WO2020139544A2

WO2020139544A2 - Shape adaptable multi-layered intra-saccular flow reduction device and methods of manufacturing same

Info

Publication number: WO2020139544A2
Application number: PCT/US2019/065248
Authority: WO
Inventors: Stephen Porter
Original assignee: Stryker Corporation; Stryker European Holdings I, Llc
Priority date: 2018-12-27
Filing date: 2019-12-09
Publication date: 2020-07-02
Also published as: WO2020139544A3

Abstract

A vaso-occlusive device having a delivery configuration when restrained within a delivery catheter and having a deployed configuration when released from the delivery catheter into an aneurysmal sac is provided, the device comprising a tubular structure including a distal portion configured for expanding within the aneurysmal sac when distally deployed from the delivery catheter into the aneurysmal sac, a proximal portion configured for inverting and expanding into the expanded distal portion when distally deployed from the delivery catheter, thereby creating multi-layer scaffolding within the aneurysmal sac, and an inflection region between the distal portion and the proximal portion, wherein the inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion.

Description

SHAPE ADAPTABLE MULTI-LAYERED INTRA-SACCULAR FLOW REDUCTION DEVICE AND METHODS OF MANUFACTURING SAME

FIELD OF THE INVENTION

[0001] The present disclosure relates generally to medical devices and intravascular medical procedures and, more particularly, to devices and methods for occluding vascular defects, such as aneurysms.

BACKGROUND

[0002] Medical devices, such as coils, tubular mesh elements, and other expandable members, collectively referred to hereinafter as“embolic devices,” are often utilized for treating various types of vascular defects, particularly, aneurysms. An aneurysm is a localized, blood-filled dilation of a blood vessel caused by disease, blood flow/pressure exerted in the vessel and/or weakening of the vessel wall. An aneurysm usually assumes a sac or balloon-like configuration that extends from a blood vessel. An aneurysm can rupture and cause hemorrhage, stroke (e.g., an intracranial aneurysm) and other damaging consequences to the patient.

[0003] During endovascular treatment of an aneurysm, an embolic device is loaded onto a delivery system in a collapsed or radially compressed delivery configuration and then introduced into an aneurysm sac. Once delivered within the aneurysmal sac, the embolic device may then be placed into an expanded configurations, filling and occluding the aneurysmal sac. Embolic devices may have a variety of sizes and shapes; however, embolic devices for treatment of an aneurysm usually assume a spherical secondary configuration when deployed within the aneurysm sac. When implanted within the sac, the embolic device may further reinforce the inner walls of the aneurysm sac while occluding the aneurysm, reducing the probability of rupture or preventing further rupture of the aneurysm.

[0004] Embolic devices are commonly composed of self-expanding materials, so that when the devices are deployed from the delivery system into the target location in a patient, the unconstrained devices expand without requiring assistance. Self expanding embolic devices may be biased so as to expand upon release from the delivery catheter and/or include a shape-memory component that allows the device to expand upon exposure to a predetermined condition. Some embolic devices may be characterized as hybrid devices, which have some characteristics of both self- expandable materials and non-self-expandable materials.

[0005] Embolic devices can be made from a variety of materials, including polymers (e.g., nonbioerodable and bioerodable plastics) and metals. Embolic devices can be made from shape memory or superelastic materials, such as shape memory metals (e.g., shape memory Nitinol) and polymers (e.g., polyurethane). Such shape memory embolic devices can be induced (e.g., by temperature, electrical or magnetic field or light) to take on a shape (e.g., a radially expanded shape) after delivery to a treatment site. Superelastic embolic materials, such as superelastic Nitinol, take on a shape after delivery without the need for an inductive stimulus. Other commonly used materials include stainless steel, platinum and elgiloy. Drug delivery embolic devices can carry, and/or the surface of the device, can be coated with a bioactive or therapeutic agent (e.g., thrombosis inducing agent).

[0006] Commonly used vaso-occlusive devices include soft, helically wound coils formed by winding a platinum (or platinum alloy) wire strand about a “primary” mandrel. The coil is then wrapped around a larger,“secondary” mandrel, and heat treated to impart a secondary shape. For example, U.S. Pat. No. 4,994,069, which is fully incorporated herein by reference as though set forth in full, describes a vaso- occlusive device that assumes a linear, helical primary shape when stretched for placement through the lumen of a delivery catheter, and a folded, convoluted secondary shape when released from the delivery catheter and deposited in the vasculature. In order to better frame and fill aneurysms, complex three-dimensional secondary shapes can be imparted on vaso-occlusive devices and the stiffness/flexibility of vaso-occlusive devices can be modified.

[0007] Other three-dimensional embolic coils have been described in U.S. Patent Nos. 5,624,461 (i.e. , three-dimensional in-filling embolic coil), 5,639,277 (i.e., embolic coils having twisted helical shapes) and 5,649,949 (i.e., variable cross- section conical embolic coils). Embolic coils having little or no inherent secondary shape have also been described, such as in U.S. Patent Nos. 5,690,666 and 5,826,587.

[0008] Spherical shaped embolic devices are described in U.S. Patent No. 5,645,558, which discloses that one or more strands can be wound to form a substantially hollow spherical or ovoid shape comprising overlapping strands when deployed in an aneurysm. Other embolic devices that assume spherical shapes when deployed are described in U.S. Patent No. 8,998,947, which discloses tubular mesh having petal-like sections to form a substantially spherical shape having overlapping petals-like sections when deployed in an aneurysm, and U.S. Publication No. 2014/020060, which discloses a semi-spherical dome-like scaffolding that invert when opposing forces are exerted at the dome of the aneurysm, which is then filled with vaso-occlusive material.

[0009] In order to deliver vaso-occlusive devices to a desired site in the vasculature, e.g., within an aneurysmal sac, it is well-known to first position a small profile delivery catheter or“micro-catheter” at the site using a guidewire. Typically, the distal end of the micro-catheter is provided, either by the attending physician or by the manufacturer, with a selected pre-shaped bend, e.g., 45°, 26°,“J”, “S”, or other bending shape, depending on the particular anatomy of the patient, so that it will stay in a desired position for releasing one or more vaso-occlusive device(s) into the aneurysmal sac once the guidewire is withdrawn. A delivery or “pusher” assembly or“wire” is then passed through the micro-catheter until a vaso-occlusive device coupled to a distal end of the delivery wire is extended out of the distal end opening of the micro-catheter and into the aneurysmal sac. Once in the aneurysmal sac, portions of the vaso-occlusive device may deform or bend to allow more efficient and complete packing. The vaso-occlusive device is then released or “detached” from the distal end of the delivery assembly, and the delivery assembly is withdrawn back through the micro-catheter. A variety of mechanisms for detaching embolic devices from a delivery assembly are known; for instance, U.S. Patent Nos. 5,250,071 (i.e. , interlocking clasps), 5,312,415 (i.e. , interconnecting guidewire to deliver multiple coils), and 5,354,295 and 6,425,893, to Guglielmi (i.e., electrolytic detachment). Depending on the particular needs of the patient, one or more additional vaso-occlusive devices may be pushed through the micro-catheter and released into the same aneurysmal sac.

