Valve prosthesis

Abstract

The present invention provides a valve prosthesis, which includes: a stent and a skirt assembly; the stent has an inflow end and an outflow end relative to each other along its own axial direction; the skirt assembly includes at least two skirts, the skirt is annular around the stent, the skirt has an inner edge and an outer edge, the inner edge is a side of the skirt close to the axis of the stent, and the outer edge is a side of the skirt away from the axis of the stent; the inner edge is connected to the stent, and the outer edge forms a free end; at least two skirts are arranged at intervals along the axial direction of the stent, and have different radial outer dimensions; the outer edge of at least one skirt is used to contact with native tissue. With such a configuration, even when a small amount of blood flows into the gap between the skirt and the native tissue, it will be blocked by the skirts with different radial outer dimensions to form a low-speed blood flow area, which is conducive to blood coagulation in the low-speed area, reducing paravalvular leakage, and accelerating endothelialization. At the same time, the change in the radial outer dimension of the skirt increases the roughness of the skirt assembly, which is conducive to tissue attachment growth and endothelialization.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a valve prosthesis. Background Art

[0002] The heart contains four chambers. The left atrium and left ventricle are located on the left side of the heart, and the right atrium and right ventricle are located on the right side of the heart. The ventricular inflow tract is formed between the atrium and the ventricle, the left ventricular outflow tract is formed between the left ventricle and the aorta, and the right ventricle and the pulmonary artery form the right ventricular outflow tract. There are valves with the function of "one-way valves" at the ventricular inflow tract and the ventricular outflow tract. The human heart has four valves. They are the aortic valve connecting the left ventricle and the aorta, the pulmonary valve connecting the right ventricle and the pulmonary artery, the mitral valve connecting the left atrium and the left ventricle, and the tricuspid valve connecting the right atrium and the right ventricle. They all act as one-way valves, so that blood can only flow from one direction to another and cannot flow back. When a problem occurs in a certain valve, the heart's hemodynamics changes and the heart function becomes abnormal, which is called valvular heart disease.

[0003] With the development of social economy and the aging of population, the incidence of valvular heart disease has increased significantly. Studies have shown that the incidence of valvular heart disease in the elderly population over 75 years old is as high as 13.3%. At present, traditional surgical treatment is still the first choice for patients with severe valvular disease, but for the elderly, patients with multiple organ diseases, patients with a history of open-chest surgery and patients with poor heart function, traditional surgical treatment has high risks and mortality, and some patients do not even have the opportunity for surgery. Transcatheter valve replacement / repair has the advantages of no need for open-chest surgery, less trauma, and faster patient recovery, and has attracted widespread attention from experts and scholars.

[0004] However, in recent years, there are still some urgent problems to be solved in the field of valve implantation, such as paravalvular leakage of existing valve prostheses after implantation, slow peripheral epithelialization of valve prostheses, and easy displacement of valve prostheses after implantation. Summary of the invention

[0005] The object of the present invention is to provide a valve prosthesis to solve the problems existing in the existing valve prosthesis after implantation.

[0006] In order to solve the above technical problems, the present invention provides a valve prosthesis, which includes: a stent and a skirt component;

[0007] The support has an inflow end and an outflow end opposite to each other along its axial direction;

[0008] The skirt assembly includes at least two skirts, the skirts are annularly surrounding the bracket, and the skirts have an inner edge and an outer edge, the inner edge is a side of the skirt close to the axis of the bracket, and the outer edge is a side of the skirt away from the axis of the bracket; the inner edge is connected to the bracket, and the outer edge forms a free end;

[0009] At least two of the skirts are spaced apart along the axial direction of the stent and have different radial outer dimensions; the outer edge of at least one of the skirts is used to contact with native tissue.

[0010] Optionally, along the direction from the outflow end to the inflow end, radial outer dimensions of at least two of the skirts increase or decrease sequentially.

[0011] Optionally, the skirt assembly includes a plurality of skirts, and along the direction from the outflow end to the inflow end, the radial outer dimensions of the plurality of skirts have the same rate of change.

[0012] Optionally, the skirt assembly includes a plurality of skirts, and radial outer dimensions of the plurality of skirts increase or decrease nonlinearly along a direction from the outflow end to the inflow end.

