Bracket seal and preparation method thereof

Abstract

Various embodiments of seals for stent valves are described, and methods for making the same. In some embodiments, the seal or skirt includes a fabric wall portion and a polymeric material fused to the fabric wall portion, the polymeric material having a lower melting temperature than the fabric wall portion. The fibers of the fabric may remain unmelted at the interface with the polymeric material, the polymeric material being attached to the fibrous material of the fabric wall portion by fusion. The polymeric material may provide a welded joint to another fabric wall portion, and / or may reinforce the fabric and / or may plug pores of the fabric.

Description

[0001] This application is a divisional application of application No. 201680020037.8, application date 2016.02.02, and application titled “Stent seal and preparation method thereof”. Technical Field

[0002] The present invention relates to the field of implantable stents. Embodiments have been devised to solve problems encountered in the field of stent valves, such as heart stent valves (e.g., prosthetic heart valves). However, the concepts disclosed herein can be more widely applied to any stent or prosthesis, wherein a seal is required on the outer surface of the stent. Background Art

[0003] WO-A-2013 / 033791 and US-A-2013 / 331929 describe expandable sealing devices for intraluminal devices that are controlled actuated. These devices have the following benefits: low profile mechanisms for both self-expanding and balloon-expandable prostheses; containing only releasable materials; effectively conforming to the leak site so that the leak area is filled without destroying the physical and functional integrity of the prosthesis; and on-demand, controlled actuation that may not be pressure-actuated. Some of the examples show a removable peel-off cover on the mesh.

[0004] Reference may also be made to the improvements in WO 2014 / 072439.

[0005] However, achieving seals in prostheses, particularly heart stent valves, remains challenging, regardless of whether or not an expandable seal is used. There are many issues, including, but not limited to: manufacturability; reliably achieving a certain shelf life in toxic storage solutions; crimpability of the prosthesis for catheter insertion; hydrogel containment during and after implantation (if a hydrogel is used); ease of preparation and use by the physician; reliable deployment of the seal during and after implantation; reducing the risk of seal failure; and / or achieving a seal without compromising on the recapture / reinsertability of the prosthesis. Summary of the invention

[0006] The following presents a simplified summary of the disclosure in order to provide a basic, non-limiting understanding of some aspects of the disclosure.

[0007] One aspect of the present disclosure provides a prosthesis comprising a stent and a seal for preventing leakage of a para-prosthesis. Optionally, the prosthesis is a stent valve (e.g., a heart stent valve, such as an aortic stent valve). The seal may include any combination of one or two or more of the following features, all of which are optional:

[0008] (a) the seal may comprise a swellable material which swells when in contact with blood (or blood components);

[0009] (b) The seal may include a hollow seal envelope (also referred to herein as a cuff or seal chamber) that extends in a generally circumferential direction relative to the stent. Optionally, the hollow seal envelope may have a ring configuration, wherein the ring may have a variety of different cross-sectional shapes. The ring configuration may allow the hydrogel to migrate so that the seal expands where appropriate, and / or may allow the seal to expand substantially throughout the 360° circumference of the stent. Additionally or alternatively, the envelope may optionally be a flexible and / or compliant material to be able to conform to the irregular contours of the calcified native anatomical structure.

[0010] (c) The expandable material may be captured substantially within the interior of the seal envelope (which may also be referred to as the interior compartment of the envelope).

[0011] (d) The cladding may include at least one material segment extending around the entire circumference of the stent and being continuous in the circumferential direction of the stent. As used herein, the term "continuous" is intended to mean that the material has no seams or joints that interrupt its integrity around the circumference of the stent. Instead, the material segment is integrally formed, for example, in a closed loop or annular shape. In some embodiments, the cladding may include multiple wall portions consisting of one or more such material segments. In some embodiments, the cladding may consist substantially entirely of one or more segments of such material segments.

[0012] (e) The seal (and / or cladding) may further comprise a plurality of diffusion barrier wall portions which (at least collectively and simultaneously completely) substantially enclose the interior compartment to define a diffusion barrier to prevent liquid external to the seal from penetrating the seal.

[0013] (f) Alternatively, the seal (and / or cladding) may include a single diffusion barrier wall portion that substantially encloses the interior compartment (at least completely) to prevent liquid outside the seal from penetrating into the compartment. (Alternatively, in some embodiments, no diffusion barrier wall portion may be provided.)

[0014] (g) The diffusion barrier wall portion (if any) may include one or more metals. As used herein, the term "metal" is intended to encompass any material, including metals and / or metal compounds (e.g., oxides) and / or alloys. Examples of metal diffusion barrier materials include aluminum oxide and / or titanium.

[0015] (h) Additionally or alternatively, the diffusion barrier wall portion (if any) may include, for example, a laminate (the laminate includes at least one plastic film layer) and at least one diffusion barrier layer supported by the plastic film layer. A variety of different diffusion barrier layer materials are contemplated, including, by way of example only: metals (e.g., see above), non-metals (e.g., all materials other than metals), glass, polyvinylidene chloride (PVDC), liquid crystal, silicon oxide (SiOx). Optionally, multiple diffusion barrier layers may be provided, optionally one directly on top of another, or separated by plastic film layers. Where multiple diffusion barrier layers are used, at least some of the layers may be the same barrier material and / or at least some of the layers may be different barrier materials. For example, multiple diffusion barrier layers may include one or more non-metal layers (e.g., silicon oxide) and one or more metal layers (e.g., titanium). In some embodiments, at least two non-metal layers (e.g., silicon oxide) may sandwich a metal layer (e.g., titanium). Additionally or alternatively, in some embodiments, an alternating stack of metal (e.g., titanium) layers and non-metal (e.g., silicon oxide) layers may be provided. Additionally or alternatively, in some embodiments, at least two layers of a first barrier material (whether metal or not) may sandwich a layer of a second barrier material (whether metal or not). Additionally or alternatively, in some embodiments, a stack of alternating layers of a first barrier material (whether metal or not) and a second barrier material (whether metal or not) may be provided.

[0016] (i) In some embodiments, the diffusion barrier layer or material (e.g., in some embodiments, each layer and / or combination of layers) may be approximately not greater than about 10 μm thick, optionally approximately not greater than about 5 μm thick, optionally approximately not greater than about 4 μm thick, optionally approximately not greater than about 3 μm thick, optionally approximately not greater than about 2 μm thick, optionally approximately not greater than about 1 μm thick, optionally approximately not greater than about 500 nm thick, optionally approximately not greater than about 300 nm thick, optionally approximately not greater than about 200 nm thick, optionally approximately not greater than about 100 nm thick, optionally approximately not greater than about 50 nm thick, optionally approximately not greater than about 20 nm thick, optionally approximately not greater than about 10 nm thick. This thickness (or a suitable thickness) may be formed, for example, by a vapor deposition process (e.g., plasma vapor deposition).

[0017] (j) At least one diffusion barrier wall portion may be a non-removable integral part of the seal, for example a seal envelope. Such a non-removable wall portion may remain integral with the seal and the prosthesis during and / or after implantation.

[0018] (k) In addition or alternatively to (j), at least one diffusion barrier wall portion may be provided in the form of (or included in) a removable cover. Prior to removal, the diffusion barrier wall portion may help prevent liquid from diffusing into the envelope, for example, when the device is stored in a storage liquid environment prior to use. In use, the removable cover is configured to be removed prior to or during implantation. Removal of the cover may allow liquid to subsequently enter the envelope to communicate with the swellable material.

[0019] (l) At least one diffusion barrier wall portion may be substantially transparent so as not to obstruct the general visibility of underlying structures. For example, the removable cover may be substantially transparent.

[0020] (m) One or more non-removable barrier wall portions may be backed by a fabric. For example, the backing may overlap substantially the entire face of the non-removable barrier wall portion. The fabric may be bonded to the non-removable barrier wall portion substantially over its entire surface (forming, for example, an integral laminate), or the fabric may be bonded to the non-removable barrier wall portion in one or more discrete areas, for example, around the perimeter of the barrier wall portion. For example, using a fabric as a backing may provide easier suturing, and / or provide physical protection and / or reinforcement of the barrier wall portion. In some embodiments, the fabric backing may extend beyond at least one perimeter and / or end and / or edge of the diffusion barrier wall portion.

[0021] (n) Whether or not a diffusion barrier wall portion is provided, the cladding may comprise first and second fabric wall portions which sandwich edge regions of the membrane and are welded together to define a joint between the fabric wall portions and the membrane. The membrane may be directly joined to at least one, optionally both, of the fabric wall portions. Additionally or alternatively, the fabric wall portions may optionally extend beyond the periphery of the membrane to define a fabric-to-fabric direct weld region surrounding the membrane edge. Such a joint may provide a secure fastening of the membrane even if one surface of the membrane is not readily weldable (e.g. if the membrane is a laminate comprising a surface material layer, such as a metal which is not readily weldable to the fabric).

[0022] (o) The cladding may include at least one wall portion of at least partial conical shape. The at least one wall portion may, for example, be a radially inner wall portion. The at least partial conical shape may optionally match (or at least substantially match) a portion of the stent outer profile. The stent outer profile may include at least a partial conical stent segment.

[0023] (p) The cladding may include at least a first wall portion having an at least partially conical shape, and a second wall portion having an at least partially convex and / or outward channel shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions substantially matching each other at the respective axially spaced regions.