[0010] It is important that such vaso-occlusive devices be chronically retained within the aneurysm. However, aneurysms with larger mouths, commonly known as “wide neck aneurysms,” present difficulty in the placement and retention of vaso- occlusive devices within the aneurysm sacs, particularly with small and relatively thin vaso-occlusive coils that lack the substantial secondary shape strength to maintain in position within such aneurysm sacs no matter how skillfully they are placed. For this reason, a supplemental flow diversion device, such as a stent or a balloon, must typically be deployed in the vessel adjacent the neck region of the aneurysm to ensure that the vaso-occlusive coils are retained within the aneurysmal sac, thereby complicating the procedure.

[0011] Spherical devices, such as those described in U.S. Patent Publication No. 2014/020060, are designed to be used within such wide neck aneurysms without having to employ additional flow diversion devices, by creating a scaffolding within such wide neck aneurysms that is then filled with additional vaso-occlusive material. However, the spherical vaso-occlusive devices described in U.S. Patent Publication No. 2014/020060 must have an opposing force applied by the dome of the aneurysmal sac in order to facilitate inversion of scaffolding, thereby potentially leaving the neck of the aneurysm open during deployment of the scaffolding, as well as during introduction of additional vaso-occlusive material within the scaffolding. As such, there is a risk of migration of the vaso-occlusive material out of the aneurysmal sac due to flow of blood adjacent the wide neck of the aneurysm.

[0012] There, thus, is an ongoing need to provide a vaso-occlusive device that occludes fully occludes wide neck aneurysms during delivery of vaso-occlusive material into such aneurysms without having to resort to supplemental flow diversion devices.

SUMMARY

[0013] In accordance with a first aspect of the present inventions, a vaso- occlusive device has a delivery configuration when restrained within a delivery catheter, and a deployed configuration when released from the delivery catheter into an aneurysmal sac. The vaso-occlusive device comprises a tubular structure (e.g., mesh) that includes distal portion configured for expanding within the aneurysmal sac when distally deployed from the delivery catheter into the aneurysmal sac, a proximal portion configured for inverting and expanding into the expanded distal portion when distally deployed from the delivery catheter, thereby creating multi-layer scaffolding within the aneurysmal sac, and an inflection region between the distal portion and the proximal portion. The inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion.

[0014] In one embodiment, the distal portion and proximal portion are configured for self-expanding into, e.g., a spherical, ovoid, or bulbous shape. The distal portion may comprise a non-expanding distal-most terminal end. In an optional embodiment, the tubular structure further comprises a third portion configured for inverting and expanding into the expanded proximal portion when distally deployed from the delivery catheter into the aneurysmal sac, thereby adding another layer to the scaffolding within the aneurysmal sac, and another inflection region between the proximal portion and the other proximal portion. The other inflection region is configured for urging inversion of the other proximal portion into the expanded proximal portion. The vaso-occlusive device may further comprise an elongate embolic element (e.g., an embolization coil or ribbon) proximally coupled to the tubular structure. In this case, the elongate embolic element is configured for filling an interior region of the multi-layer scaffolding when distally deployed from the delivery catheter into the aneurysmal sac.

[0015] In one embodiment, the inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion absent an application of an opposing proximal force on a distal end of the expanded distal portion of the tubular structure. In another embodiment, the inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion in free-space. In still another embodiment, the inflection region maintains the tubular structure is in its lowest-energy state when the proximal portion is expanded and inverted into the expanded distal portion. In yet another embodiment, the distal portion and the proximal portion are pre-shaped to have similar geometries.

[0016] In accordance with a second aspect of the present inventions, a vaso- occlusive assembly, comprises the vaso-occlusive device described above, and a pusher member to which the vaso-occlusive device is detachably coupled (e.g., electrolytically).

[0017] In accordance with a third aspect of the present inventions, a vaso- occlusive treatment system comprises the vaso-occlusive assembly described above, and the delivery catheter in which the vaso-occlusive assembly is disposed.

[0018] In accordance with a fourth aspect of the present inventions, a method of treating an aneurysm in a patient comprises inserting a delivery catheter into the patient until a distal end of the delivery catheter is adjacent a neck of the aneurysm, distally advancing a tubular structure (e.g., a mesh) within the delivery catheter, deploying a distal portion of the tubular structure from the distal end of the delivery catheter into the aneurysmal sac (e.g., having spherical, ovoid, or bulbous shape), expanding (e.g., self-expanding) the distal portion of the tubular structure within the aneurysmal sac, thereby creating a single-layer scaffolding that lines a wall of the aneurysmal sac, and deploying a proximal portion of the tubular structure from the distal end of the delivery catheter. The method further comprises initiating inversion of the proximal portion of the tubular structure at an inflection region between the distal portion and proximal portion of the tubular structure. The inflection region urges inversion initiation of the proximal portion of the tubular structure. The method further comprises inverting, while expanding (e.g., self-expanding), the proximal portion of the tubular structure within the expanded distal portion of the vaso- occlusive device, thereby creating a multi-layer scaffolding that lines the wall of the aneurysmal sac.

[0019] An optional method further comprises deploying another proximal portion of the tubular structure from the distal end of the delivery catheter, and initiating inversion of the other proximal portion of the tubular structure at another inflection region between the proximal portion and the other proximal portion of the tubular structure. The other inflection region urges inversion initiation of the other proximal portion of the tubular structure. This optional method further comprises inverting, while expanding, the other proximal portion of the tubular structure within the multi layer scaffolding, thereby adding another wall to the multi-layer scaffolding.

[0020] In one method, the inversion of the proximal portion at the inflection region is initiated absent an application of an opposing proximal force on a distal end of the expanded distal portion of the tubular structure by a dome of the aneurysmal sac. In another method, the inflection region maintains the tubular structure is in its lowest- energy state when the proximal portion is expanded and inverted into the expanded distal portion. In still another method, the expanded distal portion and the expanded proximal portion have similar geometries. Yet another method further comprises filling an interior region of the multi-layer scaffolding with an embolic material (e.g., an elongate embolic element (e.g., an embolization coil or ribbon) proximally coupled to the tubular structure. The vaso-occlusive device may be distally advanced within the delivery catheter via a pusher member coupled to the vaso-occlusive device, in which case, the method may further comprise decoupling the vaso-occlusive device from the pusher member after the multi-layer scaffolding is formed within the aneurysmal sac.

[0021] In accordance with a fifth aspect of the present inventions, a method of manufacturing a vaso-occlusive device comprises inserting an elongate tubular member (e.g., a mesh) through a lumen of a spherical, ovoid, or bulbous mandrel, such that a free end of the elongate tubular member extends from a first side of the mandrel, inverting the free end of the elongate tubular member in a first axial direction from the first side of the mandrel to a second opposite side of the mandrel, cinching (e.g., via a thread) the elongate tubular member adjacent the second side of the mandrel, such that a proximal portion of the elongate tubular member conforms to the mandrel, inverting the free end of the elongate tubular member in a second opposite axial direction from the second side of the mandrel to the first side of the mandrel, cinching (e.g. , via a thread) the elongate tubular member adjacent the first side of the mandrel, such that a distal portion of the elongate tubular member conforms to the proximal portion of the elongate tubular member over the mandrel, heat treating the elongate tubular member, thereby imparting a self-expanding spherical, ovoid, or bulbous shape onto the distal portion and the proximal portion of the elongate tubular member, uncinching the elongate tubular member, and removing the mandrel from the elongate tubular member from the mandrel. An optional method further comprises bonding an elongate embolic element (e.g., an embolization coil or ribbon) to the proximal portion of the elongate tubular member.

