.

It should also be appreciated that the width of the reinforcing member 145 may be the same along the length, or may vary along the length, in the sense that the reinforcing member 145 exists as one or more strips circumferentially disposed along the length of the outer layer 140. In terms of the width of the stiffening member 145 varying along the length of the outer layer 140, this stiffening member 145 may have any of the width values disclosed above.

In a further aspect, at least one stiffening member 145 is configured to provide axial stiffening to the outer layer 140. In such exemplary aspects, at least one reinforcing member 145 may be disposed along the length of the outer layer 140 or along a portion of the length of the outer layer 140. In some aspects, at least a portion of the length of the outer layer 140 in which the stiffening member 145 is disposed at the distal end and/or the proximal end of the outer layer 140. In other aspects, stiffening members 145 may also be positioned anywhere along the length of outer layer 140.

As described above, and as shown in fig. 39, the outer layer 140 of the sheath comprises a two-layer construction comprising a first polymer layer 146 (disposed adjacent to the inner liner of the sheath) and a second polymer layer 147 (disposed farther from the inner liner of the sheath and forming the outer layer of the sheath). However, it should also be appreciated that depending on the location, the outer layer may have both a two-layer construction and a three-layer construction. In some aspects, the layer formed from the second polymer may provide abrasion resistance (e.g., between the sheath and calcified lesions) and better resistance to hydrophilic coating processes, while the layer formed from the first polymer comprises a more lubricious material (e.g., prevents the outer layer from sticking to the inner lining of the sheath during expansion) and provides higher pressure resistance or resistance to swelling and hemostatic effects. In some aspects, the layer formed of the first polymer 146 forms an inner surface of the outer layer 140 and the layer formed of the second polymer 147 forms an outer surface of the outer layer of the sheath, with the reinforcement member 145 disposed between the outer surface of the first polymer layer 146 and the inner surface of the second polymer layer 147.

In some examples, first polymer layer 146 may be composed of Pebax or polyurethane having a shore hardness of 25D to 35D. In some examples, the first polymer layer 146 includes PTFE powder, an optional inorganic filler, and an optional viscosity-reducing additive to reduce friction as the inner member 108 of the sheath expands by sliding against the outer layer 140. In some examples, the second polymer layer 147 of the outer layer 140 is composed of polyurethane or polyurethane/Styrene Block Copolymer (SBC) having a shore a hardness of less than about 60, such as Neusoft 597-50A having a shore a hardness of about 55A. In certain examples, the first polymer layer 146 is composed of a polyether block amide, such as Pebax having a shore D hardness of less than about 35.

As provided in fig. 39 and 40, the reinforcement member 145 is at least partially embedded in the first polymer layer 146. In some examples, the thickness of the reinforcement member 145 is less than the thickness of the first polymer layer 146. For example, as shown in fig. 40, the thickness of the reinforcement member 145 ranges from 0.0005 inches to 0.00155 inches. In some examples, the stiffening member 145 has a thickness of about 0.001 inches. In an example configuration, the stiffening member 145 has a thickness of 0.001 inches and the first polymer layer has a thickness of 0.00154 inches. In another not shown example, the reinforcement member 145 has a thickness corresponding to the thickness of the first polymer layer 146. In another example, the thickness of the reinforcement member 145 is greater than the thickness of the first polymer layer 146. In some examples, first polymer layer 146 and reinforcing member 145 are co-extruded. Similarly, first polymer layer 146, reinforcement member 145, and second polymer layer 147 are co-extruded with reinforcement member 145 positioned between first polymer layer 146 and second polymer layer 147. In other examples, the first polymer layer 146 is disposed over the stiffening member 145 and the two components are bonded or fused together by at least one of heating or compression.

FIG. 41 illustrates a cross-sectional view of another exemplary outer layer in a resting (unexpanded) configuration, including a reinforcing member, taken along section line B-B of 35.

As described above, the reinforcing member 145 is composed of a material harder than the main body portion (the first polymer layer 146, the second polymer layer 147) of the outer layer 140, and a material having a low friction coefficient (e.g., high-density polyethylene). In some examples, the stiffening member 145 is composed of a polymer compatible with the first and second polymer layers, including, for example, high durometer Pebax or polyurethane. The stiffening member 145 may also be constructed of a material having a shore D hardness in the range of 45D to 76D.

Additional examples of sheaths that may be used with the outer layers disclosed herein may be found in U.S. application Ser. No. 63/021,945, the contents of which are incorporated herein in their entirety.

Fig. 42A-42C illustrate additional exemplary bilayer configurations. In such a configuration, for example, the reinforcing member may be part of the inner layer, wherein the reinforcing member has substantially the same thickness as the inner layer (shown at 4200 of fig. 42A and 42B).

In some exemplary and non-limiting aspects, if the two polymer layers of the outer layer are formed separately, the tie layer may be disposed between the two polymer layers. It should also be appreciated that any of the above disclosed tie layers may be utilized.

As discussed in detail above, one important function of the sheath is to have clinically acceptable thrust for all patient anatomies.

To reduce the thrust, various types of lubricants may be used. Some of the various lubricant types and methods are disclosed above. As disclosed, any of the disclosed lubricants (lubricating materials, lubricating fillers, lubricious liners) can reduce friction between the various layers of the sheath that slide over one another, making it easier for the delivery system to open the sheath. However, lubrication between the inner liner and the outer layer may allow the outer layer to easily slide over the sheath shaft. When a majority of the outer layer slides together, the outer layer may bunch together, increasing the Outer Diameter (OD), known as bunching. This may lead to obstruction of insertion or retrieval of the sheath and more traumatic interaction with the vessel.

In certain aspects, to avoid this problem, the outer layer may be bonded to the inner liner of the expandable sheath to prevent movement of the outer layer along the sheath axis.

In certain aspects, bonding of the inner liner and outer layer may occur at any location. In a further aspect, such bonding may occur in the region of the sheath cross-section where the outer layer is arranged to undergo minimal stretching during expansion. Bonding is also performed at locations where no lubricant is applied.

Accordingly, aspects are disclosed herein in which at least a portion of the innermost surface of the outer layer is bonded to at least a portion of the outermost surface of the inner liner. Fig. 27A and 27B also depict such exemplary aspects. It should be appreciated that this bond may alternatively be present in any of the sheath configurations disclosed above. Bonding may be performed by any method known in the art. In some aspects, bonding is performed by laser welding, compression bonding, and/or selective ultrasonic welding.

In certain aspects, the bonding of the outer layer to the liner may occur in a section of the sheath cross-section where the outer layer is not expected to stretch too much or move relative to the liner during expansion. In further exemplary and non-limiting aspects, the portion of the inner member immediately adjacent the end of its outer layer meets this criterion. As shown in fig. 27A-27B, bonding 2790 occurs at portions between the inner liner 2702 and the outer layer 2708 that are not expected to stretch too much or move relative to the inner liner. In such aspects, the lubricant 2707 is not applied in this location on the liner to ensure good adhesion between the two components. At this location, the outer layer may be bonded in place along the length of the sheath shaft to prevent longitudinal movement over the inner member. In other aspects, the outer layer may be bonded to the inner liner at a portion of the sheath. Since the bond as disclosed herein does not interfere with movement of the liner relative to the outer layer or stretching of the outer layer itself, the force required to expand the sheath is not adversely affected by the bond.

In further aspects, it should be appreciated that the bond location may be important to minimize thrust. However, in other aspects, the bond covers a relatively small portion of the circumference of the sheath. In other respects, a method of forming the bonding portion needs to be precisely controlled, and process reproducibility needs to be ensured. The specific method of forming the bond is described in detail below.

In further aspects, two or more portions of the inner liner and outer layer may be bonded together. In such exemplary aspects, the bonding portions may be formed in a predetermined pattern. In further aspects, the bond pattern may be aligned with the lubricant pattern. In such aspects, the bonding may be performed at any portion of the sheath where no lubricant is present.

It will be appreciated that when the sheath is used to deliver a prosthetic device into a patient's vessel, the hemostatic effect may be compromised if blood in the patient's arteriotomy penetrates between the inner and outer layers. In this case, the outer layer is the only sheath element that is antihypertensive and maintains the hemostatic effect.

The outer layer is typically formed of a material that, on the one hand, allows the liner to readily expand and, on the other hand, exerts an inward force on the liner to collapse the liner to an initial unexpanded configuration. However, sufficiently high blood pressure may cause the outer layer to "bulge" and even rupture and impair the hemostatic effect at a certain point in time. Fig. 29A-B show schematic representations of such phenomena. An exemplary sheath 2900 having an inner liner 2902 and an outer layer 2908 is connected to hub 2911 and is inserted into patient anatomy 2913. When hemostatic effects are not maintained, the outer layer may "bulge" 2915 and undesirably affect the patient.

For the portion of the sheath below the patient's skin level, potential bulge may be suppressed and antihypertensive by the tissue surrounding the sheath, but for the portion of the sheath outside the patient's body, this undesirable phenomenon may still occur. The portion of the sheath that remains outside the patient will vary and will depend on the patient's body shape and anatomy and the physician's preference.

Making the outer layer material stiff enough that the outer layer material will be antihypertensive and not bloating may create an undesirable tradeoff that increases the force required to expand the liner and thus the force required to push the delivery system through the sheath.

The aspects described herein address this problem and help prevent excessive outer layer ballooning of the portion of the sheath left outside the patient while having minimal impact on the force of expanding the sheath.

Aspects described herein aim to strengthen the outer layer of the sheath along the proximal section of the sheath without significantly affecting the ability of the sheath to expand as the delivery system is pushed through the sheath. It should be appreciated that in some aspects described herein, the reinforced portion of the outer layer may remain entirely outside of the patient's arteriotomy. However, in other aspects, at least a portion of the reinforcing portion may be inserted into a patient's vessel. 29C-D illustrate some exemplary schematics of the disclosed aspects, wherein a stiffening layer 3025 is provided on the outer layer 2908 and substantially prevents the "ballooning" effect. As shown in fig. 29D, the stiffening portion of the sheath may be long enough such that at least a portion of this stiffening portion is inserted into the anatomy 2913 of the patient.

In such aspects, reinforcing the outer layer at the proximal portion of the sheath may be achieved by disposing a reinforcing sheath having a proximal end and a distal end over at least a portion of the outer layer. The reinforcement sheath as disclosed herein may include an elastomeric material and a reinforcement element. This reinforcing sheath is then positioned over the proximal portion of the outer layer. In such aspects, the ends of the reinforcing sheath are substantially seamlessly bonded to at least a portion of the outer surface of the outer layer. This smooth transition between the outer layer and the reinforcing sheath allows the sheath to be inserted into the patient.

In further aspects, the proximal end of the reinforcement sheath may be bonded to the proximal end of the outer layer. However, aspects are also disclosed in which the proximal end of the reinforcement sheath is not bonded to the proximal end of the outer layer.

In certain aspects, the reinforcing sheath can have a length of about 5 to about 15cm, including exemplary values of about 6cm, about 7cm, about 8cm, about 9cm, about 10cm, about 11cm, about 12cm, about 13cm, and about 14 cm.

In a further aspect, the elastomeric material present in the reinforcing sheath may be any elastomer known in the art. In some aspects, the elastomeric material includes polyether block amides, styrene-based elastomers, polyurethanes, latexes, copolymers thereof, blends thereof, or co-extrudates thereof. In further aspects, the elastomer may comprise a silicon-based elastomer.

In further aspects, the elastomeric material can have a shore hardness of about 10A to about 80A, including exemplary values of about 20A, about 25A, about 30A, about 35A, about 40A, about 45A, about 50A, about 55A, about 60A, about 65A, about 70A, and about 75A.

In a further aspect, the reinforcement sheath includes a reinforcement element. Fig. 30A-B illustrate some exemplary schematic views of various reinforcement jackets. The reinforcement sheath 3025 is seamlessly bonded to the outer layer 3008 disposed over the liner 3002 at the distal end of the reinforcement sheath. The proximal end of the reinforcement sheath may or may not be bonded to the liner and/or hub 3011. Reinforcing filaments 3027 are disposed within the elastomer. The reinforcement element that has the least impact on the resistance of the outer layer increases dramatically in resistance when it expands to a certain diameter.

When the delivery system is pushed through the sheath, it requires only a limited amount of expansion to accommodate the OD of the crimped valve. This limited expansion will not engage the stiffening element, so the effect on the force to expand the sheath to accommodate the OD will be minimal and only result from the low durometer elastomer. In the event that the bulge phenomenon begins, the diameters of the outer layer and the reinforcing layer will only increase until the reinforcing element acts and prevents excessive bulge.

In certain aspects, the reinforcing element may include a plurality of filaments arranged in a braid configuration. In such aspects, the plurality of filaments may be disposed within the reinforcing sheath in a plurality of circumferential rows, wherein each of the plurality of filaments has a sinusoidal form or any irregular form, or any combination thereof. In certain aspects, the braid or coil may be an expandable braid or coil.

In further aspects, the plurality of filaments may comprise stainless steel, nitinol, polymeric material, or composite material. In certain non-limiting aspects, the filaments may comprise nitinol and/or other shape memory alloys. In other non-limiting aspects, the filaments may comprise polyester or nylon. In some other exemplary aspects, the filaments may include spectroscopic fibers, polyethylene fibers, aramid fibers, or combinations thereof.

Fig. 4A-4D illustrate some exemplary aspects of braid or coil construction. In certain aspects, the braid or coil may be a generally thin, hollow, generally cylindrical tube, including arrangements, patterns, structures or configurations of filaments or struts, although other geometries may also be used. Suitable filaments may be round with a diameter of less than about 0.015", less than about 0.01", less than about 0.008", less than about 0.005", less than about 0.002", less than about 0.001", less than about 0.0008", or less than about 0.0005". In other aspects, suitable filaments may be round with diameters ranging from about 0.0005 "inches thick to about 0.015" thick, comprising exemplary values of about 0.0006", about 0.0007", about 0.0008", about 0.0009", about 0.001", about 0.002", about 0.003", about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014 ". In other aspects, suitable filaments can be flat filaments having a height of less than about 0.006", less than about 0.005", less than about 0.004", less than about 0.003", less than about 0.001", less than about 0.0009", less than about 0.0008", less than about 0.0007", less than about 0.0006", and about 0.0005". In other aspects, the flat filaments can have a width of greater than about 0.003 "to about 0.015", including exemplary values of about 0.004", about 0.005", about 0.006", about 0.007", about 0.008", about 0.009", about 0.01", about 0.012", about 0.013", and about 0.014". However, other geometries and sizes are also suitable for use in particular aspects.

In further aspects, the braid may have a crossover Per Inch (PIC) of less than 50, less than 40, less than 30, less than 20, or less than 10. In other aspects, the braid may have a PIC number from 10 to 2, including exemplary values 9, 8, 7, 6, 5, 4, and 3. In further aspects, the PIC may vary along the longitudinal axis of the lumen. In other aspects, the weave pattern may vary along the longitudinal axis of the lumen. In aspects where the braid or coil comprises nitinol filaments, the nitinol expands in diameter d _e And (5) heat setting. In a further aspect, wherein the filament comprises stainless steel or nitinol, the filament is configured to be atraumatic at least at the distal end of the sheath. Fig. 4A-4D illustrate partial elevation views of various structures of braid or coil 28. It should be appreciated that the configuration of the braid or coil 28 may vary between different sections, varying along the length of the sheath. It should also be appreciated that the structures shown in fig. 4A-4D are not necessarily drawn to scale and are merely illustrative and non-limiting in nature. It should also be appreciated that the braid or coil is configured to provide the ability of the sheath to twist during insertion of the prosthetic device.

