Outer skirt for artificial heart valve

Abstract

An outer skirt for an artificial heart valve is disclosed. As an example, the artificial heart valve may include an annular frame and an outer skirt disposed around the outer surface of the frame. The outer skirt can include a first portion including a polymeric material and a second portion including a fabric, and the polymeric material has a greater thromboresistance than the fabric. The second portion is fixed to the inflow end of the frame and extends toward the middle portion of the frame, and the first portion extends from the second portion toward the outflow end of the frame.

Description

Technical Field

[0001] Cross - reference to related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 366,599, filed on June 17, 2022, which is hereby incorporated by reference in its entirety.

[0002] The present disclosure relates to artificial heart valves, particularly to a coating or skirt composed of multiple layers for an artificial heart valve.

Background Art

[0003] The human heart can suffer from various valvular diseases. These valvular diseases can cause severe heart dysfunction and may ultimately require either repairing the native valve or replacing the native valve with an artificial valve. A number of repair devices (e.g., stents) and artificial valves are known, and also a number of methods for implanting those devices and valves into the human body are known. By using percutaneous and minimally invasive surgical approaches in various procedures, an artificial medical device can be delivered to locations within the patient's body that are not easily accessible surgically and to locations where access without surgery is desirable. In one specific example, an artificial heart valve can be mounted in a crimped state on the distal end of a delivery device and advanced through the patient's vasculature (e.g., through the femoral artery and aorta) to reach the implantation site within the heart. Thereafter, the artificial valve is expanded to its functional size, for example, by inflating a balloon on which the artificial valve is mounted, or by driving a mechanical actuator that applies an expanding force to the artificial valve, or by deploying the artificial valve from the sheath of the delivery device so that the artificial valve can self - expand to its functional size.

[0004] Most expandable artificial heart valves include a cylindrical metal frame, i.e., a stent, and an artificial valve leaflet mounted within the frame. These valves can also include one or more coatings (or skirts) extending around the perimeter of the frame on the inner or outer surface of the frame. These coatings can be configured to adhere and seal to native tissue when the artificial heart valve is placed at the implantation site (and thus may also be referred to as a sealing member). However, native tissue (e.g., the native valve annulus or arterial wall surrounding a native valve) can have an irregular shape while the frame of an artificial heart valve is generally cylindrical. As a result, even with a coating on the artificial heart valve, a gap can be formed between the artificial heart valve and the native heart valve annulus when the artificial heart valve is implanted within the native heart valve annulus. Thus, an improved coating or outer skirt for an artificial heart valve is needed.

Summary of the Invention

[0005] Described herein are an artificial heart valve, a delivery device, and a method for implanting an artificial heart valve. In particular, described herein are embodiments of an outer skirt for an artificial heart valve and methods of manufacturing and using the outer skirt. The artificial heart valve can include a frame and a leaflet assembly disposed on the inner surface of the frame. The artificial heart valve can include an outer skirt disposed around the perimeter of the frame and provided on the outer surface of the frame. The outer skirt can include two or more portions or layers including different materials. For example, the outer skirt can include a first portion including a polymeric material and a second portion including a fabric, and the first portion extends further toward the outflow end of the frame than the second portion. In some embodiments, the first portion can be the inner layer of the outer skirt and the second portion can be the outer layer of the outer skirt. The first portion can have a higher thromboresistance than the second portion. Thus, the skirt and artificial heart valve disclosed herein can, among other things, overcome one or more deficiencies of typical artificial heart valves.

[0006] An artificial heart valve may include a frame and a valve structure coupled to the frame. In addition to these components, the artificial heart valve can further include one or more of the components disclosed herein.

[0007] In some embodiments, the artificial heart valve may include a sealing member configured to reduce paravalvular leakage.

[0008] In some embodiments, the sealing member may be an outer skirt disposed around an outer surface of the frame.

[0009] In some embodiments, the outer skirt may include a first portion including a polymeric material and a second portion including a fabric.

[0010] In some embodiments, the second portion is fixed to an inflow end of the frame and extends toward an intermediate portion of the frame, and the first portion extends from the second portion toward an outflow end of the frame.

[0011] In some embodiments, the outer skirt includes an outer layer including a fabric and an inner layer including a polymeric material and covering an inner surface of the outer layer.

[0012] In some embodiments, the inner layer extends toward an outflow end of the frame beyond an outflow edge portion of the outer layer.

[0013] In some embodiments, the outer fabric layer is removably attached to the inner layer.

[0014] In some embodiments, the sealing member includes at least one layer including a plurality of microscales formed on its surface.

[0015] In some embodiments, the sealing member includes a base layer including a polymeric material, the base layer is disposed relative to an outer surface of the frame, and a plurality of outwardly extending threads are adhered to an outer surface of the base layer and extend radially outwardly away from the base layer.

[0016] In some embodiments, the artificial heart valve includes an annular frame having an inflow end, an outflow end, and an intermediate portion disposed between the inflow end and the outflow end, and an outer skirt disposed around the outer surface of the frame. The outer skirt includes a first portion including a polymeric material and a second portion including a fabric. The polymeric material has a greater thrombus resistance than the fabric, the second portion is fixed to the inflow end of the frame and extends toward the intermediate portion, and the first portion extends from the second portion toward the outflow end of the frame.

[0017] In some embodiments, the artificial heart valve includes an annular frame and an outer skirt disposed on the outer surface of the frame. The outer skirt includes an outer layer including a fabric and forming an exposed surface for contacting tissue, and an inner layer including a polymeric material and covering the inner surface of the outer layer, and the inner layer extends toward the outflow end of the frame beyond the outflow edge portion of the outer layer.

[0018] In some embodiments, the artificial heart valve includes an annular frame having an inflow end, an outflow end, and an intermediate portion disposed between the inflow end and the outflow end, and an outer skirt disposed around the outer surface of the frame. The outer skirt includes an inner layer including a polymeric material and an outer layer including a fabric and attached to the inner layer. The outer layer includes a first outer layer portion and a second outer layer portion, the first outer layer portion extends from the inflow end of the frame toward the intermediate portion of the frame, and the second outer layer portion extends from the first outer layer portion toward the outflow end. The outflow edge portion of the inner layer axially extends toward the outflow end of the frame beyond the outflow edge portion of the second outer layer portion such that the outflow edge portion of the inner layer is disposed closer to the outflow end of the frame than the outflow edge portion of the second outer layer portion.

[0019] In some embodiments, the artificial heart valve includes an annular frame having an inflow end and an outflow end, and an outer skirt disposed on the outer surface of the frame. The outer skirt includes an inner layer and a woven outer layer removably attached to the inner layer by a plurality of whip stitches and tension sutures. The plurality of whip stitches extend around the tension suture and through the inner and outer layers, and the tension suture is configured to be pulled through and released from the whip stitches to thereby remove the outer layer from the inner layer.

[0020] In some embodiments, the artificial heart valve includes an annular frame, a valve structure disposed within the frame and configured to regulate one-way blood flow through the frame, and a skirt coupled to the frame, the skirt including at least one layer having a plurality of microscales formed on its surface.

[0021] In some embodiments, the artificial heart valve includes an annular frame and an outer skirt disposed on the outer surface of the frame. The outer skirt includes a base layer containing a polymer material, the base layer being disposed relative to the outer surface of the frame, and a plurality of outwardly extending threads adhered to the outer surface of the base layer and extending radially outwardly away from the base layer.

[0022] In some embodiments, the artificial heart valve includes one or more of the components listed in Examples 1-78 below.

[0023] The various innovations in the present disclosure can be used in combination or individually. This summary is provided to introduce, in a simplified form, a selection of concepts that are further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description, from the claims, and from the accompanying drawings.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0025] General Considerations For the purposes of this specification, specific aspects, advantages, and novel features in the embodiments of the present disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed to all novel and non-obvious features and aspects, alone and in various combinations and sub-combinations with each other, related to the various disclosed examples. The methods, apparatuses, and systems are not limited to any specific aspect or feature, or combination thereof, and it is not necessary for the disclosed examples to have any one or more specific advantages or to solve any problems.

[0026] The operations in some of the disclosed examples are described in a particular sequential order for convenience of presentation, but it should be understood that this mode of description encompasses permutations unless a particular order is required by the specific language set forth below. For example, operations described sequentially may, in some cases, be permuted or may be performed concurrently. Moreover, for simplicity, the accompanying drawings may not show the various ways in which the disclosed methods may be used in combination with other methods. Additionally, in the description, terms such as "provide" or "achieve" are sometimes used to describe the disclosed methods. These terms are high-level abstractions related to the actual operations being performed. The actual operations corresponding to these terms may vary depending on the specific implementation and will be readily recognizable to those of ordinary skill in the art.

[0027] As used in this application, and in the claims, the singular forms "a", "an", and "the" include the plural unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises". Further, the term "coupled" generally means physically, mechanically, chemically, magnetically, and / or electrically coupled or connected, and does not exclude the presence of intermediate elements between the members being coupled or associated unless a specific contrary statement is made.

[0028] As used herein, the term "proximal" refers to the position, direction, or portion of a device that is closer to the user and farther from the implantation site. As used herein, the term "distal" refers to the position, direction, or portion of a device that is farther from the user and closer to the implantation site. Thus, for example, proximal movement of a device is movement of the device away from the implantation site and towards the user (e.g., out of the patient's body), while distal movement of a device is movement of the device away from the user and towards the implantation site (e.g., into the patient's body). The terms "longitudinal" and "axial" refer to an axis extending in the proximal and distal directions unless otherwise explicitly defined.

[0029] As used herein, "e.g." means "for example", and "i.e." means "that is".

[0030] Summary of the Disclosed Technology The artificial valves disclosed herein can be radially expandable and contractable between a radially compressed state and a radially expanded state. Thus, the artificial valve can be crimped onto an implant delivery device in a radially compressed state or held by an implant delivery device while being advanced through a patient's vasculature on the delivery device. The artificial valve can expand to a radially expanded state when the artificial valve reaches the implantation site. It will be appreciated that the artificial valves disclosed herein can be used with a variety of implant delivery devices and can be implanted via a variety of delivery procedures. Also, examples of those artificial valves are described in more detail below.

[0031] As introduced above, most artificial heart valves can include an outer skirt disposed around the outer surface of the annular frame of the artificial heart valve. The outer skirt can be configured to form a seal against native tissue during implantation of the artificial heart valve, thereby reducing paravalvular leakage (PVL) through the artificial heart valve when it expands against the native anatomical structure. FIG. 1 shows an exemplary artificial device (e.g., an artificial heart valve) including a frame, valve leaflets fixed inside the frame, and an outer skirt disposed around the outer surface of the frame. The artificial device can be advanced through a patient's vasculature, e.g., to a native heart valve, by a delivery device such as the delivery device illustrated in FIG. 2.

[0032] In some embodiments, the outer skirt for an artificial heart valve, such as the outer skirt shown in FIGS. 3 and 4, is composed of a portion that extends radially outward (towards the surrounding native anatomy) from the frame of the artificial heart valve and can increase the PVL seal against the native anatomy. For example, the outer skirt shown in FIGS. 3 and 4 can include a relatively high density arrangement of threads that project outward. However, in some instances, such a configuration can increase the crimp profile of the artificial heart valve when radially compressed on the delivery device. Thus, in some instances, the outer skirt can include an inner thromboresistant layer and an outer fabric layer that includes a low density arrangement of threads that project outward, as illustrated in the various embodiments of FIGS. 5 - 8B. As a result, the density of the threads that project outward from the fabric layer can be reduced such that the overall crimp profile of the artificial heart valve is reduced while maintaining an effective PVL seal (through the thromboresistant inner layer).

[0033] In some embodiments, the frame of the artificial heart valve may include a first row extending circumferentially of the elongated first cell (at the outflow end of the frame). The outflow end of the outer skirt of the artificial heart valve can be fixed to the frame along the lower struts forming the first row of cells, as shown in FIG. 9. However, such a configuration can result in an outer skirt having a relatively short axial height, thereby providing less surface area for sealing with the native anatomical structure at the implantation site. When the outflow end of the outer skirt extends over a portion of the first row of cells (e.g., the inflow or lower end portion of the first cell), more surface area for the PVL seal will be created. However, due to the elongated axial length of the first cell, the portion of the outer skirt extending across the first cell (between the axial struts forming the upper cell) may extend into the interior of the artificial heart valve (through the first cell) or may be fluttery. Thus, in some examples, the outer skirt can include an outflow (or upper) portion including a polymeric material (e.g., thermoplastic polyurethane (TPU)) and an inflow (or lower) portion including a reinforced fabric (e.g., a woven fabric that promotes in-growth and PVL sealing with respect to native tissue), and the outflow portion is configured to stretch around and cover a portion of the first cell, as shown in FIGS. 10 - 12B. As a result, an increase in the surface area of the PVL seal can be generated without the outer skirt extending into the interior of the frame through the elongated first cell.