[0022] Other and further aspects and features of embodiments will become apparent from the ensuing detailed description in view of the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings illustrate the design and utility of preferred embodiments of the disclosed inventions, in which similar elements are referred to by common reference numerals. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention, which is defined only by the appended claims and their equivalents. In addition, an illustrated embodiment of the disclosed inventions needs not have all the aspects or advantages shown. Further, an aspect or an advantage described in conjunction with a particular embodiment of the disclosed inventions is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated.

[0024] In order to better appreciate how the above-recited and other advantages and objects of the disclosed inventions are obtained, a more particular description of the disclosed inventions briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0025] Fig. 1 is plan view of a vaso-occlusive treatment system constructed in accordance with one embodiment of the disclosed inventions, particularly showing a vaso-occlusive device in a delivery configuration;

[0026] Fig. 2 is a plan view of the vaso-occlusive treatment system of Fig. 1 , particularly showing the vaso-occlusive device in a deployed configuration;

[0027] Fig. 3 is a cut-away plan view of one embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0028] Fig. 4 is a cut-away plan view of an alternative embodiment of a vaso- occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0029] Fig. 5 is a cut-away plan view of another alternative embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0030] Fig. 6 is a cut-away plan view of still another alternative embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0031] Fig. 7 is a cut-away plan view of yet another alternative embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0032] Fig. 8 is a cut-away plan view of yet another alternative embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0033] Fig. 9 is a cut-away plan view of yet another alternative embodiment of a vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0034] Fig. 10 is a plan view of one embodiment of a constrained vaso-occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ;

[0035] Fig. 11 is a cut-away cross-sectional view of the constrained vaso- occlusive structure of Fig. 10;

[0036] Fig. 12 is a plan view of one embodiment of an unconstrained vaso- occlusive structure used in the vaso-occlusive treatment system of Fig. 1 ; [0037] Fig. 13 is a cut-away cross-sectional view of the unconstrained vaso- occlusive structure of Fig. 12;

[0038] Fig. 14A is a perspective of a spherical mandrel used in an inflection region of the vaso-occlusive structure of Fig. 10;

[0039] Fig. 14B is a close up view of an opening in the spherical mandrel of Fig. 14A;

[0040] Fig. 15 is a flow diagram illustrating one method of manufacturing a vaso- occlusive device used in the vaso-occlusive treatment system of Fig. 1 ;

[0041] Figs. 16A-16G are cut-away cross-sectional views illustrating various process stages of the vaso-occlusive device constructed in accordance with the method illustrated in Fig. 15;

[0042] Fig. 17 is a flow diagram illustrating one method of treating an aneurysm using the vaso-occlusive treatment system of Fig. 1 ; and

[0043] FIGS. 18A-18N are plan views illustrating the treatment of the aneurysm in accordance with the method illustrated in Fig. 17.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0044] Referring to Figs. 1 and 2, one embodiment of a vaso-occlusive treatment system 10 constructed in accordance with the disclosed inventions will now be described. The vaso-occlusive treatment system 10 comprises a delivery catheter 12 and a vaso-occlusive assembly 14 slidably disposed within the delivery catheter 12. The vaso-occlusive assembly 14 comprises a vaso-occlusive device 16 and a pusher member 18 to which the vaso-occlusive device 16 is detachably coupled at a junction 20.

[0045] The delivery catheter 12 has a tubular configuration, and can, e.g., take the form of a micro-catheter, a sheath, or the like. The delivery catheter 12 comprises an elongate sheath body 22 having a proximal portion 24 and a distal portion 26, and a lumen 28 (shown partially in phantom) extending through the sheath body 22 between the proximal portion 24 and the distal portion 26. The proximal portion 24 of the sheath body 22 remains outside of the patient and accessible to the operator when the vaso-occlusive treatment system 10 is in use, while the distal portion 26 of the sheath body 22 is sized and dimensioned to reach remote locations of the vasculature of the patient, and is configured to deliver the vaso-occlusive device 16 to an aneurysm. The delivery catheter 12 comprises a distal port 30 in communication with the lumen 28 of the delivery catheter 12 and from which the vaso-occlusive device 16 is deployed, and may have at least one proximal port 32 in fluid communication with the lumen 28 of the delivery catheter 12, which is used to introduce fluids into the sheath body 22. The vaso-occlusive assembly 14 is disposed in the lumen 28 of the delivery catheter 12, as better appreciated in Fig. 1.

[0046] The delivery catheter 12 may include one or more, or a plurality of regions along its length having different configurations and/or characteristics. For example, the distal portion 26 of the sheath body 22 may have an outer diameter less than the outer diameter of the proximal portion 24 of the sheath body 22 to reduce the profile of the distal portion 26 and facilitate navigation in tortuous vasculature. Furthermore, the distal portion 26 may be more flexible than the proximal portion 24. Generally, the proximal portion 24 may be formed from material that is stiffer than the distal portion 26 of the sheath body 22, so that the proximal portion 24 has sufficient pushability to advance through the patient’s vascular system, while the distal portion 26 may be formed of a more flexible material so that the distal portion 26 may remain flexible and track more easily over a guidewire to access remote locations in tortuous regions of the vasculature. The sheath body 22 may be composed of suitable polymeric materials, metals and/or alloys, such as polyethylene, stainless steel or other suitable biocompatible materials or combinations thereof. In some instances, the proximal portion 24 may include a reinforcement layer, such a braided layer or coiled layer to enhance the pushability of the sheath body 22. The sheath body 22 may include a transition region between the proximal portion 24 and the distal portion 26.

[0047] In general, the vaso-occlusive device 16 has a delivery configuration when restrained within a delivery catheter 12 (Fig. 1) and has a deployed configuration when released from the delivery catheter 12 (Fig. 2) into an aneurysmal sac. The vaso-occlusive device 16 may be inserted into the patient’s vasculature (e.g., minimally invasively) to reach the aneurysm site. The delivery catheter 12 is, thus, made as small as possible, and has an extremely narrow inner diameter (i.e. , lumen 28) (e.g., between 0.015” and 0.025”, and preferably between 0.015” and 0.018”).

[0048] The pusher member 18 may be a coil, wire, tendon, or the like, having a sufficient columnar strength to permit pushing of the vaso-occlusive device 16 into the aneurysmal sac. The junction 20 at which the pusher member 18 is coupled to the vaso-occlusive structure 16 may, e.g., take the form of an electrolytically degradable segment for electrolytically decoupling the vaso-occlusive device 16 from the pusher member 18, although other alternative detachment mechanisms for decoupling the vaso-occlusive device 16 from the pusher member 18 may include mechanical, thermal, and hydraulic mechanisms.

[0049] The pusher member 18 has a proximal end 34 that extends proximal from the proximal portion 24 of the delivery catheter 12 and a distal end 36 to which the vaso-occlusive device 14 is attached. The pusher member 18 may be made of a conventional guidewire, torqueable cable tube, or a hypotube. In either case, there are numerous materials that can be used for the pusher member 18 to achieve the desired properties that are commonly associated with medical devices. Some examples can include metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material. For example, the pusher member 18 may include nickel-titanium alloy, stainless steel, a composite of nickel-titanium alloy and stainless steel. In some cases, the pusher member 18 can be made of the same material along its length, or in some embodiments, can include portions or sections made of different materials. In some embodiments, the material used to construct the pusher member 18 is chosen to impart varying flexibility and stiffness characteristics to different portions of the pusher member 18. For example, the proximal region and the distal portion 34 of the pusher member 18 may be formed of different materials, for example materials having different moduli of elasticity, resulting in a difference in flexibility. For example, the proximal portion 32 can be formed of stainless steel, and the distal portion 34 can be formed of a nickel-titanium alloy. However, any suitable material or combination of material may be used for the pusher member 18, as desired.

