Prosthetic heart valve with a perivalvular sealing layer

Abstract

The stented prosthetic heart valve includes a tubular stent frame with multiple stent frame support structures that collectively define an inner surface, an outer surface, and multiple cell units. The stented prosthetic heart valve also includes a valve structure comprising valve leaflets disposed within and secured to the stent frame and defining an attachment edge. The stented prosthetic heart valve includes one or both of a paravalvular leak-proof outer wrapping and an inner skirt for supporting the valve leaflets. In various embodiments, the outer wrapping is entirely positioned on one side of the attachment edge. In embodiments including an inner skirt, the outer wrapping and inner skirt are on opposite sides of the attachment edge such that the inner skirt and outer wrapping do not overlap. In other embodiments, the outer wrapping includes multiple regions of varying thicknesses.

Description

Background Technology

[0001] This disclosure relates to a stented prosthetic heart valve having a perivalvular sealing envelope.

[0002] The human heart comprises four valves that determine the path of blood flow: the mitral, tricuspid, aortic, and pulmonary valves. The mitral and tricuspid valves are atrioventricular valves located between the atria and ventricles, while the aortic and pulmonary valves are semilunar valves located in the arteries leading out of the heart. Ideally, the natural leaflets of the heart valves move away from each other when the valve is in the open position and come into contact or "close" when the valve is in the closed position. Potential valve problems include stenosis, where the valve does not open properly; and / or insufficiency or regurgitation, where the valve does not close properly. Stenosis and insufficiency can occur concurrently in the same valve. The effects of valvular dysfunction vary depending on the severity of the disease and can have significant physiological impacts on patients.

[0003] Recently, flexible prosthetic valves for cardiac and venous valve replacement have been developed. These flexible prosthetic valves are supported by a stent structure and can be percutaneously delivered using a catheter-based delivery system. These prosthetic valves may include a self-expanding or cystoscopically expandable stent structure, with leaflets attached within the stent structure. The diameter of the prosthetic valve can be reduced by being gripped onto a cystic catheter or by being contained within a sheath component of the delivery catheter, and the prosthetic valve can advance through the venous or arterial vascular system. Once the prosthetic valve is positioned at the treatment site, such as within a dysfunctional natural valve, the stent structure can expand to hold the prosthetic valve securely in place. An example of a stented prosthetic valve is disclosed in U.S. Patent No. 5,957,949 to Leonhardt et al., entitled "Percutaneous Placement Valve Stent". Another example of a stented prosthetic valve for percutaneous pulmonary valve replacement surgery is described in U.S. Patent Application Publication No. 2003 / 0199971 A1 and U.S. Patent Application Publication No. 2003 / 0199963 A1 filed by Tower et al.

[0004] While transcatheter delivery methods have provided a safer and less invasive approach for replacing defective natural heart valves, leakage between the implanted prosthetic valve and the surrounding natural tissue remains a recurring problem. Leakage sometimes occurs because minimally invasive, percutaneous heart valve replacement typically does not involve the actual physical removal of the diseased or injured valve. Instead, the stented prosthetic valve for replacement is delivered to the valve site in a compressed state, where it expands within the natural valve to its operational position. Calcified or diseased natural leaflets are forced open by radial forces from the stent frame of the prosthetic valve. These calcified leaflets may not conform perfectly to the stent frame, and any gap between the stent frame and the natural valve can become a source of paravalvular leakage (“PVL”). The closure pressure gradient across the prosthetic valve causes blood to leak through the gap between the implanted prosthetic valve and the calcified anatomy. Such paravalvular leakage can be very detrimental to the patient.