However, in other aspects, the reinforcing element may include wires disposed in a plurality of circumferential rows embedded within the elastomeric material. In such aspects, the lead may have any shape configured to expand or contract. For example, the wire may have a sinusoidal or wave shape. The phase and amplitude of the wire may vary depending on the desired application. Furthermore, it should be appreciated that the frequency and total number of circumferential rows present in the elastomeric material may also vary depending on the desired application. The expansion of the wire will allow the outer layer of the sheath to continue to expand until the stiffening elements present in the elastomeric material tighten. In this configuration, the reinforcing sheath stops further expansion, thus maintaining the hemostatic effect.

In further aspects, a tie layer may be disposed between the reinforcing sheath and the outer layer of the sheath.

Additional configurations of the reinforcing sheath are also disclosed. In this aspect, the outer layer does not extend to the proximal end of the sheath, and wherein at least a portion of the liner at the proximal end of the sheath is substantially free of the outer layer. The proximal portion of the sheath not covered by the outer layer may be of any length. In some aspects, this proximal portion is about 5cm to about 15cm, including exemplary values of about 6cm, about 7cm, about 8cm, about 9cm, about 10cm, about 11cm, about 12cm, about 13cm, and about 14 cm.

The proximal portion of this outer layer may be bonded to the inner liner to ensure that there is no separation between the inner liner and the outer layer when the sheath is inserted into the patient. Such an adhesive also prevents the outer layer from sliding when the sheath is inserted into the patient. In such aspects, a reinforcement sheath having a proximal end and a distal end is then positioned over at least a portion of the outer surface of the liner at the proximal end of the sheath, the portion being substantially free of the outer layer. It should be appreciated that in this configuration, the proximal end of the reinforcement sheath abuts the proximal end of the sheath and is at least partially bonded to at least a portion of the proximal end of the outer surface of the liner.

Likewise, the reinforcement sheath may have a length substantially similar to the length of the proximal portion of the sheath without the outer layer. In some exemplary and non-limiting aspects, the length of the reinforcing sheath can be about 5 to about 15cm, including exemplary values of about 6cm, about 7cm, about 8cm, about 9cm, about 10cm, about 11cm, about 12cm, about 13cm, and about 14 cm.

In a further aspect, the distal end of the reinforcement sheath abuts or at least partially covers the proximal portion of the outer layer. It should also be appreciated that the distal end of the reinforcement sheath is seamlessly bonded to at least a portion of the proximal portion of the outer surface of the outer layer. It should be understood that the reinforcement sheath as described in this aspect may include all of the components of the reinforcement sheath disclosed above.

In a further aspect, a sheath having any of the configurations disclosed above and including a bulge guard is also disclosed. Similar to the reinforcement sheath disclosed above, the bulge guard is configured to prevent excessive outer layer bulge of the sheath on the portion of the sheath remaining outside the patient's body while accommodating different insertion depths of the sheath and not affecting the force of expanding the sheath. The bulge guard is configured to remain outside the patient and not be inserted into the anatomy of the patient.

In aspects disclosed herein, the bulge guard has a proximal end and a distal end and is disposed over at least a portion of the outer layer, and wherein the bulge guard is configured to remain outside of a blood vessel of a subject and substantially maintain a hemostatic effect.

The bulge guards as described in this disclosure may be collapsible. In other aspects, the bulge guard may be configured such that its length may be adjusted based on the insertion depth of the sheath.

In some aspects, the inner diameter of the ballooning shield may be large enough or minimal resistance to expansion to a diameter such that it does not affect the force of expanding the sheath nor the force of advancing the delivery system through the sheath. Once the bulge guards reach a certain diameter, the force to expand the bulge guards increases significantly so that the bulge guards can be antihypertensive and stop bulge. It should be appreciated that while the ballooning shield may not prevent the onset of ballooning, it may contain ballooning so that the outer layer does not excessively dilate, rupture, and compromise the hemostatic effect. Fig. 29E to 29F show some exemplary schematic views of the bulge guards. The bulge shield 3125 is disposed over the outer layer 2908 such that while blood 2915 may enter the portion between the outer layer 2908 and the inner layer 2902, it does not cause rupture of the sheath and helps maintain a hemostatic effect.

In a further aspect, the proximal end of the bulge guard is connected to the proximal-most portion of the outer layer and/or the hub of the sheath. While the distal end of the bulge shield radially circumscribes at least a portion of the outer layer, and wherein the distal end is not bonded to the outer layer. It should be appreciated that the bulge guard seals against the skin of the subject and is not inserted into the anatomy 2913 of the subject, as described herein.

In further aspects, the bulge guard may comprise a braided or coiled sleeve comprising a plurality of filaments. Any of the plurality of filaments disclosed above may be utilized. In some aspects, at least a portion of the plurality of filaments at the distal end of the ballooning shield are coupled to one another in the presence of the braided or wrapped sleeve to allow the braided or wrapped sleeve to shorten and seal against the outer layer and the skin of the patient.

In further aspects, the braided or coiled sleeve may also include a polymer. Any of the elastomeric polymers disclosed above may be used. In certain aspects, the braid or coil may be embedded with a polymer. It should be appreciated that the braid or coil material may be any material known in the art. In certain aspects, the braid or coil material may comprise a metal or metal alloy. In certain aspects, the braid or coil may be fabricated from any metal or metal alloy known in the art for use in medical devices. In some aspects, the braid or coil may be made of a memory shape material. In further aspects, the braid or coil may be any braid or coil as disclosed herein.

In other aspects, the woven material may comprise a polymer. It should be understood that polymers known in the art may be used to form the braid. In such exemplary and non-limiting aspects, the polymer may comprise any known polyolefin, any known polyamide, or any known polyester. In further aspects, the braid material may comprise a fabric. In further aspects, the braided sleeve may comprise a fabric. However, in further aspects, the bulge guard may comprise an e-PTFE tube, the bulge guard comprising an e-PTFE tube, a bellows, or any polymer tube having a shape configured to be compressed. In certain aspects, the bulge guard may comprise an e-PTFE tube. In such exemplary and non-limiting aspects, the e-PTFE tube may be compressed without losing its shape. While in a further aspect, the bulge guard may comprise a bellows. The bellows allows the shield to be compressed and the length of the shield to be adjusted.

In such exemplary and non-limiting aspects, the bulge guard may be made of any polymeric material that may have a shape such that such material may be compressed. For example, the tube may be formed from any polymer known in the art. The walls of the tube may allow it to be compressed without losing the pattern cut of the original shape.

Additionally, some aspects of any of the sheath constructions disclosed herein may comprise an outer hydrophilic coating on the outer surface of the outer layer. Such hydrophilic coatings may facilitate insertion of any of the sheaths disclosed herein into a patient's vasculature. Examples of suitable hydrophilic coatings include Harmony ^TM Advanced lubricious coatings, and other advanced hydrophilic coatings available from SurModics, inc. Of Eden Prairie, MN. The DSM medical coating (available from Koninklijke DSM N.V of herlen, the netherlands) and other coatings (e.g., PTFE, polyethylene, polyvinylidene fluoride) are also suitable for use with the sheath.

Additionally, as shown in fig. 11, the soft tip 102 may be used with any of the sheath configurations disclosed herein. In certain aspects, the tip may comprise Low Density Polyethylene (LDPE) and may be configured to minimize trauma or injury to a patient's vasculature when the sheath is guided through the vasculature. For example, in some aspects, the soft tip portion 102 may be slightly tapered to facilitate passage through a vessel. The soft tip portion 102 may be secured to the distal end 104 of the sheath 100, for example, by thermally bonding the soft tip portion 102 to the inner and outer layers of the sheath 100. Such a soft tip portion 102 may have a lower hardness than other portions of the sheath 100. In some aspects, the soft tip 102 may have a shore hardness of about 25A to about 40A, including exemplary values of about 28A, about 30A, about 32A, about 35A, and about 38A. It should also be appreciated that the shore hardness may have any value between any two of the foregoing values. In other aspects, the soft tip 102 may have a shore hardness of about 25D to about 40D, including exemplary values of about 28D, about 30D, about 32D, about 35D, and about 38D. The tip portion 102 is configured to be radially expandable to allow the prosthetic device to pass through the distal opening of the sheath 100.

The sheath disclosed herein may be configured such that it locally expands along the length of the lumen at a particular location corresponding to the location of the medical device, and then locally contracts when the medical device has passed the particular location. Thus, as the medical device is guided through the sheath, ridges running longitudinally along the length of the sheath can be seen, which represent continuous local expansion and contraction as the device travels along the length of the sheath. In some aspects, after removal of any radially outward (insertion) force, each segment of the sheath may locally contract such that it resumes the initial resting diameter d of the lumen _r 。

Fig. 44-66 disclose examples of an expandable sheath 4400 including a proximal section 4402 and a distal tip section 4404 that may be permanently separated to facilitate removal of a medical device, and methods of making the same. Sheath 4400 defines a lumen 4406 extending therethrough to facilitate passage of a medical device, such as those described above. For example, the proximal section 4402 may include a reel or spiral expandable inner liner 4408 having slits along itself, allowing overlapping of its edges. Under the bias of the surrounding elastomeric sheath or outer layer 4410, the inner liner 4408 locally expands and collapses as the medical device passes therethrough. The tip section 4404 extends from the distal end 4416 of the proximal section 4402 and defines a slit 4412 that extends most of the length of the tip section, in some cases, except for the distal end 4422 of the tip section. The slit 4412 also extends through most or all of the layers of the tip section 4404. In this manner, the portion of the lumen 4402 defined through the tip section 4404 may be expanded by the passage of a medical device therethrough.

Advantageously, the slit 4412 in the tip section 4404 exhibits a low thrust force of less than about 25 newtons (5.6 pounds force), or on the other hand, less than about 15 newtons (3.4 pounds force), for opening and remaining open for partial or complete removal of the medical device if necessary. The elastomeric outer layer 4410 extends over all or part of the tip section and helps smooth the surface, thereby maintaining the hemostatic and atraumatic properties of the tip section 4404. In addition, the expandable sheath 4400 may include radiopaque markers 4428 embedded in the tip section 4404 to improve positioning of the expandable sheath, as shown in fig. 66.

In fig. 44-46, for example, the proximal section 4402 includes an elongate body 4418 extending between a proximal end 4414 and a distal end 4416. The elongate body 4418 defines a proximal portion of a lumen 4406 extending through the expandable sheath 4400. The tip section 4404 extends distally from the distal end 4416 of the proximal section 4402. The tip section 4404 includes a proximal end 4420, a distal end 4422, and a generally tapered tip body 4424 extending between the proximal end 4420 and the distal end 4422. The tip body 4424 defines a distal portion of a lumen 4406 extending through the expandable sheath 4400.

The tip section 4404 contains at least an inner liner 4408 defining a slit 4412 and some relatively soft structures extending and/or coating the inner liner to make the tip section atraumatic, such as an outer (sheath) layer 4410 and/or an intermediate layer 4426. In general, in some aspects, the outer layer 4410 prevents blood loss through the inner liner 4408 and extends over the proximal section 4402 to bias the rolled inner liner 4408 into a compressed configuration, as better described above. In other aspects, the middle layer 4426 may be used to bond the inner liner 4408 to the outer layer 4410. (middle layer 4426 may be the only article holding tip section 4404 together.) middle layer 4426 may also mediate blood loss through inner liner 4408. The intermediate layer 4426 may comprise its own sub-layers, e.g., two or three layers, including a tie layer. Unlike the scored layer, most or all of the layers of the tip section 4404 may be completely scored (and slightly sealed by thermal reflow) for reduced thrust and cleaner, more definitively expanded or separated conditions, as shown in fig. 47-48.

The atraumatic tip section 4404 may be used in any catheter where a smooth liner such as HDPE (high density polyethylene) inner liner 4408 and an elastomeric outer sheath such as sheath outer layer 4410 composed of copolyamide such as polyether block amide (Pebax) benefit from thermal bonding and good adhesion of the intermediate layer 4426. In some cases, the intermediate layer is the atraumatic portion of the tip, as the intermediate layer extends distally furthest as a single layer.

The inner liner 4408 may be an extension of the same layer in the proximal section 4402 that performs a "rolling" function with a free edge defined by a helically elongated slit that expands and contracts during passage of the medical device. The inner liner 4408 may have a composition that is generally harder than the other layers, and may be composed of polyethylene such as High Density Polyethylene (HDPE) or Low Density Polyethylene (LDPE), as well as other relatively hard and/or lubricious polymers described herein, for example.

The inner liner 4408 at the tip section 4404 may be manufactured by modifying the distal end of the spool-type inner liner of the proximal section 4402. For example, as shown in fig. 49, a manufacturer cuts inner liner 4408 with two different cuts. A first incision 4444 extends proximally from a distal edge 4432 of the inner liner 4408. The second incision 4434 extends from the proximal end of the first incision 4444 perpendicular to one of a pair of lateral edges 4436 of the inner liner 4408. These two cuts form a flap 4438 which is then rewound into a reel-to-reel configuration as shown in fig. 50-52. Incisions 4444, 4434 are positioned to define a portion of slit 12 through inner liner 4408. Specifically, the first cutout 4444 is positioned in alignment with a transverse edge 4436 on a radially inner portion of the spool-type configuration opposite the flap 4438. Thus, the inner liner 4408 does not prevent the slit 12 from extending into the lumen 4406 even in the collapsed state, as shown in fig. 51 and 52.

The flaps 4438 may have different sizes and shapes depending on the size and shape of the expandable sheath 4400, which in turn is related to the size, shape, and nature of the medical device being passed therethrough. However, for stented heart valves and similar devices, the first incision 4444 may extend proximally about.157 inches (4 mm) and be positioned inwardly from the lateral edge 36 about.5 inches (12.7 mm). The second cut 4434 may extend from it to the lateral edge by a.485 inch (12.3 mm), leaving about 0.015 inch (.38 mm) uncut and connecting the flap to the rest of the inner liner 4408. Thus, the flaps have rectangular dimensions of about 4mm and 12 mm. The width of the inner liner 4408 between the lateral edges 4436 is about 1.068 inches (27.1 mm) so the flaps are about 40% to 50% of the width of the inner liner. Once fully formed, the first incision 4444 will typically extend about 4mm to 6mm, or about 2/3 of the final length of the tip section 4404.

In some cases, as part of forming the tip section 4404, additional or redundant portions of the inner liner 4410 may be trimmed away. For example, an additional small (2 mm to 3mm or about 2.5 mm) rectangular piece may be removed from distal edge 4432, as shown in fig. 53, to facilitate conical or tapered shaping. As described above with respect to other aspects, the inner liner 4410 included in the proximal section 4402 may include a lubricant to facilitate relative movement of the layers during expansion and contraction. In general, however, the tip section 4404 will not include a lubricant because it will be reflowed to form a unitary structure.

