JP2004513703A - Hybrid sleeve materials and configurations - Google Patents

Abstract

The present invention relates to a stent delivery system including a catheter having a stent mounting area. The stent is disposed about the stent mounting area of the catheter, has a distal end and a proximal end, and has an unexpanded state and an expanded state. The at least one stent retaining sleeve has a first end overlapping the end of the stent when the stent is in an unexpanded state and a second end engaging at least a portion of the catheter adjacent the stent mounting area. The outer surface of the stent retaining sleeve comprises a first material and at least a portion of the first end of the inner surface comprises a second material. The first material has a first predetermined hardness, and the second material has a second predetermined hardness. The second predetermined hardness has a durometer value higher than the first predetermined hardness.

Description

[0001]
(Background of the Invention)
The present invention relates generally to medical catheter delivery devices, and more particularly to balloon catheters used to deliver medical devices, such as stents, to required locations in the body, such as in blood vessels. More particularly, the present invention relates to socks or sleeves used in holding the stent in an unexpanded state to reduce frictional contact with the end of the stent and / or balloon cone. In the present invention, such reduced frictional contact is possible by providing a sleeve characterized in that at least a part of the inner surface is harder than the outer surface.
[0002]
(Related documents)
Stents and stent delivery assemblies are utilized in many medical procedures and settings, and the construction and function of stents and stent delivery assemblies are well known. A stent is a generally cylindrical prosthesis, typically introduced in a reduced diameter via a catheter into the lumen of a vessel in the body and then expanded to the size of the vessel. Is done. In this expanded state, the stent supports and reinforces the vessel wall while opening and maintaining the vessel unobstructed.
[0003]
Both self-expanding and expandable expandable stents are well known and are widely available in various designs and configurations. The self-expanding stent needs to be held under external positive pressure to maintain a reduced diameter while being delivered to the site to be deployed. The inflatable expandable stent is crimped to a reduced diameter around the delivery catheter, manipulated to the site to be deployed, and reduced in size to the diameter of the vessel by fluid expansion of the balloon placed on the delivery catheter. The diameter is expanded. The present invention relates specifically to the delivery and placement of expandable expandable stents, but is generally applicable to self-expanding stents when used with balloon catheters.
[0004]
There are many important points to consider when advancing an expandable expandable stent through a body vessel. The stent must ensure that it maintains its axial position on the delivery catheter without moving proximally or distally, particularly without being separated from the catheter. Stents need to be particularly protected at their distal and proximal ends to prevent stent distortion, reduce wear, and / or reduce trauma to the vessel wall.
[0005]
Inflatable expandable stent delivery and deployment assemblies are well known and utilize prevention means to rest on the stent during delivery. U.S. Pat. No. 4,950,227 to Savin et al. Relates to an inflatable expandable stent delivery system. In this stent delivery system, the sleeve covers the distal or proximal edge (or both) of the stent during delivery. The patent discloses a stent delivery system in which a catheter carries the stent to its distal end, the stent being held in place around the catheter before and during percutaneous delivery by one sleeve, and preferably two sleeves. Have been. The sleeve is positioned on the circumference of the catheter with one of the ends attached to the catheter and overlaps the end (s) of the stent to hold the stent in place in a contracted position on the catheter. Each sleeve is elastomeric in nature to stretch and release the stent as it expands for implantation. The stent can be expanded by the expandable balloon of the catheter. While expanding at the site where the stent is to be deployed, the stent edge is released from the protective sleeve. U.S. Pat. No. 5,403,341 to Solar et al. Relates to a stent delivery and deployment assembly. This assembly uses retention sheaths located on the periphery of the ends of the compressed stent. The solar retaining sheath tears under pressure as the stent is radially expanded, releasing the stent from engagement with the sheath. U.S. Pat. No. 5,108,416 to Ryan et al. Discloses a stent delivery system. The stent introduction system uses one or two flexible end caps and one annular socket surrounding the balloon to place the stent in place while introducing the stent to the deployment site.
[0006]
U.S. patent application Ser. No. 09 / 407,836, filed Sep. 28, 1999, entitled "Stent Security Leaves and Optional Coatings and Methods of Use," is hereby incorporated by reference in its entirety. The patent application also provides a stent delivery system having a sleeve. In that patent application, the sleeve may be comprised of a mixture of polytetrafluoroethylene (PTFE) and one or more thermoplastic elastomers. Other literature discloses various stent retaining sleeves.