[0005] Because the aforementioned prosthetic valve is delivered via transcatheter surgery, there is a concern regarding the profile of the prosthetic valve to reduce compression during delivery while still providing a paravalvular leak-proof wrapping. This disclosure addresses the problems and limitations in the relevant art. Summary of the Invention

[0006] As described above, stented prosthetic heart valves can leave paravalvular leak paths in some patients, especially those with very difficult-to-move or highly calcified natural valve leaflets. The disclosed embodiments include stented prosthetic heart valves (hereinafter referred to as "prosthetic valves") comprising a stent frame with an outer wrapping or skirt to fill the paravalvular leak path. In the disclosed embodiments, the location of the outer wrapping is configured to reduce the profile of the compressed prosthetic valve during delivery while maximizing the thickness of the outer wrapping.

[0007] Various embodiments include a prosthetic valve comprising a tubular support frame having multiple support frame structures that collectively define an inner surface, an outer surface, and multiple cell units. The prosthetic valve also includes valve leaflets fixed to the inner surface of the support frame. The valve leaflets define an attachment edge. The prosthetic valve includes one or both of an outer wrap portion (“outer wrap portion”) for preventing paravalvular leakage and an inner skirt portion for supporting the valve leaflets. In various embodiments, the outer wrap portion is positioned entirely on one side of the attachment edge. In various embodiments that include an inner skirt portion supporting the valve leaflets, the outer wrap portion and the inner skirt portion are positioned so as not to overlap along the length of the support frame. In this embodiment, the outer wrap portion is on one side of the attachment edge (e.g., the inflow side), and the inner skirt portion is on the opposite side of the attachment edge (e.g., the outflow side). In this way, the outer wrap portion can have increased thickness without increasing the profile of the compressed prosthetic valve during delivery. In various embodiments, the outer wrap portion includes at least two regions of different thicknesses. Attached Figure Description

[0008] Figure 1 This is a perspective view of an exemplary stented prosthetic heart valve that can be modified according to this disclosure.

[0009] Figure 2 This is a front view of a stent-supported prosthetic heart valve with an inner skirt and an outer sheath.

[0010] Figure 3 yes Figure 2 Side view of a stented prosthetic heart valve.

[0011] Figure 4 yes Figure 2-3 A top view of a prosthetic heart valve with a stent.

[0012] Figure 5 This is a front view of an alternative stent-supported prosthetic heart valve with an inner skirt and an outer wrapping section, the outer wrapping section having areas of varying thickness.

[0013] Figure 6 This is a front view of an alternative stent-supported prosthetic heart valve with an inner skirt and an outer wrapping section, the outer wrapping section having areas of varying thickness.

[0014] Figure 7 This is a front view of another alternative stent-supported prosthetic heart valve with an inner skirt and an outer wrapping section, the outer wrapping section having areas of varying thickness. Detailed Implementation

[0015] Specific embodiments of this application are now described with reference to the accompanying drawings, wherein similar reference numerals indicate the same or functionally similar elements. As used herein with reference to prosthetic heart valves, the term "outflow" is understood to mean downstream in the direction of blood flow, while the term "inflow" is understood to mean upstream in the direction of blood flow. Although this disclosure has been described with reference to preferred embodiments, those skilled in the art will recognize that various changes in form and detail may be made without departing from the spirit and scope of this disclosure.

[0016] Certain aspects of this disclosure relate to a transcatheter stented prosthetic heart valve delivery device that delivers a stented prosthetic heart valve (hereinafter referred to as "prosthetic valve") in a compressive arrangement during delivery to a target site, and allows the prosthetic valve to expand and unfold at the target site. As background art, in Figure 1 The diagram shows general components of a non-limiting example of a stented prosthetic heart valve 10, which is useful for various aspects of this disclosure.

[0017] Paravalvular leakage may occur after the prosthetic valve 10 is deployed at the target site. Therefore, this will be discussed in detail below. Figure 2-7 As shown, the prosthetic valve disclosed herein includes an outer wrapping portion (hereinafter referred to as the "outer wrapping portion") to prevent paravalvular leakage.