As shown in fig. 54-57, the inner liner 4408 configuration of fig. 50-52 may be mounted on a mandrel or heated mold and reflowed (with heat applied) to a tapered conical shape (as shown in fig. 67) and then trimmed to present a relatively flat distal end. In this intermediate configuration shown in fig. 54, the tip section 4404 extends about 4mm beyond the distal end 4416 of the proximal section 4402. In addition, slit 4412 extends the entire length of the conical tapered shape. It is also worth noting that the proximal section 4402 still maintains a spool configuration with an elongated edge 4440 for free expansion and contraction as described above. The two slots 4412 and 4440 are circumferentially offset from one another by about 44 to 120 degrees, or in some aspects 70 to 120 degrees. The larger scale reflects aspects such as the greater overlap of the sheath with the rolled liner. The larger overlap facilitates the passage of larger medical devices, such as larger heart valves. However, as shown in fig. 56, at the portion of the distal tip section 4404 overlapping the inner liner 4408, the reel type inner liner has been reflowed to form a unitary wall structure. In particular, the wall structure is thicker, with the reflowed inner liner 4408 having the overlapping configuration of fig. 50-52, and thinner at the ends of the flaps 4438 where there is only a single layer thickness. The wall thickness of the distal end of the inner liner 4408 is reduced at its thinnest point by heating to less than.005 inches (13 mm) for a circumferential length of about.080 inches (2 mm).

As shown in the plan views of fig. 56-57, the slit 4412 narrows slightly due to reflow, and adjacent overlapping layers of liner 4408 have been reflowed together to form a single wall thickness. However, the overlapping reel configuration at the proximal section 4402 remains visible because the inner liner 4408 has not been reflowed proximal to the tip section 4404. In this way, the ability of the inner liner 4408 to expand and contract in the proximal section 4402 of the expandable sheath 4400 is maintained.

As shown in fig. 58-62 and 67, in one aspect, the next step in manufacturing tip section 4404 is to apply intermediate layer 4426 to shaped and trimmed inner liner 4408 of fig. 54-57. The middle layer 4426 is formed of a relatively soft thermoplastic that facilitates the connection of the inner liner 4408 and the outer layer 4410 and is atraumatic. (in other aspects, the intermediate layer 4426 is not required, and the layers 4408, 4410 may be coupled to one another via reflow, adhesives, mechanical fasteners, etc.) the intermediate layer 4426 also reflows at a lower temperature and provides a greater bonding area for the elastomeric outer layer 4410, thereby improving bond strength. Another advantage is that the intermediate layer 4426 can provide a more lubricious inner diameter to the tip section 4404 for easier deployment and removal of the medical device. The intermediate layer 4426 may also impart some structural rigidity to the distal end 4422 and avoid deformation at the distal end, such as ovalization or "fish-mouth".

In one aspect, the middle layer 4426 extends distally beyond the inner liner 4408 and the outer layer 4410 by about 0.040 inches (or 2mm to 3 mm). In other aspects, the middle layer 4426 extends up to about 0.080 inches distal of the layers 4408, 4410. Intermediate layer 4426 may be less stiff than inner liner 4408 such that intermediate layer 4426 is more prone to bending due to axial forces than inner liner 4408.

The middle layer 4426 may be a cylindrical single layer, such as a tie layer of about.012 inches (.3 mm) and an inner diameter of about.199 inches (5 mm), as shown in fig. 68. The middle layer 4426 may have several sublayers, such as a bilayer or trilayer, as shown in fig. 69. For the sublayers, the tubes formed into the intermediate layer 4426 may be co-extruded. The material of the intermediate layer 4426 and its (optional) sub-layer comprises a thin polymer tube or film of a thermally bondable tie layer, such as Orevac 1840M (maleic anhydride modified LLDPE), orevac9318 or Orevac 9444 (maleic anhydride modified EVA). These may be intermediate sublayers in a three-layer construction or outer layers in a two-layer construction.

Referring again to fig. 58-59, an intermediate layer 4426 is placed over the distal end of the conical inner liner 4408. The intermediate layer 4426 is then heated and flowed down to coat the formed inner liner 4408 to form the structure shown in fig. 60-62 and 67. Additionally or alternatively, the intermediate layer 4426 may be heat shrunk over the inner liner 4408. Advantageously, reflowing the intermediate layer 4426 eliminates the need for mandrels that flow over the formed surface of the inner liner 4408.

On the other hand, as shown in fig. 67, the intermediate layer 4426 does not completely melt and is above the inner liner 4408. Alternatively, the intermediate layer extends beyond inner liner 4408. For example, a thermally bondable tip tube is cut to about.250 inches (6.35 mm) long and about.160 inches (4 mm) of thermally bondable tip tube overlaps with.160 inches (4 mm) long thinned HDPE liner 4408, leaving an intermediate layer 4426 extending a few millimeters beyond the liner 4408. This extension may then be trimmed to a tip of 1mm to 2mm beyond the inner liner 4408. In addition, the now extended length of the tip section 4404 may be cut or scored again to refurbish the slit 4412 and extend the slit through the middle layer 4408 and, if desired, to within about.040 inches (1 mm) or.080 inches (2 mm) of the distal end 4402 of the tip section 4404. (notably, when such an outer layer is employed, this additional 1mm to 2mm remains uncovered by the outer layer 4410.)

In other aspects, the intermediate layer 4426 may comprise two sublayers. For example, the thermally bondable tie sub-layer may be formed by coextrusion with the HDPE or LDPE inner sub-layer. In one example, the inner sublayer may have an inner diameter of about.199 inches and a thickness of.010+/-.001 inches and be composed of LDPE or HDPE. The outer sublayer is.002+/-.0005 inches and is composed of the tie layer material.

In another aspect, the intermediate layer 4426 may comprise two sublayers, such as an Orevac 1840M outer sublayer to be bonded to the elastomeric outer layer 4410 and an LDPE inner sublayer to be bonded to the inner liner 4408. The Orevac layer may have a thickness of about.002 inches, while the LDPE layer may have a greater thickness, for example.010 inches. For example, the middle layer may be bonded with an FEP heat shrink tube at 450 degrees Fahrenheit for about 1 minute.

In yet another aspect, the outer sublayer may comprise Pebax 45D (shore D) and Orevac inner sublayers. The Orevac inner sublayer may have an inner diameter of about.200 inches and a thickness of.006 inches. The Pebax 45D outer sublayer may also have a wall thickness of about.006 inches. The outer sub-layer may be thermally bonded to an outer elastomeric layer 4410, such as an outer layer of Pebax 25D. The inner sub-layer may be thermally bonded to the inner layer of inner liner 4408, such as an inner layer of HDPE.

As shown in fig. 69, in another aspect, the intermediate layer 4426 may comprise three sublayers: an outer sublayer 4442, an intermediate sublayer 4444, and an inner sublayer 4446. The inner sub-layer may have a larger diameter than the middle sub-layer 4444 and the outer sub-layer 4442. For example, the inner sub-layer 4446 may have a thickness of about.006 inches to.008 inches, the middle sub-layer 4444 may have a thickness of about.002 inches to.003 inches, and the outer sub-layer 4442 may have a thickness of about.002 inches to.003 inches. The inner sub-layer 4446 may be composed of a lubricious or relatively stiff polymer (e.g., HDPE or LDPE). Intermediate sub-layer 4444 may be composed of tie layer material. Outer sublayer 4442 may be composed of about Pebax 25D to 45D.

In yet another aspect, the inner sub-layer 4446 may have a thickness of about.005 inches, an inner diameter of.200 inches, the intermediate sub-layer 4444 may have a thickness of about.002 inches, and the outer sub-layer 4442 may have a thickness of about.005 inches. The inner sub-layer 4446 may comprise, for example, LDPE. Intermediate sub-layer 4444 may comprise Orevac and outer sub-layer 42 may comprise Pebax 45D. While the various layers disclosed herein for the intermediate layer 4426 may be mixed to form different combinations of thickness and materials, the LDPE of the inner sub-layer 4446 bonds well to the HDPE inner liner 4408 and the Pebax 45D outer sub-layer 4442 bonds well to the Pebax 25D outer layer 4410. In addition, with the LDPE inner sub-layer 4446, the tip section 4404 can be easily removed from the stainless steel forming mandrel.

In yet another aspect, the middle layer 4408 comprises an inner LDPE sub-layer 4446 having an inner diameter of.200 inches and a wall thickness of.006 inches, an intermediate Orevac sub-layer 4444 having a wall thickness of.003 inches, and an outer Pebax 25D sub-layer 4442 having a wall thickness of.003 inches. Notably, for this aspect, the inner sub-layer has twice the thickness of the other sub-layers.

In another aspect, the intermediate layer 4426 may be formed as a multilayer coextrusion of an HDPE or LDPE inner sub-layer 4446, an intermediate heat bondable tie sub-layer 4444, and a Pebax 25D or 35D outer sub-layer 4442.

The tie sub-layer between the Pebax and LDPE sub-layers may be Orevac. Other tie layers may also be used, alone and in combination, such as functionalized olefins, e.g., maleic anhydride grafted ethylene vinyl acetate, polyolefins modified with acrylic acid, and other polar functional groups are possible.

As another aspect, the tip section 4404 of the expandable sheath 4400 may also include a radiopaque marker 4428. As shown in fig. 66, for example, in terms of being used to deliver a stent-mounted heart valve, the tip section 4404 supports the marker 4428 in close proximity to the tip, which is within 6mm of the length of the marker. Having a marker in the tip section 4404 facilitates more accurate positioning of the medical device.

Fig. 63-65 schematically illustrate one example of incorporating a radiopaque marker 4428 into the tip section 4404. Specifically, the marker may be incorporated into the inner liner 4410 below the flap 4438. As shown in fig. 63, when the inner layer is cut into the shape of fig. 48, the marker may be placed before the flap 4438 is folded back onto the inner winding of the inner liner 4410. The radiopaque marker 4428 may then be encapsulated into the inner liner, as shown in fig. 54-57, for example, by a reflow process and/or a heat shrink process (using the intermediate layer 4426). This also contributes to the thickened wall portion of inner liner 4408 shown in fig. 56. Advantageously, the additional step of heat shrinking the middle layer 4426 and the outer layer 4410 may additionally secure the radiopaque marker 4428. Fig. 64-65, on the other hand, illustrate forming the distal end of the tip section 4408 by heat shrinking and trimming the intermediate layer 4426 to form another 1-2mm tip, and applying an outer jacket layer 4410. The radiopaque markers are shown in fig. 63-64 as not yet folded into the inner liner 4408 to illustrate their relative positioning during the assembly process.

In another aspect, the radiopaque marker may be bonded between the middle layer 4426 and the inner liner 4408 or between the outer layer 4410 and the middle layer 4426. In any event, having a radiopaque marker in the tip section 4404 facilitates positioning of the expandable sheath 4400 by allowing for more accurate visualization.

Generally, the radiopaque marker 4428 has a rectangular shape and is bent into a C-shape as it is folded into the tip section 4404. In one aspect, as shown in fig. 63, the radiopaque marker has an axial length of about 2.5mm and is axially centered under the flap 4438, leaving, for example,.75 mm on either side for a 4mm inner liner 4408 in the tip section 4404, or 1.25mm on either side for a 5mm length inner liner. As shown in fig. 64, the intermediate layer 4426 overlaps the trimmed and formed inner liner 4408 by about 1-2mm and extends distally by about 2-3mm. As shown in fig. 65, an outer layer 4410 is applied covering an intermediate layer 4426 of about 1mm, and the distal portion of the intermediate layer is trimmed to about 1-2mm.

As shown in fig. 44-46, in one aspect, the outer elastomeric layer 4410 extends over the inner liner 4408 and the intermediate layer 4426 of both the proximal section 4402 and the distal section 4404 of the expandable sheath 4400. For example, the outer layer 4410 slides over the entire length of the rolled inner liner 4408 and tip section, leaving an uncovered tip of about.040 inches to.080 inches (1-2 mm) at the distal end of the sheath 4400, as shown in fig. 65. Generally, the outer layer 4410 has a thickness of about.005 inches. The outer layer may also have a taper to accommodate the shape of the access section 4402 and the tip section 4404. For example, the taper may be formed due to thermal shrinkage of the FEP HS tube on a tapered mandrel.

The outer elastomeric layer 4410 may be a single layer, such as a polyurethane layer, or comprise multiple sublayers. For example, the elastomeric layer may comprise two sublayers having a shore D hardness of less than about 25-35, such as an inner layer of low hardness PEBA (e.g., pebax from armema). In another aspect, the outer layer 4410 may have a shore D hardness of 35 to 65. In addition, the outer layer may comprise a low durometer polyurethane having a shore a hardness of less than about 65 to 75. One example is Neusoft 597-50 from NEU specialty engineering materials.

In another aspect, the outer elastomeric layer 4410 may have Neusoft 55A sliding over the entire length of the rolled inner liner 4408, exposing the distal tip of the intermediate layer 4426. The layers are then heat shrunk for bonding. In one aspect, the outer layer 4410 may be directly bonded to the inner liner 4408, for example, when the outer layer is composed of Neusoft and the inner liner is composed of HDPE. Further, the outer layer 4410 may be pulled over the intermediate layer 4426 at the tip section 4404, and the FEP shrink tube slid over the outer layer to thermally bond the outer layer to the intermediate layer.

In another aspect, the elastomeric layer 4410 may be composed of Pebax 25D with an intermediate layer 4426 sliding over to facilitate thermal bonding of the layers of the tip section. As described above, an optional lubricant, such as Nusil, may be applied to the outer surface of inner liner 4408 to facilitate expansion and contraction of inner liner 4408. In general, however, the tip section 4404 will not have a lubricant due to the thermal bonding of the layers.

In another aspect, the elastomeric layer 4410 may include a radiopaque filler, such as barium sulfate, for one layer or multiple sublayers.

As described above, for an expandable sheath 4403 for cardiovascular applications (e.g., delivering a stent-mounted heart valve), the slit 4412 has a length of about 3.8mm to 4mm and less than 1-3mm, in one aspect less than 2mm, from the distal end of the tip section 4404. Thus, the slit 4412 is about 60% to 80% of the length of the tip section 4404. (furthermore, the un-scribed length is 20% to 40% of the length of the tip section 4404.) as shown in fig. 45-46 and 65-66, for example, the slit is linear in shape and may have a gap, or may be partially sealed by reflow in various construction steps, depending on the manner in which the manufacturer wishes to adjust the push force required to tear the tip section 4404. In another aspect, the outer layer 4410 and the intermediate layer 4426 may be separated together in a single step, such as at the end of a manufacturing process.

Although the aspect shown has only a single linear slit 4412, the shape and number of slits may vary depending on the amount of thrust required. In general, more slits will reduce the thrust. The slit may also have a shape that is wider at some points and narrower at other points, e.g., if less pushing force is required at the proximal end 4420, the slit may be wider or may diverge into two slits. Or two shorter slits may be used. In addition, by reducing the width or length of the slit, for example, tapering or refluxing the distal end of the slit 4412, the thrust force may be higher. The slit need not be linear and may be helical, bifurcated, contain a series of enlarged gaps, etc. In general, however, the goal is to reduce the force of the medical device through the end of the expandable sheath 4400 and/or facilitate retrieval by tearing the tip section 4404.

The tip section 4401 is permanently altered during expansion by tearing the distal end 4422 through the intermediate layer 4426 to elongate the slit 4412. For example, the tip section 4404 may change from a tapered shape having a smaller first diameter to a more expanded diameter after the medical device is passed through. For example, the first inner diameter may be about 4.7mm or 0.184 inches. The expanded second inner diameter may be about 5.5mm or.216 inches to about 9.0mm or 0.354 inches, depending on the crimped valve outer diameter and the deployed valve outer diameter mounted on the valve delivery system, for example, in the case where the medical device is a heart valve.

