Prosthetic heart valve

Abstract

To provide a radially collapsible and expandable prosthetic heart valve.SOLUTION: The prosthetic valve can comprise an annular frame, leaflets, an inner skirt, and an outer skirt. The outer skirt can be secured to an outside of an inflow end portion of the frame, and have longitudinal slack that buckles outward radially when the valve is in an expanded configuration and which lies flat when the valve is in a collapsed configuration. In some embodiments, the outer skirt is stiffer in the axial direction of the valve than in the circumferential direction of the valve. In additional embodiments, the outer skirt comprises a self-expandable fabric comprising fibers made of a shape memory material having a shape memory set to enhance the radially outward buckling of the outer skirt. Methods of crimping such valves to a collapsed or partially collapsed configuration are also disclosed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] SUMMARY The present disclosure relates to implantable, expandable prostheses and methods for crimping the prostheses. [Background technology]

[0002] The human heart can suffer from a variety of valvular heart diseases. These valvular heart diseases can result in significant dysfunction of the heart and ultimately the need to replace the natural valve with an artificial valve. There are many known artificial valves and many known methods of implanting these artificial valves in humans. Due to the drawbacks associated with traditional open heart surgery, percutaneous and minimally invasive surgical approaches are gaining increasing attention. In one technique, the artificial valve is configured to be implanted in a much less invasive procedure by catheter insertion. For example, a collapsible transcatheter artificial heart valve can be crimped into a compressed state, introduced percutaneously in the compressed state onto a catheter, and expanded to a functional size at the desired location by balloon inflation or by utilizing a self-expanding frame or stent.

[0003] Prosthetic valves for use in such procedures may include a radially contractible and expandable frame to which the leaflets of the prosthetic valve may be coupled. For example, U.S. Patent No. 6,730,118, U.S. Patent No. 7,393,360, U.S. Patent No. 7,510,575, and U.S. Patent No. 7,993,394 describe exemplary contractible transcatheter prosthetic heart valves.

[0004] Prosthetic valves for use in such procedures may comprise a radially collapsible and expandable frame to which the leaflets of the prosthetic valve may be attached and which may be percutaneously introduced in a collapsed configuration on a catheter and expanded at a desired location by balloon inflation or by the use of a self-expanding frame or stent. A difficulty with catheter-implanted prosthetic valves is the control of paravalvular regurgitation around the valve that may occur over a period of time after initial implantation. Further difficulties include the process of crimping such prosthetic valves into a profile suitable for percutaneous delivery to a subject and for storage and / or shipment to a healthcare provider. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 6,730,118 [Patent Document 2] U.S. Patent No. 7,393,360 [Patent Document 3] U.S. Patent No. 7,510,575 [Patent Document 4] U.S. Patent No. 7,993,394 [Patent Document 5] US Patent Application Publication No. 2012 / 0123529 [Patent Document 6] International Publication No. 2011 / 126758 Brochure [Patent Document 7] International Publication No. 2012 / 048035 Brochure [Patent Document 8] International Publication No. 2014 / 004822 Brochure [Patent Document 9] International Publication No. 2010 / 022138A2 Brochure [Patent Document 10] U.S. Patent No. 8,591,570 [Patent Document 11] U.S. Patent No. 8,613,765 [Patent Document 12] US Patent Application Publication No. 2013 / 0030519 [Patent Document 13] U.S. Patent No. 8,007,992 [Patent Document 14] U.S. Patent No. 6,534,004 [Patent Document 15] US Patent Application Publication No. 2009 / 0164005 [Patent Document 16] U.S. Patent No. 7,530,253 [Patent Document 17] U.S. Patent Application Serial No. 14 / 211,775 [Patent Document 18] US Patent Application Publication No. 2012 / 0239142 Summary of the Invention [Means for solving the problem]

[0006] Disclosed herein are embodiments of a radially contractible and expandable prosthetic valve with an improved outer skirt for controlling paravalvular regurgitation, a method for crimping such a prosthetic valve, and a device comprising such a prosthetic valve. In embodiments, the disclosed prosthetic valve is configured as a replacement heart valve for implantation in a subject.

[0007] In some embodiments, a radially contractible and expandable prosthetic heart valve is provided that includes an annular frame having an inflow end portion and an outflow end portion, a leaflet structure positioned within the frame, and an annular outer skirt positioned about an outer surface of the frame. The outer skirt includes an inflow edge radially secured to the frame at a first location, an outer edge radially secured to the frame at a second location, and an intermediate portion between the inflow and outflow edges. The intermediate portion of the outer skirt has slack that buckles or waves radially outward from the inflow and outflow edges of the outer skirt when the prosthetic valve is in an expanded configuration. When the prosthetic valve is contracted to a contracted configuration, the axial distance between the inflow edge of the outer skirt and the outflow edge of the outer skirt increases, thereby reducing slack in the intermediate portion of the outer skirt. The outer skirt can comprise one of: (a) a fabric that is more stiff in the axial direction of the valve than in the circumferential direction to enhance radial outward buckling of slack; and / or (b) a self-expandable fabric that includes fibers made from a shape memory material that has a shape memory configured to enhance radial outward buckling of slack in the outer skirt.

[0008] In embodiments where the outer skirt comprises a fabric that is more stiff in the axial direction of the valve than in the circumferential direction, the outer skirt can comprise a woven of a first set of fibers parallel to the axial direction of the prosthetic valve and a second set of fibers perpendicular to the axial direction of the prosthetic valve. In some embodiments, the fibers in the first set of fibers have a higher stiffness than the fibers in the second set of fibers. The first set of fibers can include a set of monofilament fibers. The second set of fibers can include a set of microfilament fibers, a set of multifilament fibers, or a set of microfilament and multifilament fibers. In further embodiments, the second set of fibers includes fibers that have no residual strain after the prosthetic valve is expanded from a contracted configuration to an expanded configuration.

[0009] In embodiments in which the outer skirt comprises a self-expandable fabric comprising fibers made from a shape memory material, the self-expandable fabric can comprise a woven arrangement of warp and weft fibers, one or more of the weft fibers comprising fibers made from a shape memory material. The woven arrangement of warp and weft fibers can comprise a combination of multiple weave patterns. For example, the woven arrangement of warp and weft fibers can comprise a combination of a plain weave pattern comprising warp and weft fibers made from a non-shape memory material and a satin weave pattern comprising warp fibers made from a non-shape memory material and weft fibers made from a shape memory material. In some embodiments, the shape memory material can be a nickel titanium alloy, for example, the fibers made from a shape memory material can be nickel titanium wire having a diameter of 0.5 to 15 mils.

[0010] One exemplary embodiment of an assembly for implanting a prosthetic heart valve within a patient's body includes a delivery device having an elongate shaft and a radially expandable prosthetic heart valve mounted on the shaft in a radially contracted configuration for delivery into the body.

[0011] In some embodiments, a method of crimping a prosthetic valve includes partially inserting a prosthetic valve in an expanded configuration into the crimping jaws of a crimping device, where a portion of the prosthetic valve with an outer skirt extends outside of the crimper jaws. The prosthetic valve is then crimped to a first partially contracted configuration, after which the prosthetic valve is fully inserted into the jaws of the crimping device. The prosthetic valve is then crimped to a second partially contracted configuration, and optionally to a fully contracted configuration, after which it is removed from the crimping device.

[0012] The foregoing and other features and advantages of the present disclosure will become more apparent from the following detailed description of several embodiments, which proceeds with reference to the accompanying drawings. [Brief description of the drawings]

[0013] [Figure 1]1 illustrates an exemplary embodiment of a prosthetic heart valve. [Diagram 2] 1 illustrates an exemplary embodiment of a prosthetic heart valve. [Diagram 3] 1 illustrates an exemplary embodiment of a prosthetic heart valve. [Figure 4] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Diagram 5] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 6] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 7] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 8] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 9] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 10] FIG. 2 illustrates an exemplary frame for the prosthetic heart valve of FIG. 1. [Figure 11] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 12] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 13] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 14] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 15A] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 15B] FIG. 1 illustrates another exemplary frame for use in a prosthetic heart valve. [Figure 16A] 2A-2C show an exemplary inner skirt of the prosthetic heart valve of FIG. 1. [Figure 16B] 2A-2C show an exemplary inner skirt of the prosthetic heart valve of FIG. 1. [Figure 17] 13A-13C show another embodiment of a prosthetic heart valve having a modified frame. [Figure 18] FIG. 2 illustrates the prosthetic heart valve of FIG. 1 in a deflated configuration and mounted on an exemplary balloon catheter. [Figure 19A] 16B shows the assembly of the inner skirt of FIG. 16A with the frame of FIG. 4. FIG. [Figure 19B] 16B shows the assembly of the inner skirt of FIG. 16A with the frame of FIG. 4. FIG. [Figure 20] 16B shows the assembly of the inner skirt of FIG. 16A with the frame of FIG. 4. FIG. [Figure 21] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 22] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 23] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 24] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Diagram 25] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 26] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 27] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 28] 1A-1D illustrate the assembly of an exemplary leaflet structure. [Figure 29] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 30] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 31] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 32] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 33] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 34] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 35] 13 shows the assembly of the joint portion of the leaflet structure with the window frame portion of the frame. [Diagram 36] FIG. 13 shows assembly of the leaflet structure with an inner skirt along the lower edge of the leaflet. [Figure 37] FIG. 13 shows assembly of the leaflet structure with an inner skirt along the lower edge of the leaflet. [Figure 38] FIG. 13 shows assembly of the leaflet structure with an inner skirt along the lower edge of the leaflet. [Figure 39] FIG. 13 shows assembly of the leaflet structure with an inner skirt along the lower edge of the leaflet. [Diagram 40] FIG. 13 shows assembly of the leaflet structure with an inner skirt along the lower edge of the leaflet. [Diagram 41] FIG. 2 is a flat view of an exemplary outer skirt. [Diagram 42] FIG. 2 illustrates the exemplary prosthetic heart valve of FIG. 1. [Diagram 43] FIG. 2 illustrates the exemplary prosthetic heart valve of FIG. 1. [Diagram 44] FIG. 2 is a portion of the outer skirt fabric detailing the warp and weft fibers. [Diagram 45] 5 illustrates a portion of the frame of FIG. 4 in a radially collapsed configuration. [Figure 46] FIG. 5 shows a cross-sectional profile of the frame of FIG. 4, illustrating the general taper from the outflow end to the inflow end. [Figure 47] FIG. 5 shows the frame of FIG. 4 in an unfolded flat configuration. [Figure 48] FIG. 2 illustrates the prosthetic heart valve of FIG. 1 in a deflated configuration and mounted on an exemplary balloon catheter. [Figure 49] 13A-13C show balloon expansion of an alternative embodiment of a frame for a prosthetic valve having inflow and outflow end portions of reduced thickness. [Figure 50]13A-13C show balloon expansion of an alternative embodiment of a frame for a prosthetic valve having inflow and outflow end portions of reduced thickness. [Figure 51] 13A-13C show balloon expansion of an alternative embodiment of a frame for a prosthetic valve having inflow and outflow end portions of reduced thickness. [Figure 52] 1A-1D illustrate a process for crimping an expandable and contractible prosthetic valve with an outer skirt. [Diagram 53] 1A-1D illustrate a process for crimping an expandable and contractible prosthetic valve with an outer skirt. [Figure 54] 1A-1D illustrate a process for crimping an expandable and contractible prosthetic valve with an outer skirt. [Figure 55] 1A-1D illustrate a process for crimping an expandable and contractible prosthetic valve with an outer skirt. [Figure 56] 1A-1D illustrate a process for crimping an expandable and contractible prosthetic valve with an outer skirt. [Figure 57] FIG. 2 is a portion of the outer skirt fabric detailing the warp and weft fibers. [Figure 58] FIG. 2 is a schematic diagram showing a portion of an outer skirt fabric detailing three different pattern designs of warp and weft fibers. [Figure 59] FIG. 2 is a schematic diagram showing a portion of an outer skirt fabric detailing three different pattern designs of warp and weft fibers. [Figure 60] FIG. 2 is a schematic diagram showing a portion of an outer skirt fabric detailing three different pattern designs of warp and weft fibers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Herein, in this description, some aspects, advantages, and novel features of the disclosed embodiments are described. The described methods, systems, and devices should not be construed as limiting in any respect. Instead, the disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, both alone and in various combinations and subcombinations with each other. The disclosed methods, systems, and devices are not limited to any particular aspect, feature, or combination thereof, and the disclosed methods, systems, and devices do not require any of one or more particular advantages to exist or problems to be solved.

