Scaffolds and valve prostheses for valve implants

Abstract

This invention relates to a stent for a valve prosthesis and the valve prosthesis itself. The valve prosthesis includes an artificial leaflet, a skirt, and a stent. The artificial leaflet is fixed within the lumen of the stent, and the skirt covers the inner and / or outer surfaces of the stent. The stent has a profile adapted to the native valve annulus, and includes a first leaflet portion, a commissure portion, and a second leaflet portion distributed circumferentially. The commissure portion is located between the first and second leaflet portions. The height of both the first and second leaflet portions is greater than the height of the commissure portion, so that the inflow end of the stent has a shape that is high at both ends and low in the middle. The stiffness of both the first and second leaflet portions is less than the stiffness of the commissure portion. This ensures that the valve prosthesis can dynamically adapt to the native valve annulus during cardiac systole and diastole, improving the lifespan of the valve prosthesis and reducing its impact on ventricular remodeling.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a stent for a valve prosthesis and a valve prosthesis. Background Technology

[0002] The heart has 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. The atria and ventricles form the ventricular inflow port, the left ventricle and the aorta form the left ventricular outflow port, and the right ventricle and the pulmonary artery form the right ventricular outflow port. At the ventricular inflow and outflow ports are valves that function as one-way valves, ensuring normal blood flow within the heart chambers. When these valves malfunction, cardiac hemodynamics change, and cardiac function becomes abnormal; this is called valvular heart disease.

[0003] With socioeconomic development and population aging, the incidence of valvular heart disease has increased significantly. Studies show that the incidence rate in people over 75 years old is as high as 13.3%. Currently, traditional surgical treatment remains the first-line treatment for patients with severe valvular disease. However, for elderly patients, those with multiple organ diseases, those with a history of open-heart surgery, and those with poor cardiac function, traditional surgery carries high risks and mortality rates, and some patients may not even have the opportunity to undergo surgery. Transcatheter valve replacement / repair has advantages such as not requiring open-heart surgery, minimal trauma, and rapid patient recovery, and has received widespread attention from experts and scholars. However, after implantation, existing valve prostheses are too rigid. During heartbeat, the native tissue compresses the valve prosthesis, affecting its lifespan. Simultaneously, the reaction force of the valve prosthesis on the heart affects ventricular remodeling, leading to poor ventricular compliance and heart failure. Furthermore, existing valve prostheses alter intraventricular hemodynamics, increasing intraventricular energy consumption and cardiac workload, thus contributing to heart failure.

[0004] Therefore, for those skilled in the art, designing a valve prosthesis that can dynamically adapt to the native valve annulus during cardiac systole and diastole is a problem that urgently needs to be solved.

[0005] It should be noted that the information disclosed in the background section of this application is intended to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a stent and a valve prosthesis for use in valve prostheses, in order to solve the problem that existing valve prostheses cannot dynamically adapt to the movement of the native valve annulus during heartbeat, thereby affecting their service life and ventricular remodeling.

[0007] To achieve the above objectives, the present invention provides a stent for a valve prosthesis, the stent having a profile adapted to the original valve annulus, and the stent comprising a first leaflet portion, a commissure portion, and a second leaflet portion distributed circumferentially thereon, the commissure portion being located between the first leaflet portion and the second leaflet portion, the height of the first leaflet portion and the height of the second leaflet portion being greater than the height of the commissure portion, so that the inflow end of the stent presents a shape that is high at both ends and low in the middle, and the stiffness of the first leaflet portion and the stiffness of the second leaflet portion being less than the stiffness of the commissure portion.

[0008] In one embodiment, the height of the first leaflet is greater than the height of the second leaflet.

[0009] In one embodiment, the distance from the first leaflet to the center of the connecting portion is L1, the distance between the first leaflet and the second leaflet is L2, and L1 / L2≥0.5.

[0010] In one implementation, L1 / L2 ≤ 0.8.

[0011] In one implementation, L1 / L2 = 0.75.

[0012] In one embodiment, the support is a one-piece molded structure or at least partially a split molded structure.

[0013] In one embodiment, the inflow end of the bracket is connected to a flange, the outer diameter of which is larger than the outer diameter of the connection between the flange and the inflow end, and / or, at least one anchor is provided on the outer surface of the bracket away from the inflow end.