[0013] Optionally, the skirt edge close to the outflow end overlaps the adjacent skirt edge away from the outflow end.

[0014] Optionally, two axially adjacent skirts and the bracket enclose a vortex cavity.

[0015] Optionally, the skirt includes a first surface and a second surface connected to each other, the first surface and the second surface intersect to form the inner edge; along the direction from the inner edge to the outer edge, the first surface and the second surface gradually move away from each other.

[0016] Optionally, the skirt further includes a third surface, wherein the third surface is connected to the first surface and the second surface respectively, and the first surface, the second surface and the third surface are enclosed to form the skirt, and the outer edge is located on the third surface.

[0017] Optionally, the third surface includes an inwardly inclined section, the inwardly inclined section extends from the outer edge toward the inflow end, and the inwardly inclined section is inclined inwardly toward the axial direction of the bracket.

[0018] Optionally, the first surface, the second surface and the third surface form a curved surface with a smooth transition.

[0019] In summary, the valve prosthesis provided by the present invention includes: a stent and a skirt assembly; the stent has an opposite inflow end and an outflow end along its own axial direction; the skirt assembly includes at least two skirts, the skirt is annular around the stent, and the skirt has an inner edge and an outer edge, the inner edge is the side of the skirt close to the axis of the stent, and the outer edge is the side of the skirt away from the axis of the stent; the inner edge is connected to the stent, and the outer edge forms a free end; at least two of the skirts are arranged at intervals along the axial direction of the stent, and have different radial outer dimensions; the outer edge of at least one of the skirts is used to contact native tissue.

[0020] With such configuration, during the systolic period, the skirt assembly can block the blood flow through the gap between the valve prosthesis and the tissue, and during the diastolic period, the skirt assembly can block the backflow of blood. Since the radial outer dimensions of at least two skirts are different, and the outer edge of at least one skirt is used to contact the native tissue, even when a small amount of blood flows into the gap between the skirt and the native tissue, it will be blocked by the skirts with different radial outer dimensions to form a blood flow low-speed zone, which is conducive to blood coagulation in the low-speed zone, reducing paravalvular leakage and accelerating endothelialization. At the same time, at least two skirts with different radial outer dimensions arranged axially at intervals increase the roughness of the skirt assembly, which is conducive to tissue attachment and growth, and is conducive to endothelialization, and can effectively increase the friction between the valve prosthesis and the tissue, reducing the risk of displacement of the valve prosthesis after implantation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0022] Figure 1 is a schematic axial cross-sectional view of a valve prosthesis according to an embodiment of the present invention, wherein the radial outer dimension of the skirt gradually increases in a direction from the outflow end to the inflow end;

[0023] Figure 2 yes Figure 1 A partial enlarged view of the valve prosthesis is shown;

[0024] Figure 3 is a schematic axial cross-sectional view of a valve prosthesis according to an embodiment of the present invention, wherein the radial outer dimension of the skirt gradually decreases in a direction from the outflow end to the inflow end;

[0025] Figure 4 is a schematic axial cross-sectional view of a valve prosthesis according to an embodiment of the present invention, wherein the radial outer dimension of the skirt increases and decreases nonlinearly;

[0026] Figure 5 is a schematic axial cross-sectional view of a skirt according to an embodiment of the present invention;

[0027] Figure 6 is a schematic axial cross-sectional view of a valve prosthesis according to an embodiment of the present invention, wherein the axial cross-section of the skirt is in a teardrop shape.

[0028] In the attached figure:

[0029] 10- support; 100- flow channel; 11- inflow end; 12- outflow end; 20- skirt; 21- inner edge; 22- outer edge; 23- first surface; 24- second surface; 25- third surface; 250- inwardly inclined section; 30- leaflet; 40- swirling cavity; 41- recessed area; 50- native tissue. DETAILED DESCRIPTION

[0030] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0031] As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features. The term "proximal end" is usually the end close to the operator, and the term "distal end" is usually the end close to the patient, that is, the end close to the lesion. "One end" and "the other end" as well as "proximal end" and "distal end" usually refer to two corresponding parts, which not only include the endpoints. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. In addition, as used in the present invention, an element is arranged on another element, which usually only means that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and it cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, an element can be in any position such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The inventors have found that the main body of the valve prosthesis includes an expandable stent, which can be self-expandable or balloon-expandable. Since the stent is often a mesh structure, in order to prevent blood from leaking out of the mesh of the stent, the periphery of the stent is often covered with a skirt. However, the general skirt does not have a good bonding force with the tissue at the implantation site. As described in the background art, it is often easy to form paravalvular leakage, displacement of the valve prosthesis, and other problems.