[0015] It is to be understood that a feature, integer, property, complex, chemical moiety, or group described in combination with a particular aspect, embodiment, or example of the invention is applicable to any other aspect, embodiment, or example described herein, except where incompatible. All of the features disclosed herein (including any accompanying claims, abstract, and drawings), and / or all of the steps of any method or process similarly disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any of the foregoing embodiments. The invention extends to any novel one or any novel combination of the features disclosed herein (including any accompanying claims, abstract, and drawings), or to any novel one or any novel combination of the steps of any method or process similarly disclosed.

[0016] Although some operations in the disclosed methods are described in a particular sequential order for convenience of presentation, it should be understood that the described method encompasses modifications unless a particular order is required by specific language set forth below. For example, in some cases, operations described sequentially may be modified or performed simultaneously. Moreover, for the sake of simplicity, the accompanying drawings may not show the various ways in which the disclosed methods, systems, and apparatus can be used in combination with other systems, methods, and apparatus.

[0017] As used herein, the terms "a," "an," and "at least one" include one or more of a specifically identified element. That is, where two particular elements are present, one of these elements is also present, so there is "one" element. The term "a plurality of" means two or more of a specifically identified element.

[0018] As used herein, the term "and / or" used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase "A, B, and / or C" means "A," "B," "C," "A and B," "A and C," "B and C," or "A, B, and C."

[0019] As used herein, the term "coupled" generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items unless language to the contrary exists.

[0020] 1-3 show various views of a prosthetic heart valve 10 according to one embodiment. The prosthetic valve shown is configured to be implanted in the native aortic valve annulus, but in other embodiments, it may be configured to be implanted in other native valve annuluses of the heart, such as the pulmonary, mitral, and tricuspid valves. The prosthetic valve may also be configured to be implanted in other tubular organs or passageways in the body. The prosthetic valve 10 may have four main components, namely a stent or frame 12, a valve structure 14, an inner skirt 16, and a perivalvular sealing means, and may have an inflow end portion 15, a middle portion 17, and an outflow end portion 19. In the illustrated embodiment, the perivalvular sealing means comprises an outer skirt 18.

[0021] The valve structure 14 can include three leaflets 40, which collectively form the leaflet structure. The leaflets 40 can be configured to contract in a tricuspid configuration, as best shown in FIG. 2. Desirably, the lower edge of the leaflet structure 14 has a wavy, curved, wave shape (the suture line 154 shown in FIG. 1 follows the wave shape of the leaflet structure). Forming the leaflets with this wavy geometry reduces stress on the leaflets, which further improves the durability of the prosthetic valve. Additionally, the wavy shape can eliminate or at least minimize creases and folds in the ridges (the center of each leaflet), which are areas that can cause premature calcification. The wavy geometry also reduces the amount of tissue material used to form the leaflet structure, thereby providing a smaller, more uniform crimped profile at the inflow end of the prosthetic valve. The leaflets 40 may be formed from pericardial tissue (eg, bovine pericardial tissue), a biocompatible synthetic material, or a variety of other suitable natural or synthetic materials known in the art and as described in US Pat. No. 6,730,118.

[0022] The bare frame 12 is shown in FIG. 4. The frame 12 may be formed with a plurality of circumferentially spaced slots or seam windows 20 (three in the illustrated embodiment) configured to attach seams of the valve structure 14 to the frame, as described in more detail below. The frame 12 may be made from any of a variety of suitable plastically expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nickel-titanium alloys (NiTi), such as Nitinol) as known in the art. If made from a plastically expandable material, the frame 12 (and thus the prosthetic valve 10) may be crimped into a radially contracted configuration on a delivery catheter and then expanded inside the patient by an inflatable balloon or equivalent expansion mechanism. If made from a self-expanding material, the frame 12 (and thus the prosthetic valve 10) may be crimped into a radially contracted configuration and restrained in the contracted configuration by insertion into a sheath or equivalent mechanism of a delivery catheter. Once in place within the body, the prosthetic valve may be advanced out of the delivery sheath, allowing the prosthetic valve to expand to its functional size.

[0023] Suitable plastically expandable materials that may be used to form the frame 12 include, but are not limited to, stainless steel, biocompatible high-strength alloys (e.g., cobalt-chromium alloys or nickel-cobalt-chromium alloys), polymers, or combinations thereof. In certain embodiments, the frame 12 is made from a nickel-cobalt-chromium-molybdenum alloy, such as MP35N® alloy (SPS Technologies, Jenkintown, PA), which is equivalent to UNS R30035 alloy (covered by ASTM F562-02). MP35N® alloy / UNS R30035 alloy includes 35% nickel, 35% cobalt, 20% chromium, and 10% molybdenum by weight. It has been found that the use of MP35N® alloy to form the frame 12 provides better structural performance than stainless steel. In particular, when MP35N® alloy is used as the frame material, less material is required to achieve the same or better performance in resistance to radial crush forces, fatigue resistance, and corrosion resistance. Furthermore, because less material is required, the crimped profile of the frame can be reduced, thereby allowing for a lower profile prosthetic valve assembly for percutaneous delivery to a treatment site within the body.

[0024] 4 and 5, in the illustrated embodiment, the frame 12 comprises a first lower row I of angled struts 22 arranged end-to-end and extending circumferentially at the inflow end of the frame, a second row II of circumferentially extending angled struts 24, a third row III of circumferentially extending angled struts 26, a fourth row IV of circumferentially extending angled struts 28, and a fifth row V of circumferentially extending angled struts 32 at the outflow end of the frame. A plurality of substantially straight axially extending struts 34 may be used to interconnect the struts 22 of the first row I to the struts 24 of the second row II. The angled struts 32 of the fifth row V are connected to the angled struts 28 of the fourth row IV by a plurality of axially extending window frame portions 30 (defining the seam window 20) and a plurality of axially extending struts 31. Each axial strut 31 and each frame portion 30 extends from a point defined by the convergence of the lower ends of two angled struts 32 to another point defined by the convergence of the upper ends of two angled struts 28. Figures 6, 7, 8, 9, and 10 are enlarged views of portions of frame 12 identified by the letters A, B, C, D, and E, respectively, in Figure 4.

[0025] Each joint window frame section 30 mounts a respective joint of the leaflet structure 14. As shown, each frame section 30 is secured at its upper and lower ends to the struts of the adjacent row to provide a robust configuration that enhances fatigue resistance under cyclic loading of the prosthetic valve as compared to known cantilever struts that support the joints of the leaflet structure. This configuration allows for a smaller crimped diameter of the prosthetic valve to be achieved by reducing the frame wall thickness. In certain embodiments, the thickness T (FIG. 4) of the frame 12 measured between the inner and outer diameters is about 0.48 mm or less.

[0026] The struts and frame portions of the frame collectively define a plurality of open cells in the frame. At the inflow end of frame 12, struts 22, 24, and 34 define a lower row of cells that define an opening 36. The second row of struts 24, the third row of struts 26, and the fourth row of struts 28 define two middle rows of cells that define an opening 38. The fourth row of struts 28 and the fifth row of struts 32, together with frame portions 30 and struts 31, define an upper row of cells that define an opening 40. The opening 40 is relatively large and sized such that portions of the leaflet structure 14 may protrude or bulge into and / or through the opening 40 when frame 12 is crimped to minimize the crimp profile.

[0027] As best shown in FIG. 7, the lower end of the strut 31 is connected to two struts 28 at nodes or junctions 44, and the upper end of the strut 31 is connected to two struts 32 at nodes or junctions 46. The strut 31 can have a thickness S1 that is less than the thickness S2 of the junctions 44, 46. FIG. 45 shows a portion of the frame 12 in a contracted configuration. The junctions 44, 46, along with the junction 64, prevent complete closure of the opening 40. FIG. 18 shows the prosthetic valve 10 crimped onto a balloon catheter. As shown, the geometry of the struts 31 and the junctions 44, 46, and 64 help create enough space in the opening 40 in the contracted configuration to allow portions of the prosthetic leaflets to protrude or bulge outwardly through the opening. This allows the prosthetic valve to be crimped to a relatively smaller diameter than if all of the leaflet material was constrained within the crimped frame.