[0007]
A common problem that arises in catheter assemblies is friction or adhesion at various sites that periodically reciprocate during a medical procedure. For example, friction can occur between a guide catheter and a guidewire, between an introducer sheath and a guide catheter, or between a guide catheter and a balloon catheter. This increases the difficulty of insertion and makes it difficult to position the catheter, discomforts the patient, or damages the vasculature. In catheters with stent-retaining socks or sleeves, friction between the balloon and the sleeve and / or between the stent and the sleeve causes more troublesome retraction of the sleeve. In stent delivery systems that use a relatively soft coating on the stent surface, such as a drug carrier, the relatively soft coating increases friction on the sock or sleeve system. An example is found in U.S. Patent No. 5,693,085 to Burge et al., Which is incorporated herein by reference in its entirety.
[0008]
Accordingly, it is desirable to reduce the operational friction between various components of a catheter assembly. US patent application Ser. No. 09 / 549,286, filed Apr. 14, 2000, describes a reduced columnar strength stent retaining sleeve having a plurality of cavities. The relatively reduced columnar and radiant intensity provided by the cavity causes the sleeve to retract from the stent without the need for a lubricant.
[0009]
However, lubricants are used in various stent delivery systems. Many lubricants and lubricious coating types have been used with balloon catheters. Hydrophilic and hydrophobic coatings and lubricants are well known in the catheter art. For example, U.S. patent application Ser. No. 09 / 407,836, filed Sep. 28, 1999, entitled Stent Security Leaves and Optional Coatings and Methods of Use, provides a stent delivery system having a sleeve. In that patent application, the sleeve may be comprised of a mixture of polytetrafluoroethylene (hereinafter PTFE) and one or more thermoplastic elastomers. US patent application Ser. No. 09 / 427,805, filed Oct. 27, 1999, entitled “End Sleep Coating for Stent Delivery” describes a stent-retaining sleeve having a lubricious coating applied to the stent. are doing.
[0010]
U.S. patent application Ser. No. 09 / 273,520, filed Mar. 22, 1999 (Lubricated Sleep Material For Stent Delivery), also describes the use of a stent-retaining sleeve and lubricant.
[0011]
A stent delivery system that does not require the use of a lubricant has also been proposed, such as in the aforementioned US patent application Ser. No. 09 / 549,286. Another example of a stent delivery system and stent retaining sleeve that does not require the use of a lubricant is U.S. patent application Ser. No. 09 / 668,496, filed Sep. 22, 2000, titled Striped Sleep For Stent Delivery. And describes a two component sleeve having one or more substantially longitudinally extending strips of hard and soft material. The configuration of the band material in the sleeve causes the sleeve to expand radially, but also provides limited or non-longitudinal expansion. The unique expansion characteristics provided by the band configuration avoids the need to use a lubricant with the sleeve, but the lubricant can be utilized with the sleeve as needed.
[0012]
The entire contents of all patents and applications mentioned in this patent application are incorporated herein by reference.
(Brief summary of the invention)
The present invention relates to a medical device delivery system comprising a catheter assembly having a medical device receiving area and at least one retaining sleeve for holding the medical device in the receiving area prior to delivery. An expandable medical device, such as a stent, is disposed on the periphery of the medical device receiving area of the catheter assembly. At least one retaining sleeve is disposed on one end of the expandable medical device and a peripheral surface of a portion of the catheter assembly.
[0013]
The at least one retaining sleeve further comprises an inner surface and an outer surface. At least a portion of an outer surface made of the first material and an inner surface configured to cover the stent made of the second material. The first and second materials have different hardnesses, and the second material is harder than the first material. As is well known, in most polymer materials, hardness is expressed by elongation when the polymer is subjected to an external actuation force, and especially in the case of elastomeric materials, hardness is definitely indicated by elongation (e.g., The lower the hardness, the higher the elasticity of the material).
[0014]
The present application derives from US patent application Ser. No. 09 / 668,496, which provides a sleeve that has contracted to store longitudinal elongation, but unlike the patent application, the present invention is harder than most sleeve materials. Improving the retraction capability of the sleeve by providing at least a portion of the inner surface of the sleeve over the stent with the material. Such a relatively hard material desirably provides a surface to the sleeve that has low frictional engagement with the stent.
[0015]
In one embodiment of the present invention, the first material and the second material are co-extruded polymers.
In one embodiment of the invention, the second material is a coating on the first material.
[0016]
In one embodiment of the present invention, the inner surfaces are all made of a second material.
In one embodiment of the present invention, only a portion of the inner surface configured and arranged to cover the stent comprises a harder material.
(Detailed description of the invention)
The present invention relates to a stent delivery catheter indicated by reference numeral 10 as shown in FIG. The catheter 10 includes a stent mounting area 12. The mounting area 12 may be an inflatable portion of the catheter or another balloon attached to the catheter shaft 14. The balloon 12 changes between an unexpanded state and an expanded state. The stent 16 is disposed around the stent mounting area 12 and is delivered when the balloon 12 expands to an expanded state.