[0033] Therefore, the object of the present invention is to provide a valve prosthesis to solve the problems existing in the existing valve prosthesis after implantation.

[0034] Please refer to Figure 1 and Figure 2 ,in, Figure 1 is a schematic axial cross-sectional view of a valve prosthesis according to an embodiment of the present invention, Figure 2 yes Figure 1 The embodiment of the present invention provides a valve prosthesis, which includes: a stent 10 and a skirt component; the stent 10 is axially ( Figure 1 The skirt assembly includes at least two skirts 20, the skirt 20 is annular around the stent 10, and the skirt 20 has an inner edge 21 and an outer edge 22. The inner edge 21 is the side of the skirt 20 close to the axis of the stent 10, and the outer edge 22 is the side of the skirt 20 away from the axis of the stent 10. The inner edge 21 is connected to the stent 10, and the outer edge 22 forms a free end. At least two skirts 20 are arranged at intervals along the axial direction of the stent 10, and have different radial outer dimensions. The outer edge 22 of at least one skirt 20 is used to contact the native tissue 50 (referring to the native tissue of the implantation site, such as the native valve ring, etc.). It should be noted here that since the skirt 20 is annular, the inner edge of the ring is the inner edge 21, and the outer contour of the entire skirt 20 is the farthest from the axis of the stent 10, which is the outer edge 22. The radial outer dimension of the skirt 20 refers to the maximum outer dimension of the skirt 20 along the radial direction of the stent 10, that is, the maximum radial dimension of the outer edge 22. In an alternative embodiment, the outer circumference of the skirt 20 is circular, and the radial outer dimension of the skirt 20 is its outer diameter. If the outer circumference of the skirt 20 is polygonal, the radial outer dimension of the skirt 20 is the diameter of its circumscribed circle. The radial outer dimensions of the other components described below are also the same. It should be noted that this embodiment does not limit the outer circumference of the stent 10 and the skirt 20. It can be circular, or it can be elliptical or polygonal according to the shape of the implantation site and the actual process.

[0035] Furthermore, the stent 10 has a through flow channel 100 along its axial direction, and the valve prosthesis further includes a leaflet 30, which is arranged in the flow channel 100 to block the flow of fluid from the outflow end 12 to the inflow end 11 (i.e. Figure 1The stent 10 can provide several functions for the valve prosthesis, including serving as the main structure of the valve prosthesis, supporting the internal leaflets 30, and connecting to the delivery system (hanging ears or fixing ears are provided on the stent 10). Optionally, the stent 10 is formed by weaving or cutting. Optionally, the stent 10 is made of materials such as nickel-titanium, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, or a biocompatible metal frame made of other biocompatible metals known to those skilled in the art, or a laser-cut solid metal tube, preferably nickel-titanium material. The stent 10 can also be made of elastically or plastically deformable materials, which can be applied to balloon expansion scenarios.