[0028] The frame 12 is configured to reduce, prevent, or minimize overexpansion of the prosthetic valve, particularly at the outflow end portion 19 of the frame, that may occur at a given balloon pressure supporting the leaflet structure 14. In one embodiment, the frame is configured to have a relatively larger angle 42a, 42b, 42c, 42d, 42e between the struts as shown in FIG. 5. The larger the angle, the greater the force required to open (expand) the frame. This phenomenon is shown diagrammatically in FIGS. 15A and 15B. FIG. 15A shows the struts 32 when the frame 12 is in its contracted configuration (e.g., mounted on a balloon). The vertical distance d1 between the ends of the struts is greatest when the frame is compressed, resulting in a relatively large moment between the forces F1 and F2 acting on the ends of the struts in opposing directions upon application of an opening force by inflation of the balloon (or by expansion of another expansion device). When the frame is radially expanded, the vertical distance between the ends of the struts decreases to a distance d2 as shown in FIG. 15B. As the vertical distance decreases, the moment between forces F1 and F2 also decreases. It can therefore be seen that the decrease and decrease in the vertical distance and moment between the ends of the struts requires a relatively larger expansion force. Furthermore, strain hardening at the ends of the struts increases as the frame expands, which increases the expansion force required to induce further plastic deformation at the ends of the struts. Therefore, the angles between the struts of the frame can be selected to limit the radial expansion of the frame at a given opening pressure (e.g., the inflation pressure of the balloon). In certain embodiments, these angles are at least 110 degrees or more when the frame is expanded to its functional size, and even more specifically, these angles are up to about 120 degrees when the frame is expanded to its functional size.

[0029] Furthermore, the inflow and outflow ends of the frame generally tend to overexpand more than the middle portion of the frame due to the "dog-boning" effect of the balloon used to expand the prosthetic valve. To protect against overexpansion of the leaflet structure 14, the leaflet structure is desirably secured to the frame 12 below the upper row of struts 32 as best shown in FIG. 1. FIG. 47 shows a flattened view of the frame 12 similar to FIG. 5, but with dashed lines 176 superimposed on the frame to indicate the approximate location of the upper edges of the leaflets 40 in some embodiments. Thus, if the outflow end of the frame becomes overexpanded, the leaflet structure is positioned at a height below where overexpansion would otherwise occur, thereby protecting the leaflet structure from overexpansion.

[0030] In known prosthetic valve structures, portions of the leaflets may protrude longitudinally beyond the outflow end of the frame when the prosthetic valve is crimped if the leaflets are attached too close to the distal end of the frame. If the delivery catheter to which the crimped prosthetic valve is attached includes a pushing mechanism or stop member that pushes or abuts the outflow end of the prosthetic valve (e.g., to maintain the position of the crimped prosthetic valve on the delivery catheter), the pushing or stop member may damage the exposed portion of the leaflet that extends beyond the outflow end of the frame. Another advantage of attaching the leaflets at a location spaced from the outflow end of the frame is that when the prosthetic valve is crimped onto the delivery catheter as shown in FIG. 48, the outflow end of the frame 12, rather than the leaflets 40, becomes the most proximal component of the prosthetic valve 10. Thus, if the delivery catheter includes a pushing mechanism or stop member that pushes or abuts the outflow end of the prosthetic valve, the pushing mechanism or stop member contacts the outflow end of the frame, rather than the leaflets 40, to avoid damage to the leaflets.

[0031] Also, as shown in FIG. 5, the apertures 36 of the bottom row of apertures in the frame are relatively larger than the apertures 38 of the two middle rows of apertures. As shown in FIG. 46, this allows the frame, when crimped, to assume an overall tapered shape that tapers from a maximum diameter D1 at the outflow end of the prosthesis to a minimum diameter D2 at the inflow end of the prosthesis. When crimped, the frame 12 has a reduced diameter region, indicated by reference numeral 174, that extends along the portion of the frame adjacent the inflow end of the frame, which generally coincides with the area of ​​the frame that is covered by the outer skirt 18. In some embodiments, the diameter of region 174 is smaller than the diameter of the upper portion of the frame (not covered by the outer skirt) so that the outer skirt 18 does not increase the overall crimped profile of the prosthesis. When the prosthesis is deployed, the frame may expand to the generally cylindrical shape shown in FIG. 4. In one example, the frame of a 26 mm prosthetic valve, when crimped, had a diameter D1 of 14 French at the outflow end of the prosthetic valve and a diameter D2 of 12 French at the inflow end 174 of the prosthetic valve.

[0032] 11 and 12 show an alternative frame 50 that may be incorporated into the prosthetic valve 10. The frame 50 comprises multiple rows of circumferentially extending angled struts 52 interconnected at nodes or connectors 54 and 56. The top row of struts 52 are connected to adjacent rows of struts by multiple axially extending struts 58 and seam window frame portions 60. Each seam frame portion 60 defines a slot or seam window 62 for attachment of a respective seam portion of the valve structure, as described in further detail below. In certain embodiments, the thickness T of the frame 50 is about 0.45 mm or less. Of course, the thickness T of the frame is selected to provide sufficient strength to the frame. As such, one of ordinary skill in the art will appreciate that the thickness T may vary for different subcomponents and / or assemblies of the frame in some embodiments. FIGS. 13 and 14 are enlarged views of the portions of the frame 50 identified by the letters A and B, respectively, in FIG. 12.

[0033] The primary function of the inner skirt 16 is to aid in the fixation of the valve structure 14 to the frame 12 and to aid in the formation of a good seal between the prosthetic valve and the native annulus by preventing the flow of blood through the open cells of the frame 12 under the lower edge of the leaflets. Desirably, the inner skirt 16 comprises a tough, tear-resistant material such as polyethylene terephthalate (PET), although a variety of other synthetic or natural materials can be used. Desirably, the skirt has a thickness of less than about 6 mils (0.15 mm), desirably less than about 4 mils (0.1 mm), and even more desirably about 2 mils (0.05 mm). In certain embodiments, the skirt 16 can have a variety of thicknesses, for example, the skirt can be thicker at at least one of its edges than at its center. In one implementation, the skirt 16 can comprise a PET skirt having a thickness of about 0.07 mm at its edges and about 0.06 mm at its center. A thinner skirt can allow for better crimping performance while still providing a good perivalvular seal.

[0034] The skirt 16 may be secured to the interior of the frame 12 by sutures 70 as shown in FIG. 39. The valve structure 14 may be attached to the skirt by one or more reinforcing strips 72 (which may collectively form a sleeve), such as thin PET reinforcing strips discussed below, which allow for secure suturing and protect the pericardial tissue of the leaflet structure from tearing. The valve structure 14 may be sandwiched between the skirt 16 and the thin PET strips 72 as shown in FIG. 38. The sutures 154 securing the PET strips and leaflet structure 14 to the skirt 16 can be any suitable suture, such as Ethibond Excel® PET suture (Johnson & Johnson, New Brunswick, NJ). Desirably, the sutures 154 follow the curve of the lower edge of the leaflet structure 14, as described in more detail below.

[0035] Known fabric skirts comprise a woven web of warp and weft fibers that extend perpendicular to one another, with one set of fibers extending longitudinally between the upper and lower edges of the skirt. When the metal frame to which the fabric skirt is secured is radially compressed, the overall axial length of the frame increases. Unfortunately, fabric skirts, which are inherently elastically limited, are unable to stretch with the frame and therefore tend to deform the struts of the frame and prevent uniform crimping.

[0036] 16B, in contrast to known fabric skirts, desirably the skirt 16 is woven from a first set of fibers, or yarns or strands 78 and a second set of fibers, or yarns or strands 80, both of which are non-perpendicular to the upper and lower edges 82 and 84 of the skirt. In certain embodiments, the first set of fibers 78 and the second set of fibers 80 extend at an angle of about 45 degrees to the upper and lower edges 82 and 84. The skirt 16 may be formed by weaving the fibers at an angle of 45 degrees to the upper and lower edges of the fabric. Alternatively, the skirt may be cut diagonally (diagonally cut) from a vertically woven fabric (where the fibers extend perpendicular to the edges of the material) such that the fibers extend at 45 degrees to the cut upper and lower edges of the skirt. 16B, desirably both short edges 86, 88 of the skirt are non-perpendicular to the upper and lower edges 82, 84. For example, desirably the short edges 86, 88 extend at an angle of about 45 degrees to the upper and lower edges, and are therefore aligned with the first set of fibers 78. The overall shape of the skirt thus assumes the overall shape of a rhomboid or parallelogram.

[0037] 17 shows an example of a crimped prosthetic valve in which the struts are deformed in multiple locations, as indicated at 100, with a skirt having fibers extending perpendicular to and / or longitudinally between the upper and lower edges of the skirt. Additionally, the fabric tends to bunch up or create bulges of excess material in some locations, which limits the minimum crimped profile and prevents uniform crimping.

[0038] 19A and 19B show the skirt 16 after both short edge portions 90, 92 have been sewn together to form the annular shape of the skirt. As shown, the edge portion 90 is placed in overlapping relationship with the opposing edge portion 92, and the two edge portions may be sewn together with a diagonal extending stitching line 94 parallel to the short edges 86, 88. The upper edge portion of the skirt 16 may be formed with a plurality of protrusions 96 that define a wavy shape that generally follows the shape or profile of the fourth row of struts 28 immediately adjacent the lower end of the axial strut 31. In this manner, the upper edge of the skirt 16 may be securely secured to the struts 28 by the sutures 70, as best shown in FIG. 20. The skirt 16 may also be formed with slits 98 to facilitate attachment of the skirt to the frame. The slits 98 are sized to allow the upper edge portion of the skirt to be partially wrapped around the struts 28 and to relieve stress on the skirt during the attachment procedure. For example, in the illustrated embodiment, the skirt 16 is placed inside the frame 12 and the upper edge portions of the skirt are wrapped around the upper surfaces of the struts 28 and secured in place by sutures 70. By wrapping the upper edge portions of the skirt around the struts 28 in this manner, a stronger and more durable attachment of the skirt to the frame is achieved. Additionally, the skirt 16 may be secured to the first row of struts 22, the second row of struts 24, and the third row of struts 26 by sutures 70, respectively.

[0039] Referring again to FIG. 16B, the angular orientation of the fibers relative to the upper and lower edges allows the skirt to undergo greater elongation in the axial direction (i.e., from upper edge 82 to lower edge 84).

[0040] Thus, when the metal frame 12 is crimped (as shown in FIG. 18), the skirt 16 may stretch axially with the frame, thus resulting in a more uniform and predictable crimped profile. Each cell of the metal frame in the illustrated embodiment includes at least four angled struts that rotate axially upon crimping (e.g., the angled struts become aligned along the length of the frame). The angled struts of each cell act as a mechanism for rotating the fibers of the skirt in the same direction of the struts, allowing the skirt to stretch along the length of the struts. This allows for greater stretching of the skirt and avoids undesirable deformation of the struts when the prosthetic valve is crimped.