[0050] The vaso-occlusive device 16 generally comprises a tubular structure 38 and an elongate embolic element 40. The tubular structure 38 has a compact delivery configuration when radially retained within the delivery catheter 12, as illustrated in Fig. 1 , and is biased to assume a three-dimensional unconstrained configuration, and in particular, a spherical, ovoid, or bulbous shape for deployment within the aneurysmal sac, as illustrated in Fig. 2. The tubular structure 38 has a distal end 42 and a proximal end 44. The distal end 42 of the tubular structure 38, in this case, is typically free or loose (allowing maximal expansion), while the proximal end 44 of the tubular structure 38 is coupled/attached to the elongate embolic element 40. Thus, the distal end 42 of the tubular structure 38 is free-floating.

[0051] The elongate embolic element 40 comprises a distal end 46 coupled to the proximal end 44 of the tubular structure 38, and a proximal end 48 detachably coupled to the pusher member 18 via the junction 20. The elongate embolic element 40 can take the form of, e.g., a helical coil or ribbon, and may be configured to trail the tubular structure 38 when deployed within an aneurysmal sac and fill in the hollow volume from within (e.g. like a traditional aneurysm embolic coil). In an optional embodiment, the proximal end 48 of the elongate embolic element 40 (or alternatively the distal end 36 of the pusher member 18) includes a radiopaque marker 50 to provide a visual indication that the elongate embolic element 40 is completely deployed within the tubular structure 38 when expanded within the aneurysmal sac.

[0052] Significantly, as will be described in further detail below, the tubular structure 38 has a unique design that allows it to invert within itself (merely by removing the restraining force of the delivery catheter 12) to provide a multi-layer scaffolding within the aneurysmal sac, while also serving as a flow diverter to prevent, or at least minimize, the inflow of blood within the neck of the aneurysm that may otherwise dislodge embolic material (and in this case, the elongate embolic element 40) subsequently delivered into the interior region of the multi-layer scaffolding. The tubular structure 38, when it assumes the multi-layer scaffolding, is in its lowest energy state, thereby resisting pulsatile forces applied to it by blood flow that may otherwise dislodge or cause instability in scaffolding that is not in its lowest- energy state. As will also be described in further detail below, the multi-layer scaffolding that the tubular structure 38 assumes also forms a relatively small aperture through which the embolic material can be introduced, thereby facilitating retention of the embolic material within the multi-layer scaffolding during and after delivery of the embolic material into the aneurysmal sac.

[0053] As best shown in Fig. 3, the tubular structure 38 is porous and, in the illustrated embodiment, is formed by braiding or weaving wires 52 (e.g., having a wire count in the range of 8-96 wires, typically in the range of 16-48 wires) together into the tubular configuration. Although all of the wires 52 from which the tubular structure 38 is composed may be of identical size and composition, it should be appreciated the wires 52 may have different sizes and composition. Preferably, the tubular structure 38 has an unconstrained braid angle 54 (i.e. , the angle between two crossing wires 52) in the range of 60°-150°, more preferably in the range of 70°-120° In general, a braid angle 54 can be the angle between two crossing wires 52 viewed long the direction of the longitudinal axis. Selecting the constrained braid angle which generally is smaller than the aforementioned unconstrained braid angle 54) may enhance pushability of the tubular structure 38 within the delivery catheter 12 by preventing collapse of the tubular structure 38, which could otherwise result in bunching of the tubular structure 38 in the delivery catheter 12 when pushing and causing jamming of the tubular structure 38 within the delivery catheter 12. Ultimately, the number of wires 52 in the tubular structure 38, the braid angle 54, and/or the expanded configuration relative to the collapsed configuration of the tubular structure 38 can be selected to optimally fit the inner diameter of the delivery catheter 12 used.

[0054] In alternative embodiments, instead of using wires 52, the tubular structure 38 may comprise a plurality of woven ribbon-like elements 54 (Fig. 4) or filaments 56 (Fig. 5). In other embodiments, the tubular structure 38 may be formed as a monolithic structure, e.g., by etching or cutting a pattern from a tube or sheet of stent material, or by cutting or etching a sheet of material according to a desired pattern whereupon the sheet may be rolled or otherwise formed into the desired substantially tubular, bifurcated or other shape. For example, the tubular structure 38 may comprise a single sheet of material 58 having fenestrations 60 (Fig. 6). It should be further appreciated that there may be other suitable configurations of the tubular structure 38, so long as the configuration is able to reversibly expand and collapse to and from the appropriate configurations.

[0055] The tubular structure 38 may be composed of biocompatible metallic and/or polymeric materials, alloys or combinations thereof. For example, the wires 52, or alternatively the ribbon-like elements 54, filaments 56, or sheet 58, may have a platinum core with a respective outer layer of Nitinol. In the embodiments where the tubular structure 38 is braided, woven, or a mesh, the distal end 42 and/or proximal end 44 may be secured, having the plurality of wires 52 (or alternatively the ribbon-like elements 54, filaments 56, or sheet 58) attached or coupled to each other, or to another element (e.g., a cap, non-traumatic tip, or the like) at the respective distal end 42 and/or proximal end 44 via adhesive, clamping, or the like, as shown at the distal end 42 in Fig. 7. Alternatively, the respective distal end 42 and/or proximal end 44 of the tubular structure 38 may be unsecured, having the plurality of wires 52 (or alternatively the ribbon-like elements 54, filaments 56, or sheet 58) at the respective distal end 42 and/or proximal end 44 lose and free, as shown at the distal end 42 in Fig. 8. The vaso-occlusive device 16 optionally comprises a helical coil 62 (which may be fibered) or other embolic substances, ribbons, or the like, coupled to the distal end 42 of the tubular structure 38, as shown in Fig. 9. The coil 62 may be composed of shape memory material and may assume a loop like configuration (not shown) when in an unconstrained configuration. The coil 62 when disposed at the distal end 42 of the tubular structure 38 may be configured to lead the tubular structure 38 when deployed within the aneurysmal sac.

[0056] Referring to Figs. 10 and 11 , the constrained tubular structure 38 comprises a longitudinal axis 64, an outer surface 90, an inner surface 68, and a lumen 70 extending along the longitudinal axis 64. The constrained tubular structure 38 may have a length l_i along the longitudinal axis 64 that ranges from 2 to 40 centimeters, and in some embodiments, the length l_i may range from 5 to 25 centimeters. The constrained tubular structure 38 further comprises a width Wi that may range from approximately 0.3 to 0.8 millimeters, and in some embodiments, the width Wi may range from approximately 0.4 to 0.5 millimeters. Additionally, the constrained tubular structure 38 comprises a thickness Ti that may range from approximately 0.02 to 0.2 millimeters, and in some embodiments, the thickness Ti may range from approximately 0.05 to 0.1. In some embodiments, one or both of the width Wi and thickness Ti of the constrained tubular structure 38 remain constant along the length l_i . In other embodiments, one or both of the width Wi and thickness Ti of the tubular structure 38 may varied along the length l_i (e.g., a tapered configuration).