[0036] The leaflets 30 dynamically switch between the open and closed states. In the closed state, the leaflets 30 are tightened or converged in a sealed abutment manner. The leaflets 30 can be formed of a suitable material or a combination of materials. In some embodiments, biological tissues such as chemically stable tissues from the heart valves of animals (such as pigs) can be selected, or pericardial tissues of animals such as cows (bovine pericardium), sheep (sheep pericardium), pigs (pig pericardium) or horses (horse pericardium), preferably bovine pericardium tissue. The leaflets 30 can also be made of submucosal tissue of the small intestine. In addition, synthetic materials can also be used for the leaflets 30. For example, expanded polytetrafluoroethylene or polyester. Optionally, the material of the leaflets 30 also includes a combination of one or more of thermoplastic polycarbonate, polyurethane, polyether polyurethane, segmented polyether polyurethane, silicone polyether polyurethane, silicone-polycarbonate polyurethane, and ultra-high molecular weight polyethylene. In addition, the leaflet 30 can also be made of a biocompatible polymer material, such as polyolefins, elastomers, polyethylene glycol, polyethersulfone, polysulfone, polyvinyl pyrrolidone, polyvinyl chloride, other fluorinated polymers, silicone polyesters, siloxane polymers and / or oligomers, and / or polylactones, and a combination of one or more of their block copolymers. Optionally, the leaflet 130 has a surface treated with (or reacted with) an anticoagulant, and the anticoagulant includes but is not limited to a heparinized polymer. Those skilled in the art can reasonably configure the material, structure and size of the leaflet 30 and the stent 10 according to the prior art, such as the invasive artificial heart valve disclosed in the Chinese patent application with publication number CN105726167A, or the heart valve prosthesis disclosed in the Chinese patent application with publication number CN104000672A, etc., all of which are incorporated herein by reference. The valve prosthesis provided in this embodiment can be applied to the aortic valve, pulmonary valve, mitral valve or tricuspid valve. Those skilled in the art can reasonably configure the shape, size, structure, material of the stent 10 and the skirt 20, as well as the number of skirts 20 included in the skirt assembly according to different application sites.

[0037] Please refer to Figure 1 and Figure 2Preferably, the skirt 20 extends from the inner edge 21 to the outer edge 22 gradually toward the inflow end 11. During the systolic period, the blood flow direction is from the inflow end 11 to the outflow end 12 ( Figure 1 At this time, since the annular outer edge 22 of the skirt 20 extends outward, and the outer edge 22 of at least one skirt 20 contacts the native tissue 50, the skirt component can hinder blood flow through the gap between the valve prosthesis and the native tissue 50. Please refer to Figure 2 During the diastole period, blood flows backward from the outflow end 12 to the inflow end 11 ( Figure 2 In the figure, the valvular leaflets 30 are in a closed state, and the backflowing blood cannot pass through the inside of the stent 10. Between the skirt assembly and the native tissue 50, since at least two skirts 20 have different radial outer dimensions, and the outer edge of at least one skirt 20 is used to contact the native tissue 50, even when a small amount of blood flows into the gap between the skirt 20 and the native tissue 50, it will be blocked by the skirts 20 with different radial outer dimensions to form a blood flow low-speed zone. Under long-term action, the effect of blood coagulation is achieved, and endothelialization can be accelerated. Therefore, in addition to blocking the backflow of blood, the skirt assembly can also solidify the backflow blood flowing into the gap between the valve prosthesis and the native tissue 50. At the same time, at least two skirts 20 with different radial outer dimensions arranged axially at intervals increase the roughness of the skirt assembly, which is conducive to the attachment and growth of the native tissue 50, and is conducive to endothelialization, and can effectively increase the friction between the valve prosthesis and the native tissue 50, reducing the risk of displacement of the valve prosthesis after implantation.

[0038] Optionally, the inner edge 21 of the skirt 20 is fixedly connected to the bracket 10 by gluing or sewing. Preferably, the inner edge 21 is connected to the bracket 10 by sewing. For further information, please refer to Figure 2 , the outer edge 22 of the skirt 20 close to the outflow end 12 overlaps with the skirt far away from the outflow end 12. The overlap here means that, of the two adjacent skirts 20, the skirt 20 located on the side close to the outflow end 12 abuts against the skirt 20 on the side far away from the outflow end 12. In particular, the abutment here is not fixedly connected. A small amount of blood flow can pass through the gap where the two abut. Furthermore, the axially adjacent skirts 20 and the stent 10 are enclosed to form a vortex cavity 40. The shape of the vortex cavity 40 is irregular. The vortex cavity 40 is connected to the aforementioned gap. When a small amount of blood flows through the gap into the vortex cavity 40, a low-speed blood flow zone will be formed, which is conducive to blood coagulation in the low-speed zone, reduces paravalvular leakage, and accelerates endothelialization.