[0034] In some embodiments, the surface of the artificial heart valve, such as the inner surface of the outer skirt, may include a microscale structure configured to reduce drag, and in some examples, simulate shark scales. Examples of such surfaces and examples of forming these surfaces are shown in FIGS. 13A - 15. As a result, the inner surface of the outer skirt can be configured to reduce the accumulation and / or ablation of debris thereon, thereby increasing the long-term durability of the outer skirt.

[0035] Furthermore, in some embodiments, the outer skirt may include an inner layer comprising a polymeric material (such as TPU), and an outer layer including one or more fabric portions attached to the inner layer and configured to contact tissue at the implantation site. The outflow edge portion of the inner layer may extend beyond the outflow edge portion of the outer layer. In some examples, the outer layer may include a first outer layer portion including a fabric wound around the inflow tip of the frame, and a second outer layer portion including a plurality of floating fibers extending between leno lines of the second outer layer portion. The second outer layer portion may extend from the first outer layer portion toward the outflow end of the frame, and the outflow edge portion of the second outer layer portion may be axially offset from the upper edge portion of the inner layer. In some examples, the outer layer may be removably attached to the inner layer by a tensile suture (FIGS. 19 and 20). As a result, an artificial heart valve including the frame and the inner layer of the outer skirt can be easily implanted during the described procedure.

[0036] Examples of the Disclosed Technology FIG. 1 shows an exemplary artificial valve 10 according to one embodiment. Although all of the artificial valves disclosed herein are configured to be implanted in the native aortic valve annulus, in other embodiments, they can also be configured to be implanted in other native valve annuli of the heart (pulmonary valve, mitral valve, and tricuspid valve). The disclosed artificial valves can also be implanted inside blood vessels in communication with the heart, including the pulmonary artery (to replace the function of a diseased pulmonary valve), the superior vena cava or the inferior vena cava (to replace the function of a diseased tricuspid valve), or various other veins, arteries, and blood vessels of the patient. The disclosed artificial valves can also be implanted inside an artificial valve previously implanted in a valve-in-valve procedure (which can be an artificial surgical valve or an artificial transcatheter heart valve).

[0037] In some embodiments, the disclosed artificial valve can be implanted within a docking device or an anchor device that is implanted within the native heart valve or blood vessel. For example, in one embodiment, the disclosed artificial valve can be implanted within a docking device implanted within the pulmonary artery to replace the function of a diseased pulmonary valve, as disclosed in U.S. Patent Application Publication No. 2017 / 0231756, which is incorporated herein by reference. In another embodiment, the disclosed artificial valve can be implanted within a docking device implanted within or on a native mitral valve, as disclosed in, for example, International Publication No. 2020 / 247907, which is incorporated herein by reference. In another embodiment, the disclosed artificial valve can be implanted within a docking device implanted within the superior or inferior vena cava to replace the function of a diseased tricuspid valve, as disclosed in, for example, U.S. Patent Application Publication No. 2019 / 0000615, which is incorporated herein by reference.

[0038] The artificial valve 10 includes four main components, namely, a stent or frame 12, a valve leaflet structure 14, an inner skirt 16, and a perivalvular outer sealing member or outer skirt 18. The artificial valve 10 can have an inflow end portion 15, an intermediate portion 17, and an outflow end portion 19. The inner skirt 16 can be disposed on and / or coupled to the inner surface of the frame 12, while the outer skirt 18 can be disposed on and / or coupled to the outer surface of the frame 12.

[0039] The valve leaflet structure 14 can include three leaflets 40 that collectively form a leaflet structure. These three leaflets can be configured to collapse in a tricuspid arrangement, although in other embodiments, a greater or lesser number of leaflets can be present (e.g., one or more leaflets 40). The leaflets 40 can be fixed to each other at adjacent sides, thereby forming the commissures 22 of the leaflet structure 14. The lower edge of the valve leaflet structure 14 can have a scalloped shape with undulations and can be fixed to the inner skirt 16 by a suture (not shown). In some embodiments, the leaflets 40 can be formed from pericardial tissue (e.g., bovine pericardial tissue), a biocompatible synthetic material, or various other suitable natural or synthetic materials known in the art as described in U.S. Patent No. 6,730,118, which is incorporated herein by reference.

[0040] The frame 12 can be radially compressible (crushable) and expandable (e.g., the expanded configuration shown in FIG. 1) and can include a plurality of interconnected struts 24. A plurality of circumferentially spaced-apart tips 26 are formed at the inflow end portion 15 and the outflow end portion 19 of the frame 12 (in FIG. 1, only the tip 26 at the outflow end portion 19 can be seen). Each tip 26 is formed at the junction between two inclined struts 24, either at the inflow end portion 15 or the outflow end portion 19. FIG. 1 illustrates a known frame design having a tip 26 that forms a U-shaped curve between two inclined struts 24. In some embodiments, the angle 30 between the two inclined struts 24 that are connected at the tip 26 can be in the range of 90 degrees to 120 degrees.

[0041] Frame 12 can be formed to have a plurality of circumferentially spaced slots, i.e., commissure windows 20, adapted to attach commissures 22 of the valve leaflet structure 14 to the frame. Frame 12 can be formed from any of a variety of suitable plastically expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nitinol). When composed of a plastically expandable material, frame 12 (and thus artificial valve 10) can be crimped into a radially collapsed configuration on a delivery catheter or delivery device and then expanded inside the patient by an inflatable balloon or equivalent expansion mechanism. When composed of a self-expandable material, frame 12 (and thus artificial valve 10) can be crimped into a radially collapsed configuration and held in the collapsed configuration by inserting it into the sheath of a delivery catheter or an equivalent mechanism. After being introduced into the body, the artificial valve can be driven forward from the delivery sheath, thereby expanding the artificial valve to its functional size.

[0042] Suitable plastically expandable materials that can be used to form frame 12 include metal alloys, polymers, or combinations thereof. Exemplary metal alloys can include one or more of nickel, cobalt, chromium, molybdenum, titanium, or other biocompatible metals. In some embodiments, frame 12 can include stainless steel. In some embodiments, frame 12 can include cobalt chromium. In some embodiments, frame 12 can include nickel cobalt chromium. In some embodiments, frame 12 can be made of a nickel-cobalt-chromium-molybdenum alloy such as MP35N (trademark) (a trade name of SPS Technologies), which is equivalent to UNS R30035 (covered by ASTM F562-02). MP35N (trademark) / UNS R30035 contains 35 wt% nickel, 35 wt% cobalt, 20 wt% chromium, and 10 wt% molybdenum.

[0043] Additional details regarding the prosthetic valve 10 and its various components are described in International Patent Application Publication No. WO2018 / 222799, which is hereby incorporated by reference in its entirety.

[0044] FIG. 2 shows a delivery device 100 according to an example that can be used to implant an expandable prosthetic heart valve (e.g., the prosthetic heart valve 10 of FIG. 1 and / or any other prosthetic heart valve described herein). In some embodiments, the delivery device 100 is specifically adapted for use in introducing a prosthetic valve into the heart.

[0045] The delivery device 100 in the example illustrated in FIG. 2 is a balloon catheter and includes a handle 102 and a steerable outer shaft 104 extending distally from the handle 102. The delivery device 100 can further include an intermediate shaft 106 (which can also be referred to as a balloon shaft) extending proximally and distally from the handle 102, and the portion extending distally from the handle 102 also extends coaxially through the outer shaft 104. Additionally, the delivery device 100 can further include an inner shaft 108 extending distally from the handle 102 coaxially through the intermediate shaft 106 and 104 and extending proximally from the handle 102 coaxially through the intermediate shaft 106.

[0046] The outer shaft 104 and the intermediate shaft 106 can be configured to translate (e.g., move) longitudinally relative to each other along the central longitudinal axis 120 of the delivery device 100 to facilitate delivering and positioning the prosthetic valve at the implantation site within the patient's body.

[0047] The intermediate shaft 106 can include a proximal end portion 110 extending proximally from the proximal end of the handle 102 to the adapter 112. A rotatable knob 114 can be attached to the proximal end portion 110 and configured to rotate the intermediate shaft 106 relative to the outer shaft 104 about the central longitudinal axis 120.

[0048] The adapter 112 can include a first port 138 configured to receive a guide wire therethrough and a second port 140 configured to receive fluid (e.g., inflation fluid) from a fluid source. The second port 140 can be fluidly coupled to the lumen of the intermediate shaft 106.

[0049] The intermediate shaft 106 can further include a distal end portion that extends distally beyond the distal end of the outer shaft 104 when the distal end of the outer shaft 104 is positioned spaced apart from the inflatable balloon 118 of the delivery device 100. The distal end portion of the inner shaft 108 can extend distally beyond the distal end portion of the intermediate shaft 106.

[0050] The balloon 118 can be coupled to the distal end portion of the intermediate shaft 106.

[0051] In some embodiments, the distal end of the balloon 118 can be coupled to the distal end of the delivery device 100, such as a nose cone 122 (as shown in FIG. 2), or to an alternative component (e.g., a distal shoulder) at the distal end of the delivery device 100. The intermediate portion of the balloon 118 can cover the valve attachment portion 124 of the distal end portion of the delivery device 100, and the distal end portion of the balloon 118 can cover the distal shoulder 126 of the delivery device 100. The valve attachment portion 124 and the intermediate portion of the balloon 118 can be configured to receive an artificial heart valve in a radially compressed state. For example, as schematically shown in FIG. 2, an artificial heart valve 150 (which can be one of the artificial valves described herein) can be attached around the balloon 118 at the valve attachment portion 124 of the delivery device 100.

[0052] The balloon shoulder assembly, including the distal shoulder 126, is configured to maintain the artificial heart valve 150 (or other medical device) at a fixed position on the balloon 118 during delivery through the patient's vasculature.

[0053] The outer shaft 104 can include a distal tip portion 128 attached to its distal end. The outer shaft 104 and the intermediate shaft 106 can be translated axially relative to each other such that when the prosthetic valve 150 is attached in a radially compressed state on the valve attachment portion 124 (as shown in FIG. 2), and when delivering the prosthetic valve to the target implantation site, the distal tip portion 128 is positioned adjacent to the proximal end of the valve attachment portion 124. Thus, the distal tip portion 128 can be configured such that when the distal tip portion 128 is disposed adjacent to the proximal side of the valve attachment portion 124, the prosthetic valve 150 is oriented proximally in the axial direction relative to the balloon 118 and resists movement relative to the balloon 118.

[0054] An annular space can be defined between the outer surface of the inner shaft 108 and the inner surface of the intermediate shaft 106, and this annular space can be configured to receive fluid from a fluid source via the second port 140 of the adapter 112. The annular space can be fluidly coupled to a fluid passage formed between the outer surface of the distal end portion of the inner shaft 108 and the inner surface of the balloon 118. Thus, fluid from the fluid source can flow from the annular space into the fluid passage, thereby expanding the balloon 118 and radially expanding and deploying the prosthetic valve 150.

[0055] The lumen of the inner shaft can be configured to receive a guide wire therethrough for maneuvering the distal end portion of the delivery device 100 to the target implantation site.

[0056] The handle 102 can include a steering mechanism configured to adjust the curvature of the distal end portion of the delivery device 100. In the illustrated example, for instance, the handle 102 includes an adjustment member such as the rotatable knob 160 shown, and this adjustment member is operably coupled to the proximal end portion of a pull wire. The pull wire can extend distally from the handle 102 through the outer shaft 104 and has a distal end portion fixed to or near the distal end of the outer shaft 104. By rotationally driving the knob 160, the tension of the pull wire can be increased or decreased, thereby adjusting the curvature of the distal end portion of the delivery device 100. Further details regarding the steering mechanism or bending mechanism in the delivery device can be found in U.S. Patent No. 9,339,384, which is hereby incorporated by reference herein.

[0057] The handle 102 can further include an adjustment mechanism 161 including an adjustment member such as the rotatable knob 162 shown, and an associated locking mechanism including another adjustment member configured as a rotatable knob 178. The adjustment mechanism 161 is configured to adjust the axial position of the intermediate shaft 106 relative to the outer shaft 104 (e.g., for fine positioning at the implantation site). Further details regarding the delivery device 100 can be found in PCT Application No. PCT / US2021 / 047056, which is hereby incorporated by reference herein.