[0024] (q) The cladding may include at least one wall portion having an at least partially conical shape, and a second wall portion having an axially collapsed conical shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions substantially matching each other at the respective axially spaced regions. The term "axially collapsed conical shape" as used herein refers to a wall portion that is axially collapsed from an uncollapsed state, in which the wall portion has (and / or will have, and / or has) an at least partially conical shape having an axial height that is greater than the axial height in the collapsed state. The second wall portion may not have a precise conical shape in the collapsed state, however axially collapsing the conical shape may retain respective matching diameters to attach the first and second wall portions together, while forming excess material that can expand slightly to allow the seal to expand.

[0025] (r) The covering may include one or more wall portions of fabric, and wherein, at least when ready to be implanted, a radially inwardly facing wall portion adjacent to the stent includes a fabric surface for contacting (or forming contact with) the stent, and wherein a radially outwardly facing wall portion includes a fabric surface for contacting surrounding anatomical tissue when implanted.

[0026] (s) The envelope may comprise a fabric that substantially entirely encloses an interior compartment containing the expandable material. Optionally, a region of the fabric may be lined with a substantially non-stretchable membrane (or a laminate comprising such a membrane). The membrane may provide local reinforcement of the fabric to resist stretching. Such a configuration may be implemented, for example, in the region of the cuff facing the stent. The membrane may reduce any tendency of the fabric to expand through gaps in the stent structure. This configuration may promote expansion of the cuff in a direction away from the stent and may reduce expansion through gaps in the stent. Optionally, the membrane may be plastic or may include plastic.

[0027] (t) The envelope may comprise a fabric substantially entirely enclosing an internal compartment containing the expandable material. Optionally, an area of ​​the fabric may be lined with a diffusion barrier wall portion to hinder liquid from penetrating the area of ​​the fabric lined with the diffusion barrier wall portion. The diffusion barrier wall portion may be welded to the fabric, for example around the periphery of the diffusion barrier wall portion. The diffusion barrier wall portion may be a non-removable integral part of the seal. The diffusion barrier wall portion may have any of the previously described properties or configurations.

[0028] (u) The seal and / or cladding may include a fabric segment having a self-supporting raised shape. For example, the raised shape may include an annular protrusion or an annular channel. Additionally or alternatively, the raised shape may define a region having an outer diameter (relative to, for example, a central axis of the stent) that is greater than the outer diameter of first and second regions that axially define the raised shape. Additionally or alternatively, the raised shape may be radially collapsible and / or compliant. This aspect is not in any way limited to seals using expandable materials, but may be used with any type of seal, such as a seal in which the raised shape may facilitate sealing functionality.

[0029] (v) The raised shapes in the fabric can be set as heat-set or thermoformed shapes. The shapes can include annular raised and / or channel configurations.

[0030] (w) The cladding may comprise wall portions attached together by laser welding.

[0031] (x) The cladding or some other component of the prosthesis may include first and second fabric wall portions joined together at a weld joint, the weld joint comprising a polymeric material having a melting temperature lower than at least one, optionally both, of the fabric wall portions. Optionally, the fabric fibers may remain unmelted at the weld, the weld being achieved by fusing the polymeric material to the fibers of the fabric wall portions. In a related aspect, a method of joining the first and second fabric wall portions together may generally include: providing a fusible polymeric material at least at a target location to make a joint between (optionally, between) the fabric wall portions, the fusible polymeric material having a melting temperature lower than at least one, optionally both, of the fabric wall portions; subjecting the target location to be joined to heat to fuse the polymeric material to the fabric wall portions to achieve a joint at the interface between the fabric wall portions. Optionally, the operation is performed at a temperature lower than the melting temperature of at least one, optionally both, of the fabric wall portions.

[0032] (y) During manufacturing processes involving welding near or around an expandable material (eg, a hydrogel), the hydrogel may be protected from exposure to high temperatures that would otherwise significantly reduce the expansion properties of the expandable material.

[0033] (z) The seal may be constructed in a tubular form and assembled to the bracket in a tubular form.

[0034] (za) The seal may be incorporated into the skirt of the stent-valve and sutured to the stent at locations on both axial sides (e.g., both axially above and below) of the seal. The skirt may include fabric. The sutures may be formed at locations or areas where the skirt includes (i) fabric only or (ii) fabric reinforced by a polymeric material fused to, coated on, impregnated into, or integral with the fabric.

[0035] (zb) The seal and / or cladding and / or skirt (e.g., inner and / or outer) and / or some other component of the prosthesis may include a fabric whose pores are substantially blocked by a polymeric material. For example, the polymeric material may penetrate or impregnate the network of fabric fibers. Additionally or alternatively, at least some of the polymeric material may be disposed between the fibers. The polymeric material may, for example, be a coating on the fabric, or a membrane fused to the fabric. In some embodiments, the fabric may be dip-coated with the polymeric material. In some embodiments, the polymeric material may, for example, be or include polyurethane. Additionally or alternatively, the fabric may optionally include PET.

[0036] In a closely related aspect, a method is disclosed that includes coating a fabric with a polymeric material so as to substantially block the pores of the fabric with the polymeric material. The method may include, for example, dipping the fabric with the polymeric material, or fusing or melting the polymeric material to the fabric, but not substantially melting the fabric.

[0037] Use of such polymeric materials can strengthen the fabric and avoid the risk of uncontrolled pore growth when the fabric is subjected to stresses that could otherwise cause the fabric to stretch or pores to grow. Such stresses can be generated, for example, during a recapture or reinsertion operation to at least partially re-collapse the prosthetic stent-valve when the prosthesis is not optimally positioned and / or not functioning as desired.

[0038] (zc) The seal and / or cladding and / or skirt (e.g., inner and / or outer) and / or some other component of the prosthesis may include a composite material comprising a fabric and a polymeric material carried on and / or coated on and / or impregnated in at least a first region of the fabric. In the first region, the composite material may combine some properties of the fabric with some properties of the polymeric material. For example, like a fabric, the composite material may be sutured to other components by passing sutures through locations corresponding to holes in the fabric. The fabric fibers may provide a structural network or framework, thereby providing resistance to crack propagation caused by suture holes. Additionally or alternatively, like a polymeric material (e.g., a membrane), the composite may withstand stress but will not substantially increase the size of the hole. The polymeric material may reinforce the fabric material to resist hole enlargement; the fabric may reinforce the polymeric material to resist crack propagation. The composite material may be substantially flexible and / or thermoformable. The composite material may be weldable and / or fusible and / or heat-sealable to other fabrics or composite materials.

[0039] (zd) The seal and / or cladding and / or skirt (e.g., inner and / or outer) and / or some other component of the prosthesis may include a piece of fabric that carries polymeric material in one region to form or actually form a welded joint to another piece or surface (e.g., as described above), and (ii) carries polymeric material in another region to plug the pores of the fabric and / or reinforce the fabric (e.g., as described above). The polymeric material may be the same in both regions, for example, polyurethane. Alternatively, another region of the fabric may have substantially open pores and / or substantially non-plugged pores, for example, without the presence of polymeric material.

[0040] (ze) A seal and / or cladding may be arranged at the end of a stent and / or prosthesis in an area adjacent to one or more attachment elements to releasably attach the stent to a stent holder of a delivery catheter of the prosthesis.

[0041] (zf) The seal and / or cladding may be arranged at the end of the stent and / or prosthesis so that, in use, the seal and / or cladding generally remains restrained against expansion by restraining the sheath of the deployment catheter until the majority of the stent and / or prosthesis is withdrawn. Such an arrangement may facilitate reinsertion as desired by the operator.

[0042] Additionally or alternatively, another aspect of the present disclosure may provide a prosthesis (eg, a prosthetic heart valve) or a seal for a prosthesis, wherein the prosthesis and / or the seal includes a fabric wall portion and a polymeric material fused to the fabric wall portion.

[0043] Optionally, any one or more of the following features may be provided in any combination, all of which are optional:

[0044] (a) The polymeric material may have a melting temperature lower than that of the fabric wall portion.

[0045] (b) The fibers of the fabric may remain unmelted at the interface with the polymeric material, the polymeric material being attached to the fibrous material of the fabric wall portion by fusion.

[0046] (c) A second fabric wall portion may also be provided, to which the polymeric material is fused.

[0047] (d) The polymeric material may provide welded joints between fabric wall sections.

[0048] (e) The polymeric material may substantially block the pores of the fabric wall portion.

[0049] (f) The polymeric material may or may not extend substantially through the fabric wall portion.

[0050] (g) The fabric wall portion may comprise one or more first regions provided with polymeric material fused to the fabric wall portion, and one or more second regions where said polymeric material is absent.

[0051] (h) at least one welded region may be provided wherein the polymeric material is fused to the first and second fabric wall portions to provide a joint between the wall portions; and / or at least one non-welded region may be provided wherein the polymeric material is fused to only a single fabric wall portion.

[0052] (i) The fabric may be a woven fabric.

[0053] (j) The fibers of the fabric are capable of at least partial reorientation in areas remote from the polymeric material to allow the fabric to accommodate dimensional changes.

[0054] (k) The fabric wall portion and / or the polymer material may include a material selected from the group consisting of polyester, polyethylene terephthalate (PET), polyetheretherketone (PEEK), polypropylene (PP), polytetrafluoroethylene (PTFE), polyurethane (PU), ultra-high molecular weight polyethylene (UHMWPE), silicone, polyoxymethylene, polyphenylsulfone, polysulfone, polyvinylidene fluoride, and polyamide.

[0055] (l) The fabric wall portion may comprise polyester (eg, PET), and / or the polymeric material may comprise polyurethane.

[0056] (m) A prosthetic heart valve may include a stent assembly and a skirt carried by the stent assembly, wherein the skirt includes a fabric wall portion.

[0057] (n) The skirt may not be and / or not have a peelable cover.

[0058] (o) The skirt may define an envelope comprising a material that expands when in contact with blood or blood components.