As shown in fig. 47, the slit 4412 may have a U-shape with a rounded portion on the proximal end and then the arms extend distally-with those arms separating during expansion of the tip section 4404. Notably, the U-shape has a relatively smooth and clean perimeter to facilitate deployment and retrieval of the medical device. Fig. 48 illustrates the manner in which removal of the expansion force of the medical device allows the slit 4412 to retract slightly due to the elasticity of the layers of the tip section 4404. However, the tip section remains substantially easier to retrieve due to the tear and some residual splaying of the distal end 4422. Fig. 48 also illustrates the manner in which in one aspect, the layers may be retracted by different amounts, such as with inner layer 4408 being retracted more than outer layer 4410, and vice versa.

A method of delivering a medical device includes placing at least a distal end of an expandable sheath 4400 into a patient vessel. As described above, the radiopaque marker 4428 is adjacent to the distal end 4422 of the tip section 4404. The marker allows the medical technician to closely approximate the position of the distal end 4422 by looking at the position of the radiopaque marker 4428. The radiopaque marker is observed by a medical technician through a device such as an x-ray device. The radiopaque markers are advanced axially and aligned at a desired location in the vessel (e.g., at a calcified aortic valve). The medical device is advanced distally through sheath 4400, expanding lumen 4406 to accommodate the size of the medical device.

As the medical device passes through the tip section 4404, the tip is radially expanded by expanding the slit 4412 and tearing the distal-most end of the tip section, such as shown in fig. 47. Once the medical device has passed through the distal end 4416 of the tip section 4404, and the slit 4412 has been axially extended through the distal end 4422 of the tip section 4404, the diameter at the distal end of the sheath 4400 is partially retracted (e.g., as shown in fig. 48) to a diameter that is less than the expanded configuration but greater than the unexpanded configuration. If necessary, medical devices such as prosthetic heart valves can be partially or fully withdrawn through the still slightly expanded (and often looser or more compliant) tip section 4404. The medical device may also be redeployed by expanding the tip section 4404 to its maximum diameter.

In certain aspects, the distal tip section 4404 of the expandable sheath 4400 may be manufactured according to methods described below. The distal tip section 4404 disclosed herein may be combined with any of the other aspects of the sheath disclosed herein. In some aspects, an elongated sheet of liner material (as described above) as shown in fig. 47 is rolled up helically or helically to form an elongated tube, which will eventually become liner 4408, as shown in fig. 50-52. Extending proximally from the distal edge 4432 of the inner liner 4408 is a first incision 4444. The second incision 4434 extends from the proximal end of the first incision 4444 perpendicular to one of a pair of lateral edges 4436 of the inner liner 4408.

When the sheet is rolled into the elongated tubular inner liner 4408, the flaps 4438 formed by the first and second cuts extend outwardly as shown in fig. 63. In one aspect, the flap 4438 is held by the remaining uncut portion between the second cut 4434 and the adjacent lateral edge 4436 forming the tab. Thus, the flap is an extension of the sheet rolled into liner 4408. The radiopaque marker 4428 may be positioned between the extension flap 4438 and the bottom layer prior to a subsequent heat treatment step, thereby encapsulating the radiopaque marker 4428. In some examples, the radiopaque marker is preformed in a C-shape, but in other examples, the radiopaque marker is any other shape suitable for positioning between the flap 4438 and the bottom layer. The flap composition itself may also comprise a radiopaque compound. It should be noted that cuts 4444 and 4434 may also be cut after the web is rolled into liner 4408.

When wrapping the ends of the flaps 4438, the ends of the flaps align with the inner longitudinally extending ends of the rolled inner liner 4408 and will eventually become part of the slit 4412. The rolled elongated tube of inner liner 4408 is wrapped around flaps 4438 at a slight angle such that the (partially assembled) tip section 4404 tapers toward the distal end 4422 of sheath 4400. The distal end 4422 of the flap 4438 is trimmed perpendicular to the longitudinal axis. The distal tip section 4404 is shrink wrapped separately from the proximal section 4402 of the expandable sheath 4400. The heat shrink wrap is formed and provided with a tapered shape, for example, by thinning the wall structure of the inner liner 4408.

The proximal section 4402 and the tip section 4404 of the rolled elongated inner liner 4408 are placed on a mandrel. Then, during a first reflow step, heat is applied to the distal tip section 4404, melting the flaps 4438 to the remaining inner liners 4408 of the tip section. The area of the previous first incision 4444 is visible even after melting and reopens to form a portion of the slit 4412, as shown in fig. 50-52. The tab between the end of the second incision 4434 and the adjacent lateral edge 4436 is cut to release the proximal section 4402 of the inner liner 4408 to helically or spirally expand and collapse, as shown in fig. 63.

In one aspect, as described above, the radiopaque marker 4428 may be positioned between the flap 4438 and the uncut portion of the rolled inner liner 4408 prior to the first reflow step. The flap is reflowed over the radiopaque marker 4428, encapsulating the radiopaque marker within the inner liner 4408, as shown in fig. 63 and 66. Some thinning and tapering of the material may also occur at this step (as well as other heating and reflow steps), such as shown in fig. 56.

Next, as shown in fig. 64, the intermediate layer 4426 is positioned at the distal end of the distal tip section 4404 of the inner liner 4408 such that the intermediate layer 4426 overlaps a portion of the inner liner 4408. In the second reflow step, the intermediate layer 4426 reflows (melts) about the inner liner 4408 such that the intermediate layer extends proximally over the outer surface of the inner liner. Some thinning of the soft intermediate layer 4426 (and other layers) may also occur at this step, as shown in fig. 61.

As shown in fig. 65, the outer layer 4410 is then positioned partially over the inner layer 4408 and a portion of the intermediate layer 4426 such that a portion of the intermediate layer extends distally of the outer layer 4410. The outer layer is heat treated by a third reflow/heat treatment step to join with the middle layer 4426. Thus, the middle layer 4408 couples the outer layer 4410 to the inner liner 4408. In some aspects, prior to the second reflow step, an intermediate layer may be sandwiched between the inner liner 4408 and the outer layer 4410 such that the inner liner 4408, the intermediate layer 4426, and the outer layer 4410 are coupled to one another simultaneously during the second reflow step.

Once the outer layer 4410 is bonded to the distal tip section 4404, a slit 4412 is cut through at least a portion of the inner liner 4408, outer layer 4410, and intermediate layer 4426 of the tip section. The slit 4412 does not reach the distal end of the intermediate layer 4426, such that the distal end 4422 of the distal tip section 4404 is complete and circumferentially continuous, as shown in fig. 65.

Advantages of the tip section 4404 disclosed above include ease of manufacture, lower force to separate the tip without stretching and cleaner separation, absence of distal or proximal shoulders formed by layers, marker 4428 embedded in a safe location near the distal-most end of the sheath 4400, the spit tip having some dynamic recovery after device retest, intermediate layer 4426 well bonding the outer layer (sheath) to the inner liner and being atraumatic to the body lumen. In addition, the tip section 4404 avoids premature opening during sheath insertion, and alignment of the edges of the inner liner 4408 with the slit 4412 avoids delamination. The outer edge of the spool-type inner liner 4408 of the proximal section 4402 is flush behind the tip section 4404, eliminating any distally or proximally facing edges.

Method

Aspects of the present disclosure also relate to a method of manufacturing a sheath having a proximal end and a distal end, the method comprising: forming a variable diameter liner by rolling up a sheet having a first edge and a second edge, and wherein the sheet is defined by an inner surface and an outer surface, is of a helical configuration such that at least a portion of the inner surface of the sheet overlies at least a portion of the outer surface of the sheet, thereby forming an overlying portion, and wherein the first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and the second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the sheath, the lumen having a longitudinal axis; forming an outer layer having an inner surface and an outer surface and extending around at least a portion of the variable diameter liner such that the inner surface of the outer layer is positioned adjacent to the outer surface of the liner, wherein the outer layer comprises: a braid; and an elastomeric polymer layer having a predetermined thickness and having an inner surface and an outer surface; wherein the variable diameter liner is configured to move from a predetermined resting diameter d during application of a radially outward force by the medical device through the lumen of the liner by sliding a first edge of the sheet along at least a portion of the inner surface and a second edge of the sheet along at least a portion of the outer surface _r Expanded to an expanded diameterd _e 。

Various methods may be used to produce the sheaths discussed above and below throughout the present disclosure. For example, fig. 7 and 8 illustrate block diagrams of exemplary methods of producing a sheath in various aspects. The individual method steps are also depicted in fig. 9A-9K and fig. 31. In certain aspects, and as shown in fig. 9A, the liner may be formed from an extruded tube 903 having an inner surface and an outer surface, and having any of the thicknesses described above. The extruded tube may be cut 905 along the length to form a sheet. In certain aspects, the inner and/or outer surfaces of the tube may be surface treated, such as by plasma etching, chemical etching, or other suitable surface treatment methods. In some exemplary aspects, when the outer surface of the liner is treated, the treatment may provide better adhesion to the outer layer as the outer layer is formed. In other aspects, the inner surface of the liner may be ribbed. In these exemplary aspects, the ribbed surface helps reduce contact points with the prosthetic device and may reduce friction. In further aspects, the initial extruded tube 903 may be produced by co-extrusion of the same or different polymers as the multilayers described herein. It should be appreciated that one of ordinary skill in the art may select the composition of the liner depending on the desired application. In certain aspects, the decision to use a particular material for the liner may depend on the stiffness, wall thickness, and lubrication optimization desired. In other aspects, and as described above, the tube may also be cut to form a longitudinal slit 911 (shown in fig. 31) such that when the formed sheet is wound, it forms a spiral reel configuration as shown in fig. 32.

In a further aspect, an elongated single lumen tube for forming a liner has an inner surface and an outer surface, wherein at least a portion of the outer surface of the elongated single lumen tube comprises a first plurality of protrusions and/or wherein at least a portion of the inner surface of the elongated single lumen tube comprises a second plurality of protrusions. When forming the helical configuration of the inner member, this tube is longitudinally cut at least a portion of its circumference to form a sheet having a first longitudinal edge and an opposing second longitudinal edge. In such aspects, the cutting is performed such that at least a portion of the first plurality of protrusions is disposed adjacent to the first longitudinal edge of the sheet, and/or wherein at least a portion of the second plurality of protrusions is disposed adjacent to the second longitudinal edge of the sheet. In further exemplary aspects, when the sheet is wound in a spiral configuration, at least a portion of an inner surface of the sheet covers at least a portion of an outer surface of the sheet, thereby forming an overlap portion, wherein at least a portion of the first plurality of protrusions and/or the second plurality of protrusions are disposed within the overlap portion, thereby reducing a contact area between the inner surface and the outer surface of the sheet within the overlap portion. In further aspects, the tube having the first plurality of protrusions disposed on an outer surface thereof and/or the second plurality of protrusions disposed on an inner surface thereof may be manufactured by any method known in the art. In some aspects, the tube is formed by co-extrusion when the first plurality of protrusions and/or the second plurality of protrusions are co-extruded with the remainder of the sheath. In further aspects, the first plurality of protrusions and/or the second plurality of protrusions may be formed by molding using a mold having a desired shape.

It should be appreciated that aspects of the second plurality of protrusions being formed on the inner surface of the tube in addition to or instead of the first plurality of protrusions on the outer surface are also disclosed herein. In such aspects, for example, if the second plurality of protrusions is formed on the inner surface, the tube is cut such that the second plurality of protrusions abuts the second longitudinal edge such that the second plurality of protrusions is also disposed in the overlapping portion when the sheath is in the spool configuration. It should also be appreciated that if a second plurality of protrusions is present on the inner surface of the sheet, such second plurality of protrusions may include any of the protrusions disclosed above. Similarly, where a second plurality of protrusions is disposed on the inner surface, such second plurality of protrusions may be disposed at least a portion of the length of the liner or along the entire length of the liner. Similar to the aspect that the first plurality of protrusions are present on the outer surface, the second plurality of protrusions may be located outside the overlapping portion when present on the inner surface, or even along the entire circumference of the liner when in a spool configuration.

In a further aspect, an elongated single lumen tube for forming a liner has an inner surface and an outer surface, wherein at least a portion of the outer surface of the elongated single lumen tube includes a plurality of bond sites at least partially embedded within a wall of the elongated single lumen tube. When forming the helical configuration of the inner member, this tube is longitudinally cut at least a portion of its circumference to form a sheet having a first longitudinal edge and an opposing second longitudinal edge. In further exemplary aspects, at least a portion of the inner surface of the sheet covers at least a portion of the outer surface of the sheet when the sheet is wound in a spiral configuration, thereby forming an overlap. In such aspects, the outer surface of the sheet in the overlap portion is substantially free of the plurality of bond sites, and at least a portion of the outer surface of the sheet outside the overlap portion includes the plurality of bond sites.

In further aspects, the tube having the plurality of bond sites may be manufactured by any method known in the art. In some aspects, when multiple bond sites are co-extruded with the remainder of the sheet, the tube is formed by co-extrusion. In further aspects, the plurality of bond sites may be formed by molding using a mold having a desired shape.

In other aspects, methods are also disclosed when one or more bond sites are positioned on an inner surface of an outer layer. It should be appreciated that such bond sites may also be formed by any method known in the art and suitable for the desired application. In certain aspects, such exemplary bond sites may be formed by coextrusion or molding.

In further aspects, one or more mandrels may be provided (steps 700 or 800 in fig. 7 and 8, respectively). The mandrel may have an external coating, e.gCoating, and the diameter of the mandrel may be based on the desired resting diameter d of the resulting sheath _r Predetermined. As shown in fig. 9B, a sheet formed by cutting 905 an extruded tube 903 may be rolled about a mandrel 901 in a spiral configuration (steps 702 and 802 in fig. 7 and 8, respectively) to form a liner 902 such that at least a portion of an inner surface of the sheet covers at least a portion of an outer surface of the sheet, thereby forming an overburden portion 902c, and wherein a first edge (not shown) of the sheet may be along at least the inner surface of the sheet A portion slides and the second edge 902b can slide along at least a portion of the outer surface of the sheet. When the slit is formed in a similar manner to 911 of fig. 31, the step of rolling the sheet around the mandrel is similar, but a helical configuration is provided instead of a spiral configuration.

In further exemplary aspects, in steps 705 and 805 (fig. 7 and 8, respectively), an amount of a first lubricant 910 (fig. 9C-9E) may optionally be applied to the outer surface of the liner. The presence of such lubricant material may reduce friction between the inner and outer layers of the final sheath. In other aspects, in steps 703 and 803, an amount of a second lubricant 908 may be applied between the covered portion and the sliding portion of the liner to further improve slidability and reduce friction. (fig. 9D depicts a liner with two alternative lubricants, with the mandrel hidden from view). In a further aspect, it should be appreciated that the liner formed using the mandrel may have any resting diameter, as described above. In certain aspects, the resting diameter d _r Is substantially uniform along the longitudinal axis of the lumen. While in other aspects the resting diameter d _r Along the longitudinal axis of the lumen, and wherein the resting diameter d at the proximal end _r Greater than the resting diameter d at the distal end _r . It should also be appreciated that aspects are described herein in which lubricant material between the liner and the outer layer is absent.