[0058] Figures 3 and 4 show another exemplary outer skirt 206 of the artificial heart valve 200 configured to increase the PVL leakage seal with the native anatomical structure when the artificial heart valve 200 is radially expanded within the native anatomical structure (such as the native heart valve annulus). In the embodiment of FIG. 3, the outer skirt 206 is shown disposed around the outer surface of an annular frame 202 that is radially expandable and compressible of the artificial heart valve, while a plurality of valve leaflets 204 are fixed to and disposed on the inside of the frame 202. The frame 202 may be similar to the frame 12 of the artificial valve 10 of FIG. 1. In some examples, the outer skirt 206 may be used in place of the outer skirt 18 on the artificial valve 10.

[0059] The outer skirt 206 may include a woven body formed from a plurality of strands or yarns that are woven, knitted, or otherwise secured together. In some examples, the outer skirt 206 may include a woven fabric or knitted fabric including a woven base layer 207 and a plurality of pile yarns (e.g., loop yarns) or floating yarns 208 extending radially outwardly from the frame 202 (FIGS. 3 and 4). For example, the base layer 207 can include warp and weft yarns knitted in a mesh-like structure, and the pile yarns or floating yarns 208 can be knitted or woven into the base layer 207 and extend outwardly from the base layer 207.

[0060] The pile yarns or floating yarns 208 can give the outer skirt 206 a fuzzy, plush, or velour-like appearance. Further, the outwardly projecting floating yarns 208 can be packed together at a relatively high density (as shown in FIG. 4) and configured to increase the PVL seal with the native anatomical structure during implantation of the artificial heart valve 200. However, the floating yarns 208 packed at a high density can increase the crimp profile of the artificial heart valve 200 when radially compressed on a delivery device (such as the delivery device 100 of FIG. 2).

[0061] Further details regarding the skirt of an artificial heart valve including a braided or woven material and a pile or floating thread are disclosed in U.S. Patent Publication No. 2019 / 0374337 and International Patent Publication No. WO2021 / 202636, which are incorporated herein by reference.

[0062] In some embodiments, as shown in FIGS. 3 and 4, the outer skirt 206 may further include a plurality of loops 210 extending along the upper or outflow edge portion 212 of the outer skirt 206. However, when the valve leaflets 204 are in the open position, they can contact the loops 210 or the floating threads 208 (e.g., when the loops 210 are not included). Such contact can, in some instances, cause undesirable abrasion or wear of the valve leaflets 204.

[0063] Accordingly, the inventors herein recognize that it would be desirable to provide an artificial heart valve (or alternative artificial device) having an outer skirt that includes an inner thromboresistant layer or coating (which can include a polymeric layer such as TPU) and an outer woven layer that can include a plurality of threads protruding outwardly. The presence of the inner TPU layer configured to reduce or prevent PVL leakage allows the density of the threads protruding outwardly to be reduced relative to the threads 208 of the outer skirt 206, thereby reducing the crimp profile of the artificial heart valve to which the outer skirt is attached.

[0064] Figures 5-8C show examples of such outer skirts disposed about the outer surface 306 of an exemplary frame 302 of an artificial heart valve (which may be similar or identical to frame 202 of FIG. 3 or frame 12 of FIG. 1). As schematically shown in FIGS. 5-8C, the leaflets 304 of the artificial heart valve can be disposed on the inner surface 308 (or inside) of the frame 302, and the frame 302 can have a central longitudinal axis 309. Although the frame 302 is schematically shown in FIGS. 5-8C, the frame can have any of a variety of configurations such as frame 12 of FIG. 1, or any of a variety of frames that are balloon-expandable, self-expandable, or mechanically expandable. Further, the frame 302 can be part of an artificial heart valve that includes one or more of the above-described components for the artificial valve 10, including leaflets 40 and inner skirt 16. In some embodiments, the artificial heart valve shown in FIGS. 5-8C can be the artificial valve 10, except that the outer skirt 18 is exchanged with the outer skirt 300. Further details regarding balloon-expandable artificial valves can be found in U.S. Patent No. 9,393,110, U.S. Provisional Patent Application No. 63 / 178,416, filed April 22, 2021, U.S. Provisional Patent Application No. 63 / 194,830, filed May 28, 2021, and U.S. Provisional Patent Application No. 63 / 279,096, filed November 13, 2021, all of which are incorporated herein by reference. Further details regarding mechanically expandable artificial valves can be found in International Application No. PCT / US2021 / 052745, filed September 30, 2021, and further details regarding self-expandable artificial valves can be found in U.S. Patent No. 8,652,202, all of which are incorporated herein by reference.

[0065] Referring first to FIG. 5, the outer skirt 300 can include an inner layer 310 disposed against the outer surface 306 of the frame 302 and an outer layer 312 attached to the inner layer 310 and separated from the frame 302 by the inner layer 310. In some embodiments, the inner layer 310 can be disposed in a plane parallel to the outer surface 306 of the frame 302. Further, in some examples, the outer layer 312 can be directly adhered or joined to the inner layer 310 via an adhesive or via a chemical bond (e.g., heating), etc. As will be further described below, FIGS. 5-8B show various arrangements of the end portions of the inner layer 310 with respect to the outer layer 312.

[0066] The inner layer 310 can include a polymeric material. In some examples, the polymeric material can be relatively thromboresistant or have a greater thromboresistance than that of a woven material. Further, the polymeric material can be relatively non-abrasive or smooth. For example, in some examples, the polymeric material of the inner layer 310 can be TPU. In other embodiments, the inner layer 310 can include a different relatively thromboresistant material such as polytetrafluoroethylene (PTFE). In this way, in-growth within the tissue does not occur on the inner layer 310, and contact between the leaflet tip 304 and the inner layer 310 may not result in wear of the leaflet tip 304. The inner layer 310 can be a relatively thin layer having a thickness in the range of 10-20 μm.

[0067] As shown in FIG. 8B, the outer layer 312 can be a woven layer that includes a plurality of outwardly extending threads 314. For example, the outwardly extending threads 314 can extend radially outwardly away from the inner layer 310 and the frame 302.

[0068] In some examples, the outwardly extending yarns 314 can be knitted or woven into the base layer 316 of the outer layer 312 that can include the weave of one or more fibers or yarns and extend outwardly therefrom. For example, in some examples, the outer layer 312 can be similar to the outer skirt 206 described above. In some examples, the outer layer 312 can include rows extending circumferentially of the woven portion, and the outwardly extending yarns 314 extend between adjacent woven portions. For such outer layers 312, due to the inclusion of the inner layer 310 (which can prevent leakage through the outer skirt 300), the density of the outwardly extending yarns 314 can be reduced compared to the outer skirt 206 of FIG. 4.

[0069] In other examples, the outwardly extending yarns 314 of the outer layer 312 can be individual texturized yarns 314 directly adhered to the inner layer 310 (e.g., without a fabric base layer 316 therebetween). For example, as shown in FIG. 8C, the outer skirt 350 can include the inner layer 310 and an outer layer including a plurality of outwardly extending yarns 314 directly adhered or bonded to the inner layer 310 (e.g., by an adhesive or chemical bond such as by heating or another bonding method). The outwardly extending yarns 314 can be spaced apart from each other across the outer surface of the inner layer 310. Since the outwardly extending yarns 314 can be directly individually bonded to the polymeric inner layer 310 instead of being woven or knitted into a fabric structure or base layer, the density or number of the outwardly extending yarns 314 can be further reduced and selected to achieve a desired crimp profiled for the selected artificial heart valve while providing an appropriate seal with the self - assembly (during implantation of the artificial heart valve). As a result, the outer layer including the outwardly extending yarns 314 can be more easily customized for the selected artificial heart valve and / or application.

[0070] In some embodiments, the outer layer 312 may include a plurality of loops (one loop 311 shown in the cross-section of FIG. 8B) extending along the upper edge 318 (or outflow edge) of the outer layer 312 (similar to the loop 210 shown in FIG. 3 for example). In such embodiments, the upper edge portion 322 (or outflow edge portion) of the inner layer 310 may extend beyond the upper edge 318 of the outer layer 312 (above in FIG. 5) (FIG. 5). In some examples, the upper edge portion 322 can extend sufficiently beyond the upper edge 318 (axially) such that the upper edge portion 322 of the inner layer 310 covers the loop 311 of the upper edge 318 of the outer layer 312 and / or the thread 314 extending outwardly and blocks contact with the valve tip 304.

[0071] In some examples, as shown in FIG. 6, the upper edge portion 322 of the inner layer 310 can wrap around the upper edge end 318 of the outer layer 312, thereby forming a "J" shape with the upper edge portion 322. In this way, the upper edge portion 322 of the inner layer 310 may extend over the loop 311 extending from the upper edge end 318 of the outer layer 312 and, in some examples, can cover the loop 311 (as shown in FIG. 8B).

[0072] In some embodiments, as shown in FIGS. 5 and 6, the lower edge portion 324 (or inflow edge portion) of the inner layer 310 may extend beyond the lower edge 320 (or inflow edge) of the outer layer 312 (below in FIGS. 5 and 6). In some examples, the lower edge portion 324 can extend beyond the lower edge 320 and beyond the inflow end of the frame 302 by an amount of 1 / 4 to 1 / 3 of the outer diameter of the frame 302.

[0073] In some examples, as shown in FIG. 7, the lower edge portion 324 of the inner layer 310 can wrap around the lower edge 320 of the outer layer 312, thereby forming a "J" shape with the lower edge portion 324. In this way, the lower edge portion 324 may extend over the lower edge 320 and cover a portion of the outer surface of the lower edge portion of the outer layer 312.

[0074] By extending the lower edge portion 324 of the inner layer 310 (Figs. 5 and 6) and / or wrapping it around the lower edge 320 and over a portion of the outer surface of the outer layer 312 (Fig. 7), tissue ingrowth in this region of the outer skirt 300 can be reduced, thereby providing easier access to the lower portion of the artificial heart valve (e.g., the native annulus or below it) during the explanatory procedure. As a result, the explanation of the artificial heart valve from the native annulus can be facilitated.

[0075] In some embodiments, as shown in FIGS. 8A and 8B, the upper edge portion 322 and / or the lower edge portion 324 of the inner layer 310 can be folded and fused to form loops 326 that extend above or below the respective upper edge 318 or lower edge 320 of the outer layer 312, while the remaining portions of the folded upper edge portion 322 or lower edge portion 324 (e.g., the sagging or free end portions) extend further over the respective upper edge 318 or lower edge 320. Further, in some examples, the remaining portions folded over the upper edge portion 322 or lower edge portion 324 can extend along a portion of the outer surface 328 of the outer layer 312 such that the respective upper edge 318 or lower edge 320 is covered (Figs. 8A - 8B).

[0076] Figure 9 shows another exemplary artificial heart valve 400 that includes an annular frame 402 that is radially expandable and / or compressible, a plurality of valve leaflets 404 mounted within the frame 402, and an outer skirt 406 fixed to and around the outer surface 434 of the frame 402. The frame 402 can include a plurality of interconnected struts 414, and a plurality of tips (outflow tips 408 and inflow tips 438) circumferentially spaced around the inflow end 416 (or “inflow end portion”) and the outflow end 418 (or “outflow end portion”) of the frame 402. Each tip 408, 438 is formed at the junction of two angled struts 414 at either the inflow end 416 or the outflow end 418. The frame 402 includes a plurality of axially extending struts 410 (referred to herein as “axial struts 410”), some of which define a commissural window therein. The commissural tabs of adjacent valve leaflets 404 can pair together and extend through the commissural window, thereby forming a commissure 412 fixed to the frame 402. The axial struts 410, together with a first row of struts 414 that form the outflow end 418 and a second row of struts disposed (axially) adjacent to the first row of struts, can form a circumferentially extending row (which can also be referred to as the first cell or upper cell) of outflow cells 426. The outflow cells 426 may be axially elongated relative to the cells of the remaining rows of cells of the frame 402 (e.g., a second row of intermediate cells 425 disposed adjacent to the intermediate portion 417 of the frame 402 and a third row of inflow cells disposed at the inflow end 416 of the frame 402). Further details regarding the artificial heart valve 400, including details of the frame 402, can be found in U.S. Provisional Patent Application No. 63 / 279,096, which is already incorporated by reference above.