[0059] (p) Sutures may be provided to secure the skirt to the stent assembly, wherein the sutures pass through the polymeric material.

[0060] (q) Sutures may be passed through the fabric wall portion and the polymeric material fused to the fabric wall portion.

[0061] (r) A prosthetic valve comprising a fabric wall portion is compressible to a collapsed configuration for introduction into the heart via a catheterization technique and is expandable to an implant configuration.

[0062] Another aspect of the present disclosure may provide a seal or skirt for a prosthetic heart valve, the seal or skirt comprising a fabric wall portion and a polymeric material fused to the fabric wall portion. The polymeric material may have a melting temperature lower than that of the fabric wall portion. The fibers of the fabric may remain unmelted at the interface with the polymeric material, the polymeric material being attached to the fibrous material of the fabric wall portion by fusion. The polymeric material may provide a welded joint to another fabric wall portion, and / or may reinforce the fabric and / or may plug holes in the fabric.

[0063] As used herein, the term fabric means any woven or non-woven material consisting of a network of fibers or filaments. The terms fiber and filament are used interchangeably herein. In particular, the fabric may be a woven fabric.

[0064] Although certain features, aspects, and concepts have been particularly emphasized above and / or in the appended claims, protection is sought for any novel features or concepts described herein and / or illustrated in the drawings whether or not emphasized. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0066] Figure 1 Schematic diagram of a stent-valve suitable for use with some embodiments of the present disclosure. The figure is broken along the centerline of the stent-valve. The stent structure is shown on the right, and a cross-section showing the location of the valve, skirt, and seal is shown on the left.

[0067] Figure 2 To show in more detail Figure 1 An enlarged schematic cross-sectional view of the seal 40 in FIG. Figure 2 In the following figures, the seal is shown on the right side of the section (not Figure 1 to the left in the figure, but without any technical consequences).

[0068] Figure 3 Schematic diagram of a technique for providing a shape in a fabric tube.

[0069] Figure 4 Schematic diagram of cutting a material blank from a fabric sheet oblique to the orthogonal weave and / or thread direction of the fabric.

[0070] Figure 5 Schematic diagram of cutting a tapered membrane segment from a catheter balloon.

[0071] Figure 6 To show Figure 2 Schematic cross-sectional view of welding details.

[0072] Figure 7 is a schematic diagram illustrating a technique for forming an axially collapsed conical skirt portion.

[0073] Figure 8 Schematic diagram of a skirt with an outer wall portion after axial collapse.

[0074] Fig. 9 For similar Figure 2 A schematic diagram showing stent-valve storage in a liquid storage solution.

[0075] Fig.10 is a schematic cross-sectional view of another example of a stent-valve including a heat-cured fabric skirt.

[0076] Fig.11 For similar Figure 2 A schematic cross-sectional view of another example of a skirt structure in FIG.

[0077] Fig.12 Schematic diagram of the welding technique used to join fabric panels.

[0078] Fig.13 Schematic diagram of how the swelling ability of a hydrogel is achieved by exposure to high temperature.

[0079] Fig.14For similar Fig.11 A schematic cross-sectional view of another example of a skirt structure in FIG.

[0080] Fig.15 For similar Fig.14 A schematic cross-sectional view of another example of a skirt structure in FIG.

[0081] Fig.16 Schematic diagram of the technology for fusing polymeric materials to fabrics.

[0082] Fig.17 for Fig.16 Schematic diagram of the fabric after the polymer material is fused.

[0083] Fig.18 For similar Figure 2 A schematic cross-sectional view of another example of a skirt structure in FIG.

[0084] Fig.19 For similar Fig.18 A schematic cross-sectional view of another example of a skirt structure in FIG.

[0085] Fig. 20 For similar Fig.18 A schematic cross-sectional view of another example of a skirt structure.

[0086] Fig.21 For similar Figure 1 A schematic cross-sectional view of an alternative seal position is shown.

[0087] Fig. 22 Schematic diagram of implantation using a catheter sheath, shown in a partially deployed state. DETAILED DESCRIPTION

[0088] Reference Figure 1 , a stent prosthesis according to some embodiments is shown in the form of a stent-valve 10. The stent-valve may include a seal 40 (described further below) for sealing against surrounding tissue when the stent-valve 10 is implanted. The stent-valve 10 may be a cardiac stent-valve, such as an aortic stent-valve, a mitral stent-valve, a pulmonary stent-valve, or a tricuspid stent-valve, for implantation at various locations in a human heart.

[0089] Details of an alternative example of a stent-valve structure are described first, followed by a detailed description of details of an exemplary sealing structure.

[0090] The stent-valve 10 can be compressed to a radially compressed state (not shown) for delivery using a delivery catheter (not shown), and can be expanded to an effective or expanded state (similar to that shown) when implanted. The stent-valve 10 may include a stent 12 carrying a plurality of leaflets to define a valve 14 (the location of the valve 14 is schematically depicted by a boundary imaginary line). Various geometric shapes of the stent 12 can be used. In some embodiments, the stent 10 may include one or more of the following: a lower tubular or crown portion 16 (e.g., defining an inlet section), an upper crown portion, a plurality of upright joint supports 20, and a plurality of stable arches 22. The stent 12 may have opposing first and second ends. The lower tubular crown portion 16 may define a first end of the stent. The upper crown portion 16 may have a free edge located between the two ends (e.g., separated by the two ends). The joint support 20 may be optionally separated by the two ends. The stable arch 22 may extend between the joint support 22 and the second stent end. Stabilizing arches 22 can define a second bracket end (e.g., a tip and / or an arch vertex of stabilizing arches 22 can define a second bracket end). Stabilizing arches 22 can overhang and interconnect the joint support members 20. In addition or alternatively to any of the above, stabilizing arches 22 can bend or flex substantially independently of each other and relative to the joint support members 20.

[0091] In use, the lower portion of the stent 12 can be configured to be deployed after other areas of the stent 12. For example, the arch 22, the support 20, and the upper crown 18 can be deployed at least partially before the lower portion 16 (in this order, or in the opposite order, or in a different order). Once at least the upper crown 18 has been at least partially deployed, the stent 12 can be advanced and / or displaced in the direction of arrow 24 to abut the upper crown 18 against the native leaflets at the implantation site. The lower portion 16 is deployed last to secure the stent 12 in its final position.

[0092] Optional portions of the lower portion 16 and upper crown 18 may be formed by a lattice structure of the stent. The lattice structure may define cells or holes or gaps, for example, generally diamond-shaped holes (although not strictly diamond-shaped in some embodiments).

[0093] The native leaflets may generally overlap a portion of the stent 26. The native valve annulus may overlap a portion of the stent 28.

[0094] Alternatively, the stent-valve 10 may also include an inner skirt 30 that is communicated with the leaflet 14 and is carried on the inside of the stent 12. Alternatively, the inner skirt 30 is directly connected to the leaflet 14. In addition or alternatively, the stent-valve 10 may also include an outer skirt 32 that is carried on the outside of the stent 12. When two skirts are provided, the skirts may overlap at least in part. In some embodiments, one skirt (e.g., outer skirt 32) may optionally extend more toward the lower end of the stent 12 than another skirt (e.g., inner skirt 30). In addition or alternatively, one skirt (e.g., inner skirt 30) may optionally extend more toward the upper end of the stent 12 than another skirt (e.g., outer skirt 32). The skirt may be any suitable flexible and / or compliant material, for example, a fabric (e.g., PET fabric) or a biological tissue (e.g., pericardial biological tissue). The skirt may be the same specific material, or the same type of material (e.g., biological tissue, fabric), or different types of materials. In some examples described below, the outer skirt 32 may be fabric, and the inner skirt may be fabric or biomaterial as desired.

[0095] Optionally, the inner skirt 30 and the outer skirt 32 may be directly fixed to each other along at least one substantially continuous or discontinuous attachment line. The attachment may be one or more of the following: for example, suturing, welding, fusion, bonding. The attachment line may optionally extend around the entire circumference of the stent-valve. The attachment may reduce the risk of blood leakage in the stent space between the inner skirt 30 and the outer skirt 32.

[0096] Optionally, the outer skirt 32 is positioned at least so that the upper crown 18 is substantially unobstructed by the outer skirt 32. Such an arrangement may facilitate good blood flow to the coronary arteries (eg, in the case of a stent-valve for an aortic valve).

[0097] In some embodiments, the lower portion 16 has an end (eg, a lower end or an inlet end) formed by a generally zigzag shape. The zigzag shape may be composed of a lower vertex 16a and an upper vertex 16b. The upper vertex 16b is at Figure 1 The outer skirt 32 may be masked by the superposition demonstration of the frontmost unit and the last unit of the grid structure. The zigzag shape around the circumference of the stent 12 may be substantially continuous. The outer skirt 32 may have a zigzag circumference that roughly matches the zigzag shape of the end of the lower portion 16. Such an arrangement can avoid excessive material at the end, thereby facilitating the crimping (crimp) of the stent valve 10. At the same time, the outer skirt 32 covers (e.g., completely covers) the open cells of the grid structure downwardly until the end of the stent to reduce the risk of blood leaking through the holes of these cells. The outer skirt 32 may also be provided with a material layer on the struts of the stent to ease the engagement between the stent and the sensitive natural heart tissue.

[0098] The stent-valve 10 (e.g., valve 14) may optionally include biological tissue (e.g., pericardium (such as porcine pericardium and / or bovine pericardium) and / or native heart valve leaflets (e.g., native porcine heart valve leaflets, optionally attached to a portion of native heart wall tissue)). The biological tissue may be fixed, for example, using glutaraldehyde.