In further aspects, the method may further comprise the step of providing a braid or coil (steps 704 and 804). It should be understood that any of the aforementioned braids or coils may be used for this step. In a further aspect, and as shown in step 706 of fig. 7, a braid or coil is installed over the liner. In some exemplary aspects, and as shown in fig. 9F, the braid or coil 904 may be mounted over a first lubricant 910, which may be present on the outer surface of the liner. It should be appreciated that in some aspects, the second lubricant may be present only on a portion of the outer surface of the liner. In other aspects, the disclosed sheath may have a segment with a first lubricant present and a braid or coil mounted over the segment, while the sheath may have other segments without a second lubricant present and the braid or coil is mounted directly over the outer surface of the liner. It should be appreciated that the location of these particular segments may be determined by one of ordinary skill in the art depending on the desired application. It should be appreciated that the installation of the braid or coil may be performed by any method known in the art. In some non-limiting aspects, a braid or coil may be provided as a cylindrical tube, and it may be slipped over the liner or first lubricant (if present).

In a further aspect, and as shown in step 708, the method may further include the step of providing an elastomeric polymer layer. In such exemplary aspects, this elastomeric polymer layer may serve as an outer layer of the sheath. It should be understood that any of the elastomeric polymers disclosed above may be used. The particular polymer may be selected based on the desired properties of the disclosed sheath, such as stiffness, hemostatic effect, etc. The elastomeric polymer layer may be provided in any form known in the art. In certain and non-limiting aspects, an elastomeric polymer may be provided as the cylindrical tube 906 (fig. 9G). In yet another aspect, an elastomeric polymer may be mounted on the liner and braid or coil (step 710). For example, fig. 9G depicts an aspect in which a cylindrical tube 906 of elastomeric polymer is used to slide over a liner having a first lubricant 910 covering the outer surface of the liner and braid or coil 904.

In further aspects, the disclosed methods may include the step of embedding (step 711 of fig. 7) the braid or coil into an elastomeric polymer layer that serves as an outer layer. It should be appreciated that the sheath may comprise a plurality of segments. In some aspects, some segments may include braids or coils embedded within the elastomeric polymer layer, while in other segments, braids or coils are separate from the elastomeric polymer layer. It should also be understood that in some aspects the sheath may have a braid or coil embedded within the elastomeric polymer throughout the entire length of the sheath, while in other aspects the braid or coil is not embedded within the elastomeric polymer throughout the entire length of the sheath. It should also be appreciated that any method known in the art may be used to embed the braid or coil within the elastomeric polymer. In some aspects, application of heat may be utilized. In certain aspects, the use of heat shrink tubing may be used to embed a braid or coil within an elastomeric polymer. It should be appreciated that after the embedding step is completed, the heat shrink tube is removed. In other aspects, the braid or coil may be embedded within the elastomeric polymer layer by placing the assembly in an oven or otherwise heating the assembly.

In a further aspect, the method further comprises thermally bonding the elastomeric polymer used as the outer layer to the inner liner through at least a portion of the plurality of bond sites.

In a further aspect, an atraumatic tip may be provided at the distal end of the resulting sheath (step 712). In a further aspect, an outer layer comprising a braid or coil, and an elastomeric polymer layer are at least partially bonded to the inner liner. It should be appreciated that such bonding may also be accomplished by any method known in the art. In certain aspects, and as shown in step 714, a heat shrink is applied to the bonded and heated portion to form a bond between the inner liner and the outer layer. In other aspects, bonding between the inner liner and the outer layer may be achieved by placing the assembly in an oven or otherwise heating. In a further aspect, bonding is performed by heating at a temperature of about 350°f to about 550°f for a period of time effective to form a bond between at least a portion of the outer layer and at least a portion of the inner liner. In further aspects, the heating may be performed at a temperature of about 375°f, about 400°f, about 425°f, about 450°f, about 475°f, about 500°f, or about 525°f. In further aspects, the period of time effective to form the bond may comprise from 1 second to about 60 seconds, including exemplary values of about 5 seconds, about 10 seconds, about 15 seconds, about 20 seconds, about 25 seconds, about 30 seconds, about 35 seconds, about 40 seconds, about 45 seconds, about 50 seconds, and about 55 seconds. However, it should be further understood that the time period is not limiting and that it may have any value required to provide an effective bond, for example, it may have any value from about 1 second to about 5 hours. It should also be appreciated that if heat shrink tubing is used to obtain the desired bond, the heat shrink tubing is removed (step 716 of fig. 7).

In a further aspect, and as shown in fig. 9I, the bonding step may further include applying a first strip 920 of elastomeric polymer to at least a portion of the outer surface of the sheet that does not include the covering portion 902c along at least a portion of the longitudinal axis of the lumen before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9I, the first strap may be applied prior to installing the braid or coil. In a further aspect, the location where the first strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations.

In further exemplary aspects, the method may include applying a second strip 922a of elastomeric polymer to at least a portion of the outer surface of the sheet at the proximal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9J, the second strip may be applied prior to installing the braid or coil. In a further aspect, the location where the second strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations. In other aspects, the method may include applying a third strip 922b of elastomeric polymer to at least a portion of the outer surface of the sheet at the distal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9J, the second strip may be applied prior to installing the braid or coil. In a further aspect, the location where the third strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations. In a further aspect, both the second elastomeric polymer and the third elastomeric polymer are present. While in other aspects only one of the second elastomeric polymer or the third elastomeric polymer is present. It should also be understood that the first elastomeric polymer, the second elastomeric polymer, and the third elastomeric polymer may be the same or different. It should also be appreciated that the first elastomeric polymer, the second elastomeric polymer, and the third elastomeric polymer may be the same as the elastomeric polymer layers present in the outer layer, and may include any of the elastomeric polymers described herein.

Fig. 9K shows a cross-sectional view of the sheath at step 718 of fig. 7. The sheath 900 made according to the described methods and processes may be attached or bonded to the housing 101, for example, by bonding the proximal end of the sheath 900 to the polycarbonate housing 101.

Fig. 8 and 9H illustrate some alternative aspects. In such alternative aspects, the outer layer is preformed and then mounted on a liner positioned on a mandrel. In such aspects, the provided elastomeric polymer layer is first mounted on the braid or coil (step 808) and then mounted on the liner. In other aspects, the method may further include the step of installing the braid or coil over the liner after the braid or coil is partially embedded within the elastomeric polymer layer (step 809). However, the step of partially embedding the braid or coil within the elastomeric polymer layer may be performed after the braid or coil and elastomeric polymer layer are installed on the liner (step 811). Steps 812-818 may be performed similarly to steps 712-718.

In a further aspect, and as shown in fig. 9I, the bonding step may further include applying a first strip 920 of elastomeric polymer to at least a portion of the outer surface of the sheet that does not include the covering portion 902c along at least a portion of the longitudinal axis of the lumen before or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9I, the first strip may be applied prior to installing the preformed outer layer comprising the braid or coil and the elastomeric polymer. In a further aspect, the location where the first strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations.

It should also be appreciated that these alternative aspects may also include the step of applying the second strip of elastomeric polymer 922a to at least a portion of the outer surface of the sheet at the proximal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9J, this second strip may be applied prior to installing the preformed outer layer comprising the braid or coil and the elastomeric polymer. In a further aspect, the location where the second strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations. In other aspects, the methods may further include applying a third strip 922b of elastomeric polymer to at least a portion of the outer surface of the sheet at the distal end of the sheath prior to or during the step of bonding at least a portion of the inner surface of the elastomeric polymer layer to at least a portion of the outer surface of the sheet of the liner. It should be appreciated that in some exemplary aspects, and as shown in fig. 9J, this third strip may be applied prior to installing the preformed outer layer comprising the braid or coil and the elastomeric polymer. In a further aspect, the location where the third strip is applied does not include the first lubricant. However, it should be understood that in such aspects, the first lubricant may be present at other locations. In a further aspect, both the second elastomeric polymer and the third elastomeric polymer are present.

It should be appreciated that where there are multiple bond sites, bonding between the inner liner and the outer layer (or elastomeric polymer) may be performed by the multiple bond sites.

Methods of making additional configurations of the sheath are also disclosed herein. For example, disclosed herein is a method of manufacturing a sheath having a proximal end and a distal end. Such methods include: forming a variable diameter liner by providing an elongated single lumen tube comprising at least one polymer layer; longitudinally cutting at least a portion of the circumference of the elongate single lumen tube to form a sheet having a first longitudinal edge and an opposing second longitudinal edge and having an inner surface and an outer surface; and then forming the variable diameter liner by rolling the sheet into a helical configuration such that at least a portion of an inner surface of the sheet overlies at least a portion of an outer surface of the sheet, thereby forming an overlying portion, and wherein a first edge of the sheet is slidable along at least a portion of the inner surface of the sheet and a second edge is slidable along at least a portion of the outer surface of the sheet, wherein the inner surface of the sheet defines a lumen of the sheath, the lumen having a longitudinal axis.

It should be appreciated that the elongate single lumen tube may be extruded or co-extruded from any of the polymers or compounds disclosed above. For example, but not limited to, the elongate single lumen tube can include at least one polymer including a polyolefin, a polyamide, a fluoropolymer, copolymers thereof, co-extrudates thereof, or blends thereof. In other aspects, however, a compound material includes a polyolefin and a lubricating filler. In such exemplary aspects, the polyolefin may be a high density polyethylene. However, in other aspects, the lubricating filler may include Polytetrafluoroethylene (PTFE) filler. In such aspects, the lubricating filler may be present in an amount of from about 5 wt% to about 20 wt% of the total weight of the compound material.

For example, but not limited to, a tubular body may be extruded to form an elongated tube comprising a compound material. The compound material may include a polyolefin present in an amount of greater than 0 wt% to less than 100 wt%, based on the total weight of the compound, and a lubricating filler present in an amount of about 5 wt% to about 20 wt%, based on the total weight of the compound material.

The extruded or co-extruded elongate single lumen tube can have a coefficient of friction of less than about 0.5.

In further aspects, the single lumen tube may be produced by co-extrusion of the same or different polymers as the multilayers described herein. In other aspects and as described above, this tube can be coextruded with any of the tie layers disclosed above. In such exemplary aspects, the elongate tube may comprise any of the polymers disclosed above, for example, in the presence of a tie layer, and the tie layer is disposed on the inner surface of the tube or/and the outer surface of the tube.

It should be appreciated that this elongated tube is used to form the liner, and any of the materials disclosed above may be used. In a further aspect prior to cutting the tube to form the helical configuration of the liner, a smooth liner may be provided on the inner surface of the tube and/or the outer surface of the tube. It will be appreciated that such a lubricious liner, if present, may be disposed on the tie layer. In certain aspects, the tie layer is used to bond the lubricious liner to the polymer layer forming the elongate tube. In a further aspect, at least a portion of the inner surface of the elongated tube may be ribbed. In these exemplary aspects, the ribbed surface helps reduce contact points with the prosthetic device and may reduce friction.

However, in other aspects where a tie layer and/or a lubricious liner is present, at least a portion of the lubricious liner may also be ribbed. Further, in such aspects, a pipe comprising any of the polymers, tie layers, and lubricious liners disclosed above has a coefficient of friction of less than about 0.5.

The elongate tube is then positioned over the mandrel and cut at least a portion of the circumference of the tube, as disclosed above. In further aspects, the methods of forming the liner are similar to those shown in fig. 9A. The liner may be formed from a single lumen extrusion tube 903 having an inner surface and an outer surface and having any of the thicknesses described above. The extruded tube may be cut 905 along the length to form a sheet.

In addition, in certain aspects, the inner and/or outer surfaces of any of the single lumen tubes disclosed above may be further surface treated, such as by plasma etching, chemical etching, or other suitable surface treatment methods. In some exemplary aspects, when the outer surface of the liner is treated, the treatment may provide better adhesion to the outer layer as the outer layer is formed. It should be appreciated that one of ordinary skill in the art may select the composition of the liner depending on the desired application. In certain aspects, the decision to use a particular material for the liner may depend on the stiffness, wall thickness, and lubrication optimization desired.

The formed sheet may then be positioned on an additional mandrel. The mandrel may have an external coating, e.gCoating, andthe diameter of the mandrel may be based on the desired resting diameter d of the resulting sheath _r Predetermined. As shown in fig. 9B, a sheet formed by cutting 905 an extruded tube 903 may be rolled into a helical configuration about a mandrel 901 to form a liner 902 such that at least a portion of an inner surface of the sheet covers at least a portion of an outer surface of the sheet, thereby forming an overburden portion 902c, and wherein a first edge (not shown) of the sheet may slide along at least a portion of the inner surface of the sheet and a second edge 902B may slide along at least a portion of the outer surface of the sheet. It should be appreciated that any of the spiral configurations disclosed above may be obtained.

For example, the sheet material is wound such that the first edge and the second edge of the sheath are substantially aligned in spaced apart relation along a vertical axis through the thickness of the sheath. In such aspects, the spaced apart relationship may include a portion of the sheet positioned between the first edge and the second edge along the vertical axis. In certain aspects, the sheet material is wound such that when the sheath is in an unexpanded, rest state, the liner includes at least two layers of sheet material that overlie one another along at least a portion of the circumference of the sheath. In yet other aspects, at least a portion of the circumference of the sheath comprises three layers of sheet material that overlie one another when the sheath is in an unexpanded, rest state. Also disclosed are aspects in which, when the sheath is wound in a helical configuration, the first edge of the sheet may be substantially aligned with a vertical axis through the thickness of the sheath, while the second edge is circumferentially offset from the vertical axis. In this configuration, in some aspects, the liner comprises a layer of sheet material at least a portion of the circumference of the sheath without any cover portions.

However, in certain aspects, the liner may be formed from an extruded double lumen tube. The extruded dual lumen tube may comprise any of the polymers or compounds disclosed above. Figures 20A-20C illustrate exemplary schematic diagrams of a method whereby a dual lumen tube is fabricated into a liner. The dual lumen 2000 may include a first channel 2002 having an inner surface 2002a and an outer surface 2002b, and a second channel 2004 having an inner surface 2004a and an outer surface 2004 b. The second channel 2004 is positioned within the first channel 2002 such that at least a portion of the circumference of the first channel and at least a portion of the circumference of the second channel have at least one shared inner surface and at least one shared outer surface 2006. In this configuration, the outer surface 2002b of the first channel 2002 defines the outer surface of the double lumen tube.

It should be appreciated that this dual lumen tube may include any of the layers disclosed above.

For example, a dual lumen tube may be co-extruded from the compound materials described above. In such exemplary aspects, the first channel may comprise a compound material, or the second channel may comprise a compound material, or both may comprise a compound material as described above.

In further aspects, the dual lumen tube can be coextruded with any of the tie layers disclosed above, wherein the tie layer can be coextruded with the first channel or the second channel, or both. In further aspects, any of the smooth liners disclosed above may be provided at the tie layer. The lubricious liner may be disposed, for example, within the first channel or the second channel or both.

In further aspects, and as shown in fig. 20B, the first channel may be cut longitudinally along at least a portion of the first channel circumference 2008 that is not shared with the second channel circumference to form a first sheet. The first sheet 2010 has a first edge 2012 and a second edge 2014, and the second channel is longitudinally disposed along at least a portion of the first sheet 2004 such that at least a portion of the circumference of the second channel includes at least a portion having a surface 2016 shared with the first sheet along the length of the sheet and along the length of the second channel.