[0077] The outer skirt 406 of the artificial heart valve 400 may include an inflow edge portion 420 (or lower edge portion) that is fixed to a strut 414 forming the inflow end 416 of the frame 402 (inflow strut 415) via one or more fasteners (e.g., the whip stitch 424 shown in FIG. 9). The outer skirt 406 may also include an outflow edge portion 422 (or upper edge portion) that is fixed to a second row of struts 414 of the struts forming the lower or inflow edge of the outflow cell 426. In some examples, as shown in FIG. 9, the outflow edge portion 422 of the outer skirt 406 extends along and follows the shape of the struts 414 forming the inflow edge of the outflow cell 426, thereby causing the outflow edge portion 422 to follow the zigzag pattern of the struts 414 of the outflow cell 426. Such a configuration can result in a tight attachment of the outflow edge portion 422 of the outer skirt 406 to the frame 402, but can result in an outer skirt 406 having a relatively short axial height 428 (e.g., the height along the portion of the outer skirt 406 that extends axially from the non-tapering joint at the inflow end 416 to the bottom joint of the outflow cell 426) (FIG. 9).

[0078] The inventors herein recognize that it is desirable to extend the outer skirt beyond the inflow struts 414 of the outflow cell 426 (e.g., toward the outflow end 418 and near the mid-height of the outflow cell 426) in order to increase the surface area of the PVL seal at the implantation site, such that the portion of the outer skirt 406 that extends across the outflow cell 426 can extend across (due to the relatively large size of the outflow cell 426) or loosely wrap around the outflow cell 426.

[0079] In some embodiments, as shown in FIGS. 10 - 12A, an outer skirt 500 for an artificial heart valve (such as the artificial heart valve 400 in FIG. 9) can include a first portion 502 that includes a first material (e.g., a fabric) and a second portion 504 that includes a second material (e.g., a polymeric material). The first portion 502 can define an inflow edge portion 506 of the outer skirt 500 that is configured to be fixed to the inflow end of the frame of the artificial heart valve in some examples. The second portion 504 can define an outflow edge portion 508 of the outer skirt 500 that is configured to extend toward the outflow end of the frame and, in some examples, across a portion of the elongated outflow cells of the frame. In some embodiments, instead of being relatively straight and parallel with respect to the outflow edge portion 508, the inflow edge portion 506 of the outer skirt 500 can have a wavy shape that conforms to and follows the shape of the struts at the inflow end of the frame (e.g., as shown in FIG. 11).

[0080] The outer skirt 500 and additional outer skirts (e.g., outer skirts 650, 700, and 800) described herein are illustrated as being fixed to the frame 402, but the frame can have any of various configurations such as the frame 12 in FIG. 1 or any of various frames that are balloon-expandable, self-expandable, or mechanically expandable as disclosed for the above-described uses.

[0081] In some embodiments, as shown in FIG. 11, the inflow edge portion 506 of the outer skirt 500 can be fixed to the support post 414 that defines the inflow end 416 of the frame 402. The second portion 504 extends from the upper or outflow end of the first portion 502 (around the intermediate portion 417 of the frame 402) toward the outflow end 418 and across a portion of the elongated outflow cell 426 of the frame 402. In some examples, as shown in FIG. 11, the outflow edge portion 508, which is the upper or free edge of the second portion 504, can extend circumferentially along the frame 402 at the intermediate portion (or axial mid-height) of the elongated outflow cell 426. For example, the outflow edge portion 508 can extend across the axial support post 410 at approximately the mid-height of the axial support post (e.g., between the inflow and outflow ends of the axial support post 410). In some examples, the outflow edge portion 508 can be disposed closer to the outflow end 418 of the frame 402 than shown in FIG. 11 such that the second portion 504 extends across about 1 / 2 to 3 / 4 of the axial height of the outflow cell 426.

[0082] The interface surface 510 (or intersection) between the first portion 502 and the second portion 504 of the outer skirt 500 on the outer surface 512 of the outer skirt 500 (the surface that faces radially outward and away from the frame 402) can be disposed along the frame 402 proximate to or adjacent to the lower portion or inflow tip 430 of the outflow cell 426 (FIG. 11). In some examples, the interface surface 510 can be closer to the inflow end 416 than shown in FIG. 11 such that the first portion 502 extends only to the inflow tip 430 of the outflow cell 426. In other words, the first portion 502 can have an axial height 520 (FIG. 10) that is designated such that the first portion 502 covers a portion of the frame 402 disposed between the inflow end 416 and the inflow tip 430 of the outflow cell 426.

[0083] In some embodiments, the first portion 502 and the second portion 504 can be fixed together along the interface surface 510 via one or more fasteners (e.g., stitches). In some examples, the first portion 502 and the second portion 504 can at least partially overlap each other along the interface surface 510 and be fixed together by an adhesive or a bond (e.g., a chemical bond).

[0084] The first portion 502 can be a reinforcing layer including a fabric (such as a woven fabric). In some examples, the first portion 502 can include a fabric (such as a polyethylene terephthalate, or PET, fabric) having outwardly extending fibers 514 (e.g., which can be the same as or similar to the outwardly extending yarns 208 in FIG. 4 or 314 in FIGS. 8A and 8B). (FIG. 12A). In some examples, the outwardly extending fibers 514 can be leno yarns or fibers woven in a leno weave pattern having a base fabric layer 515 of the first portion 502 as disclosed in U.S. Patent Publication No. 2019 / 0374337, which has already been incorporated by reference above. In some examples, the first portion 502 can include a fabric formed by fibers woven together (when disposed around the frame 402) and angled at about 45° with respect to the horizontal or circumferential direction, as schematically illustrated in FIGS. 10 and 11 (FIG. 10 shows a reference axis indicating the circumferential direction 516 and the axial direction 518, which can be relative to the central longitudinal axis 432 of the frame 402 (FIG. 9) when the outer skirt 500 is disposed around the outer surface of the frame 402 as shown in FIG. 11). The angled fibers of the first portion 502 provide an increase in longitudinal extensibility to the outer skirt 500 (in the axial direction 518) when the artificial heart valve is radially compressed into a compressed configuration (e.g., for delivery to a delivery device as shown in FIG. 2).

[0085] The second portion 504 can be a polymer layer that includes a polymeric material. In some embodiments, the polymeric material can have a greater blood clotting resistance than the fabric of the first portion 502. In some examples, the polymeric material is a non-woven fabric. Further, in some examples, the polymeric material is elastic and is configured to circumferentially stretch when the frame 402 radially expands from a radially compressed configuration to a radially expanded configuration. In this way, the second portion 504 can form a slip fit around the frame 402 when the frame 402 is in the radially expanded configuration. As a result, the second portion 504 can extend along the outer surface 434 of the frame 402 (e.g., toward the valve tip 404) within the frame 402, along the outflow cell 426, without fluttering or extending therethrough. As used herein, it should be noted that "elastic" or "elastic material" can refer to elastic and partially elastic materials (e.g., those that fall into plasticity) as long as the material retains its structural integrity under stretch (e.g., is not torn).

[0086] In some embodiments, the polymeric material of the second portion 504 can be TPU. In alternative embodiments, the second portion 504 can include a different polymeric material such as ePTFE. In some examples, the second portion 504 can be configured to stretch in both the axial direction 518 and the circumferential direction 516.

[0087] In some embodiments, as shown in FIG. 12A, the first portion 502 and the second portion 504 can be arranged adjacent to each other (or connected to each other at the interface 510) such that the second portion 504 extends from the upper end or the outflow end 522 of the first portion 502. Thus, in some examples, the outer skirt 500 can include a single layer having a first portion 502 forming the lower portion of the outer skirt 500 and a second portion 504 forming the upper portion of the outer skirt 500. In such embodiments, both the inner surface 524 of the first portion 502 and the inner surface 526 of the second portion 504 can be arranged adjacent to the outer surface 434 of the frame 402 without any additional intervening layer therebetween. In some examples, at least the inner surface 526 of the second portion 504 can be coplanar with the outer surface 434 of the frame 402.

[0088] In an alternative embodiment, as shown in FIG. 12B, the outer skirt 550 can include the first portion 502 and the second portion 504, but the second portion 504 can extend along the inner surface 524 of the first portion 502 such that the second portion 504 covers all or most of the inner surface 524 of the first portion 502. As a result, the inner surface 526 of the second portion 504 can be arranged relative to the outer surface 434 of the frame 402 and can be arranged (separately) between the frame 402 and the first portion 502. Thus, in some examples, the outer skirt 550 can include two layers of 500, the second portion 504 forms the first inner layer of the outer skirt 500, and the first portion 502 forms the first outer layer of the outer skirt 550 that extends from the inflow edge portion 506 to the position of the middle portion of the outer skirt 550 between the inflow edge portion 506 and the outflow edge portion 508 (at the interface 510 in FIG. 12B). In other words, the outer skirt 550 can include an outflow portion or an upper portion including only the second portion 504 of the polymer and an inflow portion or a lower portion including the first portion 502 of the fabric (as the outer layer) and the second portion 504 of the polymer (as the inner layer) (FIG. 12B).

[0089] In some examples, instead of the fibers 514 of the first portion 502 extending outwardly from the base fabric layer 515 of the first portion 502, the fibers 514 forming the first portion 502 can be at least partially embedded within the lower region of the second portion 504 (e.g., the region between the inflow edge portion 506 and the interface surface 510) and extend outwardly therefrom. For example, in some examples, the fibers 514 forming the second portion 502 can be directly adhered or bonded to the lower region of the second portion 504, similar to what was described above with reference to FIG. 8C.

[0090] In some examples, the outer surface 528 of the first portion 502 can also be covered by the second portion 504. For example, in some examples, the first portion 502 can be encapsulated by the layer of the second portion 504 or between its layers. However, the second portion 504 can still extend beyond the first portion 502 over a portion of the outflow cell 426 as described above such that the upper or outflow portion of the outer skirt 500 includes only the second portion 504 and lacks the fabric or fibers of the first portion 502.

[0091] In this way, the second portion 504 can be configured to reduce or prevent PVL across the frame 402 (e.g., across the upper region of the scallop line of the valve tip), while the first portion 502 further functions to prevent PVL axially along the artificial heart valve at the portion between the frame 402 and the native tissue at the implantation site. Additionally, the first portion 502 can promote in-growth of tissue therein.

[0092] In some examples, since stretchable or elastic materials can creep over time, an artificial heart valve including the outer skirt 500 can be stored in a partially compressed state (rather than being fully expanded), thereby preventing creep and loss of tension of the second portion 504 prior to valve implantation. For example, the artificial heart valve can be radially expanded and then partially compressed to a diameter smaller than its fully expanded diameter and then stored in this state until ready for implantation.

[0093] In some embodiments, components of an artificial heart valve, such as an inner skirt (e.g., inner skirt 16 of FIG. 1), an outer skirt (e.g., outer skirt 18 of FIG. 1, 206 of FIG. 3, 300 of FIGS. 5 - 8B, 406 of FIG. 9, 500 of FIGS. 10 - 12B, 700 of FIGS. 16 - 18, or 800 of FIGS. 19 - 21), or an alternative skirt or connection component, may have a surface configured to mimic the structure of shark skin. In this way, the drag of the flow on the surface can be reduced. As a result, the skirt or connection component of the artificial heart valve may be more resistant to ablation and / or accumulation of debris when implanted in a patient. It should be noted that the microscale structures described below can also be implemented on the surface of additional implantable medical devices such as stents.

[0094] FIGS. 13A - 13B show SEM images of the shark skin surface 600 at magnifications of 50 times (FIG. 13A), 200 times (FIG. 13B), and 1000 times (FIG. 13C). FIGS. 13A - 13B show the riblet structure or riblets 602 of the shark skin surface 600 (see, e.g., Xia et al., Braz. arch. biol. technol. 2015;60, which uses a bio - replication forming technique to fabricate the shark skin surface). The riblets 602 of the shark skin surface 600 can reduce the drag of the flow on the shark skin surface 600.

[0095] The shark skin surface such as the shark skin surface 600 in FIGS. 13A to 13C can be replicated (on a microscale) by the PDMS elastomer stamp method (as shown in FIG. 14A) or by the PDMS-embedded type elastomer stamp method (FIG. 14B) (for example, see Xia et al., using bio-replication forming technology to fabricate the shark skin surface, Braz. arch. biol. technol. 2015;60). As shown in FIGS. 14A and 14B, the shark skin sample 610 can be inserted into the plate 612 filled with PDMS 614 (FIG. 14A), or can be pressed into the plate 612 containing PDMS 614 (FIG. 14B) to form a negative mold 616 of the shark skin sample 610. The negative mold 616 can then be filled with a desired material such as TPU, ePTFE, etc. to form a material layer 618 including the simulated microscale 620.