[0018] like Figure 1 As shown, the prosthetic valve 10 has a compressible delivery configuration and a normal expansion arrangement. The prosthetic valve 10 includes a tubular stent frame 12 having an inflow end 14 and an outflow end 16 and can take any of the forms described herein, and is generally configured such that it can expand from a compressible arrangement to a normal expansion deployment arrangement. In other embodiments, the stent frame 12 can be expanded to an expansion arrangement by a separate device (e.g., a sac located within the stent frame 12). A valve structure 18 is assembled to the stent frame 12 and provides two or more (typically three) leaflets 22. The valve structure 18 can take any of the forms described herein and can be assembled to the stent frame 12 in various ways, such as by sewing the valve structure 18 to the stent frame 12. Alternatively, as referenced below… Figure 2-4 The valve structure 18 discussed can be fixed to the support frame 12 using the inner skirt.

[0019] As mentioned herein, the stented prosthetic heart valve 10, or a prosthetic valve that can be modified to include the outer envelope and inner skirt disclosed herein, can present a variety of different configurations. For example, the prosthetic heart valve can be a bio-scaffolded prosthetic heart valve with tissue leaflets or a synthetic heart valve with polymeric, metallic, or tissue-engineered leaflets, and can be specifically configured to replace any natural heart valve. Thus, prosthetic valves can be generally used for the replacement of natural aortic, mitral, pulmonary, or tricuspid valves, as venous valves, or for replacing failed bioprosthetics, such as, for example, in the region of the aortic or mitral valve.

[0020] In general, the stent or stent frame 12 of this disclosure includes a generally tubular support structure 24 defining a plurality of cells 28 and having an inner surface 30 and an outer surface 32 (only one of the plurality of cells 28 and the support structure 24 is labeled for ease of illustration). A valve structure 18, including a connecting column 20 supporting a plurality of valve leaflets 22, is fixed to the inner surface 30. The valve leaflets 22 define attachment margins 36. The valve leaflets 22 can be made of a variety of materials, such as autologous homologous tissue, xenograft tissue, or synthetic materials known in the art. The valve leaflets 22 can be provided as homologous biological valve structures, such as porcine, bovine, or equine valves. Alternatively, the valve leaflets 22 can be provided independently of each other (e.g., bovine, porcine, or equine pericardial leaflets) and subsequently assembled to the support structure of the stent frame 12. In another alternative, the support frame 12 and the valve leaflet 22 can be fabricated simultaneously, for example using a high-strength nanofabricated NiTi membrane produced by, for instance, AdvanceBioProsthetic Surfaces (ABPS). The support frame 12 is generally configured to contain at least two (typically three) leaflets; however, replacement prosthetic valves of the type described herein may contain more or fewer than three leaflets.

[0021] In some configurations, the stent frame support structure 24 can be a series of wires or wire segments arranged such that they can self-transition from a compressed or collapsed arrangement to a normal radially expanded arrangement. In this embodiment, the stent frame 12 can be laser-cut from a single piece of material or assembled from many different components. The stent frame support structure 24 of the stent frame 12 can be formed from a shape memory material such as a nickel-titanium alloy (e.g., Nitinol™). With this material, the support structure can self-expand from a compressed arrangement to a normal expanded arrangement, for example by applying heat, energy, or by removing external forces (e.g., compressive forces). The stent frame 12 can be compressed and re-expanded multiple times without damaging the stent frame support structure 24. These stent frame support structures 24 are arranged such that the stent frame 12 allows folding, compression, or collapse into a compressed arrangement in which the inner diameter is smaller than the inner diameter in the normal expanded arrangement. In the compressed configuration, this stent frame 12 with the attached valve leaflets 22 can be mounted onto a delivery device. An example of a suitable delivery device is disclosed in U.S. Patent No. 8,579,963 to Tabor, the entire disclosure of which is incorporated herein by reference. The support frame support structure 24 is configured such that, for example, by relative movement of one or more sheaths relative to the support frame 12 along a length defined between the inlet end 14 and the outlet end 16, they can be repositioned to their normal expanded arrangement.