[0014] Furthermore, based on the same inventive concept, the present invention also provides a valve prosthesis, including an artificial leaflet, a skirt, and a stent for the valve prosthesis as described in any one of the above, wherein the artificial leaflet is fixed in the inner cavity of the stent, and the skirt covers the inner surface and / or outer surface of the stent.

[0015] In one embodiment, the artificial valve leaflet includes a first leaflet and a second leaflet, the first leaflet being larger in size than the second leaflet, and when the artificial valve leaflet is open, the blood flow channel formed by the first leaflet is larger in size than the blood flow channel formed by the second leaflet.

[0016] In one embodiment, when the artificial leaflet closes, the distance from the first leaflet to the center of the merging portion is greater than the distance from the second leaflet to the center of the merging portion, and the height of the first leaflet is equal to the height of the second leaflet; or, when the artificial leaflet closes, the distance from the first leaflet to the center of the merging portion is equal to the distance from the second leaflet to the center of the merging portion, and the height of the first leaflet is greater than the height of the second leaflet.

[0017] Compared with the prior art, the stent and valve prosthesis provided by the present invention have at least the following beneficial effects:

[0018] The stent has a contour adapted to the native valve annulus, and a first leaflet, commissure, and second leaflet that are adapted to the saddle-like shape of the native valve annulus. This enhances the fit between the valve prosthesis and the native valve annulus. Furthermore, the first leaflet, commissure, and second leaflet are matched with different stiffnesses, thus ensuring that the valve prosthesis can dynamically adapt to the native valve annulus during cardiac systole and diastole. This improves the lifespan of the valve prosthesis and reduces its impact on ventricular remodeling.

[0019] Furthermore, by limiting the distance from the center of the first leaflet to the commissure, the stent can support the asymmetrically designed artificial leaflet, thereby forming blood flow channels of different sizes to obtain vortices similar to the original blood flow in the human body, thereby reducing blood flow energy dissipation, improving the heart's pumping efficiency, and reducing the risk of heart failure. Attached Figure Description

[0020] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0021] Figure 1 This is a schematic diagram of the overall structure of a valve prosthesis provided according to an embodiment of the present invention;

[0022] Figure 2a This is a side view of the stent in a valve prosthesis provided according to an embodiment of the present invention;

[0023] Figure 2b This is a schematic diagram of the end face of the stent in the valve prosthesis provided according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the motion state of the original valve annulus during contraction and relaxation;

[0025] Figure 4a and Figure 4b This is a schematic diagram of a structure with relatively low stiffness for the first and second leaflets according to an embodiment of the present invention.

[0026] Figure 5a and Figure 5b This is a schematic diagram of a structure with high rigidity for the connecting part according to an embodiment of the present invention;

[0027] Figure 6 This is a structural schematic diagram of the bracket with flanges and anchors provided according to an embodiment of the present invention;

[0028] Figure 7a It is the flow state of blood when the native mitral valve is open;

[0029] Figure 7b It refers to the blood flow state when a mechanical valve is implanted;

[0030] Figure 7c It refers to the blood flow state when a symmetrically designed bioprosthetic valve is implanted;

[0031] Figure 8a This describes the blood flow state when using the valve prosthesis provided in this embodiment of the invention; the arrow indicates the direction of blood flow.

[0032] Figure 8b This is a schematic diagram of the end face of a valve prosthesis provided according to an embodiment of the present invention;

[0033] Figure 9 The arrows indicate the blood flow state when the valve prosthesis provided in the embodiment of the present invention uses artificial valve leaflets of different heights. Detailed Implementation

[0034] To make the content of this invention clearer and easier to understand, the invention will be further described below with reference to the accompanying drawings. Of course, this invention is not limited to the specific embodiments provided below, and common substitutions well known to those skilled in the art are also covered within the scope of protection of this invention.

[0035] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in this application are also intended to include the plural forms unless the context clearly indicates otherwise. It should be understood that words such as “a” or “one” do not indicate a quantity limitation, but rather indicate the presence of at least one; “a plurality” indicates two or more. Words such as “comprising” or “including” mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. Furthermore, the present invention has been described in detail using schematic diagrams, but these diagrams are only for the purpose of elaborating on examples of the invention and should not be construed as limiting the invention.