[0099] The stent 12 can optionally be self-expanding and can be compressed (e.g., crimped) to a compressed configuration for loading into a delivery catheter (not shown) having a sheath for constraining the stent in a compressed configuration for delivery to an implantation site. In use, the stent 12 self-expands to or toward an operational configuration by removing the constraining effect of the sheath. The self-expanding stent can have, for example, a shape memory material, such as a shape memory metal alloy, such as a nickel-titanium alloy (e.g., Nitinol). Additionally or alternatively, the stent 12 can be configured to expand by applying an axial foreshortening force from a delivery catheter and / or by applying a radial expansion force from a delivery catheter, such as by using an expansion balloon.

[0100] The stent-valve 10 may also include a seal 40 for sealing against surrounding natural tissue when the stent-valve 10 is implanted. The seal 40 may be disposed at any suitable location on the stent 12. In some embodiments, the seal 40 may be disposed between the end of the upper crown 18 and the end of the lower crown or tubular portion 16. In some embodiments, the seal 40 may be selectively positioned closer to the upper crown portion 18, or selectively closer to the lower crown or tubular portion 16, or selectively between the ends of the two crowns 16 and 18, or selectively at the waist or trunk section between the two crowns 16 and 18. In some embodiments, the seal 40 is carried on the exterior of the stent 12.

[0101] As described above, in some embodiments, the (e.g., lower or inlet) periphery of the stent 12 has a generally zigzag shape. The zigzag shape may include a lower apex 16a and an upper apex 16b. If desired, the seal 40 may be arranged to be located only between the end of the upper crown 18 and the upper apex 16. For example, the seal 40 may not extend to occupy the space between the upper apex 16b and the lower apex 16a. Positioning the seal 40 away from the lower apex 16a can reduce the amount of material at the end and facilitate crimping. Additionally or alternatively, the seal may be positioned to substantially not cover the upper crown 18. The uncovered upper crown 18 can enhance blood flow to the coronary arteries (e.g., in the case of a replacement valve in the position of an aortic valve).

[0102] The seal 40 may be configured to seal against surrounding native tissue when the stent-valve 10 is implanted. In some embodiments, the seal 40 may be provided as an integral part of the stent-valve 10.

[0103] Reference Figure 2 , the seal 40 is shown as being incorporated into the outer skirt 32 to provide for convenient construction and installation of the seal 40. However, the same principles may be used in other embodiments where the seal 40 is not so incorporated.

[0104] The seal 40 may include a hollow envelope 42 arranged to extend circumferentially around the stent 12 and define an interior compartment 44 containing an expandable material 46 that expands when in contact with blood (or blood components). In some embodiments, the seal envelope 42 has a toroidal configuration to define a circumferentially continuous interior compartment 44. The expandable material 46 may be captured within the envelope 42. Various types of expandable materials may be used, including but not limited to hydrogels and / or superabsorbent materials. Examples of suitable materials may be found in the foregoing description.

[0105] In some embodiments, the cladding 42 includes a first, e.g., radially inner wall portion 48 and a second, e.g., radially outer wall portion 50. In some embodiments, the first wall portion 48 and the second wall portion 50 may be formed from different pieces of material joined together. In some other embodiments, the first wall portion 48 and the second wall portion 50 may be a single piece of material or include portions of a single piece of material that is folded to define the cladding shape. Other configurations are also contemplated, and the following description applies to all configurations.

[0106] In the illustrated form, the second wall portion 50 may be axially longer than the first wall portion 48. The second wall portion 50 may generally define the outer surface of the outer skirt 32, thereby avoiding any exposed seams or joint lines or other abrupt interruptions that may complicate the ability to (i) slide the stent-valve axially through the compression funnel to compress or "crimp" the stent-valve, and / or (ii) recapture the stent-valve into the catheter, which is desirable during implantation. In some embodiments described subsequently, the skirt 32 may include a seam or joint line that extends generally axially. Axially extending seams or joint lines may also avoid circumferentially extending interruptions, thereby avoiding complicating the ability to crimp the stent-valve and / or recapture the stent-valve, as described above.

[0107] The second wall portion 50 may include the zigzag skirt edge previously described.

[0108] The radially inner wall portion 48 may optionally be generally conical, or at least partially conical. The radially inner wall portion 48 may optionally substantially match (e.g., be partially conical) the shape of the lower portion of the stent 12. In other embodiments, the inner wall portion 48 may be generally non-conical and / or may not match the shape of the lower portion of the stent 12. For example, one or both of the wall portions 48 and 50 may be generally cylindrical.

[0109] The second wall portion 50 may optionally have a raised or raiseable area 52 axially bounded on either side (e.g., bounded from above and below) by areas 54 and 56 that generally match the diameter of respective areas of the first wall portion 48 to provide an attachment area between the first and second wall portions.

[0110] In other embodiments, the inner wall portion 48 may be generally non-tapered, and / or may not match the shape of the lower portion of the bracket 12. For example, one or both of the wall portions 48 and 50 may be generally cylindrical.

[0111] The first wall portion 48 and the second wall portion 50 can be any suitable material, including biological, natural or synthetic materials. In some embodiments, the first and second wall portions are fabrics or include fabrics. The fabrics can be the same or similar in the two wall portions, or different fabrics can be used for each wall portion. The fabrics can be arranged as one or more pieces joined together to define a ring and / or annular form.

[0112] In one example, the fabric may have a thickness of at least about 10 microns, optionally at least about 20 microns, optionally at least about 30 microns, optionally at least about 40 microns, optionally about 40 microns. Additionally or alternatively, the fabric may have a thickness of approximately not greater than about 100 microns, optionally approximately not greater than about 75 microns, optionally approximately not greater than about 50 microns, optionally approximately not greater than about 25 microns.

[0113] In addition or alternatively to any of the above thickness examples, the fabric may have a pore size of at least about 10 microns, optionally at least about 15 microns, optionally at least about 20 microns, optionally about 20 microns. Additionally or alternatively, the pore size may be approximately not greater than about 50 microns, optionally approximately not greater than about 100 microns, optionally approximately not greater than about 75 microns, optionally approximately not greater than about 50 microns, optionally approximately not greater than about 25 microns.

[0114] exist Figure 2 In the form shown, region 52 of second wall portion 50 may optionally have a self-supporting convex shape, although some other embodiments disclosed herein may not use such a self-supporting convex shape. Region 52 may extend radially outward to a diameter greater than the diameter of regions 54 and 56 that define region 52. Region 52 may be flexible and / or compliant. Such a form or shape may be, for example, a material that is thermoformed or thermoset. For example, referring to Figure 3, material 62 (e.g., a fabric) can be set by placing a tube of material on a mandrel 64, which has an outer contour representing the shape to be set of the material and includes corresponding annular protrusions 65. The protrusions may have any desired cross-sectional or contour shape. By way of example only, the protrusions 65 may have a contour that is any of circular, arcuate, semicircular, triangular, or trapezoidal. The tube of material 62 may be generally or at least partially cylindrical, and / or it may be at least partially conical. The material 62 may be provided in the form of an integral tube, or the tube shape may be formed by winding and fixing material cut from a sheet to define the tube shape. In the case of a fabric (whether cut from a sheet or provided in an integral tubular shape), in some embodiments, the direction of the braid and / or fibers may be inclined to the axial direction and / or circumferential direction of the tube. For example, referring to Figure 4 The blank 66 of the fabric material can be cut to form a partial tapered shape when wound into a tubular form, and the fabric blank is cut along a direction oblique to the braid direction and / or the fabric fiber direction. Cutting oblique to the braid direction and / or the fiber direction can reduce the resistance to thermal curing deformation.

[0115] Refer again Figure 3 , the shape defined by the mandrel can be set into the material 62, for example by using heat and shrinking techniques. In some embodiments, a heat shrink sleeve 68 can be fitted or wrapped around the material 62. When appropriately heated, the material 62 can be pulled against the surface of the mandrel 64 (as shown by the arrows) by the combination of the heat shrink material 68 tending to shrink against the mandrel 64 and the thermal deformation of the material 62. When subsequently cooled, the material is set or molded in the shape defined thereby. In addition to or in lieu of the heat shrink material, positive and / or negative pressure can be applied in combination with heat to pull the material against the mandrel to affect heat curing / thermoforming.

[0116] Whether or not such a forming operation is used, in the case of a fabric (whether cut from a sheet or provided in an integral tube form), in any embodiment described herein, the orientation of the braid and / or fibers may be oblique to the axial direction and / or circumferential direction of the tube. Such orientation of the braid and / or orientation of the fibers may, for example, enhance the functional conformity of the fabric during expansion of the outer wall portion 52 during crimping of the stent-valve and / or when the expandable material (whether or not provided in a self-supporting convex shape) is expanded.

[0117] Reference again Figure 2, at least one of the wall portions (e.g., the first wall portion 48) may optionally include (or optionally also include) a barrier wall portion 70, for example, that effectively hinders liquid diffusion. If present, the barrier wall portion 70 may, for example, be or include a metal and / or a non-metal. In some embodiments, the barrier wall portion 70 may include a laminate (the laminate includes at least one plastic film layer) and at least one diffusion barrier layer supported by the film layer. A variety of different diffusion barrier layer materials can be imagined, including, by way of example only: metal, non-metal, glass, polyvinylidene chloride (PVDC), liquid crystal, silicon oxide (SiOx). Optionally, multiple diffusion barrier layers may be provided, optionally one directly above the other, or separated by a plastic film layer. In the case of using multiple diffusion barrier layers, at least some of the layers may be the same barrier material and / or at least some of the layers may be different barrier materials. For example, multiple diffusion barrier layers may include one or more non-metal layers (e.g., silicon oxide) and one or more metal layers (e.g., titanium). In some embodiments, at least two non-metallic layers (e.g., silicon oxide) may sandwich a metal layer (e.g., titanium). Additionally or alternatively, in some embodiments, an alternating stack of metal (e.g., titanium) and non-metallic (e.g., silicon oxide) layers may be provided. Additionally or alternatively, in some embodiments, at least two layers of a first barrier material (whether or not metal) may sandwich a second barrier material layer (whether or not metal). Additionally or alternatively, in some embodiments, a stack of alternating layers of a first barrier material (whether or not metal) and a second barrier material (whether or not metal) may be provided.