[0057] The tubular structure 38 may be composed of any number of biocompatible, compressible, elastic materials or combinations thereof, including polymeric materials, metals, and metal alloys, such as stainless steel, tantalum, or a nickel titanium alloy such as a super-elastic nickel titanium alloy known as Nitinol. Certain super-elastic alloys may be desirable for their shape recoverable features, which tolerate significant flexing without deformation even when used in small dimensioned tubular structure 38. Further, the unconstrained tubular structure 38 is biased to expand into the predetermined deployed configuration, which will be described in further detail below. Some super-elastic alloys include nickel/titanium alloys (48-58 atomic % nickel and optionally containing modest amounts of iron); copper/zinc alloys (38-42 weight % zinc); copper/zinc alloys containing 1-10 weight % of beryllium, silicon, tin, aluminum, or gallium; or nickel/aluminum alloys (36-38 atomic % aluminum).

[0058] The tubular structure 38 may include radio-opaque markers or be coated with a layer of radiopaque materials. Additionally, the tubular structure 38 may carry, and/or the surfaces of the tubular structure 38 may be coated, with a bioactive or therapeutic agent (e.g., thrombosis inducing agent). Furthermore, the tubular structure 38 may be composed of suitable metals and alloys that include the Platinum Group metals, such as, platinum, rhodium, palladium, rhenium, as well as tungsten, gold, silver, tantalum, and alloys of these metals, such as platinum/tungsten alloy, or the like and combinations thereof. These metals have significant radiopacity and in their alloys may be tailored to accomplish an appropriate blend of flexibility and stiffness. They may also be used in composite structures (such as core filled wire or lamellar sheets) with super-elastic or other materials to achieve a blend of mechanical and radio-opacification properties.

[0059] As briefly discussed above, the tubular structure 38 has a unique design that allows it to invert within itself to create a multi-layer scaffolding within the aneurysmal sac while serving as a flow diverter during and after the subsequent delivery of the elongate embolic element 40 within the aneurysmal sac. To this end, the constrained tubular structure 38 includes a distal portion 72 configured for expanding within the aneurysmal sac when distally deployed from the delivery catheter 12 into the aneurysmal sac, and a proximal portion 74 configured for inverting and expanding into an aperture 78 of the expanded distal portion 72 when distally deployed from the delivery catheter 12, thereby creating a multi-layered scaffolding 80 having an outer wall 82 (formed by the expanded distal portion 72 of the tubular structure 38) and an inner wall 84 (formed by the expanded proximal portion 74 of the tubular structure 38), as illustrated in Figs. 12 and 13.

[0060] Preferably, the distal portion 72 and proximal portion 74 of the tubular structure 38 are pre-shaped to have similar geometries; that is, if the distal portion 72 is pre-shaped to expand into a sphere, the proximal portion 74 will likewise be pre shaped to expand into a sphere; if the distal portion 72 is pre-shaped to expand into an ovoid, the proximal portion 74 will likewise be pre-shaped to expand into an ovoid; and if the distal portion 72 is pre-shaped to expand into a bulb, the proximal portion 74 will likewise be pre-shaped to expand into a bulb. In this manner, the expanded proximal portion 74 will better conform to expanded distal portion 72 to create a more integrated and stable multi-layered scaffolding 80. Notably, the aperture 78 of the expanded distal portion 72 remains in the multi-walled scaffolding 80 to allow passage therethrough of the distal portion 30 of the delivery catheter 12 and introduction of the elongate embolic element 28 into a hollow interior region 86 of the scaffolding 80, as will be described in further detail below.

[0061] Referring back to Fig. 10, the constrained tubular structure 38 further comprises an inflection region 76 between the distal portion 72 and the proximal portion 74 of the tubular structure 38. Significantly, the inflection region 76 is configured for urging the inversion of the proximal portion 74 into the expanded distal portion 72 absent an opposing proximal force on the distal end of the expanded distal portion 72 from the dome of the aneurysmal sac. In fact, it is preferred that the inflection region 76 be configured for urging the inversion of the proximal portion 74 into the expanded distal portion 72 in free-space. In this manner, the inflection region 76 maintains the tubular structure 38 in its lowest-energy state when the proximal portion 74 is inverted and expanded within the expanded distal portion 72.

[0062] In one method, the distal portion 72, proximal portion 74, and inflection region 76 of the tubular structure 38 may be pre-shaped using a mandrel. For example, as shown in Figs. 14A-14B, one example of such a mandrel 88 has an outer surface 90, a first opening 92, a second opening 94 diametrically opposed to the first opening 92, and a lumen 96 between the first opening 92 and second opening 94. As will be described in further, the tubular structure 38 is disposed through the lumen 96 in the mandrel 88, with the outer surface 90 of the mandrel 88 serving to impart the desirable expanded shapes (e.g., spherical, ovoid, or bulbous) onto the distal portion 72 and proximal portion 74 of the tubular structure 38, as well as to pre-shape the inflection region 76 to transition the tubular structure 38 into its lowest energy state (i.e., with the proximal portion 74 inverted and expanded into the expanded distal portion 76 to create the multi-layer scaffolding 80). In the illustrated embodiment, the mandrel 88 is spherically-shaped, and thus, a spherical expanded shape will be imparted onto the distal portion 72 and proximal portion 74 of the tubular structure 38; although the mandrel 88 can be any desirable shape, including ovoid and bulbous.

[0063] The diameter Di of the mandrel 88 ranges from approximately 1 to 25 millimeters, and in some embodiments, the diameter Di ranges from approximately 3 to 12 millimeters. The first and second openings 90, 92 have a diameter D₂ that ranges from approximately 0.1 to 2 millimeters, and in some embodiments, the diameter D₂ ranges from approximately 0.2 to 1.0 millimeters. It should be appreciated that the mandrel 88 and the openings 90, 92 may comprise other suitable diameters for the manufacturing of the tubular structure 38 configured to occlude the aneurysmal sac. Additionally, the respective first and second openings 90, 92 of the mandrel 88 comprise a filleted annular edge 98 (i.e. , rounded, curved edge as shown in Figs. 14A-14B). It should be noted that the openings 90, 92 and lumen 96 therebetween are not limited to a circular cross section and may be oval or rectangular or other shapes.

[0064] Referring now to Fig. 15, one method 100 of manufacturing the vaso- occlusive assembly 14 will be described. First, an elongate tubular member 150 having a first free end 152, a second free end 154, a longitudinal axis 156, an outer surface 158, and an inner surface 160, is fabricated, e.g., by weaving wires 52 together into a braid (step 102) (see Fig. 16A). Braids may be formed using braiding machines, and may be braided around a mandrel (e.g., a mandrel having a round, oval, flat, other shape depending on the desired final cross-sectional shape of the tubular structure 38). Alternatively, the wires 52 may be woven into a flat braid and subsequently formed and heat set around a mandrel to a flat braid with a pre determined shape. After braiding, the elongate tubular member 150 may optionally be heat set (e.g., at 450°C to 650°C for 1 to 60 minutes) (step 104), although this step may not be necessary. The heat set completed braid ultimately forms the linear “primary shape” of the tubular structure 38.