[0041] Additionally, the spacing between the interwoven fibers or yarns may be increased to facilitate axial elongation of the skirt. For example, for a PET skirt 16 formed from 20 denier yarns, the yarn density may be about 15% to about 30% lower than for a typical PET skirt. In some examples, the yarn spacing of the skirt 16 may be about 60 yarns / cm (about 155 yarns / inch) to about 70 yarns / cm (about 180 yarns / inch), such as about 63 yarns / cm (about 160 yarns / inch), while for a typical PET skirt, the yarn spacing may be about 85 yarns / cm (about 217 yarns / inch) to about 97 yarns / cm (about 247 yarns / inch). The angled edges 86, 88 promote uniform and even distribution of the fabric material along the inner circumference of the frame during crimping, thereby reducing or minimizing bunching of the fabric and facilitating uniform crimping to the smallest possible diameter. Additionally, cutting the diagonal sutures vertically may leave loose fringes along the cut edges. The angled edges 86, 88 assist in minimizing this occurrence. As noted above, FIG. 17 illustrates a crimped prosthetic valve having a typical skirt with fibers that extend perpendicularly to the upper and lower edges of the skirt. Comparing FIGS. 17 and 18, it is apparent that the structure of the skirt 16 avoids undesirable deformation of the frame struts and results in a more uniform crimping of the frame.

[0042] In alternative embodiments, the skirt may be formed from woven elastic fibers that may stretch axially during crimping of the prosthetic valve. The warp and weft fibers may extend vertically and parallel to the upper and lower edges of the skirt, or alternatively, may extend at an angle between 0 and 90 degrees relative to the upper and lower edges of the skirt, as described above.

[0043] The inner skirt 16 may be sewn to the frame 12 at a point away from the suture line 154, allowing the skirt to be more flexible in that area (see FIG. 28, where the suture line follows the marking suture 136, discussed below). This configuration may avoid stress concentrations at the suture line 154, which attaches the lower edge of the leaflet to the skirt 16.

[0044] As noted above, the leaflet structure 14 in the illustrated embodiment includes three flexible leaflets 40 (although more or fewer leaflets can be used). As best seen in FIG. 21, each leaflet 40 in the illustrated configuration has an upper (outflow) free edge 110 that extends between upper tabs 112 on either side of the leaflet. Below each upper tab 112 is a notch 114 that separates the upper tab from a corresponding lower tab 116. The lower (inflow) edge portion 108 of the leaflet extending between each end of the lower tabs 116 includes vertical or axial edge portions 118 on either side of the leaflet that extend downwardly from the corresponding lower tab 116, a substantially V-shaped intermediate edge portion 120 having a smooth curved tip portion 119 at the lower end of the leaflet, and a pair of angled portions 121 extending between the axial edge portion and the tip portion. The angled portions may have a larger radius of curvature than the tip portions. Each leaflet 40 may have a reinforcing strip 72 secured (eg, sewn) to the inner surface of the lower edge portion 108, as shown in FIG.

[0045] The leaflets 40 may be secured to one another at their adjacent sides to form a seam 122 of the leaflet structure. A number of flexible connectors 124 (one of which is shown in FIG. 23) may be used to interconnect pairs of adjacent sides of the leaflets and to attach the leaflets to the seam window frame portion 30. The flexible connectors 124 may be made from strips of woven PET fabric, although other synthetic and / or natural materials may be used. Each flexible connector 124 may include a wedge 126 that extends from the lower edge to the upper edge at the center of the connector. The wedge 126 may comprise a non-metallic material, such as a rope, braided yarn, or monofilament yarn, for example, Ethibond Excel® 2-0 suture material (Johnson & Johnson, New Brunswick, NJ), secured to the connector by temporary sutures 128. The wedges 126 help prevent rotational movement of the leaflet tabs when secured to the seam window frame portion 30. The connector 124 may have a series of inner and outer notches 130 and 132 formed along its upper and lower edges.

[0046] 24 shows adjacent sides of two leaflets 40 interconnected by flexible connectors 124. Both end portions of the flexible connector 124 may be placed in overlapping relationship with the lower tabs 116 with the inner notches 130 aligned with the vertical edges of the tabs 116. Each tab 116 may be secured to the corresponding end portion of the flexible connector 124 by suturing along a line extending from the outer notch 132 on the lower edge to the outer notch 132 on the upper edge of the connector. Three leaflets 40 may be secured to one another side-by-side using three flexible connectors 124 as shown in FIG.

[0047] 26 and 27, adjacent sub-seam portions 118 of the two leaflets can be sutured directly to one another. In the illustrated example, PTFE 6-0 suture material is used to form a line stitch 133 and a comb stitch 134 that extend through the sub-seam portions 118 and the reinforcement strips 72 on both leaflets. The two remaining pairs of adjacent sub-seam portions 118 can be similarly sutured together to form an assembled leaflet structure 14, which can then be secured to the frame 12 in the following manner.

[0048] As mentioned above, the inner skirt 16 may be used to assist in suturing the leaflet structure 14 to the frame. As shown in FIG. 28, the skirt 16 may have wavy temporary marking sutures 136 to guide the attachment of the lower edge of each leaflet 40. The skirt 16 itself may be sewn to the struts of the frame 12 using sutures 70 as described above prior to the attachment of the leaflet structure 14 to the skirt 16. Desirably, the struts that cross the marking sutures 136 are not attached to the skirt 16. This allows the skirt 16 to be more flexible in the areas not secured to the frame and minimizes stress concentrations along the suture lines securing the lower edges of the leaflets to the skirt. The portion of the skirt 16 bounded by the rectangle 140 is initially left unsecured to the frame 12 and is later secured to the frame after the leaflet structure 14 is secured to the skirt as described further below. As mentioned above, when the skirt is secured to the frame, the fibers 78, 80 (see FIG. 16B) of the skirt are generally aligned with the angled struts of the frame to promote uniform crimping and expansion of the frame.

[0049] FIG. 29 is a cross-sectional view of a portion of the frame and leaflet structure showing adjacent tab portions of two leaflets secured to corresponding window frame portions 30. FIGS. 30-36 show one particular approach for securing the joint portion 122 of the leaflet structure 14 to the joint window frame portion 30 of the frame. First, as shown in FIG. 30, the flexible connector 124 securing the two adjacent sides of the two leaflets is folded widthwise and the upper tab portion 112 is folded downwardly onto the flexible connector. As best shown in FIGS. 30 and 31, each upper tab portion 112 is creased lengthwise (vertically) to present an L-shape with an inner portion 142 that is folded onto the inner surface of the leaflet and an outer portion 144 that is folded onto the connector 24. The outer portion 144 can then be sutured to the connector 124 along a suture line 146. Next, as shown in Figure 31, the seam tab assembly (consisting of a pair of lower tab portions 116 joined by a connector 124) is inserted through the seam window 20 of the corresponding window frame portion 30. Figure 32 is a side view of the frame 12 showing the seam tab assembly extending outwardly through the window frame portion 30.

[0050] 29 and 33, the seam tab assembly is compressed radially inward at the wedge 126 such that one of the lower tab portions 116 and a portion of the connector 124 is folded onto the frame 12 on one side of the window frame portion 30 and the other lower tab portion 116 and a portion of the connector 124 is folded onto the frame 12 on the other side of the window frame portion 30. A pair of suture lines 148 are formed to hold the lower tab portion 116 against the frame 12 as shown in FIG. 29. Each suture line 148 extends through the connector 124, the lower tab portion 116, the wedge 126, and another portion of the connector 124. 29 and 34, each lower tab portion 116 is then secured to a corresponding upper tab portion 112 by a primary suture line 150 that extends through one layer of connector 124, the lower tab portion 116, another layer of connector 124, another layer of connector 124, and the upper tab portion 112. Finally, as shown in FIGS. 29 and 35, the suture material used to form the primary suture line 150 may be used to further form an overlock stitch 152 on the edges of the tab portions 112, 116 that extends through the two layers of connector 124 sandwiched between the tab portions 112, 116.

[0051] As shown in FIGS. 29 and 30, the folded upper tab portion 112 forms a double layer of leaflet material at the seam. The inner portion 142 of the upper tab portion 112 is positioned flat to abut the layers of the two leaflets 40 that form the seam, such that each seam has four layers of leaflet material just inside the window frame 30. This four-layer portion of the seam may be more resistant to bending or articulating than the portion of the leaflet 40 just radially inward from the relatively stiffer four-layer portion. This allows the leaflets 40 to primarily articulate at the inner edge 143 of the folded inner portion 142 in response to blood flow through the prosthetic valve during implementation in vivo, rather than articulating around or proximal to the axial struts of the window frame 30. Because the leaflets articulate at a location spaced radially inward from the window frame 30, the leaflets may avoid contact with and damage from the frame. However, under high forces, the four layers of the seam may splay apart about a longitudinal axis 145 ( FIG. 29 ) adjacent the window frame 30 with the inner portions 142 folded into the outer portions 144. For example, this may occur when the prosthetic valve 10 is compressed and mounted onto a delivery shaft to allow for a smaller crimped diameter. The four layers of the seam may also splay apart about the axis 145 when the balloon catheter is inflated during expansion of the prosthetic valve. This may relieve some of the pressure on the seam caused by the balloon, reducing the chance of damage to the seam during expansion.

[0052] Finally, the three seam tab assemblies are secured to each window frame portion 30, and the lower edge of the leaflet 40 between the seam tab assemblies may be sutured to the inner skirt 16. For example, as shown in Figs. 36-38, each leaflet 40 may be sutured to the skirt 16 along a suture line 154 using, for example, Ethibond Excel® PET thread. These sutures may be line sutures that extend through each leaflet 40, the skirt 16, and each reinforcement strip 72. Each leaflet 40 and each reinforcement strip 72 may be individually sewn to the skirt 16. In this manner, the lower edge of the leaflet is secured to the frame 12 via the skirt 16. As shown in Fig. 38, the leaflet may be further secured to the skirt with a blanket suture 156 that loops around the edge of the reinforcement strip 72 and the leaflet 40 while extending through each reinforcement strip 72, the leaflet 40, and the skirt 16. The blanket sutures 156 may be formed from a PTFE suture material. Figures 39 and 40 show two rotated side views of the frame 12, leaflet structure 14, and skirt 16 after securing the leaflet structure and skirt to the frame and the leaflet structure to the skirt.

[0053] FIG. 41 shows a flat view of the outer skirt 18 prior to attachment to the frame 12. The outer skirt 18 may be laser cut or otherwise formed from a piece of tough, durable material. The outer skirt 18 may have substantially straight lower and upper edges 160, 162 that define a plurality of alternating projections 164 and notches 166, i.e., castellations. As best shown in FIG. 42, the lower edge 160 of the skirt 18 may be sutured to the lower edge of the inner skirt 16 at the inflow end of the prosthetic valve. As shown in FIG. 43, each projection 164 may be sutured to a strut 24 of the second stage II of the frame 12. The upper edge 162 of the projection 164 may be folded over a respective strut of stage II and secured with sutures 168.