[0017]
The stent 16 has a proximal end 18 and a distal end 20. In embodiments, the stent retaining sleeve 22 overlies at least a portion of each of the proximal end 18 and the distal end 20. As is well known in the art, both ends of the stent-retaining sleeve 22 are configured to retract from both ends 18, 20 of the stent when the balloon 12 and the stent 16 are expanded to their expanded states. In the present invention, the sleeve 22 has a unique configuration, and the inner surface 100 of the first portion 24 of the sleeve is provided with a material 34 that is harder than the outer surface 102 of the sleeve 22 so that the sleeve 22 is The first portion 24 of the overlapping sleeve provides reduced frictional engagement with the stent 16.
[0018]
A second portion 26 of the sleeve 22 is disposed and engaged around a portion of the catheter shaft 14 adjacent to the balloon 12.
As the stent 16 expands, the ends 18, 20 of the stent are gradually pulled from under the stent retaining sleeve 22. By providing a sleeve 22 having reduced frictional engagement with the ends 18, 20 of the stent, the present invention ensures delivery of the stent with improved sleeve retraction capability.
[0019]
As mentioned above, the sleeve 22 is composed of at least two materials having different hardness characteristics. The first material 30 is formed into a generally tubular body 32 that provides the sleeve with its shape and outer surface 102. At least a portion of the first end of the inner surface 100 is made of the second material 34.
[0020]
The first material 30 has a hardness measured with a Shore durometer of less than 55D. Desirably, the durometer hardness of the first material is between 40A and 100A. The second material 34 may be a material having a durometer hardness of 55D or more. In at least one embodiment of the present invention, the first material 30 has a hardness of 35D and the second material has a hardness of 70D.
[0021]
The first material 30 may be selected from one or more of the following materials: a polyester / polyether elastomer, such as Arnitel® available from DSM Engineering, Tekotan 1074A available from Thermix, Inc. Polyurethane-polyether polymers such as Tecothane®, polyester-polyurethanes such as Peletan 2102-75A (Pellethane®) sold by Dow Chemical Company, and Estane 5703P (Estain® trademark) sold by BF Goodrich. ), Polyether block amides such as Pebax 2533 (Pebax®) available from Elf Atochem, Inc. from Shell Chemical Company. It is sold Kraton D1101 (TM Kraton) styrene such as - butadiene - styrene triblock copolymer. Other materials used in the manufacture of the first material 30 include styrene block copolymer, polyurethane, silicone rubber, natural rubber, copolyester, polyamide, EPDM (ethylene propylene diene terpolymer) rubber / polyolefin, nitrile Including, but not limited to, rubber / PVC (polyvinyl chloride), fluoroelastomers, butyl rubber, epichlorohydrin, soft block copolymers, and composites thereof.
[0022]
The second material 34 may be selected from one or more of the following materials: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), nylon (Nylon®), engineering thermoplastic. Polyurethanes, fluoropolymers, polyester / polyether elastomers such as Arnitel (registered trademark) available from DSM Engineering, polyurethane-polyether polymers such as Tecotan 1055D or 1075D (Tecothane®) available from Thermedix, BF Polyester-polyurethane such as Estan 58170 (Estain®) sold by Goodrich, Elf Atochem Polyether block amides, such as Pevacs 7233 or 6333 (registered trademark Pebax), which are more available. Other materials used in the manufacture of the second material 34 include polyolefin, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene polymer, polyacrylonitrile, polyacrylate, vinyl acetate polymer, cellulose plastic, polyurethane, polyethylene terephthalate, polyacetal, Including but not limited to polyether, polycarbonate, polyamide, polyphenylene sulfide resin, polyallyl ether sulfone, polyallyl ether ketone, polytetrafluoroethylene, and any combination thereof.
[0023]
The above examples of the first material 30 and the second material 34 are not exhaustive of all possible substances or composites of substances. The invention relates to a sleeve made of a material having the hardness characteristics of each of the materials 30, 34 already mentioned.
[0024]
As shown in the drawings, the present invention can be implemented in various forms. For example, in the embodiment of FIG. 1, the catheter 10 is shown with a pair of sleeves 22, each having a first portion 24 with an inner surface 100 of a second material 34 as described above. The second material 34 may be a coating made of a curable material applied to the inner surface 100 of the sleeve 22. Alternatively, material 34 may be joined or welded to sleeve 22, or first material 30 and second material 34 may be extruded together in the form of sleeve 22 as shown. Other methods of joining the materials 30, 34 can also be used, such as any coating by baking.
[0025]
As shown in FIG. 2, the entire inner surface 100 of the sleeve 22 may be composed of the second material 34.
FIGS. 3 and 4 show the sleeve configuration described with respect to FIGS. 1 and 2, respectively, and may be attached to the sleeve 22 specifically for the stent delivery catheter 10. FIG.