[0036] In this application, "circumferential" refers to the circumferential direction of the valve prosthesis; "radial" refers to the diametrical direction of the valve prosthesis; "axial" refers to the axial direction of the valve prosthesis, which is perpendicular to the radial direction; the term "height" refers to the dimension along the axial direction of the stent, and "distance" refers to the dimension along the radial direction of the stent; the terms "inflow end" and "outflow end" are defined as the position of the valve prosthesis relative to the original valve annulus after implantation. Following the normal blood flow direction, "inflow end" is the end where blood flows into the valve prosthesis, and "outflow end" is the end where blood flows out of the valve prosthesis. In this application, "inner surface" refers to the side closer to the axis of the valve prosthesis, and "outer surface" refers to the side farther from the axis of the valve prosthesis.

[0037] The purpose of this invention is to provide a stent and a valve prosthesis for use in valvular prostheses, at least to solve the problem that existing valve prostheses cannot dynamically adapt to the movement of the native valve during heartbeats, thus affecting their lifespan and ventricular remodeling.

[0038] The following description is in conjunction with the accompanying drawings. The valve prosthesis provided by this invention is suitable for mitral or tricuspid valves. The embodiments described below use the mitral valve as an example.

[0039] like Figure 1 As shown, an embodiment of the present invention provides a valve prosthesis 100, including a stent 110, an artificial leaflet 120, and a skirt 130.

[0040] Artificial valve leaflet 120 is fixed within the lumen of stent 110. Artificial valve leaflet 120 comprises at least two leaflets. Artificial valve leaflet 120 dynamically switches between open and closed states. In the closed state, the leaflets are tightly closed or joined in a sealing manner. Artificial valve leaflet 120 can be made of biological tissue, such as chemically stable tissue from animal (e.g., pig) heart valves, or pericardial tissue from animals such as cattle (bovine pericardium), sheep (sheep pericardium), pigs (pig pericardium), or horses (equine pericardium), preferably bovine pericardial tissue. Artificial valve leaflet 120 can also be made from submucosal tissue of the small intestine. Artificial valve leaflet 120 is used to replace the native valve for opening and closing movements and to control the direction of blood flow.

[0041] The skirt 130 can cover the inner surface of the stent 110, or the outer surface of the stent 110, or both the inner and outer surfaces of the stent 110 can be covered with the skirt 130. The skirt 130 has a sealing function, which can prevent paravalvular leakage and better ensure that the blood flows through a single channel from the inflow end to the outflow end of the valve prosthesis 100. The inflow end of the valve prosthesis 100 is usually designed to conform to the shape of the native tissue. The skirt 130 is circumferentially provided on the outer side of the inflow end at the junction with the native tissue, which can effectively prevent paravalvular leakage. The skirt 130 is made of biomaterials, specifically, it can be made of knitted, woven, or braided polyester fabric, or polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), or animal pericardial material.

[0042] The stent 110 has a contracted state for delivery and an deployed state for deployment, and can dynamically switch between the two states. The stent 110 is a cylindrical structure that provides several functions for the valve prosthesis 100, including: serving as the main structure of the artificial leaflet 120, supporting the internal leaflet; and being able to connect to a delivery system for manipulation to achieve functions such as delivery and release. The stent body 110 can be detachably connected to the delivery system via its own connecting structures such as lugs or fixing lugs. The stent 110 can be woven or cut. The stent 110 is made of materials such as nickel-titanium, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, or other biocompatible metals known to those skilled in the art, with nickel-titanium being preferred. Elastic or malleable polymer materials, such as balloon-expandable materials, can also be used to fabricate the stent 110.

[0043] like Figure 2a and Figure 2b As shown, the stent 110 has different heights in its circumferential direction to mimic the shape of the original valve annulus. Given that the original valve annulus is saddle-shaped, to enhance the fit between the valve prosthesis 100 and the original valve annulus, the stent 110 is designed as a three-dimensional D-shape to maximize the mimicry of the original valve annulus's shape. Specifically, the stent 110 includes a first leaflet portion 111, a connecting portion 112, and a second leaflet portion 113 distributed circumferentially. The connecting portion 112 is located between the first leaflet portion 111 and the second leaflet portion 113, corresponding to the position where adjacent leaflets meet.