[0054] As shown in Figures 1-3 and 42-43, the outer skirt 18 is secured to the frame 12 such that there is excess material between the lower edge 160 and the upper edge 162 that does not adhere to the outer surface of the frame 12 when the frame is in its expanded configuration (i.e., deployed within a subject). The outer skirt 18 may be secured directly to the frame 12 and / or indirectly to the frame 12, for example, by securing the outer skirt to an inner skirt that is secured directly to the frame 12. In the expanded configuration of the prosthetic valve, the distance between the upper and lower attachment points of the outer skirt 18 is reduced (shortened), resulting in an outer radial buckling of the outer skirt 18. Additionally, the excess material between the lower and upper edges of the outer skirt 18 allows the frame 12 to stretch axially when crimped without any resistance from the outer skirt. In some embodiments, the skirt 18 has an axial length or height that may be substantially the same as the axial length between the upper and lower attachment points of the skirt 18 to the frame 12 when the frame is fully crimped. In such embodiments, the outer skirt may fit snugly against the outer surface of the frame 12 when the frame 12 is fully crimped.

[0055] In some embodiments, the outer skirt 18 can comprise a fabric 170 that is more stiff in an axial direction 172 than in a circumferential direction 173 when attached to the frame 12 to enhance outward radial buckling or expansion of the outer skirt 18 (see FIG. 44). For example, the fabric 170 can be woven from a first set of fibers (or yarns or strands) 176 and a second set of fibers (or yarns or strands) 178. The fabric 170 can comprise a weave of warp fibers including the first set of fibers 176 and weft fibers including the second set of fibers 178. Alternatively, the fabric 170 can comprise a weave of warp fibers including the second set of fibers 178 and weft fibers including the first set of fibers 176.

[0056] The first set of fibers 176 can include monofilaments of higher stiffness than the fibers in the second set of fibers 178. Examples of suitable monofilaments include, but are not limited to, those made from polymeric or metallic wires such as PET, PTFE, and / or NiTi. In some embodiments, the monofilaments can have a diameter of about 0.05 mm to about 0.5 mm (about 0.002 to 0.02 inches). The second set of fibers 178 can include multifilaments and / or microfibers that are less stiff than the fibers in the first set of fibers 176. Examples of suitable multifilaments and / or microfibers include, but are not limited to, those made from polymers such as PET and / or PTFE. In some embodiments, the second set of fibers 178 can include a material mixture (such as a mixture of multifilaments and microfibers) that has a lower overall stiffness than the first set of fibers 176.

[0057] The fibers in the first set of fibers or the second set of fibers do not have to be the same type of fiber, for example, the first set of fibers can include monofilaments, microfilaments, and / or microfibers, so long as the fabric 170 is more stiff axially than circumferentially when attached to the prosthetic valve 10. Similarly, the second set of fibers can include monofilaments, microfilaments, and / or microfibers.

[0058] In some embodiments, fabric 170 includes more parallel fibers per unit length in the axial direction than there are fibers per unit length in the circumferential direction, and thus fabric 170 includes a higher density of axially extending fibers compared to circumferentially extending fibers.

[0059] In further embodiments, the outer skirt 18 can comprise a self-expandable fabric 230 including one or more fibers made of a shape memory material such as NiTi (see FIG. 57). For example, one or more fibers made of a shape memory material can be included in the weave of the self-expandable fabric 230 or can be otherwise secured (e.g., by sutures) to attach to the fabric to create the self-expandable fabric 230. The shape memory of such fibers can be set to enhance radially outward buckling or expansion of the outer skirt 18 when attached to the frame 12. Additionally, the fibers of the shape memory material of the self-expandable fabric 230 can have different shape memories as needed to conform to a particular anatomical structure. Thus, the self-expandable fabric 230 can be woven or fabricated to have a plurality of fibers made of a shape memory material having a shape memory set such that the fabric has a three-dimensional shape that conforms to a particular anatomical structure of the patient.

[0060] If made from a self-expandable fabric 230, the outer skirt may be crimped into a radially contracted configuration and constrained in the contracted configuration by inserting the prosthetic valve with the outer skirt into a sheath of a delivery catheter or equivalent mechanism. Once in place within the body, the prosthetic valve may be advanced out of the delivery sheath, allowing the prosthetic valve and outer skirt to expand to their functional size.

[0061] 57, the self-expandable fabric 230 may be woven from a first set of fibers (or yarns or strands) 232 and a second set of fibers (or yarns or strands) 234. The self-expandable fabric 230 may be positioned on the frame 12 in any orientation that facilitates radially outward buckling or expansion of the outer skirt 18. For example, as shown in FIG. 57, the self-expandable fabric 230 of the outer skirt 18 may comprise a weave of axial 236 warp fibers including the first set of fibers 232 and circumferential 238 weft fibers including the second set of fibers 234. In another embodiment, the self-expandable fabric 230 of the outer skirt 18 may comprise a weave of axial 236 weft fibers including the first set of fibers 232 and circumferential 238 warp fibers including the second set of fibers 234.

[0062] The first set of fibers 232 includes one or more fibers made from a shape memory material having a shape memory set to reinforce radially outward buckling of the outer skirt 18. For example, the fibers can be NiTi wires having sufficient extensibility to withstand weaving stresses and a diameter large enough to self-load and push adjacent fibers into the set shape of the Nitinol wire.

[0063] In embodiments, such NiTi wires can have diameters of 0.5-15 mils, such as diameters of 4-6 mils, 1-5 mils, 2-5 mils, 3-5 mils, 4-7 mils, or 4-6 mils. For example, in some embodiments, the NiTi wires can have diameters of 0.002-0.005 inches, such as diameters of about 0.002 inches, about 0.003 inches, about 0.004 inches, or about 0.005 inches. The shape memory of any NiTi wires in the self-expandable fabric 230 can be set into a shape that reinforces radial outward buckling of the outer skirt 18 before it is woven into the fabric. In one example, the shape memory of the NiTi wires can be trained by heating to over 500° C. for 2 hours, followed by aging at 450° C. for 90 minutes. This heating can be performed in an air or vacuum furnace, followed by rapid (preferably water) cooling. After the shape memory of the NiTi wires is set, the wires can be woven into the self-expandable fabric 230. In some embodiments, 5-25 percent (such as 5-10, 5-15, 5-20, 10-15, 10-20, 10-25, 15-20, 15-25, or 20-25 percent) of the weft fibers in the self-expandable fabric of the outer skirt 18 can be made from a shape memory material. In some embodiments, up to 100% of the weft fibers in the self-expandable fabric of the outer skirt 18 can be made from a shape memory material.

[0064] In some embodiments, the first set of fibers 232 (including NiTi wires) are the weft fibers of the woven fabric. In alternative embodiments, the first set of fibers 232 (including NiTi wires) are the warp fibers of the woven fabric. Also, the remaining fibers in the first set of fibers and the second set of fibers may be made of a shape memory material (such as NiTi) having a shape memory configured to enhance radial outward buckling of the outer skirt 18. Alternatively, the remaining fibers may be made of a non-shape memory material such as PET or PTFE. The remaining fibers need not be the same type of fiber, for example, the first set of fibers and / or the second set of fibers can include monofilaments, microfilaments, and / or microfibers. Examples of suitable monofilaments, microfilaments, and / or microfibers include, but are not limited to, those made from polymers such as PET or PTFE. In some embodiments, the monofilaments or microfibers can have a diameter of about 0.05 mm to about 0.5 mm (about 0.002 to 0.02 inches).

[0065] As discussed above, the fabric 230 may be positioned within the frame 12 in any orientation that facilitates outward buckling and expansion of the outer skirt. In some implementations, the outer skirt 18 has shape memory fibers (e.g., NiTi wire) only in the axial direction. In other implementations, the outer skirt 18 has shape memory fibers (e.g., NiTi wire) only in the circumferential direction. In still other implementations, the outer skirt 18 has shape memory fibers (e.g., NiTi wire) in both the axial and circumferential directions.

[0066] As shown in FIG. 57, the warp and weft fibers in the self-expandable fabric 230 can be plain weave. Alternative weaving patterns may also be utilized. For example, the self-expandable fabric 230 can include shape memory weft fibers and non-shape memory warp fibers in a satin weave pattern, alternating with non-shape memory warp fibers and non-shape memory weft fibers (such as PET fibers) in a plain weave pattern, or a hybrid weave of shape memory warp fibers and non-shape memory weft fibers (see FIGS. 58-60). In a satin weave pattern, the float length of the weft fibers is longer than in a plain weave pattern. Thus, when shape memory fibers are used as weft fibers in a satin weave pattern, the outward buckling of the fabric can be increased by having fewer contact points, which gives the shape memory fibers more freedom to buckle outward. Thus, combining a plain weave of non-shape memory fibers with a satin weave of shape memory and non-shape memory fibers results in an outer skirt material that has a high radial outward buckling force.

[0067] 58-60 show weaving diagrams illustrating three example designs for the weave of the self-expandable fabric 230. In the weaving diagrams shown in FIGS. 58-60, the warp fibers are shown in columns and the weft fibers are shown in rows. The squares in the diagrams indicate the intersections of the warp and weft fibers. If the weft fiber is radially outward of the warp fiber at a particular intersection, the square is marked with a crosshatch shading (for shape memory fibers) or a crosshatch shading (for non-shape memory fibers). If the warp fiber is radially outward of the weft fiber at a particular intersection (i.e., the warp fiber "floats" on the weft fiber), the square is left blank. In the illustrated weaving diagrams, the weft fiber comprises a shape memory fiber. However, in other embodiments, the fibers can be reversed such that the weft fiber becomes the warp fiber and the warp fiber becomes the weft fiber, still achieving the same weaving pattern.

[0068] As shown in Figures 58-60, the rows of weft fibers in the woven fabric may alternate between shape memory and non-shape memory fibers in various patterns. For example, one or more rows of shape memory weft fibers may be separated by one or more (e.g., two, three, four, or five) rows of non-shape memory fibers. Additionally, the number of adjacent warp fibers that "float" above the shape memory fibers in a particular row may vary, such as from one to two adjacent warp fibers (e.g., as shown in Figure 59) or one to five adjacent warp fibers, up to ten adjacent warp fibers (e.g., two adjacent warp fibers, three adjacent warp fibers, four adjacent warp fibers, five adjacent warp fibers (as shown in Figure 58), six adjacent warp fibers, seven adjacent warp fibers, eight adjacent warp fibers (as shown in Figure 60), or nine adjacent warp fibers).

[0069] In some embodiments, the outer skirt 18 may comprise a self-expandable fabric 230 comprising a combination of plain weave and satin weave patterns, with one row of satin weave of shape memory weft fibers and non-shape memory warp fibers alternating with two rows of plain weave of non-shape memory weft fibers and non-shape memory weft fibers. The satin weave may comprise five adjacent warp fiber floats between the radially outward exposure of the shape memory weft fiber covering a single warp fiber (see FIG. 58).