[0096] In some examples, the microscale structure can be formed on the surface of the skirt of the artificial heart valve. In some embodiments, the surface can be the inner surface (for example, the surface facing radially inward toward the central longitudinal axis of the artificial heart valve).

[0097] In some examples, the simulated microscale structure can be formed on the surface of one of the outer skirt layers or portions described herein. As an example, as shown in FIG. 15, the outer skirt 650 can include an inner layer 652 that includes a simulated microscale, an intermediate layer 654 that can include a polymeric material (e.g., the same or similar to the second portion 504 described above), and an outer layer 656 that includes a fabric (e.g., the same or similar to the first portion 502 described above). In some examples, the intermediate layer 654 can extend beyond the outer layer 656 toward the outflow end 418 of the frame 402, and the inner layer 652 can cover all or most of the inner surface 658 of the intermediate layer 654. In other examples, the inner layer 652 can be part of (formed integrally with) the intermediate layer 654 such that the inner layer 652 is the inner surface on which the inner layer 652 is formed on the intermediate layer 654 (e.g., the material of the intermediate layer 654 is used in the sharkskin negative mold 616 described above, thereby forming a material layer having one relatively smooth surface and an opposite surface that includes a simulated microscale).

[0098] In other examples, the simulated microscale structure can be applied to an alternative skirt as an inner layer that includes a simulated microscale. For example, a more conventional fabric skirt, such as the outer skirt of FIG. 1 or FIG. 3, can include an inner layer, coating, or covering material that includes a simulated microscale that is adhered to the inner surface of the skirt fabric. As a result, the simulated microscale can face the frame and valve leaflets of the artificial heart valve.

[0099] By forming an outer skirt having an inner surface, coating, or layer that includes a simulated microscale (e.g., a simulated sharkskin surface), accumulation and / or ablation of debris on the inner surface of the outer skirt can be reduced or avoided, thereby increasing the long-term durability and lifespan of the artificial heart valve.

[0100] Figures 16-21 show additional examples of the outer skirt of an artificial heart valve that may include a polymeric inner layer and a fabric outer layer attached to the inner layer. In some examples, the outer layer is attached to the inner layer via a fastener (such as a suture). The polymeric inner layer can include a polymeric material (similar to the second portion 504 of the outer skirt 500 as described above with reference to FIGS. 10-12B), and can extend further toward the outflow end of the frame than the fabric outer layer. In some examples, the polymeric inner layer can extend over a portion of the outflow cells of the frame (such as an elongated outflow cell disposed at the outflow end of the frame). Further, in some examples, the fabric outer layer can include two or more fabric portions removably attached to the polymeric inner layer by tensile sutures. As a result, the artificial heart valve to which the outer skirt is attached can effectively seal with the native anatomical structure at the implantation site, while being more easily removed (transplanted) from the native anatomical structure.

[0101] Figures 16-18 show a first example of such an outer skirt 700 that can be secured around the outer surface of an exemplary frame 402 (however, in alternative examples, the outer skirt 700 can be secured around frames of different configurations, such as one of those referenced above). FIG. 16 shows a side view of a portion of the outer skirt 700 secured to a portion of the frame 402, and FIGS. 17 and 18 show schematic cross-sectional side views of the outer skirt 700 before (FIG. 17) and after (FIG. 18) being secured to the frame 402.

[0102] The outer skirt 700 can include an inner layer 702 and an outer layer 704 attached to the inner layer 702. The inner layer 702 can include a polymeric material, and the outer layer 704 can include a fabric. In some examples, the outer layer 704 can include two outer layers or outer layer portions, including a first outer layer portion 706 (also referred to as an upper or outflow outer layer portion) and a second outer layer portion 708 (also referred to as a lower or inflow outer layer portion). Further, in some examples, the outer layer 704 can extend axially toward the outflow end 418 of the frame 402 beyond the outflow edge portion 722 of the first outer layer portion 706.

[0103] The inner layer 702 may include a polymeric material such as one of the materials described herein with reference to the second portion 504 of the outer skirt 500 (e.g., TPU, ePTFE, etc.). In some examples, the inner layer 702 may be formed as a relatively thin layer so that the inner layer 702 does not increase the crimp profile of the artificial heart valve. For example, the inner layer 702 can have a thickness in the range of 5-20 μm.

[0104] In some examples, the inner layer 702 can include a sheet of polymeric material (e.g., TPU). In some examples, the inner layer 702 can include reinforcing members embedded within a polymeric material configured to increase strength and resistance to tearing, such as weft and warp threads (e.g., arranged at a non-zero angle such as about 45 degrees with respect to the central longitudinal axis of the frame). Further, the polymeric material of the inner layer 702 can be configured such that when the valve leaflet of the artificial heart valve contacts the inner layer 702, wear on the valve leaflet does not occur.

[0105] The inner layer 702 can extend from a position at or adjacent to the inflow end 416 of the frame 402 towards the outflow end 418 of the frame 402 (Figs. 16 and 18). In some examples, the inflow edge portion 710 of the inner layer 702 can extend over at least a portion of each inflow strut 415.

[0106] Furthermore, in some embodiments, the outflow edge portion 712 of the inner layer 702 may extend over at least a portion (e.g., the inflow portion) of the elongated outflow cell 426 (FIG. 16). In some examples, as shown in FIG. 16, the outflow edge portion 712 may be fixed to and extend over an inflow end portion of the axial strut 410 forming the outflow cell 426, such as an opening 440 of the axial strut 410, via a fastener 714 (e.g., a suture). As described above, the polymeric material of the inner layer 702 is elastic and may be configured to stretch (circumferentially) when the frame is radially expanded. As a result, the polymeric material of the inner layer 702 can form a slip fit around the outer surface of the frame 402 when the frame is radially expanded, such that the frame lies flat against the frame and has no excessive sagging that bulges outwardly or inwardly (e.g., through the outflow cell 426).

[0107] In an alternative embodiment, the outer skirt 700 may be used with frames of different configurations, such as the frame 12 of FIG. 1, the frame 202 of FIG. 3, or any of the various frames that are balloon-expandable, self-expandable, or mechanically expandable as disclosed for the above-described applications. Thus, in some examples, the outflow edge portion 712 of the inner layer 702 may not extend over an outflow cell of the frame (e.g., a cell disposed in a row of cells defining the outflow end of the frame), and instead may extend over an intermediate portion of the frame, as shown in FIGS. 1 and 3. However, in such examples, the inner layer 702 may still extend beyond the outer layer 704 toward the outflow end of the frame, as further described below.

[0108] The second outer layer portion 708 can include a woven fabric such as a PET fabric. In alternative embodiments, the woven fabric material of the second outer layer portion 708 can be another type of woven fabric. In some examples, the second outer layer portion 708 can include weft and warp threads woven together in a plain weave. In some embodiments, as schematically shown in FIG. 16, the weft and warp threads can be arranged at an angle of 45 degrees (with respect to the axial direction). In some examples, the second outer layer portion 708 can include a woven fabric that does not include any pile or floating fibers or threads.

[0109] The second outer layer portion 708 can be fixed to the inner layer 702 and can extend from the first outer layer portion 706 across the inner layer 702 toward the inlet end 416 of the frame 402 (FIGS. 16 and 18). Thus, the second outer layer portion 708 can be axially offset from the inlet edge portion 710 of the inner layer 702 (FIG. 17).

[0110] The second outer layer portion 708 can cover at least a portion of the inlet strut 415 (FIG. 16) and can be wrapped around the inlet tip 438 at the inlet end 416 of the frame (FIGS. 16 and 18). In this way, the second outer layer portion 708 can wrap from the outer surface 434 of the frame 402, around the inlet tip 438, across the inner surface 436 of the frame (the inner surface of the inlet strut 415) (FIG. 18). In some embodiments, the end portion of the second outer layer portion 708 that wraps around the inlet tip 438 and around the inner surface 436 of the frame 402 can be fixed to the inlet edge portion of the first outer layer portion 706 and the inlet edge portion 710 of the inner layer 702 (e.g., by stitches 726 as shown in FIG. 18).

[0111] By wrapping the second outer layer portion 708 around the inlet tip 438 such that the inlet tip 438 is covered by the second outer layer portion 708, the conical tip 438 can be prevented from rubbing against the inner surface of a guide sheath (or guide catheter) as the artificial heart valve advances toward the implantation site on the delivery device. As a result, the pushing force experienced by the user advancing the delivery device and the artificial heart valve through the guide sheath can be reduced.

[0112] The first outer layer portion 706 can be a floating yarn or fiber portion including a plurality of circumferentially extending floating Reno wires 716 (or woven fabric portions) axially spaced from each other, and a plurality of floating yarn sections 718 disposed between adjacent floating Reno wires 716 (Figs. 16-18). Each floating yarn section 718 can include a plurality of floating yarns 720 (or fibers) extending axially between adjacent Reno wires 716 and woven therein. The floating yarns 720 extend radially outwardly between the Reno wires 716, thereby forming a textured outer surface on the first outer layer portion 706 configured to increase tissue ingrowth after implantation of the artificial heart valve.

[0113] As shown in Figs. 16-18, the first outer layer portion 706 can include a first Reno wire 716a disposed adjacent to the second outer layer portion 708, a second Reno wire 716b disposed in the middle portion of the first outer layer portion 706, and a third Reno wire 716c defining the outflow edge portion 722 of the first outer layer portion 706. Further, the first outer layer portion 706 can include a first floating yarn section 718a extending axially between the first Reno wire 716a and the second Reno wire 716b, and a second floating yarn section 718b extending axially between the second Reno wire 716b and the third Reno wire 716c.

[0114] Three floating Reno wires 176a, 716b, 716c are illustrated in the embodiments of Figs. 16-18, but in other embodiments, the first outer layer portion 706 can include two floating Reno wires 716 (e.g., at the outflow and inflow edge portions of the first outer layer portion 706, thereby defining a single floating yarn section 718 therebetween), or three or more floating Reno wires (e.g., four, five, or the like), and thus three or more floating yarn sections 718.

[0115] The above-described configuration of the first outer layer portion 706, in combination with the inner layer 702, enables a reduction in the number or density of the floating threads 720 (e.g., as compared to a skirt without an inner polymer layer), thereby reducing the crimp profile of the artificial heart valve.

[0116] In some embodiments, in addition to the floating threads 720 (which can be textured and extend outwardly as described above), the floating thread section 718 can include one or more shorter threads or cords that are shorter than the floating threads 720 and are dimensioned to limit the maximum axial length of the outer skirt 700 when the artificial heart valve is in a radially compressed configuration. For example, it may be desirable to limit the extension of the outer skirt 700 to the same amount as that of the frame when radially compressing the artificial heart valve. Accordingly, the additional shorter threads can be dimensioned to match the extension of the frame that occurs during radial compression of the artificial heart valve.

[0117] As shown in FIGS. 16 - 18, the outflow edge portion 722 of the first outer layer portion 706 is axially offset from the outflow edge portion 712 of the inner layer 702, thereby defining an outflow portion 724 of the inner layer 702 that is devoid of threads. Accordingly, the outflow portion 724 may be configured to reduce paravalvular leakage across or through the frame 402 (e.g., over the upper region of the scallop line), while the first outer layer portion 706 may be configured to reduce or prevent paravalvular leakage axially along the artificial heart valve between the frame and the self - tissue.

[0118] In some embodiments, the first outer layer portion 706 and the second outer layer portion 708 of the outer layer 704 can be fixed to the inner layer 702 by a plurality of fasteners such as suturing threads. In some examples, as shown in FIG. 16, the first outer layer portion 706 and the second outer layer portion 708 of the outer layer 704 can be fixed to the inner layer 702 by a plurality of whip stitches 726 that extend around the floating Leno wire 716 (FIGS. 16 and 19).

[0119] Next, the outer skirt 700 can be fixed to the frame 402 (or the alternative frame described above) by whip stitches, in-and-out stitches, etc. that extend along a portion of the artificial heart valve following the scallop line of the valve tip and / or the outflow edge portion 712 of the outer skirt 700. As an example of one embodiment, as shown in FIG. 16, the outer skirt 700 can be fixed to the strut 414 of the frame 402 that extends along the scallop line of the valve tip by a whip stitch 728 and to the opening 440 of the axial strut 410 by a fastener 714 (e.g., a suture). In an alternative embodiment, the outer skirt 700 can be fixed to the inflow strut 415 at its inflow edge portion and to the axial strut 410 (or an alternative strut that the outflow edge portion 712 extends across) at its outflow edge portion.