[0065] Next, the elongate tubular member 150 is disposed though the lumen 96 of the mandrel 88 (e.g., by threading the second end 154 of the elongate tubular member 150 into the first opening 92, through the lumen 96, and out the second opening 94 of the mandrel 88, and pulling the second end 154 of the elongate tubular member 150 through the lumen 96 of the mandrel 88), so that the first end 152 of the elongate tubular member 150 extends from a first opening 92 of the mandrel 88, and the second end 154 of the elongate tubular member 150 extends from the second opening 94 of the mandrel 88 (step 106) (see Fig. 16B).

[0066] Next, one of the ends 152, 154 of the elongate tubular member 150 (in this case, the end 152) is fully inverted in a first axial direction 162a along its longitudinal axis 156 over the mandrel 88 (i.e., the outer surface 158 of the elongate tubular member 150 is inverted and placed in contact with the outer surface 90 of the mandrel 88) (step 108) (see Fig. 16C), and the elongate tubular member 150 is cinched (e.g., compressed, crimped, or tied) adjacent the second opening 94 of the mandrel 88, such that a first portion 166a of the elongate tubular member 150 conforms to outer surface 90 of the mandrel 88 (step 1 10) (see Fig. 16D). By way of non-limiting example, a thread 164a may be tied around the elongate tubular member 150 disposed adjacent to the second opening 94 of the mandrel 88. The thread 164a is composed of suitable materials configured to withstand high temperatures. Notably, the first portion 166a of the elongate tubular member 150 corresponds to the proximal portion 74 of the tubular structure 38 illustrated in Fig. 10, and ultimately, the inner wall 84 of the multi-layer scaffolding 80 illustrated in Fig. 13)

[0067] Next, the inverted end 152 of the elongate tubular member 150 is fully re inverted in a second axial direction 162b opposite to the first axial direction 162a along its longitudinal axis 156 around the thread 164a and over the mandrel 88 (i.e. , the inner surface 90 of the elongate tubular member 150 is inverted and placed in contact with the same inner surface 90 of the elongate tubular member 150 over the mandrel 88) (step 1 12) (see Fig. 16E), and the elongate tubular member 150 is cinched (e.g., compressed, crimped, or tied) adjacent the first opening 92 of the mandrel 88 (e.g., using a thread 92), such that a second portion 166b of the elongate tubular member 150 conforms to first portion 166a over the outer surface 90 of the mandrel 88, and a third portion 166c of the elongate tubular member 150 is wrapped around the thread 164a (step 1 14) (see Fig. 16F). By way of non-limiting example, a thread 164b may be tied around the elongate tubular member 150 disposed adjacent to the second opening 94 of the mandrel 88. The thread 164b is composed of suitable materials configured to withstand high temperatures. Notably, the second portion 166b of the elongate tubular member 150 corresponds to the distal portion 72 of the tubular structure 38 illustrated in Fig. 10, and ultimately, the outer wall 82 of the multi-layer scaffolding 80 illustrated in Fig. 13, and the third portion 166c of the elongate tubular member 150 corresponds to the inflection region 76 of the tubular structure 38 illustrated in Fig. 10, with the region of the third portion 166c that is cinched by the thread 164a forming the aperture 78 in the outer wall 82 of the single layer scaffolding 80 illustrated in Fig. 13. Furthermore, a fourth portion 166d of the elongate tubular member 150 disposed within the lumen 96 of the mandrel 88 corresponds to the proximal end 44 of the tubular structure 38 to which the elongate embolic element 40 will be coupled/attached, as illustrated in Figs. 1 and 2.

[0068] Optionally, if additional layers of the fully deployed scaffolding are desired (i.e. , more than layers), steps 106-1 14 may be repeated at the first second end 152 of the elongate tubular member 150 using another mandrel, ultimately creating additional inflection regions (not shown). Next, the elongate tubular member 150, with the mandrel 88, is heat set (e.g., at 450°C to 650°C for 1 to 60 minutes) to impart a“secondary shape”, i.e., the spherical, ovoid, or bulbous shape, onto the elongate tubular member 150 (step 1 16). That is, the second portion 166b of the elongate tubular member 150 (ultimately, the distal portion 72 of the tubular structure 38) will be pre-shaped to assume the expanded spherical, ovoid, or bulbous geometry; the first portion 166a of the elongate tubular member 150 (ultimately, the proximal portion 74 of the tubular structure 38) will be pre-shaped to assume the same expanded spherical, ovoid, or bulbous geometry; and the third portion 166c of the elongate tubular member 150 (ultimately, the inflection region 76 of the tubular structure 38) will be pre-shaped to urge the first portion 166a of the elongate tubular member 150 to invert within the second portion 166b of the elongate tubular member 150. It should be noted that the third portion 166c of the elongate tubular member 150 is pre-shaped to wrap around on itself at least ninety degrees, and preferably at least one hundred eighty degrees, as best illustrated in Fig. 16F, thereby imparting a potential energy within the inflection region 76 that releases in snapping action (in the absence of an external force) as kinetic energy that urges the first portion 166a of the elongate tubular member 150 to invert.

[0069] Next, the excess portions of the elongate tubular member 150 extending from the first and second openings 92, 94 of the mandrel 88 are removed (e.g., cutting) (step 1 18) (Fig. 16G). Then, the elongate tubular member 150 is uncinched (e.g., by removing the threads 164a, 164b), the elongate tubular member 150 is unraveled, and the mandrel 88 is removed from the elongate tubular member 150, thereby creating the tubular structure 38 shown in Figs. 10 and 11 , with the distal portion 72, proximal portion 74, and inflection region 76 of the tubular structure 38 respectively assuming the characteristics of the second portion 166b, first portion 166a, and third portion 166c of the elongate tubular member 150 described above (step 120). Optionally, the distal end 42 of the tubular structure 38 can be cinched (e.g. by crimping a small ball onto the tip) to create a non-expanding, atraumatic, distal-most terminal end (step 122).

[0070] Next, the distal end 46 of the elongate embolic element 40 is bonded (e.g., soldered or welded) to the proximal end 44 of the tubular structure 38 to complete the vaso-occlusive device 16 (shown in Figs. 1 and 2) (step 124). It is noted that the elongate embolic element 40, prior to bonding to the elongate tubular member 150, can be shaped and heat-treated in a conventional manner (e.g., in the same manner that conventional embolic coils are fabricated), and thus for purposes of brevity, will not be described herein. Lastly, the distal end 36 of the pusher member 18 is bonded (e.g., soldered or welded) to the proximal end 48 of the elongate embolic element 40 to complete the vaso-occlusive assembly 14 (shown in Figs. 1 and 2) (step 126). It should be further anticipated that the elongate embolic element 40 may be constructed from the same material and at the same time of as the tubular structure 38 via shape setting an additionally more proximal portion of the tubular structure 38 into a form suitable for the purpose of an internal placed embolic scaffold.

[0071] Referring to Fig. 17 and Figs. 18A-18J, one exemplary method 200 of treating an aneurysm with the vaso-occlusive treatment 10 system will now be described. First, a clinician gains access to the patient’s vasculature, typically through the patient’s femoral in the groin, using an introducer kit and known access techniques (step 202). Alternative entry sites are sometimes chosen (e.g., in the arm or neck), which are in general well known by clinicians.