[0022] The prosthetic valve 10 is configured for replacing the aortic valve. Alternatively, other shapes are contemplated that are adapted to the specific anatomy of the valve to be replaced (e.g., the shape and / or size of the prosthetic valve according to this disclosure may alternatively be designed to replace a natural mitral, pulmonary, or tricuspid valve). In any case, the valve structure 18 may be arranged to extend less than the entire length of the stent frame 12. Specifically, the valve structure 18 may be assembled to and extend along the inflow end 14 of the prosthetic valve 10, while the outflow end 16 may be without material of the valve structure 18. A variety of other configurations are also acceptable and within the scope of this disclosure. For example, the size and shape of the valve structure 18 may be designed to extend along the entire length or nearly the entire length of the stent frame 12.

[0023] Now turning around Figure 2-4 The prosthetic valve 10 may include an optional inner skirt 50 attached to the inner surface 30 of the support frame 12, the inner skirt 50 interconnecting with and supporting the valve leaflets 22 relative to the support frame 12. The inner skirt 50 may include treated pericardial tissue or a biocompatible synthetic material such as a bioabsorbable mesh (e.g., poly(glycerol-co-sebate), polylactic acid, and polycaprolactone). In an exemplary embodiment, the inner skirt 50 is positioned within a portion of the area of ​​at least one cell 28. As shown, the inner skirt 50 is positioned on or "above" the attachment edge 36 (i.e., on the outflow side 38a) near the outflow end 16 of the support frame 12.

[0024] The prosthetic valve 10 may also include an outer wrapping 60 for perivalvular sealing to prevent leakage of the implanted prosthetic valve 10 around the stent frame 12. The outer wrapping 60 includes a body 62 made of treated pericardial tissue or a biocompatible synthetic material, such as a woven or knitted fabric (e.g., PET, UHMWPE, polypropylene) or a bioabsorbable mesh (e.g., poly(glycerol-co-sebate), polylactic acid, and polycaprolactone). The body 62 may also be made of more than one material, if desired. In one exemplary embodiment, the outer wrapping 60 is disposed on the outer surface 32 of the stent frame 12 at a location on or "below" the attachment edge 36 (i.e., on the inflow side 38b). In various embodiments, the boundary or edge 64 of the outer wrapping 60 may be aligned with or identical to the attachment edge 36. To reduce the profile of the compressed prosthetic valve 10 while allowing for an increase in the thickness of the outer wrap 60, in various embodiments, the inner skirt 50 and the outer wrap 60 do not overlap along the length of the support frame 12. In some embodiments, the inner skirt 50 and the outer wrap 60 may be adjacent or in contact at a connection boundary (e.g., at the attachment edge 36), but in the illustrated embodiment, the inner skirt 50 and the outer wrap 60 do not overlap.

[0025] Now turning around Figure 5 The accompanying figure illustrates an alternative stented prosthetic heart valve 110. The stented prosthetic heart valve 110 is similar to the one described above. Figure 2-4 The illustrated and described stent-supported prosthetic heart valve includes an alternative outer wrapping portion 160. In this embodiment, the outer wrapping portion 160 has at least two regions 162a and 162b of different thicknesses. It is contemplated that the portion of the outer wrapping portion 160 that is not a specific target for reducing paravalvular leakage, or region 162a, will have a smaller thickness compared to region 162b, which has a higher risk of paravalvular leakage (e.g., the region between the lowest point of the valve and the inflow end). In the illustrated embodiment, the outer wrapping portion 160 has a first region 162a and a second region 162b. The second region 162b is a strip-like portion that wraps approximately along the periphery of the frame 12 near the inflow end 14. In an exemplary embodiment, the outer skirt 160 may be 0.1 mm thick in the first region 162a and 0.3 mm thick in the second region 162b. The second region 162b may include a layer of material positioned on top of the first material layer to form a double layer. Alternatively, the second region 162b may be a separate, thicker material compared to the first region 162a to provide increased thickness. In such embodiments, the first region 162a and the second region 162b may be attached by sutures or the like to form a seam that joins the two regions together, or, if a polymer material is used, the seam may be formed by fusion bonding. As in previous embodiments, regions 162a and 162b each have corresponding boundaries 164a and 164b, which are positioned on one side 38b of the attachment edge 36. Furthermore, the prosthetic heart valve 110 may optionally include an inner skirt 150 configured as shown in reference to Figure 2-4 As shown in the 50th edition of the inner skirt.