[0044] In one aspect, such as Figure 2aAs shown, the height of the first leaflet 111 is H1, the height of the commissure 112 is H2, and the height of the second leaflet 113 is H3. The relationship between H1, H2, and H3 is H1 ≥ H3 > H2, so that the support 110 presents a shape that is high at both ends and low in the middle. On the other hand, the first leaflet 111, the commissure 112, and the second leaflet 113 form a contour in the circumference of the support 110 that conforms to the original valve annulus, that is, a D-shaped contour, which is basically consistent with the outer contour of the original valve annulus. Specifically, as Figure 2b As shown, when viewed along the axial direction, the overall outline of the bracket 110 in the circumferential direction presents a D-shape.

[0045] Furthermore, considering the dynamic changes of the native valve annulus after implantation, the stiffness of the commissure 112 is greater than that of the first leaflet 111 and the second leaflet 113. This ensures that the dynamic changes of the commissure 112 during cardiac systole and diastole are less than those of the first leaflet 111 and the second leaflet 113. This enhances the fit between the valve prosthesis 100 and the native valve annulus, ensuring that the valve prosthesis 100 can dynamically adapt to the native valve annulus during cardiac systole and diastole. It also reduces the interaction forces between the native tissue and the valve prosthesis 100, thereby increasing the lifespan of the valve prosthesis 100 and minimizing its impact on ventricular remodeling.

[0046] You can also refer to Figure 3 Understand the dynamic changes of the original valve ring. Figure 3 This diagram illustrates the motion of the original mitral valve annulus during systole and diastole. A represents the anterior leaflet, P the posterior leaflet, and CC the leaflet commissure of the original mitral valve annulus. Figure 3 It is known that when the native valve moves from diastole to systole, the native valve annulus moves from the left atrium to the left ventricle. The amplitude of movement of the anterior leaflet A and the posterior leaflet P is greater than that of the leaflet commissure CC of the native mitral valve annulus. Furthermore, the anterior leaflet A and the posterior leaflet P contract in opposite directions, which is beneficial for the closure of the native valve and reduces regurgitation. However, in existing technologies, the structure of valve prostheses has not been well matched to the native valve annulus, nor has the dynamic movement process of the native valve annulus been considered. When the valve prosthesis 100 is implanted, the compression of the artificial valve leaflets by the native tissue during cardiac systole and diastole can easily lead to premature failure of the artificial valve leaflets. Simultaneously, the reaction force of the artificial valve leaflets on the heart can also affect ventricular remodeling, resulting in poor ventricular compliance and leading to heart failure. However, the valve prosthesis 100 provided in this invention can effectively overcome the defect of existing valve prostheses that cannot dynamically adapt to the native valve annulus.

[0047] Preferably, H1 > H3 > H2, which can better match the original valve annulus and better adapt to the movement of the original valve, resulting in better performance.

[0048] It should be noted that there are multiple ways to make the support 110 have different stiffnesses in the circumferential direction, and at least one of them can be selected to implement this. In practice, the different stiffnesses of the support 110 in the circumferential direction can be ensured by materials and / or structure. The following is an illustrative description.

[0049] In one example, at least one of the first leaflet 111 and the second leaflet 113 adopts... Figure 4a The first structural unit 110a shown is designed to provide relatively low stiffness in the axial direction. The first structural unit 110a typically employs a quadrilateral mesh, including a rhomboid mesh, which allows for good deformation. Multiple first structural units 110a are provided, arranged sequentially along the circumference of the support 110.

[0050] In another example, at least one of the first leaflet 111 and the second leaflet 113 adopts Figure 4b The helical structure 110b shown also provides relatively low stiffness in the axial direction. The helical structure 110b is formed by helically winding the primary structure and is expandable. Multiple helical units 110b are arranged sequentially along the circumference of the support 110.

[0051] In one example, the connecting part 112 adopts... Figure 5a The grid structure 110c shown provides significant axial stiffness. Typically, one grid structure 110c is used, but there is no limitation to having more than one. The grid structure 110c is a mesh structure composed of a series of intersecting strips of material.

[0052] In another example, the connecting part 112 adopts Figure 5b The second structural unit 110d shown, although employing a diamond-shaped mesh, also features a structural reinforcement that runs through all the diamond-shaped meshes in the axial direction, enhancing its rigidity. There is at least one second structural unit 110d.