[0072] The clinician then navigates the delivery catheter 12 through the vasculature to reach a treatment site, such that the distal port 30 of the delivery catheter 12 resides in the parent vessel V at the aneurysm site, i.e. , adjacent the neck N of the aneurysm A (step 204) (see Fig. 18A). The vaso-occlusive treatment system 10 may be used in an“over-the-wire” configuration, wherein the delivery catheter 12 is introduced into the patient over a guidewire that has been previously introduced, and the delivery catheter 12 extends over the entire length of the guidewire (not shown). Alternatively, the vaso-occlusive treatment system 10 may be used in a“rapid-exchange” configuration, where a guidewire extends through only a distal portion of the vaso-occlusive treatment system 10 from a guidewire port (not shown). In other alternative embodiments, the delivery catheter 12 may be introduced into the patient after a guidewire has been withdrawn leaving a sheath or access catheter distal portion at the target site for the delivery catheter 12 to navigate through the vasculature of the patient within the sheath or access catheter. [0073] The vaso-occlusive assembly 14 is introduced into the lumen 28 of the delivery catheter 12, which can be accomplished after or before introduction of the delivery catheter 12 into the vasculature of the patient (step 206) (see Fig. 18B). A fluid, such as saline, may be introduced through the proximal port 32 into the lumen 28 of the delivery catheter 12 before or after introduction of the vaso-occlusive assembly 14 into the delivery catheter 12 (step 208). In this manner, the friction between the vaso-occlusive assembly 14 and the lumen 28 of the delivery catheter 12 is minimized to facilitate displacement of the vaso-occlusive assembly 14 within the delivery catheter 12. Next, the vaso-occlusive device 16 is advanced within the lumen 28 of the delivery catheter 12 via the pusher member 18 (step 210).

[0074] As the vaso-occlusive device 16 is advanced out of the distal port 30 of the delivery catheter 12, it self-expands into a pre-set configuration. In particular, the distal portion 72 of the tubular structure 38 is deployed from the distal port 30 of the delivery catheter 12 into the aneurysmal sac AS (step 212) (see Fig. 18C). As a result, the distal portion 72 of the tubular structure 38 expands within the aneurysmal sac AS (e.g., radially outward shown by arrows) assuming a spherical, oval, or bulbous configuration to create single-layer scaffolding 180 that lines the inner wall of the aneurysmal sac AS (step 214) (see Fig. 18D). Next, the inflection region 76 of the tubular structure 40 is deployed from the distal port 30 of the delivery catheter 12 (step 216), and forms a proximal-facing surface 182 in the single-layer scaffolding 180, the size of which incrementally increases with the extent that the inflection region 76 of the tubular structure 40 deploys from the distal port 30 of the delivery catheter (as the inflection region 76 gradually releases potential energy) (step 218) (see Figs. 18E-18G). Significantly, the proximal-facing surface 182 of the single layer scaffolding 180 bridges the neck N of the aneurysm A, thereby serving as a flow diverter.

[0075] The inflection region 76 then forms an aperture 184 in the proximal-facing surface 182 of the single-layer scaffolding 180, thereby facilitating subsequent inversion of the proximal portion 74 of the tubular structure 38 (step 220) (see Fig. 18H). As can be appreciated from Fig. 18H, the size of the aperture 184 is much smaller than the diameter of the single-layer scaffolding 180, thereby facilitating retention of the subsequently introduced elongate embolic element 40, while being large enough to accommodate the distal end 26 of the delivery catheter 12. The aperture 184 may, e.g., range between 0.5 and 2 millimeters in diameter. As can also be appreciated between Figs. 18G and 18H, the angle that the inflection region 76 makes with the longitudinal axis of the delivery catheter 12 increases from approximately 90 degrees to approximately 150 degrees, thereby showing the “snapping” action and full release of the remaining potential energy contained within the inflection region 76 to create the aperture 184 in the proximal-facing surface 184 of the single-layer scaffolding 180. Furthermore, the aperture 184 is formed absent an application of an opposing proximal force at the distal end of the single-layer scaffolding by the dome of the aneurysmal sac AS, such that the proximal-facing surface 182 of the single-layer scaffolding 180 remains as close as possible to neck N of the aneurysm A during the entire deployment process, thereby maximizing flow diversion of blood away from the neck N of the aneurysm A.

[0076] Next, the proximal portion 74 of the tubular structure 38 is deployed from the distal port 30 of the delivery catheter 12 (step 222), and inverts, while expanding, within the fully expanded distal portion 72 of the tubular structure 38 until a multi layered (in this case, double-layered) scaffolding 186 is created within the aneurysmal sac AS (step 224) (see Figs. 18I-18L)). Significantly, the tubular structure 38, and thus the multi-layered scaffolding 186, is now in its lowest energy state, thereby providing a stable platform that resists forces caused by pulsatile blood flow. It should be appreciated that if a scaffolding is not in its lowest-energy state when disposed within an aneurysmal sac, such scaffolding will tend to find its lowest-energy state in response to dynamic forces, such as pulsatile blood flow, and therefore, would be disadvantageously unstable. Furthermore, because the inflection region 76 of the tubular structure 38 urges the inversion of the proximal portion 74 of the tubular structure 38 within the single-layer scaffolding 180 (via creation of the aperture 184), the proximal-facing surface 182 of the single-layer scaffolding 180 remains as close as possible to neck N of the aneurysm A, thereby maintaining maximum flow diversion of blood away from the neck N of the aneurysm A during the entire inversion process. In an optional method, additional portions of the tubular structure 38 with associated inflection regions can be inverted and expanded within the multi-layer scaffolding 186 to add more layers to the scaffolding.

[0077] It should be noted that the third portion 166c of the elongate tubular member 150 is pre-shaped to wrap around on itself at least ninety degrees, and preferably at least one hundred eighty degrees, as best illustrated in Fig. 16F, thereby imparting a potential energy within the inflection region 76 that releases in snapping action (in the absence of an external force) as kinetic energy that urges the first portion 166a of the elongate tubular member 150 to invert.

[0078] Next, the elongate embolic element 40 is deployed from the distal port 30 of the delivery catheter 12 through the aperture 80 to fill the interior region 188 of the multi-layer scaffolding 186 (step 226) (see Figs. 18M-18N). The optional radiopaque marker 50 disposed on the proximal end 48 of the elongate embolic element 40 can be visualized under fluoroscopy to provide an indication that the elongate embolic element 40 is completely disposed within the interior region 188 of the multi-layer scaffolding 186. The elongate embolic element 40 has a suitable length to provide additional structural strength to the double-layered scaffolding. Notably, the structure of the elongate embolic element 40 (e.g., ribbon-shaped or coil-shaped) allows the elongate embolic element 40 to easily bend in order to fill the interior region 188 of the multi-layer scaffolding 186. The embolic element 40 thereby creates and additional internal supporting structure to further shape, bolster and stabilize the entire vaso-occlusive device 16. An optional method comprises delivering additional embolic devices (ribbons, coils, fibers, particles, liquids, etc.) of the distal port 30 of the delivery catheter 12 and through the aperture 80 into the interior region 188 of the multi-layer scaffolding 186. Notably, at any time, any portion or the entirety of the vaso-occlusive device 16 may be removed or withdrawn, and collapsed back into the delivery catheter 12 by proximally withdrawing the vaso-occlusive device 16 via the pusher member 18. Another optional method comprises plugging the aperture 184 in the multi-layer scaffolding 186 (step 226). For example, a plug (not shown) can be located at the proximal end 48 of the elongate embolic element 40, such that the plug engages the aperture 184 after the elongate embolic element 40 has been delivered into the interior region 188 of the multi-layer scaffolding 186.