[0118] In some embodiments, a combination of a titanium layer and a silicon oxide layer may be used. Silicon oxide can complement the manner in which titanium is deposited, such as when a vapor deposition process is used. Titanium can be deposited in a columnar manner, while silicon oxide can fill gaps, recesses, or trenches in the titanium or other layers or surfaces, thereby achieving better adhesion and improved barrier properties.

[0119] In some embodiments, the diffusion barrier layer or material (e.g., each layer and / or a combination of layers in some embodiments) may be approximately not greater than about 10 μm thick, optionally approximately not greater than about 5 μm thick, optionally approximately not greater than about 4 μm thick, optionally approximately not greater than about 3 μm thick, optionally approximately not greater than about 2 μm thick, optionally approximately not greater than about 1 μm thick, optionally approximately not greater than about 500 nm thick, optionally approximately not greater than about 300 nm thick, optionally approximately not greater than about 200 nm thick, optionally approximately not greater than about 100 nm thick, optionally approximately not greater than about 50 nm thick, optionally approximately not greater than about 20 nm thick, optionally approximately not greater than about 10 nm thick. This thickness (or a suitable thickness) may be formed, for example, by a vapor deposition process (e.g., plasma vapor deposition).

[0120] In the illustrated form, the barrier wall portion 70 (if any) may have an at least partially conical shape, such as to generally match the shape of the underlying stent 12, as described above. The barrier wall portion 70 may include a membrane that extends around the circumference of the stent 12 and is continuous along the circumference of the stent. For example, the membrane may have an overall closed loop or annular shape. Figure 5 In some embodiments, such a membrane can be obtained by cutting the membrane from a catheter balloon 60 (e.g., a valvuloplasty balloon). The location where the membrane is cut and the balloon diameter can be selected to obtain the desired shape, tilt angle, and diameter of the membrane. A typical valvuloplasty balloon includes two tapered portions, which can allow two different portions to be cut from the same balloon.

[0121] By using a circumferentially continuous barrier wall portion (eg a film, and optionally cut from the balloon), a strong and continuous barrier can be reliably achieved without complex structures.

[0122] In the illustrated form, the barrier wall portion 70 (if any) may be a non-removable integral portion of the stent-valve and / or seal 40 and / or envelope 42 that remains intact and / or in place when the stent-valve 10 is implanted. For example, the barrier wall portion 70 is implanted with the stent-valve.

[0123] Reference Figure 6 , the barrier wall portion 70 (if any) may be attached to the fabric of the first wall portion 48 and / or the second wall portion 50 at a combined seam 74, where the barrier wall portion 70 is clamped. The barrier wall portion 70 may be directly joined to at least one, and optionally both, of the fabrics of the wall portions 48 and 50 by, for example, a weld 73. Additionally or alternatively, the fabrics of the wall portions 48 and 50 may optionally extend beyond the perimeter of the barrier wall portion to define a direct fabric-to-fabric weld area 72 surrounding the edge of the barrier wall portion 70. Such a joint may provide a secure fastening of the barrier wall portion 70, even when one surface of the barrier wall portion 70 is not easily weldable (e.g., the barrier wall portion is a film laminate that includes a surface layer of, for example, a metallic material that is not easily weldable directly to the fabric).

[0124] In some embodiments, laser welding may be used to achieve weld joint 74 (including regions 73 and 72). Laser welding can achieve precise and uniform weld joints with good control.

[0125] In some embodiments, the axial dimension of each weld region 72 and 73 may be about 1 mm, so that the combined seam 74 has an axial dimension of about 2 mm. The axial dimension of the cladding 42 (between regions 54 and 56) may be less than about 10 mm, optionally less than about 9 mm, optionally less than about 8 mm, optionally less than about 7 mm, optionally less than about 6 mm.

[0126] In some embodiments, the radial dimension of the protrusion 52 relative to the first wall portion 48 may be at least 1 mm, optionally at least 2 mm, optionally at least 3 mm.

[0127] The first wall portion 48 and the second wall portion 50 may optionally have distinct properties from one another in the region of the seal 40. The second wall portion 50 (e.g., fabric) may be porous to allow blood or blood components to pass through it into the internal compartment 44 to communicate with the expandable material 46. The second wall portion 50 may be flexible and / or compliant to allow the seal 40 to expand to fill the gap between the stent valve and the natural anatomical structure. In contrast, the barrier wall portion 70 (if any) of the first wall portion 48 may provide a substantially liquid-impermeable barrier to prevent any liquid from penetrating the first wall portion 48 into the internal compartment 44. In addition, for example, the film and / or metal constituting the barrier wall portion 70 (if any) may be substantially inextensible to strengthen the first wall portion 48 to resist radially inward deformation when the seal 40 expands. This may hinder the seal 40 from expanding inwardly through the voids of the stent 12 and, on the contrary, promote the outward expansion of the seal 40. At the same time, using fabric, such as in the first wall portion 48 and the second wall portion 50, as part of the envelope can provide a cushioning effect, thereby reducing the risk of damaging the seal envelope 42 and the expandable material 46 during preparation and / or storage and / or implantation and / or post-implantation. The fabric can also be sutured directly to the stent 12 and / or the inner skirt 30. For example, at least one, optionally at least two sutures (axially above and / or below the envelope 42, respectively) can be indicated by dashed lines. Figure 2 In the embodiment of the present invention, the outer skirt 32 is connected to the stent and / or the inner skirt. Optionally, by anchoring the sheath 42, the use of sutures above and below the sheath 42 can additionally or alternatively provide support to the material of the sheath 42, which hinders the seal 40 from expanding inwardly. More sutures (not shown) can also attach the lower edge of the outer skirt 32 to the stent (e.g., below the lower suture shown by the dashed line).

[0128] Reference Figure 7 and Figure 8 , an alternative cladding construction technique is shown. The following description focuses on the differences from the previous construction. The alternative construction may include any of the above-mentioned features and / or characteristics, whether explicitly mentioned or not.

[0129] Reference Figure 7 As an alternative to the shape setting technique for defining a self-supporting convex shape, region 52 may include excess material that allows region 52 to at least partially bulge or expand. Region 52 may be defined by an axially collapsed conical shape, with the first wall portion 48 and the second wall portion 50 joined together at respective axially spaced regions 54 and 56, with the diameters of the first and second wall portions substantially matching each other at the axially spaced regions. Figure 7 As best shown, the term "axially collapsed conical shape" describes a wall portion that is initially prepared to have an axial height greater than the expected spacing between regions 54 and 56, but with a diameter that, when axially collapsed, matches the conical shape of regions 54 and 56. Portion 52 may not have a true conical shape in the collapsed state, but axially collapsing the conical shape can maintain the respective matching diameters to attach first wall portion 48 and second wall portion 50 together while creating excess material that can expand to some extent to allow the seal to expand.

[0130] refer to Fig. 9 Before being used for implantation, the stent-valve 10 (any of the aforementioned configurations) may be stored in a storage liquid 80 to maintain its sterility and / or avoid damage to the leaflets. For example, the storage liquid may be a glutaraldehyde solution and / or an alcohol solution. To protect the seal 40 from the storage liquid entering the seal 40, the seal 40 may optionally further include a removable cover 82 that covers the area of ​​the second wall portion 50 at the seal envelope 44. The removable cover 82 may, for example, be a liquid-impermeable material and / or include a barrier wall portion similar to that described for the barrier wall portion 70 (if any). For example, the cover 82 may include a metal or a film that carries one or more barrier material layers deposited on the film. The removable cover 82 may be welded at position 84, for example aligned with the weld 72. Together, the removable cover 82 and the barrier wall portion 70 may define a liquid-impermeable barrier to protect the envelope from the ingress of liquid, even during extended storage time.

[0131] In the illustrated form, the cover 82 may have a shape that matches the protrusion 52. In other embodiments (not explicitly shown), the protrusion 52 may collapse or fold radially toward the first wall portion 48, and the cover 82 may be laid flatter relative to the first wall portion 48, if desired.

[0132] In use, the removable cover 82 (if any) can be peeled off from the sealant envelope 42 during preparation for implanting the stent valve 10, for example after flushing the stent valve (cleaning the storage solution on the stent valve as soon as it is removed from the storage solution). The location of the weld 84 can avoid any damage to the underlying envelope during peeling. The relatively strong weld areas 72 and / or 72 and / or 74 withstand peeling forces.

[0133] Reference Fig.10 Another embodiment is shown in which the stent-valve 10 carries a fabric sealing skirt 90 but does not use expandable material. Figure 3The fabric sealing skirt 90 may be set (e.g., heat cured or thermoformed) to have a convex shape according to the described technology. Therefore, the fabric skirt may have a self-expanding property to gently and / or uniformly expand into contact with the surrounding anatomical structure to fill any gap between the stent valve 10 and the surrounding anatomical structure. The skirt 90 may be generally arranged outside the stent 12, or in some embodiments, a portion 92 of the skirt 90 may be folded toward the inside of the stent 12 to define an integral inner skirt (optionally connected to the leaflet 14). The skirt 90 may include a single piece of fabric, or it may include multiple pieces of fabric attached together along one or more seams. These pieces may be attached by sutures and / or welds (e.g., laser welds) as previously described and further explained below.