[0053] However, it should be understood that the stiffness of various parts of the support can also be adjusted by changing the distribution density and size of the mesh, or by using other methods that can be recognized by those skilled in the art, such as selecting materials with low elastic modulus. This application does not limit this.

[0054] The support 110 can be manufactured as a single piece, or the first leaf 111, the second leaf 113 and the connecting part 112 can be manufactured separately and then assembled together, or the support 110 can be a split-type structure.

[0055] Furthermore, to address the problem that existing valve prostheses can easily alter intracardiac hemodynamics after implantation, this invention proposes an improved solution. For ease of understanding, the intracardiac blood flow state will first be explained.

[0056] like Figure 7a As shown, for the native mitral valve, since the native mitral valve is a dynamic saddle-shaped valve annulus and the two leaflets are asymmetrically designed with the anterior leaflet being larger than the posterior leaflet, when the mitral valve opens, it is conducive to the formation of a flow vortex A1 towards the aortic valve. The formation of vortex A1 can maintain the kinetic energy of the blood flow and eject it from the heart during ventricular contraction, reducing the dissipation of blood kinetic energy.

[0057] like Figure 7b As shown, if a bileaflet mechanical valve is used for replacement, when the bileaflet mechanical valve opens, it has three openings. The blood flow velocity is faster near the opening of the aortic valve, forming a vortex A2 towards the mechanical valve, which is exactly opposite to the direction of the vortex A1 formed by the original mitral valve. This changes the intraventricular hemodynamics, increases blood kinetic energy consumption, increases cardiac load, and increases the risk of heart failure.

[0058] like Figure 7c As shown, if a bioprosthetic valve is used for replacement, and bioprosthetic valves are mostly symmetrical structures, when the bioprosthetic valve opens, the blood flowing into the left ventricle (LV) will form two vortices A3 and A4 together with the surrounding blood with a lower flow velocity. The direction of one of the vortices A4 is exactly opposite to the direction of the vortex A1 formed by the original mitral valve, which also disperses the blood flow energy, increases the energy consumption, increases the cardiac load, and increases the risk of heart failure.

[0059] In response to the above issues, such as Figure 2b As shown, a distance L1 is defined from the center of the first leaflet 111 to the center of the commissure 112, so that the stent 110 can support the asymmetrically designed artificial leaflet 120, thereby forming blood flow channels of different sizes. Specifically, the distance from the center of the first leaflet 111 to the center of the commissure 112 is L1, and the distance between the first leaflet 111 and the second leaflet 113 is L2, where L1 / L2 ≥ 0.5. More preferably, L1 / L2 is 0.5 to 0.8, such as a ratio of 0.5, 0.6, 0.75, or 0.8. Even more preferably, L1 / L2 = 0.75, which is closer to the anatomical structure of the original valve. The position of the commissure 112 changes with the ratio of L1 to L2.

[0060] Accordingly, such as Figures 8a-8b and Figure 9 As shown, in a preferred embodiment of the present invention, the artificial valve leaflet 120 has an asymmetrical structure. After being fixedly connected with the stent 110, it can form blood flow channels of different sizes, thereby obtaining a vortex similar to the original blood flow of the human body, reducing blood flow energy dissipation, improving the heart's pumping efficiency, and reducing the risk of heart failure.

[0061] It should be understood that each leaflet in the artificial leaflet 120 includes a leaflet connecting portion, a leaflet fixing portion, and a leaflet free portion. One end of the free portion is connected to one end of the leaflet fixing portion through the leaflet connecting portion, and the other end of the free portion is connected to the other end of the leaflet fixing portion through another leaflet connecting portion. The leaflet fixing portion is generally arc-shaped or quasi-arc-shaped. Multiple leaflets are always in contact with each other at the leaflet connecting portion. The free portion of the leaflet is an arc-shaped protrusion away from the leaflet fixing portion, or an arc-shaped protrusion towards the leaflet fixing portion, or a straight shape. Both the leaflet connecting portion and the leaflet fixing portion of the leaflet need to be fixedly connected to the support 110. When the artificial leaflet 120 is closed, the free portions of each leaflet are tightly closed or meet in a sealing manner. When the artificial leaflet 120 is opened, the free portions of each leaflet open in a way that moves away from each other, allowing blood to pass through.