[0026]
In other embodiments, particularly those actually used to deliver self-expanding stents, retractable sheaths (not shown) are well known in the art, but may also be used to overlap a stent. Good. In such an embodiment, one or two sleeves, as described above, may be utilized to hold the self-expanding stent in place. As the sheath is retracted, the stent expands and retracts the sleeve.
[0027]
In addition to relating to the embodiments described above and the embodiments claimed below, the present invention further relates to embodiments having different combinations of the features described above and the features claimed below. Accordingly, the present invention also relates to other embodiments having possible combinations of the dependent characteristics claimed below.
[0028]
The above examples and disclosure are intended to be illustrative and not exhaustive. The above examples and explanations will suggest many variations and alternatives to one skilled in the art. All of the above alternatives and modifications are intended to be included within the scope of the appended claims. Those skilled in the art will recognize other embodiments that are equivalent to the specific embodiment described herein, and it is intended that equivalent embodiments be covered by the appended claims.
[Brief description of the drawings]
FIG. 1 is a side view showing a first embodiment of the present invention.
FIG. 2 is a side view showing a second embodiment of the present invention.
FIG. 3 is a side view showing a third embodiment of the present invention.
FIG. 4 is a side view showing a fourth embodiment of the present invention.

Claims (12)

A catheter having a stent mounting area,
A stent disposed on a peripheral surface of a stent mounting area of the catheter, having a distal end and a proximal end, and changing between an unexpanded state and an expanded state; an inner surface and an outer surface; and a first end and a second end At least one stent-retaining sleeve having a first end overlapping the end of the stent when the stent is in an unexpanded state and a second end engaging at least a portion of a catheter adjacent the stent mounting area. And that
An outer surface made of a first material, at least a portion of a first end of an inner surface made of a second material,
A stent delivery system comprising: a first material having a first predetermined hardness, a second material having a second predetermined hardness, and the second predetermined hardness having a durometer value higher than the first predetermined hardness. The stent delivery catheter according to claim 1, wherein the second material is smoother than the first material. 2. The stent delivery catheter of claim 1, wherein the first predetermined hardness is less than about 55D and the second predetermined hardness is a minimum of 55D. The stent delivery catheter of claim 1, wherein the first predetermined hardness is about 35D and the second predetermined hardness is about 55D. The stent delivery catheter according to claim 1, wherein the inner surface is made of a second material. The stent delivery catheter according to claim 1, wherein the first material and the second material are extruded together. The stent delivery catheter of claim 1, wherein the second material is a coating, the coating being applied to at least a first end of an inner surface of the at least one stent retaining sleeve. The stent delivery system according to claim 7, wherein the coating is a polyolefin, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene polymer, polyacrylonitrile, polyacrylate, vinyl acetate polymer, cellulose plastic, polyurethane, polyethylene terephthalate, polyacetal. , Polyether, polycarbonate, polyamide, polyphenylene disulfide resin, polyallyl ether sulfone, polyallyl ether ketone, polytetrafluoroethylene, and any combination thereof. 2. The stent delivery system according to claim 1, wherein the first material is styrene block copolymer, polyurethane, silicone rubber, natural rubber, copolyester, polyamide, EPDM (ethylene propylene diene terpolymer) rubber / A system that is at least one of polyolefin, nitrile rubber / PVC (polyvinyl chloride), fluoroelastomer, butyl rubber, epichlorohydrin, polyester elastomer, polyamide elastomer, and any combination thereof. 2. The stent delivery system according to claim 1, wherein the second material is polyolefin, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene polymer, polyacrylonitrile, polyacrylate, vinyl acetate polymer, cellulose plastic, polyurethane, polyethylene terephthalate. A system that is at least one of: polyacetal, polyether, polycarbonate, polyamide, polyphenylene disulfide resin, polyallyl ether sulfone, polyallyl ether ketone, polytetrafluoroethylene, and any combination thereof. A stent retaining sleeve for retaining the end of the stent on a balloon catheter,
A first material having a first predetermined hardness, a second material having a second predetermined hardness, the second predetermined hardness being greater than the first predetermined hardness,
The stent-retaining sleeve has an inner surface and an outer surface and a first end and a second end, wherein the inner surface of the first end is configured and arranged to overlap an end of the stent; The part is configured and arranged to contact at least a part of the catheter,
At least a part of the inner surface of the first end is made of the second material. A catheter having a stent mounting area,
A stent having a distal end and a proximal end, a non-expanded state and an expanded state, and a first end and a second end disposed around the stent mounting area of the catheter; A first end overlapping the end of the stent when in the condition, a second end engaging at least a portion of the catheter adjacent the stent mounting area;
A stent delivery system comprising at least one sleeve having an inner surface and an outer surface, and at least a portion of the inner surface characterized by being harder than the outer surface.