[0070] In some embodiments, the outer skirt 18 may comprise a self-expandable fabric 230 comprising a combination of plain weave and satin weave patterns, with one row of satin weave of shape memory weft fibers and non-shape memory warp fibers alternating with four rows of plain weave of non-shape memory warp fibers and non-shape memory weft fibers. The satin weave may comprise floats of one to two adjacent warp fibers between radially outward exposures of the shape memory weft fibers covering one to two adjacent warp fibers (see FIG. 59).

[0071] In some embodiments, the outer skirt 18 may comprise a self-expandable fabric 230 comprising a combination of plain weave and satin weave patterns, with one row of satin weave of shape memory weft fibers and non-shape memory warp fibers alternating with one row of plain weave of non-shape memory weft fibers and non-shape memory weft fibers. The satin weave may comprise eight warp fiber floats between the radially outward exposure of the shape memory weft fibers covering a single warp fiber (see FIG. 60).

[0072] As shown in FIG. 48 , in the contracted configuration, the excess material of the outer skirt 18 forms a plurality of axially extending folds 179. In this configuration, the first set of fibers 176 or 232 can extend axially in a substantially straight, unfolded configuration, while the second set of fibers 178 or 234 includes a plurality of folds 179. In some embodiments, the elastic range of the second set of fibers is not exceeded when the prosthetic valve 10 is in the contracted configuration and the outer skirt 18 forms a plurality of folds 179. Thus, when the prosthetic valve 10 is radially expanded from the contracted configuration, there is no residual strain in the second set of fibers (i.e., no wrinkles form in the second set of fibers). In some embodiments, the second set of fibers 178 or 234 comprises a set of multifilaments and / or microfibers, each individually having a sufficiently small diameter such that the elastic range of the multifilaments and / or microfibers is not exceeded when the prosthetic valve 10 is in the contracted configuration and the outer skirt 18 comprises the multiple folds 179. In such embodiments, there is no residual strain in the second set of fibers 178 or 234 after the prosthetic valve 10 is compressed into the contracted configuration. Thus, in some embodiments, the second set of fibers 178 or 234 comprises or is composed of "wrinkle-free" fibers, i.e., the second set of fibers 178 or 234 does not exceed its elastic range and has no residual strain (i.e., wrinkles) after the prosthetic valve 10 is compressed into the fully contracted configuration and forms the multiple folds 179 in the outer skirt 18.

[0073] When the prosthetic valve 10 is deployed in vivo, excess material in the middle portion of the outwardly buckling outer skirt 18 may fill the gap between the frame 12 and the surrounding native annulus to help form a good fluid-tight seal between the prosthetic valve and the native annulus. Thus, the outer skirt 18 cooperates with the inner skirt 16 to avoid paravalvular reflux after implantation of the prosthetic valve 10. In embodiments, the prosthetic valve 10 with the outwardly buckling outer skirt 18 may have reduced paravalvular reflux when implanted in a subject, as compared to a similar prosthetic valve without the outer skirt 18.

[0074] FIG. 48 shows the prosthetic valve 10 of FIGS. 1-3 and 42-43 mounted on an elongated shaft 180 of a delivery device forming a delivery assembly for implanting the prosthetic valve 10 in a patient's body. The prosthetic valve 10 is mounted in a radially contracted configuration for delivery into the body. The shaft 180 includes an inflatable balloon 182 for expanding the prosthetic valve in the body, and the crimped prosthetic valve 10 is positioned over the deflated balloon. The frame 12 of the prosthetic valve 10 can include an inflow end portion 174 in the radially compressed mounted configuration having an outer diameter D2 that is smaller than the outer diameter D1 of the outer end of the frame (see FIG. 46). The tapered shape of the frame can be at least partially due to the V-shaped leaflets 40 because the V-shaped leaflets have less leaflet material in the inflow end portion of the frame 12 compared to the rounder U-shaped leaflets. Due to the tapered shape of the frame 12 in the mounted configuration, even when the additional thickness of the outer skirt 18 is positioned around the inflow end portion 174 of the frame 12, the overall outer diameter of the inflow end portion of the prosthetic valve 10 can be approximately equal to or less than the overall outer diameter of the outflow end portion of the prosthetic valve.

[0075] Additionally, as shown in FIG. 48, the prosthetic valve 10 can include leaflet seam portions that extend radially outward through corresponding window frame portions 30 to points outside the frame and are sutured to side struts of the seam window frame. To minimize the crimped profile of the prosthetic valve, the window frame portions 30 can be forced radially inward relative to the periphery of the frame, such as the frame portions extending between adjacent seam windows, when the prosthetic valve is radially compressed onto the shaft into a contracted configuration. For example, the seam windows 30 of the frame can be forced inward a radial distance of between about 0.2 mm and about 1.0 mm relative to the portions of the frame extending between adjacent seam windows when the prosthetic valve is radially contracted. In this manner, the outer diameter of the outflow end portion of the prosthetic valve including the seam portions can be generally consistent, as opposed to seam portions that protrude outward from the periphery of the prosthetic valve, which can impede delivery of the prosthetic valve into the body. Even with a radially depressed seam window frame 30, the outer diameter of the inflow end of the frame can still be smaller or nearly the same as the outer diameter of the outflow end of the frame when the prosthesis is radially contracted onto the shaft, allowing for a minimum / maximum overall diameter of the prosthesis. By minimizing the diameter of the prosthesis when mounted onto the delivery shaft, the assembly can be accommodated within a smaller diameter catheter and therefore routed through smaller vessels in the body and generally be less invasive.

[0076] 49-51 illustrate the expansion of one embodiment of a prosthetic valve 10 from a radially contracted configuration as shown in FIG. 49 to a radially expanded state as shown in FIG. 51. The prosthetic valve 10 is mounted on a balloon 182 of a delivery shaft 180 and includes an inflow end portion 15, an outflow end portion 19, and a mid-portion 17. For clarity, the outer skirt 18 and frame 12 of the prosthetic valve 10 are shown, but other components of the prosthetic valve, such as the leaflets and inner skirt, are not shown. The frame 12 may have a thinner thickness at the inflow end portion 15 and the outflow end portion 19 compared to the mid-portion 17. As shown in FIG. 50, the thinner end portions allow the end portions 15 and 19 to offer less resistance to expansion and expand faster than the mid-portion 17 when the balloon 182 is inflated. The faster expansion of the end portions allows the frame 12 to remain constrained on the balloon 182, preventing the frame from sliding towards either end of the balloon and reducing the risk of the frame prematurely sliding off the balloon. Further inflation of the balloon, as shown in FIG. 51, may expand the mid-section 17 of the frame to the same final diameter as the end sections 15 and 19 for implantation. The balloon may then be deflated and removed. Control of the position of the prosthetic valve on the balloon may be important during delivery, especially with a frame that shortens and moves relative to the balloon upon expansion. In the embodiment shown in FIGS. 49-51, the mid-section 17 of the frame may remain constant relative to the balloon, while the two end sections shorten toward the mid-section due to the "dog-bone" effect of the balloon. Any suitable means may be used to form the frame 12 that reduces the thickness of the end sections 15 and 19, such as by contacting the end sections with an abrasive necking of the hypotube prior to laser cutting, laser ablation, water jet machining, or machining. In one embodiment, the end sections 15 and 19 of the frame have a thickness of about 0.37 mm and the mid-section 17 has a thickness of about 0.45 mm.

[0077] Although described in the context of the prosthetic valve 10, the outer skirt 18 comprising a fabric 170 that is more axially stiff than circumferentially stiff or a self-expandable fabric 230 that includes fibers made from a shape memory material may be included as an outer skirt on any suitable prosthetic valve, such as any suitable prosthetic heart valve known in the art. In embodiments, the outer skirt 18 comprising a fabric 170 that is more axially stiff than circumferentially stiff or a self-expandable fabric 230 that includes fibers made from a shape memory material may be included in place of an outer skirt on a known prosthetic heart valve. Non-limiting examples of suitable prosthetic heart valves in which the outer skirt 18 comprises a fabric 170 that is more axially stiff than circumferentially stiff or a self-expandable fabric 230 that includes fibers made from a shape memory material include those disclosed in U.S. Patent Application Publication No. 2012 / 0123529, WO 2011 / 126758, WO 2012 / 048035, WO 2014 / 004822, WO 2010 / 022138 A2, U.S. Patent No. 8,591,570, and U.S. Patent No. 8,613,765.

[0078] Additionally, although described in the context of the outer skirt 18 of the prosthetic valve 10, the self-expandable fabric 230 including fibers made from a shape memory material can also be used in sheet form as a scaffold for tissue engineering using a shape memory effect that is tailored to a particular anatomical shape.

[0079] The prosthetic valve 10 may be configured for and mounted on a suitable delivery device for implantation into a subject. Several catheter-based delivery devices are known, and non-limiting examples of suitable catheter-based delivery devices include those disclosed in U.S. Patent Application Publication No. 2012 / 0123529 and U.S. Patent Application Publication No. 2013 / 0030519.

[0080] Once assembled, the prosthetic valve may be treated with any of a variety of chemical combinations that may help prevent rejection of the prosthetic valve by the recipient, sterilize the prosthetic valve, stabilize proteins in the prosthetic valve leaflet tissue, make the tissue more resistant to mechanical fatigue, reduce degradation of the tissue by proteolytic enzymes, and / or allow packaging or delivery of the prosthetic valve in a dry form. In an alternative embodiment, the leaflets of the prosthetic valve may be treated with chemical agents before being secured to the frame.

[0081] Typically, some prosthetic heart valves are packaged in jars filled with a preservation solution for shipping and storage prior to implantation in a patient. However, techniques are also known for drying and storing bioprosthetic heart valves without immersion in a preservation solution. The term "dried" or "dry" bioprosthetic heart valves simply indicates that these bioprosthetic heart valves can be stored without a preservation solution, and the term "dry" should not be considered synonymous with brittleness or rigidity. In fact, the leaflets of a "dry" bioprosthetic heart valve may be relatively flexible even before implantation. There are several proposed methods for drying bioprosthetic heart valves, and for drying tissue implants in general, and the present application contemplates the use of bioprosthetic heart valves treated by any of these methods. A particularly preferred method for drying bioprosthetic heart valves is disclosed in U.S. Pat. No. 8,007,992 to Tian et al. An alternative impregnation method is disclosed in U.S. Pat. No. 6,534,004 to Chen et al. These and other methods for drying bioprosthetic heart valves may also be used prior to use of the crimping systems and methods described herein.