[0120] In some embodiments, after implanting the artificial heart valve into the native tissue at the implantation site (e.g., the native annulus), it may be necessary to explant (remove from the implantation site) the artificial heart valve. However, since the fabric skirt of the artificial heart valve can be configured to promote in-growth into the tissue, it can be difficult to release the fabric skirt from the tissue and explant the artificial heart valve.

[0121] Accordingly, the inventors herein have recognized that it would be advantageous to provide an artificial heart valve having a fabric outer skirt that reduces paravalvular leakage but can be removably coupled to the frame of the artificial heart valve, thereby enhancing the ease of explant of the artificial heart valve.

[0122] FIG. 19 shows another embodiment of an outer skirt 800 that can be secured around the outer surface of the exemplary frame 402. Similar to the outer skirt 700 of FIGS. 16 - 18, the outer skirt 800 can include an inner layer 802 (which may be similar to the inner layer 702 described above) and an outer layer 804 attached to the inner layer 802. The inner layer 802 can include a polymeric material, and the outer layer 804 can include a fabric. As shown in FIG. 19, the outer layer 804 can include only the first outer layer portion 706 as described above with reference to FIGS. 16 - 19, and the inner layer 802 extends over and wraps around the inflow tip 438 of the frame 402. However, in an alternative embodiment, the inner layer 802 can extend over the inflow strut 415 (e.g., as shown in FIG. 16), but may not wrap around the inflow tip 438.

[0123] The outer layer 804 can be attached to the inner layer 802 in the same manner as the outer skirt 700, as described above with reference to FIG. 16. However, the outer layer 804 can be removably attached to the inner layer 802 by a plurality of whip stitches 812 and tension sutures 810. As a result, during the explant procedure, the outer layer 804 can be released from the inner layer 802 (and the remainder of the artificial heart valve including the frame 402), and thus the artificial heart valve can be removed more easily from the implantation site (since the outer layer 804 can have tissue that adheres or grows to it).

[0124] As shown in FIG. 19, the tension sutures 810 can extend along the upper edge portion 806 of the outer layer 804 and, in some examples, along a third Reno wire 716c (FIG. 19). As shown in more detail by the schematic cross - sectional view of FIG. 20, the whip stitches 812 can extend around the tension sutures 810 and through the outer layer 804 and the inner layer 802.

[0125] For example, as shown in FIG. 20, the inner surface 814 of the outer layer 804 contacts or is disposed relative to the outer surface 816 of the inner layer 802, and the inner layer 802 is adjacent to or disposed relative to the outer surface 434 of the struts 414 of the frame 402. The tension stitching thread 810 contacts or is disposed relative to the outer surface 818 of the outer layer 804.

[0126] The whip stitch 812 of the stitching thread 820 can pass through the material of the inner layer 802, through the material of the outer layer 804 (e.g., passing through and disposed within a plurality of openings 822 in the material of the outer layer 804), and extend around the tension stitching thread 810 in a whip stitch pattern along the length of the upper edge portion 806 of the outer layer 804. In some examples, the tension stitching thread 810 can pass through and be disposed within a plurality of pre-formed openings 824 in the inner layer 802.

[0127] Each whip stitch 812 includes a leading end portion 813a that extends outwardly around the tension stitching thread 810 through the material of the inner layer 802 or, alternatively, through the opening 824 in the inner layer 802 and through the opening 822 in the outer layer 804, and transitions to a trailing end portion 813b that extends inwardly through the same opening 822 in the outer layer 804 and through a different but adjacent opening 824 in the inner layer 802 (or through the material of the inner layer 802), where the trailing end portion 813b transitions to the leading end portion of the next whip stitch 812 (FIG. 20). In this way, each whip stitch 812 is screwed through a single opening or opening 822 in the outer layer 804 and two different but adjacent openings 824 in the inner layer 802. As can be seen in FIG. 20, the tension stitching thread 810 prevents the whip stitch 812 from being pulled through the opening 822 when the tension stitching thread 810 is positioned along the stitch line across the upper edge portion 806. Accordingly, the outer layer 804 can be fixed to the inner layer 802, which is fixed to the frame 402 (FIG. 19), via the force applied by the whip stitch 812 on the tension stitching thread 810 and on the inner surface 826 of the inner layer 802 when the tension stitching thread is disposed through the stitch line and across the upper edge portion 806.

[0128] In some embodiments, the openings 822 in the material of the outer layer 804 and / or the openings 824 in the material of the inner layer 802 can be pre-formed by techniques such as laser drilling, cutting, stamping, or other suitable techniques known in the art. In other embodiments, when the whip stitches 812 are sewn through the material of the outer layer 804 and / or the material of the inner layer 802, the openings 822 in the material of the outer layer 804 and / or the openings 824 in the material of the inner layer 802 can be formed.

[0129] When the tensile suture 810 is removed (e.g., by pulling one of the unknotted ends 828a or 828b (FIG. 20) in a direction parallel to the stitch line or outward from the frame 402), the whip stitches 812 are no longer held by the tensile suture 810. Thus, when the outer layer 804 is pulled away from the inner layer 802 and the frame 402 (or the inner layer 802 and the frame 402 are pulled away from the outer layer 804), the whip stitches 812 are pulled out through the openings 822 in the outer layer 804, thereby separating (or removing or decoupling) the outer layer 804 from the inner layer 802, and the whip stitches 812 remain attached to the inner layer 802.

[0130] Since the inner layer 802 can include a blood clotting resistant polymer (or a polymer material having a greater blood clotting resistance than the textile material of the outer layer 804), the inner layer 802 resists in-growth into tissue and can be more easily separated from the outer layer 804 and the tissue at the implantation site.

[0131] In some examples, the suture 820 of the whipstitch 812 can be a thinner fiber, thread, or suture relative to the thicker tension suture 810. In some examples, the suture 820 forming the whipstitch 812 can be composed of a biocompatible doubling that is thinner and has a high tensile strength, such as ultra-high molecular weight polyethylene (UHMPE) force fibers (registered trademark) or other similar materials, or combinations thereof. In one particular embodiment, the suture 820 can be formed from UHMPE force fibers, is thin enough, and can withstand a force such that the whipstitch 812 can tear through the overgrown tissue on the outer surface of the outer layer 804 when the inner layer 802 is separated from the outer layer 804. In some examples, the tension suture 810 can be composed of a biocompatible material that is thicker and has a high tensile strength, such as a monofilament made of polypropylene (e.g., prolene 4-0), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), or other similar materials or combinations thereof. In one particular embodiment, the tension suture 810 can be a microfilament containing prolene, which is configured to be easily separated from or easily pulled away from any ingrown tissue in the vicinity when pulled by a surgeon during the extraction procedure.

[0132] In some embodiments, the tension suture 810 may have different color tones, or colored coatings (e.g., color tones or coatings such as green, black, blue, etc.), be radiopaque, and / or be tagged so as to be identifiable by a surgeon during the extraction procedure. In some examples, the entire length of the tension suture 810 may be composed of, for example, a bright-colored material or be provided with a bright-colored coating. In other examples, a portion of the tension suture 810 (e.g., the free ends or unknotted end portions 828a / 828b of the tension suture 810) may be composed of a colored material, have a bright-colored coating, and / or include a bright-colored tag or flap attached thereto. In other examples, the tension suture 810 or a portion thereof may include a material, coating, or tag such that it can be visualized using a dedicated visualization device. For example, the tension suture 810 may include a radiopaque substance or one or more radiopaque markers such that it can be visualized via fluoroscopy or an X-ray device. For example, one or more radiopaque markers can be embedded within the outer surface of the tension suture 810 or attached to the outer surface of the tension suture 810.

[0133] In some embodiments, the unknotted ends 828a, 828b of the tension suture 810 can be tied to the commissures of the artificial heart valve (e.g., commissure 856 shown in FIG. 21). Thus, during the description of the artificial heart valve, the unknotted end 828a or 828b of the tension suture 810 can be easily and quickly positioned and pulled by the surgeon, thereby pulling the tension suture 810 away from the outer skirt 800 and removing the outer layer 804 from the inner layer 802.

[0134] FIG. 21 shows an artificial heart valve 850 including a frame 402, an outer skirt 800 is disposed around and fixed to the outer surface of the frame 402, and a valve leaflet structure 852 includes a plurality of leaflets 854 disposed within the interior of the frame. The commissural tabs of adjacent leaflets 854 are fixed together within the commissural windows of the frame 402, thereby forming commissures 856. As shown in FIG. 21, the floating yarns 720 of the first outer layer portion 706 of the outer layer 804 of the outer skirt 800 can form a fuzzy, plush, or textured outer surface 858 that is configured to contact autologous tissue when the artificial heart valve 850 is radially expanded and implanted at the implantation site. As described herein, this textured outer surface 858 can be configured to promote in-growth of tissue therein, thereby increasing the perivalvular leakage seal against autologous tissue. At the same time, the artificial heart valve 850 can be more easily removed from autologous tissue during the explantation procedure due to the outer layer 804 being removably coupled to the inner layer 802 as described above with reference to FIGS. 19 and 20.

[0135] Delivery Technology To implant an artificial valve into the native aortic valve via a transfemoral delivery approach, the artificial valve is attached in a radially compressed state along the distal end portion of the delivery device. The artificial valve and the distal end portion of the delivery device are inserted into the femoral artery and driven forward through the descending aorta and through the descending aorta, around the aortic arch and through the ascending aorta. The artificial valve is positioned inside the native aortic valve and expanded radially (e.g., by inflating a balloon, by actuating one or more actuators of the delivery device, or by deploying the artificial valve from the sheath to make the artificial valve self-expanding). Alternatively, the artificial valve can be implanted inside the native aortic valve via a transapical procedure, in which case the artificial valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the artificial valve is positioned inside the native aortic valve. Alternatively, in a transaortic procedure, the artificial valve (on the distal end portion of the delivery device) is introduced into the aorta through a surgical incision in the ascending aorta, for example, by a partial J sternotomy or a small right parasternal thoracotomy, and then advanced through the ascending aorta towards the native aortic valve.

[0136] To implant an artificial valve into the native mitral valve via a transseptal delivery approach, the artificial valve is attached in a radially compressed state along the distal end portion of the delivery device. The artificial valve and the distal end portion of the delivery device are inserted into the femoral vein and advanced through the inferior vena cava and through the inferior vena cava, into the right atrium, across the atrial septum (through a puncture performed within the atrial septum), into the left atrium, and towards the native mitral valve. Alternatively, the artificial valve can be implanted into the native mitral valve via a transapical procedure, in which case the artificial valve (on the distal end portion of the delivery device) is introduced into the left ventricle through a surgical opening in the chest and the apex of the heart, and the artificial valve is positioned inside the native mitral valve.

[0137] To implant an artificial valve inside the native tricuspid valve, the artificial valve is attached in a radially compressed state along the distal end portion of the delivery device. The artificial valve and the distal end portion of the delivery device are inserted into the femoral vein and advanced into the inferior vena cava and through the inferior vena cava into the right atrium, where the artificial valve is positioned inside the native tricuspid valve. A similar approach can be used to implant the artificial valve inside the native pulmonary valve or the pulmonary artery, except that the artificial valve is advanced through the native tricuspid valve into the right ventricle and towards the pulmonary valve / pulmonary artery.

[0138] Another delivery approach is the transatrial approach, where the artificial valve (on the distal end portion of the delivery device) is inserted through a chest incision that is made through the atrial wall (the atrial wall of the right atrium or the left atrium) to access any of the native heart valves. Atrial delivery can also be performed intravascularly, for example, from a pulmonary vein. Yet another delivery approach is the transventricular approach, where the artificial valve (on the distal end portion of the delivery device) is inserted through a chest incision that is made through the wall of the right ventricle (typically at or near the base of the heart) to implant the artificial valve inside the native tricuspid valve or inside the native pulmonary valve or the pulmonary artery.

[0139] In all delivery approaches, the delivery device may be advanced over a guidewire previously inserted into the patient's vasculature. Moreover, the disclosed delivery approaches are not intended to be limiting. Any artificial valve disclosed herein can be implanted using any of a variety of delivery procedures and any of a variety of delivery devices known in the art.