[0134] Fig.12 1 shows a welding technique that can be used to join at least first and second fabric panels or wall portions 100 and 102 in some embodiments of the present disclosure. Fabric panels 100 and 102 can be the same material or different materials. The welding technique can be suitable for example Figure 2 and Fig.11 The welded joints 54 and 56 in the target area are provided with a fusible polymeric material 104 at least in the target area for joining. The fusible polymeric material may be, for example, a film 104 disposed between the fabric pieces 100 and 102, for example in the target area for joining. Additionally or alternatively, the fusible polymeric material may be carried by one or both of the fabric pieces 100 and 102. For example, the fabric pieces 100 and / or 102 may be impregnated with the fusible polymeric material. Additionally or alternatively, the polymeric material 104 may be pre-fused to one or both of the fabric pieces 100 and / or 102, as described below with respect to Fig.16 and Fig.17 The polymeric material 104 may optionally be disposed on at least one side of the fabric 100 and / or 102 for bonding to the other components 100 and / or 102, whether or not the polymeric material 104 may also extend or penetrate through the fabric to the opposite side thereof.

[0135] The polymeric material 104 may have a melting temperature lower than at least one of the fabric pieces 100 and 102 , and optionally lower than the melting temperature of both fabric pieces 100 and 102 .

[0136] When heated, the polymeric material 104 melts and fuses to the respective fabric piece 100 or 102, or to both pieces 100 and 102 collectively. By heating and / or welding at a temperature below the melting temperature of the fabric pieces 100 and 102, the integrity of the fibers of the fabric pieces 100 and 102 can be maintained, thereby maintaining fabric strength even in the traditionally weak "heat affected zone" adjacent the weld. In addition, the polymeric material 104 can act as a filler material, flowing into the fiber network to provide a strong mechanical bond with a large bond area and provide a plugged, leak-proof seal at, for example, the interface between the fabric pieces 100 and 102. Heat can be introduced to a location, such as a weld location, by any suitable technique, such as by a laser or by contact with a hot welding member or head, or by placement in a heated oven. In some embodiments, the contact pressure applied to each fabric piece 100 and / or 102 or to fabric pieces 100 and 102 collectively may be generated by heat shrinking the material in a manner similar to that already described above, or by applying external pressure (e.g., placing the fabric piece in a vacuum or reduced pressure container).

[0137] In some embodiments, the fibers of the fabric may allow at least some of the fiber directions to be reoriented away from the weld region to allow the fabric to accommodate dimensional changes, such as during crimping and expansion of the stent-valve and / or during expansion of the skirt envelope when the expandable material expands during use. For example, at least some (optionally at least a majority, optionally all or nearly all) of the fibers may be arranged obliquely (and / or non-orthogonally) to the direction of the weld region and / or the axis of the stent-valve and / or the circumference of the stent-valve.

[0138] Examples of biocompatible polymers that may be used as materials for fabric pieces 100 and 102, and polymeric material 104, are shown in Table 1 along with exemplary melting temperatures for each material (keeping in mind that when selecting a combination of materials, polymeric material 104 may have a melting temperature lower than at least one, and optionally both, of fabric pieces 100 and 102, as described).

[0139]

[0140] Table 1

[0141] In one example, the fabric pieces 100 and 102 for the outer skirt may both be PET, which has a melting temperature of about 250° C., and the polymer material 104 may be polyurethane (PU) having a melting temperature of about 210° C. The welding and / or fusing of the polymer materials is performed at a temperature of at least 210° C. but less than 250° C.

[0142] During the preparation of the skirt structures described herein, the welding operation may be performed in situ with the expandable material 46. However, the inventors have recognized that the expansion response of the material is adversely affected by exposure to elevated temperatures. Fig.13 The amount of expansion of an example hydrogel (at room temperature) (vertical axis) is shown as affected after exposure to heat within a temperature range (horizontal axis) simulated by heating in a temperature-controlled oven for 5 minutes. Fig.13 As can be seen in the figure, the amount of expansion can be reduced due to exposure to temperatures above about 150°C. This reduction is permanent, even when the hydrogel returns to room temperature. Since many of the welding temperatures discussed above exceed this temperature, there is a risk that the hydrogel will be damaged by the manufacturing process unless special care is taken. In some embodiments of the present disclosure, the expandable material 46 can be protected from excessive temperatures during the manufacture of the skirt. For example, cooling of the hydrogel or the mandrel can be achieved by, for example, injecting cold air. Another possibility is to provide the mandrel with a heat sink (which is arranged in an area aligned with the position of the expandable material) to dissipate heat from that location. Another possibility is to provide a heat shield in the area desired to be protected to reflect and / or diffuse the applied thermal energy (e.g., from the laser) to avoid local overheating of the heat shield.

[0143] Closely related to the above principles, instead of welding two fabrics together, the present disclosure also contemplates a fabric (optionally, a single piece) whose pores are substantially blocked by a polymeric material. For example, the polymeric material may penetrate or saturate the fiber network of the fabric. Additionally or alternatively, at least some of the polymeric material may be disposed between the fibers. The polymeric material may, for example, be a coating or film on the fabric, or a film fused to the fabric. In some embodiments, the fabric may be impregnated with the polymeric material.

[0144] In some embodiments, the polymeric material may be or include polyurethane, for example. Additionally or alternatively, the fabric may optionally include PET.

[0145] In a closely related aspect, a method is disclosed that includes coating a fabric with a polymeric material to substantially plug the pores of the fabric with the polymeric material. The method may include, for example, dipping the fabric with the polymeric material, or fusing or melting the polymeric material to the fabric, but not substantially melting the fabric.

[0146] The use of such polymeric materials can strengthen the fabric and avoid the risk of uncontrolled growth of pores when the fabric is subjected to stresses which could otherwise cause the fabric to stretch and thus pores to grow.

[0147] Optionally, in one or more regions of the fabric, the polymeric material provides (i) a fusible material for welding and / or fusion welding to another piece or surface, and (ii) a non-welding material that plugs the pores of the fabric and / or reinforces the fabric. The polymeric material may be the same in both regions, e.g., polyurethane. Optionally, another region of the fabric may have substantially open pores and / or substantially non-plugged pores, e.g., no polymeric material is present.

[0148] Fig.16 and Fig.17 An example is shown of fusing a polymeric material 104 to a fabric piece 100 (which may correspond to fabric pieces 100 and / or 102 described previously) to provide a fabric area 110 that at least carries the polymeric material 104, and optionally a fabric area 112 that is at least substantially free of the polymeric material 104. The fabric may refer to being coated with a polymeric material, at least in some areas.

[0149] refer to Fig.16 , the polymeric material 104 may be provided as a film. The polymeric material 104 may be provided in a pattern that matches a desired pattern on the area 110 of the fabric 100. For example, the polymeric material may be pre-cut or embossed from a sheet of material in the desired pattern and / or the polymeric material may be provided in strip form. In the illustrated form, the polymeric material 104 is provided on the first side 100a of the fabric 100, but the polymeric material 104 may be provided on both sides, in the same or different patterns, as desired.

[0150] Heat may be applied to cause the polymeric material 104 to flow and / or fuse to the fabric 100. Heat may be applied without substantially melting the fibers of the fabric 100. Heat may be applied by any suitable technique (e.g., by a laser or by contact with a hot welding member or head, or by placement in a heated oven). In some embodiments, contact pressure may be applied to force the polymeric material 104 into close contact with the fabric 100, as indicated by one or both arrows. For example, contact pressure may be applied by heat shrinking the material in a manner similar to that already described above or by applying external pressure (e.g., placing the fabric 100 and polymeric material 104 in a vacuum or reduced pressure container). In the Fig.16 In the diagram, the contact pressure can be represented by the arrow.

[0151] Reference Fig.17 , upon cooling, a composite is prepared comprising a fabric 100 having a polymeric material 104 fused thereto in one or more first regions 110, and optionally without the polymeric material 104 in one or more second regions 112. The fabric may refer to being coated with the polymeric material (e.g., at least in some regions). The polymeric material 104 may optionally provide a pad-like surface on a first side 100a of the fabric 100 (corresponding to the side from which the polymeric material flows to the fabric). Depending on the process and materials used, in some embodiments, the polymeric material 104 may not fully penetrate the fabric 100 to its opposite side. Using such an arrangement, the polymeric material may be used as a plug that plugs or blocks a hole from one side. Alternatively, in some embodiments, the polymeric material 104 may penetrate the fabric to provide a pad-like surface on both sides. Alternatively, if desired, the polymeric material may be arranged to flow to the fabric from both sides to form a mass of polymeric material that plugs the hole from both sides.

[0152] As previously described, in one or more regions 110 of the fabric, the polymeric material 104 provides (i) a fusible material for welding and / or fusion welding to another piece or surface, and (ii) a non-welding material that plugs the pores of the fabric and / or reinforces the fabric. The polymeric material 104 can be the same in both regions 110, for example, polyurethane. Alternatively, another region of the fabric 112 can have substantially open pores and / or substantially non-plugged pores, for example, without the polymeric material 104.