[0062] like Figure 8a As shown, the artificial leaflet 120 is fixedly connected to the first leaflet portion 111, the connecting portion 112, and the second leaflet portion 113 of the support 110. The connection between the artificial leaflet 120 and the support 110 can be achieved by means of sewing, bonding, or integral molding.

[0063] like Figure 8b As shown, the artificial valve leaflet 120 employs an asymmetrical leaflet design, comprising a first leaflet 121 and a second leaflet 122. The size of the first leaflet 121 is larger than that of the second leaflet 122. This can be understood as follows: when the leaflets are flattened, the planar dimension of the first leaflet 121 is larger than that of the second leaflet 122. With this configuration, when the artificial valve leaflet 120 opens, the blood flow channel formed by the first leaflet 121 is larger than that formed by the second leaflet 122. This allows blood flow to form a vortex (A1) towards the aortic valve, similar to the natural blood flow in the human body. This reduces blood flow energy dissipation and improves the heart's pumping efficiency.

[0064] It should be understood that in the application scenario of the mitral valve, the artificial leaflet 120 includes a first leaflet 121 and a second leaflet 122, while in the application scenario of the tricuspid valve, the artificial leaflet 120 includes a first leaflet 121 and two second leaflets 122. The first leaflet 121 is connected to the first leaflet portion 111 and the commissural portion 112, and the second leaflets 122 are connected to the second leaflet portion 113 and the commissural portion 112.

[0065] like Figure 8a and Figure 8bAs shown, similar to the stent 110, the distance from the center of the first leaflet 121 to the junction 112 is L1, and the distance between the first leaflet 121 and the second leaflet 122 is L2, where L1 / L2 is greater than 1 / 2. In this case, the distance from the center of the second leaflet 122 to the junction 112 is less than L1. Furthermore, when the artificial valve 120 is closed, the heights of the first leaflet 121 and the second leaflet 122 in the axial direction of the stent 110 are equal. This allows for an asymmetrical design of the artificial valve 120, resulting in a larger blood flow channel for the first leaflet 121 than for the second leaflet 122 when the artificial valve 120 is open.

[0066] like Figure 9 As shown, in another example, L1 / L2 = 1 / 2. In this case, the distance from the second leaflet 122 to the center of the connecting part 112 is also L1. The difference is that when the artificial leaflet 120 is closed, the heights of the first leaflet 121 and the second leaflet 122 in the axial direction of the stent 110 are not equal. The height of the first leaflet 121 is h1, and the height of the second leaflet 122 is h2, where h1 > h2, and the height difference between the two is h. In this way, the asymmetrical design of the artificial leaflet 120 can also be achieved, so that when the artificial leaflet 120 is opened, the blood flow channel of the first leaflet 121 is larger than that of the second leaflet 122. This is equivalent to the first leaflet 121 having a greater blood flow channel than the second leaflet 122 by a height difference h.

[0067] Next, refer to Figure 6 In one example, the inflow end of the stent 110 is connected to a flange 114. When the valve prosthesis 100 deploys, the flange 114 is used to closely adhere to the native tissue, further preventing paravalvular leakage and improving anchoring performance. The outer diameter of the flange 114 is larger than the outer diameter of the connection between the flange 114 and the inflow end of the stent 110, allowing the outer surface of the flange 114 to closely adhere to the native valve annulus and leaflets. The edge of the flange 114 can closely adhere to the inner wall of the left atrium, serving a limiting and sealing function to prevent the valve prosthesis 100 from sliding towards the left ventricle. The outer diameter at the edge of the flange 114 is the maximum diameter of the flange 114, and the outer diameter at the connection between the flange 114 and the stent 110 is the minimum diameter of the flange 114. The flange 114 is relatively flexible and easily compressed and deformed.

[0068] Continue to refer to Figure 6 In one example, at least one anchor 115 is disposed on the outer surface of the stent 110 away from the inflow end. The anchor 115 can grasp native structures (such as native leaflets) when the valve prosthesis 100 is deployed, which is beneficial for fixing the valve and native tissue. The specific location of the anchor 115 on the stent 110 is not limited, nor is the number of anchors 115 limited. The anchor 115 can have various configurations, and at least one structure can be selected to implement it, such as barbs, hooks, anchors, elongated members, etc.