[0026] Figure 6 Another stent-supported prosthetic heart valve 210 with an outer wrap 260 is shown, the outer wrap 260 comprising at least two regions 262a, 262b of different thicknesses. In the illustrated embodiment, the outer wrap 260 has a first region 262a and a second region 262b. The second region 262b is a strip-like portion wrapped around the periphery of the frame 12 near the inlet end 14. The outer wrap 260 can be constructed similarly, as the difference in thickness can be achieved in many ways: either by using different materials or by layering materials. As in the previously disclosed embodiments, regions 262a, 262b each have corresponding boundaries 264a, 264b, which are positioned on one side 38b of the attachment edge 36. Furthermore, the prosthetic heart valve 210 may optionally also include an inner skirt 250, which is constructed as shown in the reference... Figure 2-4The inner skirt part is as shown in the picture.

[0027] Figure 7 Another stent-supported prosthetic heart valve 310 with an outer wrap 360 is shown, the outer wrap 360 comprising at least two regions 362a, 362b of different thicknesses. In the illustrated embodiment, the outer wrap 360 has a first region 362a and a second region 362b. The second region 362b is a generally sinusoidal band that wraps around the periphery of the frame 12 near the inlet end 14. The outer wrap 360 can be constructed similarly, as the difference in thickness can be achieved in many ways: either by using different materials or by layering materials. As in the previously disclosed embodiments, regions 362a, 362b each have corresponding boundaries 364a, 364b, which are positioned on one side 38b of the attachment edge 36. Furthermore, the prosthetic heart valve 310 may optionally also include an inner skirt 350 constructed as shown in the reference... Figure 2-4 As shown in the 50th edition of the inner skirt.

[0028] Although this disclosure has been described with reference to preferred embodiments, those skilled in the art will recognize that various changes in form and detail may be made without departing from the spirit and scope of this disclosure.

Claims

1. A stent-supported prosthetic heart valve, said stent-supported prosthetic heart valve comprising: A tubular support frame having multiple support frame support structures that collectively define multiple cells, an inner surface, and an outer surface of the support frame; A valve structure including valve leaflets disposed within and fixed to the support frame, the valve leaflets defining an attachment edge; wherein the attachment edge defines a boundary between an inflow side and an outflow side of the attachment edge; An outer wrapping portion, the outer wrapping portion generally surrounding the outer surface of the support frame; wherein the outer wrapping portion is completely positioned on the inflow side of the attachment edge; and Inner skirt, the inner skirt supporting the valve leaflets on the inner surface of the support frame; The valve structure includes commissures positioned between adjacent valve leaflets and supporting the adjacent valve leaflets, and the outer wrapping portion defines a generally U-shaped boundary between adjacent commissures. The inner skirt is positioned entirely on the outflow side of the attached edge.

2. The stent-supported prosthetic heart valve as described in claim 1, characterized in that, The inner skirt spans an area smaller than a corresponding cell.

3. The stent-supported prosthetic heart valve as described in claim 1, characterized in that, The inner skirt and the outer wrapping together span the area of ​​a corresponding cell.

4. The stent-supported prosthetic heart valve as described in claim 1, characterized in that, The outer wrapping portion has a boundary aligned with the attachment edge portion.

5. The stent-supported prosthetic heart valve as described in claim 1, characterized in that, The outer wrapping portion includes at least two areas of different thicknesses.

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