[0153] Fig.14 By way of example, the incorporation of Figure 1 Another embodiment of a seal 40 within the outer skirt 32 is shown. Fig.14 An embodiment may be similar to Fig.11 Optionally, the embodiment may include the above Figure 2 Any one or combination or all of the details described, except that the barrier wall portion 70 may be omitted. In particular, Fig.14 The seal may include an annular envelope 42, an expandable material 46, a first (e.g., radially inner) wall portion 48, and a second (e.g., radially outer) wall portion 50. Either or both of the wall portions 48 and 50 may be or may include a fabric as previously described. The outer wall portion 50 may optionally be thermoformed in an annular raised shape. The wall portions 48 and 50 may be welded together at regions 54 and 56, for example, by laser welding. The outer skirt may be sutured to the stent and / or the inner skirt along suture lines above and below the envelope 42.

[0154] One or more regions 110 (schematically indicated by bold lines) of at least one fabric block wall portion 48 and / or 50 may be coated and / or covered with a polymeric material, for example, using any of the above-described techniques. In the illustrated example, the region 110 is disposed in the second (e.g., radially outer) wall portion 50. The one or more regions 110 may substantially cover the entire area of ​​the second wall portion 50, or only cover a selected area, for example, as shown in the figure. Another region 112 may optionally be substantially uncovered or uncoated with such a polymeric material, such as may be the first (e.g., radially inner) wall portion 48. Optionally, the first wall portion 48 also has a polymeric material coated in an area corresponding to the location of the weld joint, in preparation for forming a secure joint between the two wall portions 48 and 50. In other examples, the first wall portion 48 may be completely uncoated with a polymeric material. The polymeric material of the one or more regions 110 may have two functions. First, the polymeric material may provide a fusible material to form the weld joints 54 and 56. Secondly, in the area 110a of the region 110, the polymeric material (e.g., unwelded) can block the pores of the fabric material and / or reinforce the fabric material. Thus, the polymeric material can avoid the risk of uncontrolled increase in pores when the fabric is subjected to stress (which can otherwise cause the fabric to stretch or increase in pores). For example, such stresses may occur during an attempt to recapture and / or reinsert a prosthetic valve during implantation. Such recapture and / or reinsertion may involve forcing the constraining sheath sleeve onto the prosthesis (including the outer skirt) axially (indicated by any of the arrow heads 114) to force the stent to collapse in the constraining sheath sleeve. In such cases, the stress on the fabric material may be large, particularly when the expandable material 46 has begun to expand and causes the seal to expand or swell. The increase in pores caused by the stress may cause the expandable material 46 to escape due to leakage through the twisted fabric pores. As described above, the polymeric material can avoid such risks, thereby providing protection against accidental and undesirable escape of the expandable material.

[0155] Regions 110 of the fabric may be substantially non-porous to liquids, at least for a short duration, due to the presence of the polymeric material blocking the pores of the fabric. (For example, in the absence of a diffusion barrier material, moisture may diffuse through the polymeric material over an extended period of time.) However, blood or blood components may enter seal 40 through one or more regions 112 that are not blocked by the polymeric material.

[0156] Fig.15 Another embodiment is shown, using a method similar to Fig.14 This embodiment may include Fig.14 any feature of . Fig.15The principle difference of the embodiments is that the position of the upper suture to the stent and / or to the inner skirt can be changed, as well as the arrangement of the weld 54. The second (e.g., radially outer) wall portion 50 can be folded back on itself like a folded cuff and welded to the first (e.g., radially inner) wall portion 50 by "hiding" or covering the weld 54. The first (e.g., radially inner) wall portion 48 can extend upwardly above the weld 54 and be sutured to the stent 12 and / or the inner skirt 30.

[0157] Such modifications may be particularly resistant to recapture and / or reinsertion forces applied when forcing the constraining sheath over the skirt in direction 116. Even if second (e.g., radially outer) wall portion 50 is folded, there is a small cluster of material that may otherwise apply forces in a "peel" direction to weld 54. The fabric may protect the integrity of weld 54.

[0158] Fig.18 Shown incorporated into e.g. Figure 1 Another embodiment of a seal 40 within the outer skirt 32 . Fig.18 Embodiments may include the above Figure 2 and any or any combination or all of the details described in the subsequent figures, except that the barrier wall portion 70 may be optionally omitted. In particular, Fig.18 The seal may include an annular envelope 42 , an expandable material 46 , a first (eg, radially inner) wall portion 48 , and a second (eg, radially outer) wall portion 50 .

[0159] In the illustrated form, the wall portions 48 and 50 may be formed from a single piece of material that is folded to define the envelope 42. Such an arrangement may omit the upper joining (e.g., welding) region 54 of the previous embodiment. Instead, the material may extend continuously from the outer wall portion 50 as a whole to the inner wall portion 48 along the fold or bend. The lower edge of the inner wall portion 48 is joined (e.g., welded) to the outer wall portion 50 to complete the envelope shape by a joining (e.g., welding) region 56 similar to that previously described. The joining portion may be on the radially inwardly facing surface of the outer wall portion 50, thereby avoiding any exposed seams or weld lines or other abrupt interruptions on the outer surface of the outer wall portion 50, which may complicate the ability to: (i) slide the stent-valve axially through the compression funnel to compress or "crimp" the stent-valve, and / or (ii) recapture the stent-valve into the catheter during implantation. The second wall portion 50 may include the zigzag skirt edge previously described (see Fig.19 ).

[0160] The inner wall portion 48 and the outer wall portion 50 may be or may include fabric. The fabric may be coated and / or covered with a polymeric material in one or more regions 110, optionally using the techniques described above. The polymeric material in one or more regions 110 may provide two functions. First, the polymeric material may provide a fusible material on one or both of the wall portions 48 and 50 to form a welded joint 56. Second, in one or more areas 110a of the region 110, the polymeric material (e.g., unwelded) may block the pores of the fabric material and / or reinforce the fabric material. Thus, the polymeric material may avoid the risk of uncontrolled increase in pores when the fabric is subjected to stress (which may otherwise cause the fabric to stretch or pore to increase). For example, such stress may occur during implantation and / or during crimping of the prosthetic valve when attempting to recapture and / or reinsert the prosthetic valve. For example, the area 110a may correspond to a fold or bend line or region at the upper end of the envelope 42.

[0161] In the present example, one or more (e.g., at least some) areas 110 may be selectively provided by a face 100a of the fabric corresponding to the inner surface of the envelope 42. Such an arrangement may, for example, enhance reinforcement and / or sealing of the fabric, thereby plugging the fabric from the interior of the envelope 42 to prevent the expandable material from escaping outwardly through the holes. Additionally or alternatively, such an arrangement may reduce the amount of polymeric material exposed on the outer surface of the envelope (e.g., the radially outward facing surface of the envelope 42), which may otherwise create a discontinuous or abrupt surface or change in surface properties (which may interfere with crimping and / or recapture of the prosthetic valve).

[0162] At least one of the inner wall portion 48 and the outer wall portion 50 may include one or more porous regions 112 that are not coated and / or covered with the polymeric material, thereby allowing liquid (e.g., blood or blood components) to enter the envelope to contact the expandable material. In the illustrated form, the inner wall portion 48 and the outer wall portion 50 may each include a porous region 112. Alternatively, for example, the inner wall portion 48 may be substantially completely coated and / or covered with a polymeric material (not shown) to reinforce the inner wall portion 48 against undesirable radially inward expansion through the pores of the stent when the expandable material expands.

[0163] In some embodiments, a single piece of material for the inner wall portion 48 and the outer wall portion 50 may be provided in the form of a unitary ring without any axial joint line or seam, as described above. Alternatively, the outer skirt 32 may be formed from one or more sheets of material bent into a closed loop and / or annular shape and secured together along a generally axial joint line. The joint line may be formed using a fusible polymeric material by, for example, welding, optionally using the same welding techniques described above.

[0164] The skirt 32 may be sutured to the stent and / or inner skirt along one or more sutures 120. The sutures 120 may optionally be located beneath the envelope 42. The sutures 120 may be located at the weld areas 56, if desired.

[0165] Reference Fig.19 If desired, one or more stitching regions 122 may be provided at the bent or folded ends of the cladding 42 (e.g., at the ends opposite the weld regions 56). The stitching regions 122 may be provided, for example, by forming compression welds in the regions 110 covered and / or coated with polymeric material. The compression welds may be provided as circumferentially continuous wings or flanges of the cladding 42. Alternatively, the compression welds may be provided in one or more circumferentially spaced regions to define a plurality of circumferentially spaced stitching regions 122.

[0166] Suture region 122 may be used to provide a further suture attachment line to the stent, in a manner similar to that previously described.

[0167] Fig. 20 Another example of a skirt is shown, which is similar to Fig.18 The principles of the present invention may be used and any features of these embodiments may be used, whether or not explicitly described below. Fig. 20 In the embodiment, the upper end of the envelope 42 is defined by a membrane 130 folded into the shape of an annular channel and joined to the inner wall portion 48 and the outer wall portion 50. The membrane 130 may be joined to the fabric by any suitable technique, for example by welding, optionally using any of the welding techniques described above.

[0168] Fig.21 and Fig. 22 Another example of a skirt is shown, which can optionally use any of the principles described above, whether or not explicitly described or shown. Fig.21 In the embodiment of the present invention, the coating 42 (e.g., containing expandable material 46) is arranged adjacent to the end of the stent 12. Optionally, the coating 42 is arranged in an area adjacent to one or more attachment elements 140 to attach the stent 12 to the stent holder 142 ( Fig. 22 ). The attachment element 140 may include, for example, one or more eyes and / or holes and / or extensions and / or hooks to releasably engage through a complementary structure of the stent holder 142. The stent holder 142 may include, for example, male elements (e.g., protrusions and / or pins) and / or female elements (e.g., holes and / or eyes and / or recesses and / or pockets) to engage the attachment element to form a releasable attachment. For example, when the stent 12 expands or has expanded, the attachment may disengage or release itself, or the stent holder 142 may be actuated to release engagement with the stent 12, for example, by displacing (e.g., retracting or withdrawing) one or more locking components of the stent holder 142. The stent holder 142 is typically a single body, or it may include multiple bodies.