The second channel is then cut longitudinally at a portion 2018 of the circumference of the second channel adjacent to the shared surface 2016 of the first sheet to form a second sheet 2020 having a first edge 2022 and a second edge 2024, wherein the second edge is defined by a portion of the shared surface 2016 of the first sheet.

In a further aspect, the first sheet and the second sheet are wound into a spiral configuration, as shown in fig. 20C, such that: the shared surface 2016 between the second sheet and the first sheet forms a first portion 1802 (2016) of the liner having a first surface and an opposing second surface. At least a portion of the second sheet 1806 forms a first segment of the liner having a first surface and an opposing second surface. A portion 1810 of the first sheet adjacent to and extending to the second end of the second sheet forms a second segment 1810 of the liner having a first surface and an opposite second surface. While a portion of the first sheet adjacent to and extending to the second end 1808 of the second sheet forms a third segment 1808 of the liner having a first surface and an opposing second surface. In such a spiral configuration, and as shown in fig. 20C and 18, at least a portion of the first surface of the second segment overlaps at least a portion of the second surface of the first segment, wherein at least a portion of the first surface of the third segment overlaps at least a portion of the second surface of the second segment, and wherein at least a portion of the first surface of the third segment overlaps at least a portion of the second surface of the first segment; wherein the first surface of the first portion extends into the first surfaces of the first, second and third segments, and wherein the second surface of the first portion extends into the second surfaces of the second and third segments.

In certain aspects, whether the liner is formed from a single lumen tube or a double lumen tube, the method may include the step of disposing a quantity of lubricant prior to the cutting step. It should be appreciated that the lubricant may be disposed at any surface of any channel.

In a further aspect, the lubricant may be manually set. In yet other aspects, the lubricant may be provided by pad printing. However, in other aspects, the lubricant may be provided by spraying.

It should be appreciated that any of the lubricants disclosed above may be used.

When the lubricant is manually placed, any technique known in the art may be utilized. For example, but not limited to, the lubricant may be provided by brushes, cloths, pads, and the like.

In some aspects, the lubricant is provided by pad printing. During pad printing, a quantity of lubricant is placed in recessed channels on the plate. The length and width of the channels may be predetermined as desired. For example, the length and width of the channels may correspond to a desired area on the liner surface where lubricant is placed. The volume of the channel may also be defined to determine in part the total amount of lubricant to be transferred. In such aspects, the cushion may be immersed in the channel, absorb the lubricant, and move over the desired portion of the liner. The pad may then be capped onto a predetermined portion of the liner, thereby transferring the lubricant onto the surface of the liner.

It should be appreciated that in aspects disclosed herein, a predetermined amount of lubricant is applied to a set location (predetermined portion) of the liner surface. In such aspects, the methods disclosed herein allow for substantial control of both the application area and the volume of lubricant used. As disclosed above, since the depth of the channels may be controlled, the amount of lubricant disposed on the surface of the liner may also be substantially controlled.

Any of the lubricants disclosed above may be utilized in connection with overprinting for transferring the lubricant onto the surface of the liner. In certain aspects, the lubricant used in the pad printing process is substantially viscous. In certain exemplary and non-limiting aspects, the lubricant may have a viscosity of about 600cP to about 1,200 cP. In further aspects, it should be appreciated that the viscosity of the lubricant may be adjusted by adding more solids or more solvents to the lubricant composition. For example, but not limited to, lubricants such as MED10-6670 (or the like) can thicken to exceed their standard viscosity.

It should be appreciated that the use of padding allows lubricant to be applied to very specific portions of the liner with tight tolerances. In certain aspects, the lubricant may include a fluorescent material or any other material that will allow the determination of the specific location of the lubricant on the device. In such aspects, for example, the particular lubricant location may be determined under UV light. This allows for simple quality control to determine whether lubricant has been applied in the desired portion of the sheath.

In other aspects, however, substantially accurate padding may help reduce thrust by reducing friction in the most relevant areas of the sheath while preventing unwanted migration of lubricant.

In certain aspects, the lubricant may be applied around a portion of the circumference of the liner. However, in other aspects, the lubricant may be applied around the entire circumference of the outer surface of the liner.

In other aspects, the lubricant may be transferred in a predetermined pattern. For example, the lubricant may be transferred in a "stripe" pattern. However, it should be understood that such a pattern is merely exemplary. The pattern may have any regular or irregular shape. For example, if the pattern is a stripe pattern, the lubricant may be provided in a plurality of stripes along the entire length of the liner or along a portion of the liner. In further aspects, the pattern may have a triangular shape, a tapered shape, an oval shape, a circular shape, a rectangular shape, or any irregular shape. The pattern may be determined based on a desired application and/or a desired location on the outer surface of the liner.

In a further aspect, the pad printing machine may rotate the liner during operation so that the printer may prepare lubricant in a linear (or any other desired shape) in a new position along the surface of the liner. In addition to precisely controlling the amount of lubricant and lubricant location added to the liner, this approach also allows for more cost-effective manufacture of the sheath by reducing the amount of lubricant and reducing the number of sheaths that may be discarded due to inaccurate lubricant application that may affect overall sheath performance.

In further aspects, the lubricant may be applied by spraying. In such methods, the lubricant is loaded into a sprayer. The sheath, or more specifically the liner, is mounted on a spindle that is rotatable about the long axis of the sheath. The lubricant is then sprayed onto the rotating sheath and translated down the desired portion of the liner length, thereby ensuring substantially uniform coverage. The amount of lubricant sprayed onto the liner, the speed at which the nozzle moves along the sheath, and the sheath rotational speed may all be specified to optimize the application process.

In certain aspects, any of the lubricants disclosed above may be used. In terms of using spraying, the viscosity of the lubricant is equal to or less than 600cP. Spraying uses equipment that atomizes the liquid solution that is fed to the spraying machine. The resulting spray can be used to coat a variety of devices. In the case of expandable sheath devices, the lubricant is mixed and prepared thoroughly, and then loaded into the machine.

To apply the lubricant to the liner in a substantially uniform manner, the liner is mounted on a spindle configured to rotate at a specified speed along the long axis of the sheath. The nozzle of the applicator then sprays atomized droplets of lubricant solution onto the liner. The nozzle translates as the sheath rotates, moving horizontally along the length of the sheath. The speed may be adjusted to optimize the amount of lubricant sprayed onto the liner. It will be appreciated that if more lubricant is required, the speed may be slowed, so that the nozzle remains in a given position along the liner surface for a longer period of time, and vice versa. As with pad printing, the lubricant may be composed of a fluorescent component so that the area of the sheath coated with the lubricant is clearly visible under invisible light.

In a further aspect, the lubricant cures after the lubricant is applied to the surface of the liner. It should be appreciated that the curing may be performed under any condition effective to provide the desired result. In certain exemplary and non-limiting aspects, curing is performed in an oven. The curing temperature and timing may be defined by the particular lubricant used in the methods disclosed above.

In a further aspect, the method may further include disposing an outer layer over at least a portion of the outer layer of the liner to form a sheath configured to move from the predetermined resting diameter d during application of the radially outward force of the medical device through the lumen of the liner by sliding a first longitudinal edge of the sheet along at least a portion of the inner surface and a second longitudinal edge of the sheet along at least a portion of the outer surface _r Expanded to an expanded diameter d _e 。

In certain aspects, the outer layer may be manufactured by extruding a tubular body to form an elongated tube comprising a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt% to less than 100 wt% of a polymer comprising a polyether block amide, a polyurethane, or a combination thereof, based on the total weight of the first compound composition; less than about 65 weight percent of an inorganic filler, based on the total weight of the first compound composition; and up to about 20 wt% of a solid lubricant filler, based on the total weight of the first compound composition. This elongate tube may then be disposed over any of the liners disclosed above to form the outer layer of the sheath. It should be appreciated that any of the additional layers disclosed above may also be present between the inner liner and the outer layer.

In other aspects, the outer layer as set forth herein may be manufactured by: co-extruding an elongated bumped tube including a first polymer layer and a second polymer layer; wherein the first polymer layer comprises: a first compound composition, the first compound composition comprising: from greater than 0% to less than 100% of a polymer comprising polyether block amide, polyurethane, or a combination thereof, based on the total weight of the first compound composition; less than about 65% inorganic filler, based on the total weight of the first compound composition; and up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition; the second polymer layer comprises polyurethane, wherein the first polymer layer defines an inner surface of the tube and the second polymer layer defines an outer surface of the tube; and then disposing this tube on the surface of any of the liners disclosed herein. It should be appreciated that any of the additional layers disclosed above may also be present between the inner liner and the outer layer.

In a further aspect, the method further comprises: a) Forming a liner by any of the methods disclosed above; next b) providing a first polymer layer comprising a first compound composition comprising: from greater than 0% to less than 100% of a polymer comprising polyether block amide, polyurethane, or a combination thereof, based on the total weight of the first compound composition; less than about 65% inorganic filler, based on the total weight of the first compound composition; and up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition; wherein the first polymer layer is disposed over the proximal portion of the liner and has a length of about 5cm to about 15 cm; c) Disposing a second polymer layer comprising polyurethane over the first polymer layer, wherein the second polymer layer extends along the length of the sheath; wherein the first polymer layer and the second polymer layer together form the outer layer of the sheath.

It should be understood that any method known in the art may be used to form any of the compositions disclosed herein. In certain aspects, any of the components present in the elongate tubes disclosed herein are provided to form a compound. The compounds are then mixed to form a substantially homogeneous mixture. However, in other aspects, the mixture is homogeneous. In a further aspect, the mixture is extruded to form an elongated tube having a first polymer layer. The first polymer layer formed can include any (and any combination of) the compositions and features disclosed above.

In a further aspect, the method further comprises the step of forming an elongate tube comprising two or more layers, as disclosed above. In such aspects, for example, when the elongate tube includes any of the first and second polymer layers disclosed above, the layers can be co-extruded to form the disclosed elongate tube. Any extrusion device known in the art may be used to obtain any desired elongated tube.

Also disclosed herein are methods of bonding an outer layer and an inner liner when desired. It should be appreciated that any method known in the art may be used to form the bond. In certain aspects, heat treatment may be utilized. For example, the sheath may be inserted into the heat shrink tube and heated together to a temperature that allows at least partial bonding between the inner liner and the outer layer.

Some additional exemplary aspects may include laser welding, compression head welding, or ultrasonic welding, as shown in fig. 28A-C.

In other aspects, laser welding may be utilized. In such aspects, the liner may be formed by any of the methods disclosed above. An outer layer comprising any of the above disclosed compositions and formed by any of the above disclosed methods is then disposed over the liner to form a sheath. It should also be appreciated that any of the layers disclosed above may also be present between the liner and the outer surface. The sheath is then positioned over the mandrel configured to rotate. Laser welding uses a focused laser to heat a part in a selected location. The mandrel is aligned with a laser beam configured to move a predetermined distance along the longitudinal axis of the sheath under conditions effective to form a bond (fig. 28A). In such aspects, the head of the laser bonder is positioned directly above the center of the sheath, and the sheath may be rotated to align the laser with any desired point on the sheath diameter. The laser bonder is then moved horizontally across the sheath.

The bond may be formed between at least a portion of the outermost surface of the liner and at least a portion of the innermost surface of the outer layer at a predetermined portion of the sheath. However, it should be understood that the predetermined locations where the bond is formed are substantially free of lubricant and/or tie layers, although other additional layers, such as lubricant or tie layers, may be present.

It should be appreciated that the settings of the laser welder may be changed to optimize the heating level and bonding area on the device. The laser power in watts changes the heat imparted to the sheath, while the feed rate adjusts the length of time the laser is focused on a given portion of the sheath. The focal position, weld initiation angle, and weld distance can be used to control the area of the laser, which can be fine tuned to form a bond of appropriate size.

It will be appreciated that the settings of the laser welder may be varied in terms of watts to vary the heat imparted to the sheath, while the feed rate adjusts the length of time that the laser is focused on a given portion of the sheath. The focal position, weld initiation angle, and weld distance can be used to control the area of the laser, which can be fine tuned to form a bond of appropriate size. Additional methods of forming the bond are also disclosed herein. For example, a compression head bonder is used (fig. 28B). In such methods, the inner and outer layers are formed by any of the methods disclosed above and assembled to form the sheath. The sheath is then positioned over the mandrel into a radial compression head bonder.

Any compression head bonder known in the art may be used. In certain aspects, the compression head bonder may include a collapsible aperture configured to compress the sheath to a predetermined diameter. The radial compression head bonder includes a plurality of dies, wherein at least one of the plurality of dies is heatable to form a bond at the distal forward portion of the sheath.

An exemplary and non-limiting bonder, as shown in fig. 28B, may include, for example, a total of nine separate dies, such as eight dies and one metal die made of PEEK plastic. The metal mold may be heated prior to use. The machine brings the jaws of the aperture together to a smaller diameter and then compresses around the device inserted through the block. The heated mold will then melt the portion of the insert member in contact therewith. For use with an expandable sheath, a mandrel is inserted into the lumen of the device to prevent the sheath shaft from being compressed under the load of the bonder. In certain aspects, fluorinated ethylene propylene may be placed over the desired bond area of the sheath to uniformly transfer heat, thereby preventing the metal from directly burning the outer layer. The sheath may be supported in the machine using separate channels on the sides. In certain aspects, the width of the bonding mold may be less than the length of the sheath, so to lengthen the bonding region, the sheath may be moved horizontally after each run, and the bonding may be repeated along the sheath for a desired length.

It should be understood that the particular bond and its location may be controlled as desired. For example, the temperature of the metal mold may be determined to ensure that it is set to a temperature effective to at least partially melt both the outer layer and the liner component. In a further aspect, the compressive force applied to the part may also be adjusted such that at least partial melting is achieved without any substantial damage to the remaining components of the sheath. The final diameter reached by the pores upon bonding may also be predetermined. It will be appreciated that the larger the diameter, the more exposed the metal mold to the part and the larger the bond area available. In addition, the length of time the mold is compressed onto the sheath can also affect the degree of melting and strength of the bond of the components.

In further aspects, the method may include ultrasonic welding. In such aspects, the sheath component to be bonded is placed on a welder and then a load is applied from a movable horn. The horn is moved at an extremely fast rate so that a large amount of vibration energy is applied. This energy is absorbed by the material, which can be melted at predetermined locations. The melted materials may flow together to achieve a bond upon cooling. In some aspects, ultrasonic welding may be used prior to forming the fully assembled sheath. For example, in such aspects, ultrasonic welding may be used to bond any desired part in any step of manufacture.

Methods of making a sheath including the reinforcing sheath are also disclosed. In such methods, sheath components, such as inner and outer liners, are formed by any of the methods disclosed above and assembled together to form the sheath. Then, a reinforcing sheath having a proximal end and a distal end is provided so that it covers at least a portion of the outer layer. The method further includes substantially seamlessly bonding the distal end of the reinforcement sheath to at least a portion of the outer layer. It should be appreciated that any of the bonding methods disclosed above or generally known in the art may be used.

The reinforcement sheath may comprise any of the above-disclosed components, wherein the reinforcement sheath comprises any of the above-disclosed elastomers and any of the above-disclosed reinforcement elements.