[0082] One such strategy is to dehydrate the bioartificial tissue in a glycerol / ethanol mixture, sterilize with ethylene oxide, and package the final product in a "dry" state. This process eliminates the potential toxicity and calcifying effects of glutaraldehyde as a sterilant and storage solution. There are several proposed methods that use sugar alcohols (e.g., glycerol), alcohols, and combinations thereof in the glutaraldehyde post-treatment method so that the resulting tissue is in a "dry" state rather than a wet state in which the tissue is stored in a solution containing excess glutaraldehyde. U.S. Patent No. 6,534,004 (Chen et al.) describes the storage of bioartificial tissue in polyhydric alcohols such as glycerol. In processes in which the tissue is dehydrated in an ethanol / glycerol solution, the tissue can be sterilized using ethylene oxide (ETO), gamma irradiation, or electron beam irradiation.

[0083] More recently, Dove et al. in US Patent Application Publication No. 2009 / 0164005 propose a solution to some of the deleterious changes in dehydrated tissue that may occur as a result of oxidation. Dove et al. propose permanent sealing of aldehyde groups in the tissue (e.g., by reductive amination). Dove et al. also describe the addition of chemicals (e.g., antioxidants) to the dehydrated solution (e.g., ethanol / glycerol) to prevent oxidation of the tissue during sterilization (e.g., ethylene oxide, gamma irradiation, electron beam irradiation, etc.) and storage. Tissues processed according to the principles disclosed in Dove et al. are referred to as "sealed tissues" and bioprosthetic heart valves using such tissues are therefore referred to as "sealed tissue valves". Glutaraldehyde sealing terminates the crosslinking process by consuming all or nearly all of the free aldehyde groups, and is believed to be the most effective method to terminate the crosslinking process when combined with removal of the prosthetic tissue valve from the crosslinking solution (e.g., glutaraldehyde) by storage in a dry state.

[0084] Once treated with the appropriate chemical agents, the prosthetic valve can be crimped into a small profile suitable for implantation into a recipient and / or shipment to a healthcare provider. The prosthetic valve can be crimped directly onto a delivery device (e.g., onto the balloon of a balloon catheter or onto the shaft of a balloon catheter adjacent to the balloon). Once crimped, the prosthetic valve can be packaged in a sterile package in a dry state along with the delivery catheter (or just a portion of the delivery catheter) to which the prosthetic valve is attached, and then shipped to a healthcare facility. The prosthetic valve and delivery catheter can be stored until needed for the procedure, at which time the physician can remove the prosthetic valve and delivery catheter from the package and then implant the prosthetic valve into the patient.

[0085] FIG. 52 illustrates a multi-step process 200 for crimping an expandable and contractible prosthetic valve (such as valve 12) with outflow and inflow end portions and an outer skirt (such as outer skirt 18) on the inflow end portion. The outer skirt has upper and lower edges that are coupled to the prosthetic valve as described above with respect to outer skirt 18. Using the multi-step process 200, a prosthetic valve with an outer skirt (such as outer skirt 18) can be crimped to a small diameter without uneven buckling or collapse of the outer skirt. Using the multi-step process 200, the prosthetic valve can be crimped to a small profile suitable for implantation within a recipient. Alternatively, the prosthetic valve can be crimped to a partially contracted profile for shipment to a healthcare provider who further crimps it prior to implantation within a recipient. The prosthetic valve can be crimped directly onto a delivery device (e.g., onto the balloon of a balloon catheter or onto the shaft of a balloon catheter adjacent to the balloon). Once crimped (partially or completely), the prosthetic valve can be packaged in a sterile package, either alone or together with a delivery catheter, and then shipped to a healthcare provider. The prosthetic valve and delivery catheter can be stored until needed for a procedure, at which time a physician can remove the prosthetic valve and delivery catheter from the package and then implant the prosthetic valve in a patient. In an alternative embodiment, the prosthetic valve can be provided to a healthcare provider in a fully expanded state. Process 200 can be used by an end user to crimp a prosthetic valve onto a delivery device immediately prior to implantation.

[0086] As shown in FIG. 52, at process block 202, the process 200 begins by receiving an expandable prosthetic valve in a fully expanded configuration. The crimping process may continue at process block 204 by partially inserting the expanded prosthetic valve into a valve crimper. The outflow end portion of the prosthetic valve may be inserted into the crimping device at a location where the jaws of the crimping device may contact the frame of the prosthetic valve. The portion of the prosthetic valve covered by the outer skirt is positioned outside the crimping hole of the crimping device such that the crimper jaws (when actuated) do not contact the outer skirt, or alternatively, contact an upper edge or upper portion of the outer skirt (such as an upper edge of the outer skirt 18 or the multiple alternating projections 164 and notches 166 of the outer skirt 18) but do not contact an intermediate portion of the outer skirt.

[0087] At process block 206, the prosthetic valve is crimped into a first partially collapsed configuration. As discussed above with respect to the outer skirt 18, when the collapsible and expandable prosthetic valve is crimped into a fully collapsed configuration, the distance between the upper and lower attachment points of the outer skirt increases, resulting in the outer skirt being flattened against the frame of the prosthetic valve. Thus, at process block 206, when the prosthetic valve is crimped into the first partially collapsed configuration, the distance between the upper and lower attachment points of the outer skirt increases, resulting in the outer skirt being partially flattened against the frame of the prosthetic valve. This partial flattening is due to the stretching of the frame of the prosthetic valve in the axial direction. The partial flattening forms folds in the outer skirt that extend in the axial direction. Although the prosthetic valve is not completely inserted into the crimper, radial compression of the portion of the prosthetic valve that is inserted between the crimper jaws results in a corresponding radial contraction of the portion of the prosthetic valve that is not inserted between the crimper jaws during this crimping step.

[0088] In some embodiments, the expandable prosthetic valve may be considered to be crimped into a first partially contracted configuration, and thus process block 206 may be considered to be complete when the distance between the upper and lower attachment points of the outer skirt is stretched to about 20%, about 30%, about 40%, about 50%, or about 60% (e.g., between about 20% and about 60%) of the distance between the upper and lower attachment points of the outer skirt in the fully contracted configuration, resulting in the outer skirt partially flattening against the frame of the prosthetic valve. In other implementations, the expandable prosthetic valve may be considered to be crimped into a first partially contracted configuration, and thus process block 206 may be considered to be complete when the prosthetic valve has a diameter of about 60% or about 50% (e.g., between about 40% and about 60%) of the diameter of the prosthetic valve in the fully expanded configuration. In a further embodiment, the expandable prosthetic valve may be considered to be crimped into a first partially contracted configuration, and thus process block 206 may be considered complete when the valve outer diameter is about 15-20 mm on the outflow side and about 15-26 mm on the inflow side. The difference in outer diameter between the inflow and outflow sides of the valve is due to the outer skirt, which may add about 1-5 mm to the outer diameter of the inflow end portion.

[0089] At process block 208, the prosthetic valve is fully inserted into the crimping jaws.

[0090] The crimping process may continue by crimping the expandable prosthetic valve to a second partially contracted configuration at process block 210. In some embodiments, the expandable prosthetic valve may be considered to be crimped to the second partially contracted configuration, and thus process block 210 may be considered complete when the distance between the upper and lower attachment points of the outer skirt is stretched to about 70%, about 80%, or about 90% (such as at least about 70%) of the distance between the upper and lower attachment points of the outer skirt in the fully contracted configuration, resulting in the outer skirt further flattening against the frame of the prosthetic valve. In other embodiments, the expandable prosthetic valve may be considered to be crimped to the second partially contracted configuration, and thus process block 206 may be considered complete when the prosthetic valve has a diameter of about 40% or about 30% (such as no more than about 40%) of the diameter of the prosthetic valve in the fully expanded configuration. The outer skirt may add approximately 1-4 mm to the outer diameter of the inflow end portion of the valve in the second, partially collapsed configuration.

[0091] Optionally, the crimping process may continue at process block 212 by crimping the expandable prosthetic valve to a fully contracted configuration. In some embodiments, the expandable prosthetic valve may be considered to be crimped to a fully contracted configuration, and thus process block 212 may be considered complete when the diameter of the frame 12 of the prosthetic valve 10 is less than about 5 mm. In further embodiments, the frame 12 of the prosthetic valve 10 has a diameter of less than about 14 Fr in the fully crimped configuration. In one non-limiting example, the frame of a 26 mm prosthetic valve has a diameter of less than about 14 Fr when in a fully crimped state. The outer skirt may add about 1 Fr to the outer diameter of the inflow end portion of the valve in the fully contracted configuration.

[0092] The crimping process may continue by removing the prosthetic valve from the crimping device at process block 214. Upon completion of any of process blocks 202, 204, 206, 208, and / or 210, the process may be halted for any suitable period of time, i.e., the next process block does not have to be started immediately upon the conclusion of the preceding process block.

[0093] In various embodiments, the prosthetic valve may be removed from the crimping device upon completion of steps 206 or 210 and then packaged in a sterile package for storage and / or shipment to a healthcare provider. The remaining steps of process 200 are to be completed by the end user. In certain embodiments, the crimped or partially crimped prosthetic valve is packaged in a dry state. In alternative embodiments, the crimped or partially crimped prosthetic valve is packaged in a "wet" state in a container containing a preservation solution.

[0094] 53-55 illustrate generally process blocks 204-210 of a multi-step process 200 for crimping an expandable and contractible prosthetic valve with an outer skirt in the context of using a crimping device 215 to crimp a prosthetic valve 10 with an outer skirt 18. The crimping device 215 can include a plurality of circumferentially disposed crimping jaws 216 (two of which are shown in the drawings) that define a variable diameter crimping hole 217. The crimping jaws 216 can be moved radially inward relative to one another to reduce the size of the hole 217, thereby radially compressing the prosthetic valve disposed within the hole 217. Further details regarding the structure of the crimping device 215 are disclosed in U.S. Pat. No. 7,530,253.

[0095] As shown in Fig. 53, the outflow end portion 19 of the prosthetic valve 10 in a fully expanded configuration can be inserted between the crimper jaws 216 of the crimping device 215 up to the upper edge 162 of the outer skirt 18. The inflow end portion 15 of the prosthetic valve 10 with the outer skirt 18 protrudes from the crimper jaws 216 such that the crimper jaws (when actuated to move radially inward) do not contact the outer skirt 18. In an alternative embodiment (not shown), the prosthetic valve 10 can be inserted into the crimping device 215 up to the alternating notches 166 such that the crimper jaws 216 (when actuated) contact the alternating protrusions 164 and notches 166 but do not contact the remainder of the outer skirt 18 (Fig. 41).

[0096] As shown in Fig. 54, the crimper jaws are moved radially inward in the direction of arrows 218, resulting in radial compression of the prosthetic valve 10 into a first partially contracted configuration 222. Contraction of the prosthetic valve 10 increases the distance between the upper and lower attachment points of the outer skirt 18, resulting in the outer skirt being partially flattened against the frame 12 of the prosthetic valve 10. After being crimped into the first partially contracted configuration 222, the prosthetic valve 10 is fully inserted into the crimper jaws 216 of the crimping device 215 (Fig. 55).