[0039] Please refer to Figure 1 and Figure 3In some embodiments, along the direction from the outflow end 12 to the inflow end 11, the radial outer dimensions of at least two of the skirts 20 increase or decrease in sequence. Such a configuration reduces the overall gripping dimensions of the valve prosthesis compared to a conventional valve prosthesis (with unchanged upper and lower skirt dimensions), thereby reducing damage to the human body during the implantation process. Figure 1 As shown in FIG. 1 , when the heart contracts, the larger skirt 20 blocks the blood from passing through the gap between the native tissue 50 and the valve prosthesis. When the heart relaxes, the backflowing blood enters between the multiple skirts 20 to form a low-speed area, which is beneficial to reducing paravalvular leakage. When the radial dimensions of the multiple skirts 20 decrease in sequence along the direction from the outflow end 12 to the inflow end 11 (as shown in FIG. 1 ), the larger skirt 20 blocks the blood from passing through the gap between the native tissue 50 and the valve prosthesis. When the heart relaxes, the backflowing blood enters between the multiple skirts 20 to form a low-speed area, which is beneficial to reducing paravalvular leakage. Figure 3 As shown in FIG. 1 , when the heart contracts, the blood ejected from the ventricle enters between the multiple skirts 20 and the swirling cavity 40, forming a low-velocity blood zone, accelerating endothelialization; when the heart relaxes, the larger skirt 20 blocks the backflow of blood, which is beneficial to reducing paravalvular leakage.

[0040] Furthermore, the skirt assembly includes a plurality of the skirts 20, and the radial outer dimensions of the plurality of skirts 20 have the same rate of change along the direction from the outflow end 12 to the inflow end 11. The same rate of change of the radial outer dimensions of the plurality of skirts 20 means that the radial outer dimensions of the plurality of skirts 20 change linearly, so that the skirt assembly is truncated cone-shaped as a whole. The linear change configuration allows the force to change uniformly during the release process of the valve prosthesis. At the same time, after the valve prosthesis is implanted, the speed of the refluxed blood changes uniformly along the skirt 20, which is conducive to endothelialization. Of course, in other embodiments, the rate of change of the radial outer dimensions of the plurality of skirts 20 may also be different, for example, the skirt assembly may be formed into a trumpet shape as a whole.

[0041] Please refer to Figure 4In some other embodiments, the skirt assembly includes a plurality of skirts 20, and the radial outer dimensions of the plurality of skirts 20 increase or decrease nonlinearly along the direction from the outflow end 12 to the inflow end 11. The nonlinear increase or decrease here means that among the radial outer dimensions of the plurality of skirts 20 arranged along the axial direction of the stent 10, the radial outer dimension of at least one skirt 20 located in the middle is greater than or less than the radial outer dimensions of the skirts 20 located on both sides of the axial direction. It can be understood that to form a nonlinear increase or decrease, the skirt assembly needs to include at least three skirts 20. For example, if the skirt assembly includes three skirts 20, the radial outer dimension of the skirt 20 located in the middle is greater than or less than the radial outer dimension of the skirts 20 located on both sides of the axial direction, so that the skirt assembly as a whole can be in a gourd shape or drum shape with a concave and convex shape. Further, when the skirt assembly includes a larger number of skirts 20, the shape of the concave and convex shape is not limited to one, and each concave and convex shape is not limited to being composed of only one skirt 20. For example, the skirt assembly as a whole can present a convex and concave wave shape. It should also be noted that in some examples, the radial outer dimensions of two skirts 20 adjacent to each other along the axial direction of the stent 10 may also be the same. Taking the skirt assembly including four skirts 20 as an example, the radial outer dimensions of the two skirts 20 located in the middle may be equal, and both are smaller or larger than the radial outer dimensions of the two skirts 20 located at both ends of the axial direction. Preferably, among the multiple skirts 20 with nonlinear increase and decrease in radial dimensions, at least two larger-sized skirts 20 are in contact with the native tissue 50. Such a configuration increases the contact area between the valve prosthesis and the native tissue 50, improves the anchoring force of the valve prosthesis, reduces the risk of displacement of the valve prosthesis, and is conducive to tissue attachment and growth, accelerating endothelialization. At the same time, a recessed area 41 is formed between adjacent large-sized skirts 20, which cooperates with the vortex cavity 40 formed between adjacent skirts 20 to more effectively reduce the blood flow rate and cause the blood flow to form turbulence and coagulation.