In further aspects, the reinforcement sheath may be formed by any method known in the art. For example, the reinforcing sheath may be formed by injection molding, extrusion, or a reflow process. In further aspects, any of the reinforcement members disclosed herein can be embedded in a soft polymer to form a reinforcement sheath. For example, but not limited to, during the reflow process, the reinforcing elements may be disposed over the polymer layer and exposed to heat so that the reinforcing elements and the polymer may fuse together. In other exemplary aspects, the reinforcement sheath may be formed by injection molding. In such aspects, the reinforcing element may be positioned within the mold and the polymer injected over the reinforcing element. However, in other exemplary and non-limiting aspects, the reinforcing sheath may be formed by an extrusion process. In such exemplary aspects, the heated polymer may be extruded into a tube as the reinforcing elements are fed in parallel to allow the polymer and reinforcing elements to be combined.

There are also methods of manufacturing a sheath comprising a bulge guard. In such methods, sheath components, such as inner and outer liners, are formed by any of the methods disclosed above and assembled together to form the sheath. Then, a bulge guard having a proximal end and a distal end is disposed such that it covers at least a portion of the outer layer, and wherein the bulge guard is configured to remain outside the subject's vessel and maintain a hemostatic effect. The method further connects a proximal end of the bulge guard to a proximal-most portion of the outer layer and/or a hub of the sheath, wherein a distal end of the bulge guard radially circumscribes at least a portion of the outer layer, and wherein the distal end is not bonded to the outer layer. As described herein, the ballooning shield is configured to adjust the length of the shield according to the depth of insertion of the inner and outer layers of the sheath into the subject's vessel.

In further aspects, the methods disclosed herein can include the step of disposing a hydrophilic coating on the outer surface of the elastomeric polymer layer. Any of the hydrophilic coatings disclosed herein may be used.

The sheath of the present disclosure may be used with various methods of introducing a prosthetic device into the vasculature of a patient. One such method includes positioning an expandable sheath in a patient's vessel, passing the device through an introducer sheath, which expands the sheath around a portion of the device and conforms to the contours of the device, and automatically retracting the expanded portion of the sheath to its original size after the device has passed through the expanded portion. In some methods, the expandable sheath may be sutured to the patient's skin at the insertion site such that once the sheath is inserted a suitable distance within the patient's vasculature, the sheath does not move once the implantable device begins to pass through the sheath.

The disclosed aspects of the expandable sheath may be used with other delivery and minimally invasive surgical components, such as introducers and loaders. The introducer may be inserted into the expandable sheath and the introducer/sheath combination may be fully inserted into the vasculature through a guide device (e.g., a 0.35 "guidewire). In some aspects, once the sheath and introducer are fully inserted into the vasculature of the patient, the expandable sheath may be sutured in place at the insertion site. In this way, the expandable sheath, once positioned within the patient, may be substantially prevented from moving.

The introducer may then be removed and, in some cases, a medical device, such as a transcatheter heart valve, may be inserted into the sheath using the loader. The method may further include placing a tissue heart valve in a crimped state on a distal end portion of the elongate delivery apparatus and inserting an elongate delivery device with the crimped valve through the expandable sheath. Next, the delivery device may be advanced through the patient's vasculature to the treatment site, where the valve may be implanted.

Typically, the outer diameter of the medical device is greater than the diameter of the sheath in its original configuration. The medical device may be advanced through an expandable sheath to the implantation site, and the expandable sheath may be partially expanded to accommodate the medical device as the device is passed. The radial force applied by the medical device is sufficient to locally expand the sheath to an expanded diameter (e.g., an expanded configuration) just in the area where the medical device is currently located. Once the medical device passes a particular location of the sheath, the sheath may at least partially collapse to a smaller diameter of its original configuration. Thus, the expandable sheath can be expanded without the use of an expandable balloon or other dilator. Once the medical device is implanted, the sheath and any sutures holding the sheath in place may be removed. In some exemplary aspects, the sheath is removed without rotating the sheath.

Example

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and evaluate the compounds, compositions, articles, devices, and/or methods claimed herein, and are intended to be purely by way of example and not intended to limit the disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for.

Unless otherwise indicated, parts are parts by weight, temperature is in degrees celsius or at ambient temperature, and pressure is at or near atmospheric or full vacuum.

Fig. 16 depicts exemplary experimental data for insertion force measurements required to insert a medical device into one of the sheaths 3 disclosed herein, as compared to commercially available sheaths 1 and 2. The force is measured using a typical delivery system on a Zwick thrust tester. It can be seen that the required insertion force measured in the tapered section of the sheath is lower than that required for commercially available sheaths 1 and 2. Similarly, the insertion force measured in the shrinkage body peak shows better results for the disclosed sheath 3 than for commercially available sheaths 1 and 2.

Fig. 17 depicts experimental data for an extensional measured load according to sheath 3 and one of the commercially available sheaths 1 and 2 disclosed herein. It can be seen that the disclosed sheath exhibits comparable results to clinically acceptable commercially available sheaths.

In view of the methods and compositions described, certain more specifically described aspects of the present disclosure are described below. However, these specifically recited aspects should not be construed as limiting any of the different claims, which contain different or more general teachings described herein, or the "specific" aspects are limited in some way, rather than by the inherent meaning of the literal language and formulas.

Exemplary aspects:

example 1: a sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end, and comprises: a tubular liner having a longitudinal slit extending along a length of the tubular liner such that the tubular liner is wound in a helical reel configuration; wherein the longitudinal slit forms a first longitudinal edge and a second longitudinal edge of the tubular liner; wherein in the spiral reel configuration, at least a portion of an inner surface of the liner helically covers at least a portion of an outer surface of the liner, and wherein the first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner; wherein the inner surface of the tubular liner defines a lumen of the sheath; and wherein the tubular liner is configured to facilitate insertion of a medical device through the lumen of the liner by sliding the first edge of the liner in a helical pattern along at least a portion of the inner surface and causing the liner to move in a helical pattern during application of a radially outward force through the lumen of the liner The second edge slides in a spiral along at least a portion of the outer surface of the liner from a resting diameter d _r Expanded to an expanded diameter d _e 。

Example 2: the sheath of any of the examples herein, particularly the sheath of example 1, wherein the tubular liner is configured to expand without substantially forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

Example 3: a sheath according to any of the examples herein, particularly the sheath according to example 1 or 2, wherein the tubular liner is configured to bend when passing through a natural anatomy of a patient without forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

Example 4: a sheath according to any of the examples herein, particularly according to examples 1-3, wherein the longitudinal slit extends from a proximal end of the tubular liner to a distal end of the tubular liner in a direction offset from a longitudinal axis of the tubular liner.

Example 5: the sheath of any example herein, particularly the sheath of example 4, wherein the direction is diagonal from the proximal end of the tubular liner to the distal end of the tubular liner.

Example 6: the sheath of any of the examples herein, particularly the sheath of examples 4-5, wherein the longitudinal slit extends from the proximal end of the tubular liner to the distal end of the tubular liner at an angle of greater than about 90 degrees or less than about 90 degrees across a length of the tubular liner.

Example 7: a sheath according to any of the examples herein, particularly according to examples 1-3, wherein the longitudinal slit is formed between a proximal end of the tubular liner and a distal end of the tubular liner in a pattern other than a straight line.

Example 8: a sheath according to any of the examples herein, in particular the sheath according to examples 1 to 7, wherein the helical configuration has a predetermined pitch.

Example 9: a sheath according to any of the examples herein, particularly according to example 8, wherein the pitch is at least 4 turns per 10cm on the sheath.

Example 10: a sheath according to any of examples herein, in particular according to examples 1 to 9, wherein the resting diameter d _r Is substantially uniform along a longitudinal axis of the lumen.

Example 11: a sheath according to any of the examples herein, in particular according to examples 1 to 10, wherein the resting diameter d _r Along the longitudinal axis of the lumen, and wherein the resting diameter d at the proximal end _r Greater than the resting diameter d at the distal end _r 。

Example 12: a sheath according to any of examples herein, in particular according to examples 1 to 11, wherein the expanded diameter d _e Is configured to receive the medical device through the lumen while maintaining the helical configuration of the tubular liner.

Example 13: a sheath according to any of examples herein, particularly according to examples 1-12, wherein the sheath contracts to substantially equal the resting diameter d after the medical device passes through the lumen _r While maintaining the helical configuration of the tubular liner.

Example 14: the sheath of any of the examples herein, particularly the sheath of examples 1-13, wherein the tubular liner comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.

Example 15: the sheath of any of the examples herein, particularly the sheath of example 14, wherein the tubular liner has a multi-layer structure.

Example 16: a sheath according to any of the examples herein, particularly according to examples 1-15, wherein the inner surface of the tubular liner is at least partially ribbed.

Example 17: the sheath of any of the examples herein, particularly the sheath of examples 1-16, wherein the tubular liner is smooth and has a coefficient of friction of less than about 0.5.

Example 18: a sheath according to any of the examples herein, particularly the sheath according to examples 1-17, wherein the sheath further comprises an outer layer.

Example 19: the sheath of any of the examples herein, particularly the sheath of example 18, wherein the outer layer comprises polyether block amide, styrene-based elastomer, polyurethane, latex, copolymers thereof, blends thereof, or extrudates thereof.

Example 20: the sheath of any of the examples herein, particularly the sheath of example 19, wherein the outer layer comprises one or more layers.

Example 21: the sheath of any of the examples herein, particularly the sheath of example 20, wherein at least one layer comprises the polyether block amide.

Example 22: the sheath of any of the examples herein, particularly the sheath of example 21, wherein at least one layer comprises the styrene-based elastomer.

Example 23: a sheath according to any of examples herein, particularly the sheath according to examples 20-22, wherein at least one layer comprises polyurethane.

Example 24: the sheath of any of the examples herein, particularly the sheath of examples 22 or 23, wherein at least one layer comprises a blend of the styrene-based elastomer and polyurethane.

Example 25: the sheath of any of the examples herein, particularly the sheath of examples 22-24, wherein the styrene-based elastomer has a shore a hardness of between 20A and 50A.

Example 26: a sheath according to any of examples herein, particularly according to examples 18-20, wherein the outer layer comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt% to less than 100 wt% of a first polymer comprising a polyether block amide, polyurethane, or combination thereof, based on the total weight of the first compound composition; less than about 65% inorganic filler, based on the total weight of the first compound composition; and up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition; wherein the sheath exhibits at least a 10% reduction in insertion force as compared to a substantially identical reference sheath that does not include the first polymer layer; and wherein the outer layer is substantially kink resistant.

Example 27: the sheath of any of the examples herein, particularly the sheath of example 26, wherein the first polymer has a hardness at the proximal end of the outer layer that is different than the hardness of the first polymer at the distal end of the outer layer, and has a shore D of about 20D to about 35D.

Example 28: the sheath of any of the examples herein, particularly the sheath of examples 26-27, wherein the first polymer comprises a polyether block amide elastomer.

Example 29: a sheath according to any of examples herein, particularly according to examples 26-27, wherein the first polymer comprises polyurethane.

Example 30: the sheath of any of the examples herein, particularly the sheath of examples 26-29, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin, limestone, or any combination thereof, and is present in an amount of at least about 10% based on the total weight of the first compound composition.

Example 31: the sheath of any of the examples herein, particularly the sheath of examples 26-30, wherein the inorganic filler is present in an amount of less than about 50% based on the total weight of the first compound composition.

Example 32: the sheath of any of the examples herein, particularly the sheath of examples 26-31, wherein the solid lubricant comprises PTFE filler.

Example 33: the sheath of any of the examples herein, particularly the sheath of examples 26-32, wherein the first compound composition further comprises at least one viscosity-reducing compound present in an amount of about 1% to about 20% based on the total weight of the first compound composition.

Example 34: a sheath according to any of examples herein, particularly according to examples 26-33, wherein the outer layer comprises two or more polymer layers.

Example 35: a sheath according to any of the examples herein, particularly the sheath according to example 34, wherein the outer layer comprises at least a second polymer layer comprising a second compound composition comprising greater than 0 wt% to 100 wt% of a second polymer comprising polyether block amide, polyurethane, or a combination thereof; and wherein the second polymer has a shore a hardness of about 20A to about 65A.

Example 36: the sheath of any of the examples herein, particularly the sheath of example 35, wherein the second compound composition further comprises up to 20% of a viscosity-reducing additive based on the total weight of the second compound composition.

Example 37: the sheath of any of examples herein, particularly the sheath of examples 35-36, wherein the second polymer comprises polyurethane.

Example 38: a sheath according to any of the examples herein, particularly the sheath according to examples 35-37, wherein the outer layer has a predetermined thickness, and wherein at least about 50% of the predetermined thickness comprises the first compound composition and/or the second compound composition.

Example 39: a sheath according to any of examples herein, particularly the sheath of examples 35-38, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.

Example 40: a sheath according to any of the examples herein, particularly the sheath according to example 39, wherein the one or more additional polymer layers comprise at least one intermediate reinforcing layer extending axially at least a portion of the length of the outer layer.

Example 41: the sheath of any of the examples herein, particularly the sheath of example 40, wherein the at least one intermediate reinforcing layer comprises the first polymer, the second polymer, a polyolefin-based polymer, or a combination thereof.

Example 42: a sheath according to any of the examples herein, particularly a sheath according to example 40 or 41, wherein the at least one intermediate reinforcing layer comprises a material having a shore D hardness of about 45D to about 76D.

Example 43: the sheath of any of the examples herein, particularly the sheath of examples 40-42, wherein the at least one intermediate reinforcing layer is configured to be thermally bonded to the first polymer layer, the second polymer layer, or a combination thereof.

Example 44: a sheath according to any of the examples herein, particularly according to examples 18-43, wherein the sheath further comprises a braid disposed between the tubular inner layer and the outer layer.

Example 45: the sheath of any of the examples herein, particularly the sheath of example 44, wherein the braid is at least partially embedded within the outer layer.

Example 46: a sheath according to any of examples herein, particularly according to examples 18-45, wherein the sheath comprises a lubricant disposed at least partially between the tubular inner liner and the outer layer.

Example 47: a method of manufacturing a sheath having a proximal end and a distal end, the method comprising: the tubular liner is formed by: i) By being offset between the proximal and distal ends of the elongate single lumen tubeMoving the longitudinal axis of the elongate single lumen tube in a direction to cut the circumference of the elongate single lumen tube to form a first longitudinal edge and a second longitudinal edge to form a longitudinal slit; ii) winding the elongated single lumen tube having the longitudinal slit into a tubular liner having a helical spool configuration such that at least a portion of an inner surface of the liner helically covers at least a portion of an outer surface of the liner, and wherein the first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner, wherein an inner surface of the tubular liner defines a lumen of the sheath; and wherein the tubular liner is configured to move from a resting diameter d during application of a radially outward force by a medical device through the lumen of the liner by sliding the first edge of the liner in a spiral along at least a portion of the inner surface and sliding the second edge of the liner in a spiral along at least a portion of the outer surface of the liner _r Expanded to an expanded diameter d _e 。

Example 48: a method according to any of the examples herein, particularly according to example 47, wherein the winding step comprises positioning the elongated single lumen tube having the longitudinal slit over a mandrel having a predetermined diameter to form the helical configuration, wherein the predetermined diameter of the mandrel and a resting d of the liner _r Substantially the same.