[0069] The delivery method of the valve prosthesis 100 in this embodiment of the invention is not limited. Common delivery methods include delivery via the femoral artery, via the apex of the heart, and via the jugular vein.

[0070] In summary, compared with the prior art, the valve prosthesis and stent provided by the present invention have at least the following advantages:

[0071] (1) A three-dimensional D-shaped stent is adopted to adapt the structure of the stent to the structure of the original valve annulus. Furthermore, different parts of the stent are matched with different stiffnesses to ensure that the valve prosthesis can dynamically adapt to the original valve annulus during the heart's contraction and relaxation process, thereby improving the lifespan of the valve prosthesis and reducing the impact of the valve prosthesis on ventricular remodeling.

[0072] (2) Asymmetrically designed artificial valve leaflets are used to form blood flow channels of different sizes, thereby obtaining a vortex similar to the original blood flow of the human body, thereby reducing blood flow energy dissipation, improving the heart pumping efficiency, and reducing the risk of heart failure.

[0073] It should be noted that those skilled in the art can make various improvements and additions without departing from the scope of this invention, and these improvements and additions should also be considered within the protection scope of this invention. Any modifications, alterations, and variations made by those skilled in the art without departing from the spirit and scope of this invention, based on the disclosed technical content, are equivalent embodiments of this invention; furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of this invention still fall within the scope of this invention's technical solution.

Claims

1. A stent for a valve prosthesis, characterized in that, The stent has a profile adapted to the original valve annulus, and the stent includes a first leaflet portion, a commissure portion, and a second leaflet portion distributed circumferentially. The commissure portion is located between the first leaflet portion and the second leaflet portion. The height of both the first leaflet portion and the second leaflet portion is greater than the height of the commissure portion, so that the inflow end of the stent has a shape that is high at both ends and low in the middle. The stiffness of both the first leaflet portion and the second leaflet portion is less than the stiffness of the commissure portion. The distance from the center position of the first leaflet portion to the commissure portion is L1, the distance between the first leaflet portion and the second leaflet portion is L2, and L1 / L2 is 0.

75. At least one of the first leaflet portion and the second leaflet portion adopts a first structural unit, the first structural unit adopts a quadrilateral mesh, and a plurality of the first structural units are arranged sequentially along the circumference of the support; or, at least one of the first leaflet portion and the second leaflet portion adopts a spiral structure, and a plurality of the spiral structures are arranged sequentially along the circumference of the support. The connecting part adopts at least one grid structure or at least one second structural unit, the second structural unit adopts diamond mesh, and a structural reinforcement member is provided in the axial direction through all diamond mesh.

2. The stent for a valve prosthesis according to claim 1, characterized in that, The height of the first leaflet is greater than the height of the second leaflet.

3. The stent for a valve prosthesis according to claim 1, characterized in that, The bracket is a one-piece molded structure or at least partially a split molded structure.

4. The stent for a valve prosthesis according to claim 1, characterized in that, The inflow end of the bracket is connected to a flange, the outer diameter of which is larger than the outer diameter of the connection between the flange and the inflow end, and / or, at least one anchor is provided on the outer surface of the bracket away from the inflow end.

5. A valve prosthesis, characterized in that, The device includes an artificial leaflet, a skirt, and a stent for a valve prosthesis as described in any one of claims 1-4. The artificial leaflet is fixed in the inner cavity of the stent, and the skirt covers the inner surface and / or outer surface of the stent. The artificial leaflet includes a first leaflet and a second leaflet, wherein the size of the first leaflet is larger than the size of the second leaflet, and when the artificial leaflet is open, the size of the blood flow channel formed by the first leaflet is larger than the size of the blood flow channel formed by the second leaflet. The artificial leaflet is fixedly connected to the first leaflet portion, the connecting portion, and the second leaflet portion of the stent.

6. The valve prosthesis according to claim 5, characterized in that, When the artificial leaflet closes, the distance from the first leaflet to the center of the connecting portion is greater than the distance from the second leaflet to the center of the connecting portion, and the height of the first leaflet is equal to the height of the second leaflet; or, when the artificial leaflet closes, the distance from the first leaflet to the center of the connecting portion is equal to the distance from the second leaflet to the center of the connecting portion, and the height of the first leaflet is greater than the height of the second leaflet.

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