[0169] Regardless of whether the stent 12 includes an attachment element 140, and / or regardless of whether the catheter 144 includes a stent retainer 142, the covering may be arranged such that during use, as the constraining sheath 146 is displaced to remove the stent 12 (e.g., in the direction of arrow 148), the covering 42 remains substantially covered by the sheath 146 during at least the initial removal process, and optionally during a majority of the removal process. In some embodiments, the covering 42 may be in the area where the stent is last to be removed, optionally upon or just prior to removal of the attachment element 140 (if any). Such an arrangement may prevent the seal from swelling or expanding during the initial gradual removal process to allow the operator time to position the stent 12 for optimal implantation. Once the sheath 144 is moved to a fully open state, the seal may be allowed to expand. In such a manner, the covering 42 may be provided to the operator to prevent the seal from swelling or expanding during the initial gradual removal process. Fig. 22 In the illustrated partially extracted condition of the stent 12, the operator desires to “recapture” and / or “re-insert” the stent (e.g., to remove the stent 12 from the body, or to allow the stent to be positioned at the implant site), the operator may re-slide the sheath 146 over at least a portion of the stent 12 (e.g., in a direction opposite to arrow 148) to collapse the stent 12 again, e.g., at least partially within the sheath 146. Since the cladding 42 is not extracted, the cladding 42 does not impede such reinsertion and / or the risk of damaging the cladding 42 may be reduced.

[0170] In another related aspect, a composite material including a fabric and a polymeric material may be provided, the polymeric material being carried on and / or coated on and / or impregnated on and / or fused to at least a first region of the fabric. In the first region, the composite material may combine some properties of the fabric with some properties of the polymeric material. For example, like a fabric, the composite material may be sutured to other components by having sutures penetrate positions corresponding to fabric holes. The fibers of the fabric may provide a structural network or framework that provides resistance to crack propagation from the suture holes. Additionally or alternatively, like a polymeric material (e.g., a membrane), the composite may withstand stress but without significant pore enlargement. The polymeric material may reinforce the fabric material to resist pore enlargement; the fabric may reinforce the polymeric material to resist crack propagation. The composite material may be substantially flexible and / or thermoformable. The composite material may be weldable and / or fusible and / or heat-sealable to other fabrics and / or composite materials.

[0171] The fabric may comprise, for example, PET. The polymeric material may comprise, for example, polyurethane.

[0172] Any other suitable material (eg, from the table above) may be substituted for the fabric and polymeric materials as desired.

[0173] It should be understood that the foregoing description illustrates only exemplary forms of the present disclosure and that numerous modifications, equivalents, and improvements may be made without departing from the scope and / or spirit of the disclosure herein.

Claims

1. A stent valve, comprising: a stent and a plurality of leaflets attached thereto; a seal having a composite material comprising a fabric and a polymeric material coated on at least a first region of the fabric; wherein the seal comprises a shroud comprising an expandable material, wherein the shroud comprises at least one material segment extending around the entire circumference of the stent and continuous in the circumferential direction of the stent; and wherein the envelope comprises one or more wall portions of the fabric, and wherein radially inwardly facing wall portions abutting the stent, at least in a ready-to-implant state, comprise a fabric surface that contacts the stent, and wherein radially outwardly facing wall portions comprise a fabric surface that contacts surrounding anatomical tissue when implanted; The weaving direction of one or more wall portions of the fabric is inclined to the circumferential direction.

2. A stent-valve according to claim 1, wherein the envelope includes a plurality of diffusion barrier wall portions, which substantially enclose the interior compartment of the envelope to define a diffusion barrier to prevent liquid outside the seal from penetrating into the interior compartment.

3. The stent-valve according to claim 1, wherein the envelope comprises a diffusion barrier wall portion having a laminate comprising at least one plastic film layer and at least one diffusion barrier layer supported by the at least one plastic film layer.

4. The stent-valve according to claim 3, wherein the at least one diffusion barrier layer comprises one or more selected from the group consisting of: metal, glass, polyvinylidene chloride, liquid crystal, silicon oxide.

5. A stent-valve according to claim 1, wherein at least one diffusion barrier wall portion is provided as a non-removable integral part of the seal.

6. The stent-valve of claim 1 , wherein the envelope comprises first and second fabric wall portions sandwiching edge regions of a plastic film and welded together to define a joint between the first and second fabric wall portions and the plastic film.

7. The stent-valve of claim 6, wherein the plastic film is directly bonded to at least one of the first and second fabric wall portions.

8. The stent-valve of claim 6, wherein the first and second fabric wall portions extend beyond a perimeter of the plastic film to define a fabric-to-fabric direct weld region surrounding an edge region of the plastic film.

9. The stent-valve of claim 1, wherein the envelope comprises a first wall portion that is at least partially conical in shape.

10. A stent-valve according to claim 9, wherein the envelope further comprises a second wall portion having at least a partial protrusion and / or channel shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions being substantially matched to each other at the respective axially spaced regions.

11. A stent valve according to claim 9, wherein the envelope further comprises a second wall portion having an axially collapsed conical shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions being roughly matched to each other at the respective axially spaced regions.

12. The stent-valve of claim 1, wherein the fabric substantially completely encloses an interior compartment containing the expandable material, and areas of the fabric are lined with a substantially non-stretch membrane.

13. The stent-valve of claim 1, wherein the fabric substantially completely encloses an internal compartment containing the expandable material, and an area of ​​the fabric is lined with a diffusion barrier wall portion to hinder liquid from entering the area of ​​the fabric lined with the diffusion barrier wall portion.

14. The stent-valve of claim 1, wherein the radially outwardly facing wall portion has a self-supporting convex shape.

15. The stent-valve of claim 14, wherein the raised shape is provided as a thermoset or thermoformed shape.

16. The stent-valve of claim 1, wherein the cladding comprises wall portions attached together by laser welding.

17. The stent-valve of claim 1, wherein the envelope is constructed in tubular form or assembled to the stent in tubular form.

18. A stent valve, comprising: a stent and a plurality of leaflets attached thereto; a seal having a composite material comprising a fabric and a polymeric material impregnated into at least a first region of the fabric; as well as wherein the seal comprises a shroud comprising an expandable material, wherein the shroud comprises at least one segment of material extending around the entire circumference of the stent and continuous in the circumferential direction of the stent; wherein the envelope comprises one or more wall portions of the fabric, and wherein radially inwardly facing wall portions abutting the stent, at least in a ready-to-implant state, comprise a fabric surface that contacts the stent, and wherein radially outwardly facing wall portions comprise a fabric surface that contacts surrounding anatomical tissue when implanted; The weaving direction of one or more wall portions of the fabric is inclined to the circumferential direction.

19. The stent-valve of claim 18, wherein the envelope comprises a plurality of diffusion barrier wall portions that substantially enclose an interior compartment of the envelope to define a diffusion barrier to prevent liquid external to the seal from penetrating into the interior compartment.

20. The stent-valve of claim 18, wherein the envelope comprises a diffusion barrier wall portion comprising a laminate comprising at least one plastic film layer and at least one diffusion barrier layer supported by the at least one plastic film layer.

21. The stent-valve of claim 20, wherein the at least one diffusion barrier layer comprises one or more selected from the group consisting of: metal, glass, polyvinylidene chloride, liquid crystal, silicon oxide.

22. The stent-valve of claim 18, wherein at least one diffusion barrier wall portion is provided as a non-removable integral part of the seal.

23. The stent-valve of claim 18, wherein the envelope comprises first and second fabric wall portions sandwiching edge regions of a plastic film and welded together to define a joint between the first and second fabric wall portions and the plastic film.

24. The stent-valve of claim 23, wherein the plastic film is directly bonded to at least one of the first and second fabric wall portions.

25. The stent-valve of claim 23, wherein the first and second fabric wall portions extend beyond a perimeter of the plastic film to define a fabric-to-fabric direct weld region surrounding an edge region of the plastic film.

26. The stent-valve of claim 18, wherein the envelope comprises a first wall portion that is at least partially conical in shape.

27. A stent valve according to claim 26, wherein the envelope further comprises a second wall portion having at least a partial protrusion and / or channel shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions being substantially matched to each other at the respective axially spaced regions.

28. A stent valve according to claim 26, wherein the envelope further comprises a second wall portion having an axially collapsed conical shape, the first and second wall portions being joined together at respective axially spaced regions, the diameters of the first and second wall portions being substantially matched to each other at the respective axially spaced regions.

29. The stent-valve of claim 18, wherein the fabric substantially completely encloses an interior compartment containing the expandable material, and areas of the fabric are lined with a substantially non-stretch membrane.

30. The stent-valve of claim 18, wherein the fabric substantially completely encloses an interior compartment containing the expandable material, and an area of ​​the fabric is lined with a diffusion barrier wall portion to hinder liquid from entering the area of ​​the fabric lined with the diffusion barrier wall portion.

31. The stent-valve of claim 18, wherein the radially outwardly facing wall portion has a self-supporting convex shape.

32. The stent-valve of claim 31 , wherein the raised shape is configured as a thermoset or thermoformed shape.

33. The stent-valve of claim 18, wherein the cladding comprises wall portions attached together by laser welding.

34. The stent-valve of claim 18, wherein the envelope is constructed in tubular form or assembled to the stent in tubular form.

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