Example 49: the method of any example herein, particularly according to example 47 or 48, wherein the formed tubular liner is configured to expand without substantially forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

Example 50: the method according to any of examples herein, particularly examples 47-49, wherein the formed tubular liner is configured to bend when passing through the natural anatomy of the patient without forming a gap between the first longitudinal edge and the second longitudinal edge of the tubular liner.

Example 51: the method of any example herein, particularly examples 47-50, wherein the offset direction is diagonal to a direction from the proximal end of the tubular liner to the distal end of the tubular liner.

Example 52: the method of any example herein, particularly according to examples 47-51, wherein the longitudinal slit extends from the proximal end of the tubular liner to the distal end of the tubular liner at an angle of greater than about 90 degrees or less than about 90 degrees across a length of the tubular liner.

Example 53: the method according to any of the examples herein, particularly according to examples 47-50, wherein the longitudinal slit is formed in a pattern other than a straight line between a proximal end of the tubular liner and a distal end of the tubular liner.

Example 54: the method according to any of the examples herein, in particular according to examples 47 to 53, wherein the spiral configuration has a predetermined pitch.

Example 55: the method of any example herein, particularly example 54, wherein the pitch is at least 4 turns per 10cm on the sheath.

Example 56: the method of any one of claims 47 to 55, wherein the resting diameter d _r Is substantially uniform along a longitudinal axis of the lumen.

Example 57: the method according to any of the examples herein, in particular according to examples 47 to 56, wherein the resting diameter d _r Along the longitudinal axis of the lumen, and wherein the resting diameter d at the proximal end _r Greater than the resting diameter d at the distal end _r 。

Example 58: the method according to any of the examples herein, in particular according to examples 47 to 57, wherein the expanded diameter d _e Configured to receive the medical device through the lumenWhile maintaining the helical configuration of the tubular liner.

Example 59: the method of any example herein, particularly the method of examples 47-58, wherein after the medical device passes through the lumen, the sheath is contracted to be substantially equal to the resting diameter d _r While maintaining the helical configuration of the tubular liner.

Example 60: the method according to any of examples herein, particularly examples 47-59, wherein the tubular liner comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.

Example 61: the method according to any of the examples herein, particularly according to example 60, wherein the tubular liner has a multi-layer structure.

Example 62: the method according to any of the examples herein, particularly according to examples 47-61, wherein the inner surface of the tubular liner is at least partially ribbed.

Example 63: the method of any example herein, particularly the method of examples 47-62, wherein the tubular liner is lubricated and has a coefficient of friction of less than about 0.5.

Example 64: the method of any example herein, particularly examples 47-63, further comprising disposing an outer layer over at least a portion of an outer surface of the liner.

Example 65: the method of any example herein, particularly the method of example 64, wherein the outer layer comprises a polyether block amide, a styrene-based elastomer, a polyurethane, a latex, a copolymer thereof, a blend thereof, or an extrudate thereof.

Example 66: the method of any example herein, particularly example 65, wherein the outer layer comprises one or more layers.

Example 67: the method according to any of the examples herein, particularly the method according to example 66, wherein at least one layer comprises the polyether block amide.

Example 68: the method of any example herein, particularly example 67, wherein at least one layer comprises the styrene-based elastomer.

Example 69: the method according to any of the examples herein, particularly the method according to examples 66-68, wherein at least one layer comprises polyurethane.

Example 70: the method of any of the examples herein, particularly the method of example 68 or 69, wherein at least one layer comprises a blend of the styrene-based elastomer and polyurethane.

Example 71: the method according to any of the examples herein, particularly according to examples 68 to 70, wherein the styrene-based elastomer has a shore a hardness of between 20A and 50A.

Example 72: the method according to any of examples herein, particularly examples 64-66, wherein the outer layer comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising: from greater than 0 wt% to less than 100 wt% of a first polymer comprising a polyether block amide, polyurethane, or combination thereof, based on the total weight of the first compound composition; less than about 65% inorganic filler, based on the total weight of the first compound composition; and up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition; wherein the sheath exhibits at least a 10% reduction in insertion force as compared to a substantially identical reference sheath that does not include the first polymer layer; and wherein the outer layer is substantially kink resistant.

Example 73: the method of any example herein, particularly example 72, wherein the first polymer has a hardness at the proximal end of the outer layer that is different from the hardness of the first polymer at the distal end of the outer layer and has a shore D of about 20D to about 35D.

Example 74: the method according to any of examples herein, particularly examples 72 to 73, wherein the first polymer comprises a polyether block amide elastomer.

Example 75: the method according to any of the examples herein, particularly the method according to examples 72-74, wherein the first polymer comprises polyurethane.

Example 76: the method of any of the examples herein, particularly the method of examples 72-75, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin, limestone, or any combination thereof, and is present in an amount of at least about 10% based on the total weight of the first compound composition.

Example 77: the method according to any of the examples herein, particularly examples 72-76, wherein the inorganic filler is present in an amount of less than about 50% based on the total weight of the first compound composition.

Example 78: the method according to any of the examples herein, particularly the method according to examples 72 to 77, wherein the solid lubricant comprises PTFE filler.

Example 79: the method according to any of the examples herein, particularly the method according to examples 72-78, wherein the first compound composition further comprises at least one viscosity-reducing compound present in an amount of about 1% to about 20% based on the total weight of the first compound composition.

Example 80: the method according to any of examples herein, particularly examples 72 to 79, wherein the outer layer comprises two or more polymer layers.

Example 81: the method of any example herein, particularly according to example 80, wherein the outer layer comprises at least a second polymer layer comprising a second compound composition comprising greater than 0 wt% to 100 wt% of a second polymer comprising a polyether block amide, polyurethane, or combination thereof; and wherein the second polymer has a shore a hardness of about 20A to about 65A.

Example 82: the method of any of the examples herein, particularly the method of example 81, wherein the second compound composition further comprises up to 20% of a viscosity-reducing additive based on the total weight of the second compound composition.

Example 83: the method according to any of examples herein, particularly examples 81 to 82, wherein the second polymer comprises polyurethane.

Example 84: the method according to any of the examples herein, particularly the method according to examples 81-83, wherein the outer layer has a predetermined thickness, and wherein at least about 50% of the predetermined thickness comprises the first compound composition and/or the second compound composition.

Example 85: the method of any example herein, particularly the method of examples 81-84, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.

Example 86: the method of any example herein, particularly example 85, wherein the one or more additional polymer layers comprise at least one intermediate reinforcing layer extending axially at least a portion of the length of the outer layer.

Example 87: the method of any of the examples herein, particularly example 86, wherein the at least one intermediate reinforcing layer comprises the first polymer, the second polymer, a polyolefin-based polymer, or a combination thereof.

Example 88: the method of any example herein, particularly according to examples 86 or 87, wherein the at least one intermediate reinforcing layer comprises a material having a shore D hardness of about 45D to about 76D.

Example 89: the method of any of the examples herein, particularly the method of examples 86-88, wherein the at least one intermediate reinforcing layer is configured to be thermally bonded to the first polymer layer, the second polymer layer, or a combination thereof.

Example 90: the method of any example herein, particularly examples 64-89, further comprising disposing a braid at least a portion of the outer surface of the tubular inner layer prior to disposing the outer layer.

Example 91: the method of any example herein, particularly example 90, further comprising disposing the outer layer over the braid and at least partially embedding the braid within the outer layer.

Example 92: a method according to any of the examples herein, particularly according to examples 64-90, wherein the method comprises disposing a lubricant on at least a portion of the outer surface of the liner prior to disposing the outer layer.

Example 93: a method according to any of the examples herein, particularly according to examples 90-92, wherein the method comprises disposing a lubricant on at least a portion of the outer surface of the liner prior to disposing the braid or after disposing the braid.

Example 94: a method of delivering a prosthetic device to a surgical site, the method comprising at least partially inserting an expandable sheath into the vasculature of the patient, the expandable sheath being an expandable sheath according to any of the examples herein, particularly the expandable sheath according to examples 1-46; the tubular liner is partially expanded by sliding the first longitudinal edge and the second longitudinal edge during passage of the prosthetic device, and the sheath is partially collapsed from a partially expanded state to an unexpanded state after passage of the prosthetic device.

Example 95: the method of any example herein, particularly example 94, wherein substantially no gap is formed between the first longitudinal edge and the second longitudinal edge during the step of locally expanding the tubular liner.

Example 96: a method of delivering a prosthetic device according to any example herein, particularly the method of delivering a prosthetic device according to examples 94-95, wherein advancing the prosthetic device comprises advancing a prosthetic heart valve through an inner lumen of the inner liner of the sheath.

Example 97: the method of delivering a prosthetic device according to any example herein, particularly the method of delivering a prosthetic device according to example 96, further comprising introducing the prosthetic heart valve to the surgical site, and expanding the prosthetic heart valve within the surgical site.

Claims

1. A sheath for delivering a medical device, wherein the sheath has a proximal end and a distal end, and comprises:

a tubular liner having a longitudinal slit extending along a length of the tubular liner such that the tubular liner is wound in a helical reel configuration;

Wherein the longitudinal slit forms a first longitudinal edge and a second longitudinal edge of the tubular liner;

wherein in the spiral reel configuration, at least a portion of an inner surface of the liner helically covers at least a portion of an outer surface of the liner, and wherein the first longitudinal edge of the liner is slidable along at least a portion of the inner surface of the liner and the second longitudinal edge is slidable along at least a portion of the outer surface of the liner;

wherein the inner surface of the tubular liner defines a lumen of the sheath; and is also provided with

Wherein the tubular liner is configured to move from a resting diameter d during application of a radially outward force by a medical device through the lumen of the liner by sliding the first edge of the liner in a helical pattern along at least a portion of the inner surface and sliding the second edge of the liner in a helical pattern along at least a portion of the outer surface of the liner _r Is expanded to a straightDiameter d _e 。

2. The sheath of claim 1, wherein the tubular liner is configured to expand without substantially forming a gap between the first and second longitudinal edges of the tubular liner.

3. The sheath of claim 1 or 2, wherein the tubular liner is configured to bend as it passes through the natural anatomy of a patient without forming a gap between the first and second longitudinal edges of the tubular liner.

4. A sheath according to any one of claims 1 to 3 wherein the longitudinal slit extends from a proximal end of the tubular liner to a distal end of the tubular liner in a direction offset from a longitudinal axis of the tubular liner.

5. The sheath of claim 4, wherein the direction is diagonal from a direction from the proximal end of the tubular liner to the distal end of the tubular liner.

6. The sheath of any one of claims 4-5, wherein the longitudinal slit extends from the proximal end of the tubular liner to the distal end of the tubular liner at an angle of greater than about 90 degrees or less than about 90 degrees across a length of the tubular liner.

7. A sheath according to any one of claims 1 to 3 wherein the longitudinal slits are formed in a pattern other than a straight line between the proximal end of the tubular liner and the distal end of the tubular liner.

8. The sheath of any one of claims 1-7, wherein the helical configuration has a predetermined pitch.

9. The sheath of claim 8, wherein the pitch is at least 4 turns per 10cm on the sheath.

10. The sheath of any one of claims 1 to 9, wherein the tubular liner comprises high density polyethylene, polypropylene, polyamide, fluoropolymer, copolymers thereof, or blends thereof.

11. The sheath of any one of claims 1 to 10, wherein the inner surface of the tubular liner is at least partially ribbed.

12. The sheath of any one of claims 1 to 11, wherein the tubular liner is smooth and has a coefficient of friction of less than about 0.5.

13. The sheath of any one of claims 1 to 12, wherein the sheath further comprises an outer layer.

14. The sheath of claim 13, wherein the outer layer comprises polyether block amide, styrene-based elastomer, polyurethane, latex, copolymers thereof, blends thereof, or extrudates thereof.

15. The sheath of claim 14, wherein the outer layer comprises one or more layers.

16. The sheath of claim 15, wherein at least one layer comprises the polyether block amide.

17. The sheath of claim 16, wherein at least one layer comprises the styrene-based elastomer.

18. The sheath of any one of claims 15 to 17, wherein at least one layer comprises polyurethane.

19. The sheath of claim 17 or 18, wherein at least one layer comprises a blend of the styrene-based elastomer and polyurethane.

20. The sheath of any one of claims 13 to 15, wherein the outer layer comprises a first polymer layer, wherein the first polymer layer comprises a first compound composition comprising

From greater than 0 wt% to less than 100 wt% of a first polymer comprising a polyether block amide, polyurethane, or combination thereof, based on the total weight of the first compound composition;

less than about 65% inorganic filler, based on the total weight of the first compound composition; and

up to about 20% of a solid lubricant filler, based on the total weight of the first compound composition;

wherein the sheath exhibits at least a 10% reduction in insertion force as compared to a substantially identical reference sheath that does not include the first polymer layer; and wherein the outer layer is substantially kink resistant.

21. The sheath of claim 20, wherein the first polymer comprises a polyether block amide elastomer or polyurethane.

22. The sheath of any one of claims 20 to 21, wherein the inorganic filler comprises bismuth oxychloride, barium sulfate, bismuth subcarbonate, calcium carbonate, aluminum trihydrate, barite, kaolin, limestone, or any combination thereof, and the inorganic filler is present in an amount of at least about 10% based on the total weight of the first compound composition.

23. The sheath of any one of claims 20 to 22, wherein the solid lubricant comprises PTFE filler.

24. The sheath of any one of claims 20 to 23, wherein the first compound composition further comprises at least one viscosity-reducing compound present in an amount of about 1% to about 20% based on the total weight of the first compound composition.

25. The sheath of any one of claims 20 to 24, wherein the outer layer comprises two or more polymer layers.

26. The sheath of claim 25, wherein the outer layer comprises at least a second polymer layer comprising a second compound composition comprising greater than 0 wt% to 100 wt% of a second polymer comprising polyether block amide, polyurethane, or a combination thereof; and wherein the second polymer has a shore a hardness of about 20A to about 65A.

27. The sheath of claim 26, wherein the second compound composition further comprises up to 20% of a viscosity-reducing additive based on the total weight of the second compound composition.

28. The sheath of any one of claims 26 to 27, wherein the second polymer comprises polyurethane.

29. The sheath of any one of claims 26 to 28, wherein the outer layer has a predetermined thickness, and wherein at least about 50% of the predetermined thickness comprises the first compound composition and/or the second compound composition.

30. The sheath of any one of claims 26-29, wherein one or more additional polymer layers are disposed between the first polymer layer and the second polymer layer.

31. The sheath of claim 30, wherein the one or more additional polymer layers comprise at least one intermediate reinforcing layer extending axially at least a portion of the length of the outer layer.

32. The sheath of claim 31, wherein the at least one intermediate reinforcing layer comprises the first polymer, the second polymer, a polyolefin-based polymer, or a combination thereof.

33. The sheath of any one of claims 31-32, wherein the at least one intermediate reinforcing layer is configured to be thermally bonded with the first polymer layer, the second polymer layer, or a combination thereof.

34. The sheath of any one of claims 13-33, wherein the sheath further comprises a braid disposed between the tubular inner layer and the outer layer.

35. The sheath of claim 34, wherein the braid is at least partially embedded within the outer layer.

36. The sheath of any one of claims 13-35, wherein the sheath comprises a lubricant disposed at least partially between the tubular inner liner and the outer layer.