[0097] 56 , the crimper jaws are moved further radially inward in the direction of arrows 220, resulting in radial compression of the prosthetic valve 10 into a second, partially contracted configuration 224. Contraction of the prosthetic valve 10 increases the distance between the upper and lower attachment points of the outer skirt 18, resulting in the outer skirt being further flattened against the frame 12 of the prosthetic valve 10.

[0098] The prosthetic valve 10 may be removed from the crimping device after being crimped into the second partially crimped configuration 224. For example, in some embodiments, the prosthetic valve 10 may be crimped into a second partially contracted configuration and then removed from the crimping device and packaged for storage or shipment to a healthcare provider. The prosthetic valve may be fully crimped by a physician prior to implantation within a subject. In other embodiments, the prosthetic valve 10 may be further crimped into a fully contracted configuration prior to removal from the crimping device and then packaged for storage and / or shipment to a healthcare provider.

[0099] The degree to which the prosthetic valve is crimped can be adjusted as needed for a particular valve and / or crimping device. For example, the expandable prosthetic valve can be crimped to a first degree into a first partially crimped configuration, then crimped to a second degree into a second partially crimped configuration, and then fully crimped to a third degree. In another alternative embodiment, the degree to which the expandable prosthetic valve is crimped can be continuously variable and determined based on suitable factors, such as the resulting pressure on the leaflets due to the crimping process.

[0100] The process 200 can be used with a variety of prosthetic valves having an outer skirt and with a variety of crimping devices. The process of crimping the prosthetic valve and controlling the rate at which the prosthetic valve is crimped can be controlled and completed by any of a variety of crimping devices. For example, the prosthetic valve can be crimped manually using a manual crimping device (such as that disclosed in U.S. Patent No. 7,530,253) or automatically using an automatic crimping device (such as that disclosed in U.S. Patent Application Serial No. 14 / 211,775, filed March 14, 2014). The prosthetic valve can also be partially crimped using a crimping device (such as the automatic or manual crimping devices disclosed in U.S. Pat. No. 7,530,253 or U.S. Patent Application No. 14 / 211,775) for the first and second crimping steps, and then removed from the crimping device and drawn through a crimping cone into a delivery sheath or cylinder having an inner diameter equal to the final crimped diameter of the prosthetic valve for a further crimping step (such as that described in U.S. Patent Application Publication No. 2012 / 0239142).

[0101] Suitable crimping devices may be powered by electric motors or combustion engines, may be pressure regulated, or may be pneumatically or hydraulically powered. Such systems may include a variety of devices for collecting user input, such as buttons, levers, pedals, etc.

[0102] In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it is to be understood that the illustrated embodiments are merely preferred examples of the invention and should not be taken as limiting the scope of the invention, which is rather defined by the following claims, and therefore what is claimed as the invention is everything that falls within the scope of those claims. [Explanation of symbols]

[0103] 10 Artificial Heart Valves 12 Frames 14 Valve structure 15 Inlet end part 16 Inner Skirt 17 Middle part 18 Outer Skirt 19 Outflow end part 20 Seam Window 22 Angled strut of the first lower row I 24 Circumferentially extending angled strut of second row II 26 Circumferentially extending angled strut of the third row III 28 circumferentially extending angled strut of the fourth row IV 30 Axial extending window frame portion 31 Axial strut 32 Circumferentially extending angled strut of the fifth row V 34 substantially straight axially extending strut 36 Aperture 38 Aperture 40 leaflets 42a angle 42b angle 42c angle 42d angle 42e angle 44 Connection part 46 Connection part 50 frames 52 Circumferentially extending angled strut 54 Connecting part 56 Connecting part 58 Axially extending strut 60 Seam window frame part 62 Slot or Seam Window 64 Connection part 70 Sutures 72 Reinforcement strip 78 First set of fibers, or yarns or strands 80 Second set of fibers, or yarns or strands 82 Upper Edge 84 Lower Edge 86 Short Edge 88 Short Edge 90 Short edge part 92 Short edge part 94 Suture Line 96 Protrusion 98 Slit 100 locations 108 Lower edge part, inlet edge part 110 Upper free edge, outflow edge 112 Top tab 114 Notch 116 Lower tab 118 Axial edge part 119 Smooth curved tip 120 Essentially V-shaped mid-edge 121 Slope section 122 Joint 124 Flexible Connector 126 Wedge 128 Temporary suture 130 Inner cutout 132 Outer notch 133 Straight stitch 134 Comb stitch 136 Marking Suture 140 rectangle 142 Inner part 143 Inner Edge 144 Outer part 145 Longitudinal axis 146 Suture Line 148 Suture Line 150 Primary Suture Line 152 Overlock stitch 154 Suture Line 156 Blanket Suture 160 Lower Edge 162 Upper Edge 164 Protrusion 166 Notch 168 Sutures 170 Fabric 172 Axial 173 Circumferential direction 174 areas 176 First set of fibers 178 Second set of fibers 179 creases 180 Thin Shaft 182 Inflatable Balloon 1 215 Crimping Device 216 Crimping jaws, crimper jaws 217 Variable diameter crimped hole 222 First partial contraction configuration 224 Second Partial Contraction Configuration 230 Self-expandable fabric 232 First set of fibers 234 Second set of fibers 236 Axial 238 Circumferential direction S2 Thickness F1 force F2 force d1 Vertical distance between the ends of the struts d2 distance D1 Maximum diameter D2 Minimum diameter

Claims

1. 1. An implantable prosthetic valve, comprising: an annular frame having an inflow end and an outflow end, the annular frame being radially contractible and expandable between a radially contracted configuration and a radially expanded configuration, the annular frame defining an axial direction extending from the inflow end to the outflow end; a leaflet structure positioned within and secured to the annular frame; an annular outer skirt positioned about an outer surface of the annular frame; and wherein the annular outer skirt comprises: an inflow edge secured to the annular frame at a first location; an outflow edge secured to the annular frame at a second location; an intermediate portion between the inflow and outflow edges of the annular outer skirt having slack that buckles radially outward from the inflow and outflow edges when the prosthetic valve is in the radially expanded configuration; and (a) a fabric with higher stiffness in the axial direction of the prosthetic valve than in the circumferential direction to enhance radially outward buckling of the slack; and / or (b) a self-expandable fabric including fibers made from a shape memory material having a shape memory configured to enhance the radially outward buckling of the slack of the annular outer skirt.

1. An implantable prosthetic valve comprising:

2. 2. The implantable prosthetic valve of claim 1, wherein the outflow edge of the annular outer skirt comprises a plurality of alternating protrusions and notches, the protrusions being secured to the annular frame at the second location and the notches not directly secured to the annular frame.

3. 3. The implantable prosthetic valve of claim 1, wherein when the annular frame is in the radially contracted configuration, an axial distance between the inflow edge of the annular outer skirt and the outflow edge of the annular outer skirt is greater than when the prosthetic valve is in the radially expanded configuration, thereby reducing the slack in the intermediate portion of the annular outer skirt.

4. 4. The implantable prosthetic valve of claim 1, wherein the fabric comprises fibers that have no residual strain after the annular frame is expanded from the radially contracted configuration to the radially expanded configuration.

5. The annular outer skirt comprises a fabric having a higher stiffness in an axial direction of the artificial valve than in a circumferential direction, the fabric comprising: a plurality of first fibers parallel to the axial direction of the annular frame; a plurality of second fibers perpendicular to the plurality of first fibers; Including, 5. The implantable prosthetic valve of claim 1, wherein at least some of the fibers in the first plurality of fibers are more stiff than the fibers in the second plurality of fibers.

6. The implantable prosthetic valve of claim 5 , wherein the plurality of first fibers comprises monofilament fibers.

7. 7. The implantable prosthetic valve of claim 5 or 6, wherein the plurality of second fibers comprises microfilament fibers, multifilament fibers, or a combination of microfilament and multifilament fibers.

8. 8. The implantable prosthetic valve of claim 5, wherein the second plurality of fibers comprises fibers that have no residual strain after the annular frame is expanded from the radially contracted configuration to the radially expanded configuration.

9. 5. The implantable prosthetic valve of claim 1, wherein the self-expandable fabric comprises a woven body of warp and weft fibers.

10. 10. The implantable prosthetic valve of claim 9, wherein the weft fibers comprise fibers made from a shape memory material.

11. The woven body of the warp fibers and the weft fibers is a plain weave pattern including fibers made from a non-shape memory material; a satin weave pattern including the fibers made from the shape memory material; 11. The implantable prosthetic valve of claim 9 or 10, comprising:

12. 12. The implantable prosthetic valve of claim 11, wherein the satin weave pattern includes warp fibers made from a non-shape memory material and weft fibers made from the shape memory material.

13. 13. The implantable prosthetic valve of claim 1 or any one of claims 9 to 12, wherein the shape memory material is a nickel-titanium alloy.

14. 14. The implantable prosthetic valve of claim 1 or any one of claims 9-13, wherein the fibers made from shape memory material have a diameter of 0.5 to 15 mils.

15. 15. The implantable prosthetic valve of claim 1, wherein the annular frame comprises a plurality of leaflet mounting portions, and the leaflet structure is secured to the leaflet mounting portions of the annular frame.

16. 1. An assembly for implanting a prosthetic heart valve in a patient, comprising: A delivery device comprising an elongate shaft; 16. The prosthetic heart valve of any one of claims 1 to 15, mounted on the elongate shaft in a radially contracted configuration for delivery into the body; An assembly comprising:

17. 1. A method of radially compressing a prosthetic valve, comprising: partially inserting the prosthetic valve into a crimping device having crimping jaws while in a radially expanded configuration, such that a portion of the prosthetic valve having an outer skirt extends outside of the crimper jaws; crimping the prosthetic valve to a first partially contracted configuration; further inserting the prosthetic valve into the crimping device such that the outer skirt is positioned between the crimper jaws; crimping the prosthetic valve to a second partially contracted configuration; Optionally crimping the prosthetic valve into a fully crimped configuration; A method comprising:

18. 20. The method of claim 17, comprising the step of crimping the prosthetic valve into the fully crimped configuration.

19. (a) the prosthetic valve in the first partially contracted configuration has a diameter that is approximately 60% of a diameter of the prosthetic valve in the radially expanded configuration; (b) the prosthetic valve in the second partially contracted configuration has a diameter that is approximately 40% of a diameter of the prosthetic valve in the radially expanded configuration. (c) the prosthetic valve in a fully contracted configuration has a diameter that is about 10% of a diameter of the prosthetic valve in the radially expanded configuration; or 19. The method of claim 17 or 18, which is a combination of two or more of (a) through (c).

20. 20. The method of any one of claims 17 to 19, wherein the crimping device is an automated crimping device.

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