[0042] Preferably, the skirt 20 includes a first surface 23 and a second surface 24 connected to each other, the first surface 23 and the second surface 24 intersect to form the inner edge 21; along the inner edge 21 toward the outer edge 22, the first surface 23 and the second surface 24 gradually move away from each other. The first surface 23 and the second surface 24 extend outward from the inner edge 21 and gradually move away from each other, so that the skirt 20 gradually thickens outward from the inner edge 21. The thickness of the skirt 20 is relatively thin at a position close to the stent 10, and the thickness gradually increases at a position away from the stent 10, so that the periphery of the valve prosthesis can form a progressive layered shape, increase the roughness of the periphery, facilitate the attachment and growth of the native tissue 50, facilitate endothelialization, and effectively increase the friction between the valve prosthesis and the native tissue 50, reducing the risk of displacement of the valve prosthesis after implantation. It should be noted that the first surface 23 and the second surface 24 gradually move away from each other, and are not limited to expanding linearly, and their expansion rates are not limited to being the same, that is, the first surface 23 and the second surface 24 are not limited to being planes, and at least one of them can also be in the form of a curved surface or a folded surface.

[0043] Please refer to Figure 2 and Figure 5 Further, the skirt 20 further includes a third surface 25, the third surface 25 is connected to the first surface 23 and the second surface 24 respectively, the first surface 23, the second surface 24 and the third surface 25 are enclosed to form the skirt 20, and the outer edge 22 is located on the third surface 25. The third surface 25 is connected to the first surface 23 and the second surface 24 at one end away from the inner edge 21, respectively, and envelops and closes the first surface 23 and the second surface 24 to form the skirt 20. This embodiment does not limit the shape of the third surface 25, which can be as follows Figure 2 The plane shown can also be Figure 5 It is understandable that the outer edge 22 can be located at the intersection of the third surface 25 and the first surface 23 and the second surface 24, or can be located at the middle part of the third surface 25.

[0044] Preferably, the third surface 25 includes an inwardly inclined section 250, the inwardly inclined section 250 extends from the outer edge 22 toward the inflow end 11, and the inwardly inclined section 250 is inwardly inclined toward the axial direction of the bracket 10. Figure 2 In the illustrated example, the third surface 25 is a plane, and the entire third surface 25 is configured as an inwardly inclined section 250, and the outer edge 22 is located at the intersection of the third surface 25 and the first surface 23. The third surface 25 is inclined inwardly from the outflow end 12 to the inflow end 11, gradually approaching the axis of the bracket 10. Figure 6In the illustrated example, the third surface 25 is a curved surface, and the outer edge 22 is located in the middle of the third surface 25, that is, the third surface 25 is convex outward, and the inwardly inclined section 250 is a part of the third surface 25. The inwardly inclined section 250 is provided so that when the blood flows through the outer side of the inwardly inclined section 250, turbulence is formed and the flow rate is slowed down, which is conducive to coagulation.

[0045] Please refer to Figure 1 and Figure 2 In an alternative exemplary embodiment, the cross-section of the skirt 20 along its own annular extension direction is triangular; the inner edge 21 is located at one corner of the triangle, and the outer edge 22 is located at the side of the triangle opposite to the corner. If the cross-section of the skirt 20 is triangular, the manufacturing of the skirt 20 is simple, and the effect of the manufactured skirt assembly is also better. At this time, the cross-sectional shape of the vortex cavity 40 formed by the skirt 20 and the bracket 10 is also roughly triangular, which can effectively reduce the blood flow rate and cause the blood flow to form turbulence and coagulation. It should be understood that the triangle here is not limited to a triangle in a narrow sense, but should be broadly understood as a shape roughly having three sides, such as a rounded triangle, a triangle formed by three arc sides, etc.

[0046] Please refer to Figure 5 and Figure 6 In another alternative exemplary embodiment, the first surface 23, the second surface 24 and the third surface 25 form a smoothly transitioned curved surface, so that the cross section of the entire skirt 20 along its own annular extension direction is teardrop-shaped. In addition to reducing paravalvular leakage and accelerating endothelialization, the skirt 20 can also reduce damage to tissue when in contact with tissue due to its smooth edge.