[0140] Any systems, devices, apparatuses, etc. described in this specification can be sterilized (e.g., using heating / heat, pressure, steam, radiation, and / or chemicals, etc.) to ensure safety in use with patients, and any methods described in this specification can include sterilization of related systems, devices, apparatuses, etc. as one of the steps of the method. Examples of sterilization by heating / heat include sterilization by steam and sterilization by autoclave. Examples of radiation used for sterilization include, but are not limited to, gamma rays, ultraviolet rays, and electron beams. Examples of chemicals used for sterilization include, but are not limited to, ethylene oxide, hydrogen peroxide, peracetic acid, formaldehyde, and glutaraldehyde. Sterilization by hydrogen peroxide may be performed, for example, using hydrogen peroxide plasma.

Example

[0141] Additional Examples Relating to the Disclosed Technology In view of the above-described implementations of the disclosed subject matter, this application discloses additional examples listed below. It should be noted that one or more features of a separate example, or a combination thereof, and optionally a combination of one or more features of one or more additional examples with two or more features of that example are also further examples falling within the disclosure of this application.

[0142] Example 1. An artificial heart valve comprising an annular frame having an inlet end, an outlet end, and an intermediate portion disposed between the inlet end and the outlet end, and an outer skirt disposed around the outer surface of the frame, the outer skirt including a first portion including a polymeric material and a second portion including a fabric, the polymeric material having a greater thromboresistance than the fabric, the second portion being fixed to the inlet end of the frame and extending toward the intermediate portion, and the first portion extending from the second portion toward the outlet end of the frame.

[0143] Example 2. The frame includes a plurality of interconnected struts that define cells in a plurality of circumferentially extending rows, including a first row of outflow cells disposed at the outflow end, wherein the outflow cells in the first row of outflow cells are axially elongated relative to the remaining rows of cells in the plurality of rows of cells, and a first portion of the outer skirt covers a portion of each outflow cell in the first row of outflow cells. An artificial heart valve according to any embodiment herein, particularly embodiment 1.

[0144] Example 3. An artificial heart valve according to any embodiment herein, particularly embodiment 2, wherein a portion of the outflow cell is the inflow half of the outflow cell disposed closer to the inflow end than the outflow end of the frame.

[0145] Example 4. An artificial heart valve according to any embodiment herein, particularly embodiment 2 or 3, wherein the interface between the first portion and the second portion of the outer skirt extends circumferentially around the frame at an axial position adjacent to the inflow tip of the outflow cell.

[0146] Example 5. An artificial heart valve according to any embodiment herein, particularly any one of embodiments 2 to 3, wherein the plurality of circumferentially extending rows of cells further include a second row of intermediate cells and a third row of inflow cells, and the second portion extends across the second row of intermediate cells and the third row of inflow cells.

[0147] Example 6. An artificial heart valve according to any embodiment herein, particularly any one of embodiments 1 to 5, wherein the polymeric material is elastic and configured to stretch circumferentially when the frame expands radially from a radially compressed configuration to a radially expanded configuration.

[0148] Example 7. An artificial heart valve according to any embodiment herein, particularly any one of embodiments 1 to 6, wherein the polymeric material is configured to form a slip fit around the outer surface of the frame when the frame is in a radially expanded configuration.

[0149] Example 8. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 7, wherein the polymeric material is a non-woven fabric.

[0150] Example 9. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 8, wherein the polymeric material is thermoplastic polyurethane.

[0151] Example 10. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 9, wherein the second part of the woven fabric is a woven fabric containing polyethylene terephthalate.

[0152] Example 11. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 10, wherein the second part of the woven fabric is a reinforced woven fabric containing weft fibers and warp fibers angled at a non-zero angle with respect to the central longitudinal axis of the artificial heart valve.

[0153] Example 12. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 11, wherein the second part of the woven fabric contains a plurality of radially outwardly extending fibers configured to contact and seal against tissue.

[0154] Example 13. An artificial heart valve according to any one of the examples described herein, particularly any one of Examples 1 to 12, wherein the first part forms an inner layer of an outer skirt disposed against the outer surface of the frame, the second part forms an outer layer of the outer skirt, and the inner layer extends axially beyond the outer layer toward the outflow end of the frame such that the first part further extends across the inner surface of the second part.

[0155] Example 14. An artificial heart valve according to any one of the examples described herein, particularly the artificial heart valve described in Example 13, wherein the first part further extends across the outer surface of the second part and encloses the second part therein.

[0156] Example 15. A second portion is removably attached to the first portion by a plurality of whip stitches and a tension suture, the plurality of whip stitches extending around the tension suture and through the second and first portions, the tension suture being configured to be pulled through and released from the whip stitches, whereby the second portion is removed from the first portion, any example of the present specification, in particular the artificial heart valve described in Example 13.

[0157] Example 16. The outer skirt further includes a layer including a plurality of microscales formed on its surface, the outer skirt being disposed across one or more inner surfaces of the first and second portions, any example of the present specification, in particular the artificial heart valve described in any one of Examples 1 to 15.

[0158] Example 17. The artificial heart valve further includes a valve structure disposed within the frame and configured to regulate blood flow through the one-way frame, any example of the present specification, in particular the artificial heart valve described in any one of Examples 1 to 16.

[0159] Example 18. An artificial heart valve including an annular frame and an outer skirt disposed around the outer surface of the frame, the outer skirt including a woven fabric and an outer layer forming an exposed surface for contact with tissue, and a polymer material and an inner layer covering the inner surface of the outer layer, the inner layer extending toward the outflow end of the frame beyond the outflow edge portion of the outer layer.

[0160] Example 19. The artificial heart valve according to any example of the present specification, in particular the artificial heart valve described in Example 18, wherein the inflow edge portion of the outer layer portion is disposed at the inflow end of the frame.

[0161] Example 20. The frame includes a plurality of interconnected struts that define a plurality of circumferentially extending rows of cells, including a first row of outflow cells disposed at the outflow end of the frame, the first row of outflow cells being axially longer than the remaining rows of cells of the plurality of rows of cells, and the inner layer of the outer skirt covering at least a portion of each outflow cell of the row of outflow cells, an artificial heart valve according to any embodiment of the present specification, particularly embodiment 18 or embodiment 19.

[0162] Example 21. An artificial heart valve according to any embodiment of the present specification, particularly embodiment 20, wherein the outflow edge portion of the inner layer is fixed to the inflow end portion of the axial struts of the frame that define the first row of outflow cells.

[0163] Example 22. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 18 to 21, wherein the polymeric material is elastic and configured to stretch circumferentially when the frame expands from a radially compressed configuration to a radially expanded configuration.

[0164] Example 23. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 18 to 22, wherein the polymeric material has a greater thromboresistance than a fabric and is configured to form a slip fit around the outer surface of the frame when the frame is in a radially expanded configuration.

[0165] Example 24. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 18 to 23, wherein the polymeric material is thermoplastic polyurethane.

[0166] Example 25. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 18 to 24, wherein the outer layer includes a first outer layer portion including a plurality of floating threads extending radially outwardly away from the outer skirt and the frame.

[0167] Example 26. The first outer layer portion includes a plurality of circumferentially extending floating Reno wires that are axially spaced apart from each other, and a plurality of floating yarn sections disposed between adjacent floating Reno wires, each floating yarn section including floating yarns of a plurality of floating yarns that extend axially between and are woven into adjacent Reno wires, the artificial heart valve described in any embodiment of the present specification, particularly embodiment 25.

[0168] Example 27. The outflow edge portion of the first outer layer portion is attached to the inner layer by a plurality of whip stitches that extend through the inner layer and the first outer layer portion, the artificial heart valve described in any embodiment of the present specification, particularly embodiment 25 or embodiment 26.

[0169] Example 28. The tension suture extends along the outer surface of the outflow edge portion of the first outer layer portion, and the first outer layer portion is removably attached to the inner layer by the tension suture and a plurality of whip stitches that further extend around the tension suture, the artificial heart valve described in any embodiment of the present specification, particularly embodiment 27.

[0170] Example 29. The outer layer is fixed to the inflow edge portion of the first outer layer portion and further includes a second outer layer portion that extends from the first outer layer portion toward the inflow end of the frame, the artificial heart valve described in any embodiment of the present specification, particularly any one of embodiments 25 to 28.

[0171] Example 30. The second outer layer portion extends beyond the inner layer toward the inflow end of the frame and wraps around the inflow tip at the inflow end of the frame, the artificial heart valve described in any embodiment of the present specification, particularly embodiment 29.

[0172] Example 31. The end portion of the second outer layer portion that wraps around the inflow tip is fixed to the inflow edge portion of the first outer layer portion and the inflow edge portion of the inner layer, the artificial heart valve described in any embodiment of the present specification, particularly embodiment 30.

[0173] Example 32. An artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 29 to 31, wherein the second outer layer portion includes a woven fabric.

[0174] Embodiment 33. An artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 18 to 12, further including a valve structure disposed within the frame and configured to regulate blood flow through the one-way frame.

[0175] Embodiment 34. An artificial heart valve including an annular frame having an inflow end, an outflow end, and an intermediate portion disposed between the inflow end and the outflow end, and an outer skirt disposed around the outer surface of the frame, the outer skirt including an inner layer including a polymeric material and an outer layer including a fabric and attached to the inner layer, the outer layer including a first outer layer portion and a second outer layer portion, the first outer layer portion extending from the inflow end of the frame toward the intermediate portion of the frame, the second outer layer portion extending from the first outer layer portion toward the outflow end, and the outflow edge portion of the inner layer axially extending toward the outflow end of the frame beyond the outflow edge portion of the second outer layer portion such that the outflow edge portion of the inner layer is disposed closer to the outflow end of the frame than the outflow edge portion of the second outer layer portion.

[0176] Embodiment 35. An artificial heart valve according to any embodiment of the present specification, particularly Embodiment 34, wherein the frame includes a plurality of interconnected struts defining a plurality of circumferentially extending rows of cells, including a first row of outflow cells disposed at the outflow end of the frame, the first row of outflow cells being axially longer than the remaining rows of cells of the plurality of rows of cells, and the outer layer of the outer skirt covering at least a portion of each outflow cell of the row of outflow cells.

[0177] Embodiment 36. An artificial heart valve according to any embodiment of the present specification, particularly Embodiment 35, wherein the outflow edge portion of the inner layer is fixed to an opening in the inflow end portion of the axial strut of the frame defining the first row of outflow cells.

[0178] Example 37. The frame is radially expandable between a radially compressed configuration and a radially expanded configuration, the polymeric material is elastic, and when the frame expands radially from the radially compressed configuration to the radially expanded configuration, it is configured to stretch circumferentially, the artificial heart valve according to any embodiment of the present specification, particularly Example 35 or Example 36.

[0179] Example 38. The polymeric material is configured to be flat against the outer surface of the frame to avoid excessive sagging that bulges outward or inward within the frame when the frame is in the radially expanded configuration, the artificial heart valve according to any embodiment of the present specification, particularly any one of Examples 34 to 37.

[0180] Example 39. The polymeric material has a greater thromboresistance than a fabric, the artificial heart valve according to any embodiment of the present specification, particularly any one of Examples 34 to 38.

[0181] Example 40. The polymeric material is thermoplastic polyurethane, the artificial heart valve according to any embodiment of the present specification, particularly any one of Examples 34 to 39.

[0182] Example 41. The first outer layer portion includes a woven fabric, the artificial heart valve according to any embodiment of the present specification, particularly any one of Examples 34 to 40

[0183] Example 42. The first outer layer portion extends axially toward the inflow end of the frame beyond the inflow edge portion of the inner layer portion and wraps around the inflow tip at the inflow end of the frame, the artificial heart valve according to any embodiment of the present specification, particularly any one of Examples 34 to 41.

[0184] Example 43. The end portion of the first outer layer portion that wraps around the inflow tip and on the inner surface of the frame is fixed to the inflow edge portion of the second outer layer portion and the inflow edge portion of the inner layer, in any embodiment of the present specification, particularly the artificial heart valve described in Embodiment 42.

[0185] Embodiment 44. The artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 34 to 43, wherein the second outer layer portion includes a plurality of floating threads extending radially outward from the frame.

[0186] Embodiment 45. The artificial heart valve according to any embodiment of the present specification, particularly the artificial heart valve described in Embodiment 44, wherein the second outer layer portion includes a plurality of circumferentially extending floating Reno wires spaced apart axially from each other and a plurality of floating thread sections disposed between adjacent floating Reno wires, and each floating thread section includes floating threads among a plurality of floating threads extending axially between and woven into adjacent Reno wires.