[0079] After the elongate embolic element 40 and optional additional embolic devices have been delivered into the interior region 188 of the multi-layer scaffolding 186, the vaso-occlusive device 16 (i.e., the multi-layer scaffolding 186 and embolic elongate element 40) may be decoupled from the pusher member 18 at the junction 20 (step 228). The delivery catheter 12 is then withdrawn, leaving the implanted vaso-occlusive device 16 (i.e., the multi-layer scaffolding 186 and embolic elongate element 40, and any optional additional embolic devices) within the aneurysmal sac AS (step 230).

[0080] Although particular embodiments have been shown and described herein, it will be understood by those skilled in the art that they are not intended to limit the disclosed inventions, and it will be obvious to those skilled in the art that various changes, permutations, and modifications may be made (e.g., the dimensions of various parts, combinations of parts) without departing from the scope of the disclosed inventions, which is to be defined only by the following claims and their equivalents. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The various embodiments shown and described herein are intended to cover alternatives, modifications, and equivalents of the disclosed inventions, which may be included within the scope of the appended claims.

Claims

What is claimed is:

1. A vaso-occlusive device having a delivery configuration when restrained within a delivery catheter, and a deployed configuration when released from the delivery catheter into an aneurysmal sac, the vaso-occlusive device comprising: a tubular structure, including

a distal portion configured for expanding within the aneurysmal sac when distally deployed from the delivery catheter into the aneurysmal sac, a proximal portion configured for inverting and expanding into the expanded distal portion when distally deployed from the delivery catheter, thereby creating multi-layer scaffolding within the aneurysmal sac, and

an inflection region between the distal portion and the proximal portion, the inflection region configured for urging the inversion of the proximal portion into the expanded distal portion.

2. The vaso-occlusive device of claim 1 , wherein the inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion absent an application of an opposing proximal force on a distal end of the expanded distal portion of the tubular structure.

3. The vaso-occlusive device of claim 1 or 2, wherein the inflection region is configured for urging the inversion of the proximal portion into the expanded distal portion in free-space.

4. The vaso-occlusive device of any of claims 1-3, wherein the inflection region maintains the tubular structure is in its lowest-energy state when the proximal portion is expanded and inverted into the expanded distal portion.

5. The vaso-occlusive device of any of claims 1-4, wherein the distal portion and the proximal portion are pre-shaped to have similar geometries.

6. The vaso-occlusive device of any of claims 1-5, further comprising an elongate embolic element proximally coupled to the tubular structure, wherein the elongate embolic element is configured for filling an interior region of the multi-layer scaffolding when distally deployed from the delivery catheter into the aneurysmal sac.

7. The vaso-occlusive device of any of claims 1-5, wherein the tubular structure further comprises:

a third portion configured for inverting and expanding into the expanded proximal portion when distally deployed from the delivery catheter into the aneurysmal sac, thereby adding another layer to the scaffolding within the aneurysmal sac, and

another inflection region between the proximal portion and the other proximal portion, the other inflection region configured for urging inversion of the other proximal portion into the expanded proximal portion.

8. The vaso-occlusive device of any of claims 1-7, wherein each of the distal portion and the proximal portion is configured for self-expanding into a spherical, ovoid, or bulbous shape.

9. The vaso-occlusive device of any of claims 1-4, wherein the distal portion comprises a non-expanding distal-most terminal end.

10. The vaso-occlusive device of any of claims 1-9, wherein the tubular structure comprises a mesh.

1 1. A method of treating an aneurysm in a patient, comprising:

inserting a delivery catheter into the patient until a distal end of the delivery catheter is adjacent a neck of the aneurysm;

distally advancing a tubular structure within the delivery catheter;

deploying a distal portion of the tubular structure from the distal end of the delivery catheter into a sac of the aneurysm;

expanding the distal portion of the tubular structure within the aneurysmal sac, thereby creating a single-layer scaffolding that lines a wall of the aneurysmal sac; deploying a proximal portion of the tubular structure from the distal end of the delivery catheter; initiating inversion of the proximal portion of the tubular structure at an inflection region between the distal portion and proximal portion of the tubular structure, wherein the inflection region urges inversion initiation of the proximal portion of the tubular structure; and

inverting, while expanding, the proximal portion of the tubular structure within the expanded distal portion of the vaso-occlusive device, thereby creating a multi layer scaffolding that lines the wall of the aneurysmal sac.

12. The method of claim 1 1 , wherein inversion of the proximal portion at the inflection region is initiated absent an application of an opposing proximal force on a distal end of the expanded distal portion of the tubular structure by a dome of the aneurysmal sac.

13. The method of claim 1 1 or 12, wherein the inflection region maintains the tubular structure is in its lowest-energy state when the proximal portion is expanded and inverted into the expanded distal portion.

14. The method of any of claims 11 -13, wherein the expanded distal portion and the expanded proximal portion have similar geometries.

15. The method of any of claims 1 1-14, further comprising filling an interior region of the multi-layer scaffolding with an embolic material.

16. The method of claim 15, wherein the embolic material is an elongate embolic element proximally coupled to the tubular structure.

17. The method of claim 15 or 16, wherein the elongate embolic element is an embolization coil or ribbon.

18. The method of any of claims 1 1-14, further comprising

deploying another proximal portion of the tubular structure from the distal end of the delivery catheter;

initiating inversion of the other proximal portion of the tubular structure at another inflection region between the proximal portion and the other proximal portion of the tubular structure, wherein the other inflection region urges inversion initiation of the other proximal portion of the tubular structure; and

inverting, while expanding, the other proximal portion of the tubular structure within the multi-layer scaffolding, thereby adding another wall to the multi-layer scaffolding.

19. The method of any of claims 1 1-18, wherein the tubular structure comprises a mesh, wherein the distal portion of the tubular structure expands into a spherical, ovoid, or bulbous shape within the aneurysmal sac.

20. The method of claim 19, wherein the proximal portion of the tubular structure self-expands within the single-layered tubular structure.

21. A method of manufacturing a vaso-occlusive device, comprising:

inserting an elongate tubular member through a lumen of a spherical, ovoid, or bulbous mandrel, such that a free end of the elongate tubular member extends from a first side of the mandrel;

inverting the free end of the elongate tubular member in a first axial direction from the first side of the mandrel to a second opposite side of the mandrel;

cinching the elongate tubular member adjacent the second side of the mandrel, such that a proximal portion of the elongate tubular member conforms to the mandrel;

inverting the free end of the elongate tubular member in a second opposite axial direction from the second side of the mandrel to the first side of the mandrel; cinching the elongate tubular member adjacent the first side of the mandrel, such that a distal portion of the elongate tubular member conforms to the proximal portion of the elongate tubular member over the mandrel;

heat treating the elongate tubular member, thereby imparting a self-expanding spherical, ovoid, or bulbous shape onto the distal portion and the proximal portion of the elongate tubular member;

uncinching the elongate tubular member; and

removing the mandrel from the elongate tubular member.

22. The method of claim 21 , wherein the elongate tubular member is cinched via threads.

23. The method of claim 21 or 22, further comprising bonding an elongate embolic element to the proximal portion of the elongate tubular member.

24. The method of any of claims 21-23, wherein the elongate tubular member comprises a mesh.