[0047] Optionally, the material of the skirt 20 includes knitted, woven or braided fabric. Preferably, it is made of polyester fabric. Preferably, the material of the skirt 20 includes PTFE and / or ePTFE.

[0048] In summary, the valve prosthesis provided by the present invention includes: a stent and a skirt assembly; the stent has an inflow end and an outflow end relative to each other along its own axial direction; the skirt assembly includes at least two skirts, the skirt is annular around the stent, the skirt has an inner edge and an outer edge, the inner edge is the side of the skirt close to the axis of the stent, and the outer edge is the side of the skirt away from the axis of the stent; the inner edge is connected to the stent, and the outer edge forms a free end; at least two of the skirts are arranged at intervals along the axial direction of the stent, and have different radial outer dimensions; the outer edge of at least one of the skirts is used to contact native tissue. With such a configuration, during cardiac systole, the skirt assembly can block blood flow through the gap between the valve prosthesis and tissue, and during cardiac diastole, the skirt assembly can block blood backflow. Since at least two skirts have different radial outer dimensions, and the outer edge of at least one skirt is used to contact the native tissue, even when a small amount of blood flows into the gap between the skirt and the native tissue, it will be blocked by the skirts with different radial outer dimensions to form a low-speed blood flow area, which is conducive to blood coagulation in the low-speed area, reducing paravalvular leakage and accelerating endothelialization. At the same time, at least two skirts with different radial outer dimensions arranged axially increase the roughness of the skirt component, which is conducive to tissue attachment and growth, endothelialization, and can effectively increase the friction between the valve prosthesis and the tissue, reducing the risk of displacement of the valve prosthesis after implantation.

[0049] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the claims.

Claims

1. A valve prosthesis, characterized in that: include: Bracket and skirt assembly; The support has an inflow end and an outflow end opposite to each other along its axial direction; The skirt assembly includes at least two skirts, the skirts are annularly surrounding the bracket, and the skirts have an inner edge and an outer edge, the inner edge is a side of the skirt close to the axis of the bracket, and the outer edge is a side of the skirt away from the axis of the bracket; the inner edge is connected to the bracket, and the outer edge forms a free end; the skirt extends from the inner edge to the outer edge gradually and obliquely toward the direction of the inflow end; At least two of the skirts are arranged at intervals along the axial direction of the stent and have different radial outer dimensions; the outer edge of at least one of the skirts is used to contact native tissue; The skirt edge close to the outflow end overlaps the adjacent skirt edge far from the outflow end, and the two axially adjacent skirt edges and the bracket enclose a swirling cavity.

2. The valve prosthesis according to claim 1, characterized in that: Along the direction from the outflow end to the inflow end, radial outer dimensions of at least two of the skirts increase or decrease sequentially.

3. The valve prosthesis according to claim 2, characterized in that: The skirt assembly includes a plurality of skirts, and along the direction from the outflow end to the inflow end, the radial outer dimensions of the plurality of skirts have a same changing rate.

4. The valve prosthesis according to claim 1, characterized in that: The skirt assembly includes a plurality of skirts, and radial outer dimensions of the plurality of skirts increase or decrease nonlinearly along a direction from the outflow end to the inflow end.

5. The valve prosthesis according to claim 1, characterized in that: The skirt includes a first surface and a second surface connected to each other, wherein the first surface intersects with the second surface to form the inner edge; along the direction from the inner edge to the outer edge, the first surface and the second surface gradually move away from each other.

6. The valve prosthesis according to claim 5, characterized in that: The skirt also includes a third surface, and the third surface is connected to the first surface and the second surface respectively. The first surface, the second surface and the third surface are enclosed to form the skirt, and the outer edge is located on the third surface.

7. The valve prosthesis according to claim 6, characterized in that: The third surface includes an inwardly inclined section, the inwardly inclined section extends from the outer edge toward the inflow end, and the inwardly inclined section is inwardly inclined toward the axial direction of the bracket.

8. The valve prosthesis according to claim 6, characterized in that: The first surface, the second surface and the third surface form a smoothly transitioned curved surface.

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