[0187] Embodiment 46. The outflow edge portion of the second outer layer portion is attached to the inner layer by a plurality of stitches extending through the inner layer and the second outer layer portion, in any embodiment of the present specification, particularly any one of Embodiments 34 to 45 of the artificial heart valve of any embodiment of the present specification.

[0188] Embodiment 47. The tension suturing thread extends along the outer surface of the outflow edge portion of the second outer layer portion, and the second outer layer portion is removably attached to the inner layer by the tension suturing thread and a plurality of stitches further extending around the tension suturing thread, in any embodiment of the present specification, particularly the artificial heart valve described in Embodiment 46.

[0189] Embodiment 48. The artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 34 to 47, further includes a valve flap structure disposed within the frame and configured to regulate the flow of blood through the one-way frame.

[0190] Example 49. An artificial heart valve comprising an annular frame having an inlet end and an outlet end, and an outer skirt disposed around the outer surface of the frame, the outer skirt including an inner layer and a woven outer layer removably attached to the inner layer by a plurality of whip stitches and tension sutures, the plurality of whip stitches extending around the tension sutures and through the inner and outer layers, and the tension sutures configured to be pulled through the whip stitches so as to be released therefrom, thereby removing the outer layer from the inner layer.

[0191] Example 50. The artificial heart valve according to any example herein, particularly Example 49, wherein the tension suture extends on the outer surface of the outer layer along the outflow edge portion of the outer layer.

[0192] Example 51. The artificial heart valve according to any example herein, particularly Example 49 or Example 50, wherein each whip stitch is screwed through a single opening in the outer layer and two adjacent openings in the inner layer.

[0193] Example 52. The artificial heart valve according to any example herein, particularly any one of Examples 49 to 51, wherein the inner layer comprises a polymeric material.

[0194] Example 53. The artificial heart valve according to any example herein, particularly Example 52, wherein the frame is radially expandable between a radially compressed configuration and a radially expanded configuration, the polymeric material is elastic, and the frame is configured to circumferentially stretch when radially expanded from the radially compressed configuration to the radially expanded configuration.

[0195] Example 54. An artificial heart valve according to any embodiment of the present specification, particularly embodiment 52 or embodiment 53, wherein the polymer material is configured to be flat with respect to the outer surface of the frame when there is excessive slack that bulges outward or inward within the frame when the frame is in a radially expanded configuration.

[0196] Example 55. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 54, wherein the polymer material has a greater thromboresistance than the fabric of the outer layer.

[0197] Example 56. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 55, wherein the polymer material is thermoplastic polyurethane.

[0198] Example 57. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 56, wherein the outflow edge portion of the inner layer extends toward the outflow end of the frame beyond the outflow edge portion of the outer layer.

[0199] Example 58. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 57, wherein the inner layer is fixed to the struts of the frame.

[0200] Example 59. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 58, wherein the inflow edge portion of the inner layer extends around the inflow end of the frame.

[0201] Example 60. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 59, wherein the outer layer includes a plurality of floating threads that extend radially outward and away from the frame.

[0202] Example 61. The outer layer includes a plurality of circumferentially extending floating Reno wires spaced apart from each other in the axial direction, and a plurality of floating yarn sections disposed between adjacent floating Reno wires, each floating yarn section including floating yarns among a plurality of floating yarns extending axially between and woven into adjacent Reno wires, the artificial heart valve according to any embodiment of the present specification, particularly embodiment 60.

[0203] Example 62. The artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 52 to 61, further including a valve flap structure disposed within the frame and configured to regulate the flow of blood through the one-way frame.

[0204] Example 63. An artificial heart valve including an annular frame, a valve flap structure disposed within the frame and configured to regulate the one-way flow of blood through the frame, and a skirt coupled to the frame, the skirt including at least one layer having a plurality of microscales formed on its surface.

[0205] Example 64. The artificial heart valve according to any embodiment of the present specification, particularly embodiment 63, wherein the plurality of microscales are configured to reduce the drag force on the surface of the skirt.

[0206] Example 65. The artificial heart valve according to any embodiment of the present specification, particularly embodiment 63 or embodiment 64, wherein the skirt is an outer skirt disposed around the outer surface of the frame.

[0207] Example 66. The artificial heart valve according to any embodiment of the present specification, particularly embodiment 65, wherein the layer including the plurality of microscales is an inner layer of the skirt disposed relative to the frame, and the skirt further includes an outer layer including a fabric.

[0208] Example 67. The skirt is an inner skirt disposed around the inner surface of the frame between the valve leaflet structure and the frame, for any embodiment of the present specification, particularly the artificial heart valve described in Embodiment 63 or Embodiment 64.

[0209] Embodiment 68. The surface of the layer of the skirt including the microscale formed thereon is a radially inward surface facing the valve leaflet structure, for any embodiment of the present specification, particularly the artificial heart valve described in any one of Embodiments 63 to 67.

[0210] Embodiment 69. An artificial heart valve including an annular frame and an outer skirt disposed around the outer surface of the frame, the outer skirt including a base layer containing a polymer material disposed with respect to the outer surface of the frame, and a plurality of outwardly extending threads adhered to the outer surface of the base layer and extending radially outwardly away from the base layer.

[0211] Embodiment 70. The artificial heart valve according to any embodiment of the present specification, particularly Embodiment 69, wherein the polymer material has a thrombus resistance greater than that of the plurality of outwardly extending threads.

[0212] Embodiment 71. The artificial heart valve according to any embodiment of the present specification, particularly Embodiment 69 or Embodiment 70, wherein the polymer material is thermoplastic polyurethane.

[0213] Embodiment 72. The artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 69 to 71, wherein the threads of the plurality of outwardly extending threads are individual threads spaced apart from each other across the outer surface of the base layer.

[0214] Embodiment 73. The artificial heart valve according to any embodiment of the present specification, particularly any one of Embodiments 69 to 72, wherein the threads of the plurality of outwardly extending threads are adhered to the base layer with an adhesive.

[0215] Embodiment 74. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 69 to 72, wherein a plurality of outwardly extending threads are adhered to the base layer by chemical bonds.

[0216] Example 75. An artificial heart valve according to any embodiment of the present specification, particularly any one of embodiments 69 to 74, wherein a plurality of outwardly extending threads are arranged across the middle portion of the base layer, and the outflow edge portion of the base layer lacking the outwardly extending threads extends beyond the middle portion toward the outflow end of the frame.

[0217] Example 76. An artificial heart valve according to any embodiment of the present specification, particularly the artificial heart valve according to embodiment 75, wherein the inflow edge portion of the base layer lacking the outwardly extending threads extends beyond the middle portion toward the inflow end of the frame.

[0218] Example 77. A method comprising sterilizing an artificial heart valve, device, and / or assembly of any embodiment.

[0219] Example 78. An artificial heart valve according to any one of embodiments 1 to 76, wherein the artificial heart valve is sterilized.

[0220] Unless otherwise stated, the features described in this specification for any embodiment can be combined with the other features described for any other one or more embodiments. For example, any one or more of the features of one outer skirt for an artificial heart valve can be combined with any one or more of the features of another outer skirt for an artificial heart valve. As another example, any one or more of the features of one frame for an artificial heart valve can be combined with any one or more of the features of another frame for an artificial heart valve.

[0221] Considering the many possible aspects to which the principles of the present disclosure may be applied, it will be recognized that the illustrated configurations are illustrative of examples of the disclosed technology and should not be construed as limiting the scope of the present disclosure or the scope of the claims. Rather, the scope of the claimed subject matter is defined by the following claims and their equivalents.

Claims

**Claim 1** An artificial heart valve, comprising: an annular frame having an inlet end, an outlet end, and an intermediate portion disposed between the inlet end and the outlet end; an outer skirt disposed around an outer surface of the frame, the outer skirt including: a first portion including a polymer material; and a second portion including a fabric, wherein the polymer material has a greater thromboresistance than the fabric; wherein the second portion is fixed to the inlet end of the frame and extends toward the intermediate portion, and the first portion extends from the second portion toward the outlet end of the frame. **Claim 2** The artificial heart valve according to claim 1, wherein the frame includes a plurality of interconnected struts defining a plurality of circumferentially extending rows of cells, including a first row of outlet cells disposed at the outlet end, wherein the outlet cells of the first row of outlet cells are axially elongated relative to the remaining rows of cells of the plurality of rows of cells, and the first portion of the outer skirt covers a portion of each of the outlet cells of the first row of outlet cells. **Claim 3** The artificial heart valve according to claim 2, wherein an interface between the first portion and the second portion of the outer skirt extends circumferentially around the frame at an axial position adjacent an inlet tip of the outlet cell. **Claim 4** The artificial heart valve according to any one of claims 1 to 3, wherein the polymer material is elastic and is configured to extend circumferentially when the frame is radially expanded from a radially compressed configuration to a radially expanded configuration. **Claim 5** The artificial heart valve according to any one of claims 1 to 4, wherein the polymer material is a non-woven fabric. **Claim 6** The artificial heart valve according to any one of claims 1 to 5, wherein the polymer material is thermoplastic polyurethane. **Claim 7** The fabric of the second portion is a woven fabric including polyethylene terephthalate. The artificial heart valve according to any one of claims 1 to 6. **Claim 8** The artificial heart valve according to any one of claims 1 to 7, wherein the fabric of the second portion includes a plurality of radially outwardly extending fibers configured to contact tissue and seal against the tissue. **Claim 9** The first portion forms an inner layer of the outer skirt disposed relative to the outer surface of the frame, the second portion forms an outer layer of the outer skirt, and the inner layer further extends across the inner surface of the second portion such that the inner layer axially extends beyond the outer layer toward the outflow end of the frame. The artificial heart valve according to any one of claims 1 to 8.

10. An artificial heart valve, An annular frame, An outer skirt disposed around the outer surface of the frame, An outer layer including a fabric and forming an exposed surface for contacting tissue, An inner layer including a polymer material and covering the inner surface of the outer layer, the inner layer extending toward the outflow end of the frame beyond the outflow edge portion of the outer layer. An outer skirt including the inner layer. An artificial heart valve including the outer skirt.

11. The artificial heart valve according to claim 10, wherein an inflow edge portion of the outer layer is disposed at an inflow end of the frame.

12. The frame includes a plurality of interconnected struts defining a plurality of circumferentially extending rows of cells, including a first row of outflow cells disposed at the outflow end of the frame. The first row of outflow cells is axially longer than the remaining rows of cells in the plurality of rows of cells, and the inner layer of the outer skirt covers at least a portion of each outflow cell in the row of outflow cells. The artificial heart valve according to claim 10 or claim 11.

13. The polymer material has a greater thromboresistance than the fabric and is configured to form a slip fit around the outer surface of the frame when the frame is in a radially expanded configuration. The artificial heart valve according to any one of claims 10 to 12.

14. The artificial heart valve according to any one of claims 10 to 13, wherein the outer layer includes a first outer layer portion including a plurality of floating threads extending radially outwardly away from the outer skirt and the frame.

15. The artificial heart valve according to claim 14, wherein the outer layer further includes a second outer layer portion fixed to an inflow edge portion of the first outer layer portion and extending from the first outer layer portion toward the inflow end of the frame.

16. The artificial heart valve according to claim 15, wherein the second outer layer portion extends beyond the inner layer toward the inflow end of the frame and wraps around the inflow tip at the inflow end of the frame.

17. The artificial heart valve according to any one of claims 15 to 16, wherein the second outer layer portion includes a woven fabric.

18. An artificial heart valve, comprising: an annular frame; an outer skirt disposed around the outer surface of the frame, a base layer containing a polymer material and disposed against the outer surface of the frame, and an outer skirt including a plurality of outwardly extending threads adhered to the outer surface of the base layer and extending radially outwardly away from the base layer.

19. The artificial heart valve according to claim 18, wherein the polymer material has a greater thromboresistance than the plurality of outwardly extending threads.

20. The artificial heart valve according to claim 18 or 19, wherein the polymer material is a thermoplastic polyurethane.

21. The artificial heart valve according to any one of claims 18 to 20, wherein the threads of the plurality of outwardly extending threads are individual threads spaced apart from each other across the outer surface of the base layer.

22. The artificial heart valve according to any one of claims 18 to 21, wherein the plurality of outwardly extending threads are disposed across an intermediate portion of the base layer, and an outflow edge portion of the base layer lacking outwardly extending threads extends toward an outflow end of the frame beyond the intermediate portion.

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