Stent for valve prosthesis and valve prosthesis

Abstract

The valve prosthesis comprises an artificial valve leaflet, a skirt edge and the stent, the artificial valve leaflet is fixed in an inner cavity of the stent, the skirt edge covers the inner surface and / or the outer surface of the stent, the stent is provided with a contour matched with a native valve ring, and the skirt edge covers the outer surface of the stent. The stent comprises a first valve leaflet part, a connecting part and a second valve leaflet part which are distributed in the circumferential direction of the stent, the connecting part is located between the first valve leaflet part and the second valve leaflet part, and the height of the first valve leaflet part and the height of the second valve leaflet part are both larger than the height of the connecting part, so that the inflow end of the stent is in the form that the two ends are high and the middle is low; the rigidity of the first valve leaflet portion and the rigidity of the second valve leaflet portion are both smaller than the rigidity of the commissure portion. Thus, it is guaranteed that the valve prosthesis can dynamically adapt to the native valve ring in the cardiac contraction and relaxation process, the service life of the valve prosthesis is prolonged, and the influence of the valve prosthesis on ventricular remodeling is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a stent for a valve prosthesis and the 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 atrium and ventricle form the ventricular inflow end, the left ventricle and aorta form the left ventricular outflow end, and the right ventricle and pulmonary artery form the right ventricular outflow end. There are valves with "one-way valve" functions at the ventricular inflow end and ventricular outflow end to ensure the normal flow of blood in the heart chamber. When there is a problem with the valve, the heart's hemodynamics changes and the heart function is 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 preferred treatment for patients with severe valvular disease. However, for patients of advanced age, combined with multiple organ diseases, with a history of open-chest surgery, and with poor heart function, traditional surgical treatment has high risks and mortality rates, 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 fast patient recovery, and has received extensive attention from experts and scholars. However, after the existing valve prosthesis is implanted in the human body, the rigidity of the valve prosthesis is too large. During the beating of the heart, the native tissue squeezes the valve prosthesis, affecting the life of the valve prosthesis. At the same time, the reaction force of the valve prosthesis on the heart affects ventricular remodeling, making the ventricular compliance worse, leading to heart failure. In addition, after the existing valve prosthesis is implanted, the intraventricular hemodynamics is changed, the energy consumption of the ventricle is increased, the heart load is increased, and heart failure is caused.

[0004] Therefore, for those skilled in the art, how to design a valve prosthesis that can dynamically adapt to the native valve ring during cardiac contraction and relaxation is a problem that urgently needs to be solved.

[0005] It should be noted that the information disclosed in the background technology section of this application is intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a stent for a valve prosthesis and a valve prosthesis to solve the problem that the existing valve prosthesis cannot dynamically adapt to the movement of the native valve ring during the beating of the heart, thereby affecting the service life and ventricular remodeling.

[0007] To achieve the above-mentioned purpose, the present invention provides a stent for a valve prosthesis, the stent having a contour adapted to the native valve ring, and the stent comprising a first leaflet portion, a commissure portion and a second leaflet portion distributed along its own circumference, 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 both being greater than the height of the commissure portion, so that the inflow end of the stent presents a shape with high ends and a low middle, and the stiffness of the first leaflet portion and the stiffness of the second leaflet portion are both less than the stiffness of the commissure portion.

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

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

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

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

[0012] In one embodiment, the bracket is an integrally formed structure or at least partially a split-formed structure.

[0013] In one embodiment, the inflow end of the bracket is connected to a flange, the outer diameter of the flange 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] In addition, based on the same inventive concept, the present invention also provides a valve prosthesis, including an artificial valve leaflet, a skirt and any one of the stents for the valve prosthesis, wherein the artificial valve 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 size of the first leaflet is larger than the size of the second leaflet, and when the artificial valve leaflet is opened, 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.

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

[0017] Compared with the prior art, the stent for valve prosthesis 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 portion, a commissure portion, and a second leaflet portion adapted to the saddle-like shape of the native valve annulus, thereby enhancing the fit of the valve prosthesis to the native valve annulus. On this basis, the first leaflet portion, the commissure portion, and the second leaflet portion are matched with different stiffnesses, thereby ensuring that the valve prosthesis can dynamically adapt to the native valve annulus during cardiac contraction and relaxation, thereby increasing the life of the valve prosthesis and reducing the impact of the valve prosthesis on ventricular remodeling.

[0019] Furthermore, by limiting the distance from the first leaflet portion to the center position of the commissure portion, the stent can carry an asymmetrically designed artificial leaflet, thereby forming blood flow channels of different sizes to obtain a vortex similar to the original blood flow conditions of the human body, thereby reducing the dissipation of blood flow energy, improving the heart's pumping efficiency, and reducing the risk of heart failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

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

[0022] Figure 2a is a lateral schematic diagram of a stent in a valve prosthesis provided according to an embodiment of the present invention;

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

[0024] Figure 3 It is a schematic diagram of the motion state of the native valve ring during contraction and relaxation;

[0025] Figure 4a and Figure 4b is a schematic diagram of a structure in which the first lobe portion and the second lobe portion adopt relatively small stiffness according to an embodiment of the present invention;

[0026] Figure 5a and Figure 5b is a schematic diagram of a structure in which a joint portion adopts a larger rigidity according to an embodiment of the present invention;

[0027] Figure 6 It is a schematic diagram of the structure of the bracket provided in accordance with an embodiment of the present invention when a flange and an anchor are provided;

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

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

[0030] Figure 7c It is the blood flow state when a symmetrically designed bioprosthesis is implanted;

[0031] Figure 8a is the flow state of blood flow when the valve prosthesis provided by the embodiment of the present invention is used, and the arrow indicates the flow direction of blood flow;

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

[0033] Fig. 9 This is the flow state of blood flow when the valve prosthesis provided by an embodiment of the present invention adopts artificial valve leaflets of different heights, and the arrow indicates the flow direction of blood flow. DETAILED DESCRIPTION

[0034] To make the content of the present invention more clear and understandable, the present invention is further described below in conjunction with the accompanying drawings. Of course, the present invention is not limited to the specific embodiments provided below, and general replacements known to those skilled in the art are also included in the protection scope of the present invention.

[0035] The terms used in this application document are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should be understood that similar words such as "one" or "one" do not indicate a quantitative limitation, but rather indicate the presence of at least one; "multiple" means two or more. Similar words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Secondly, the present invention is described in detail using schematic diagrams, but these schematic diagrams are only for the convenience of detailing examples of the present invention and should not be used as limitations of the present invention.

[0036] The "circumferential direction" described in this application document corresponds to the circumferential direction of the valve prosthesis; the "radial direction" corresponds to the diameter direction of the valve prosthesis; the "axial direction" corresponds to the axial direction of the valve prosthesis, and the axial direction is perpendicular to the radial direction; the term "height" refers to the dimension along the axial direction of the stent, and the "distance" refers to the dimension along the radial direction of the stent; the terms "inflow end" and "outflow end" are defined by the position of the valve prosthesis relative to the native valve ring after implantation in the body. According to the normal flow direction of blood, the "inflow end" is the end where blood flows into the valve prosthesis, and the "outflow end" is the end where blood flows out of the valve prosthesis. The "inner surface" described in this application document refers to the side close to the axis of the valve prosthesis, and the "outer surface" refers to the side away from the axis of the valve prosthesis.

[0037] The object of the present invention is to provide a stent for a valve prosthesis and a valve prosthesis, which at least solves the problem that the existing valve prosthesis cannot dynamically adapt to the movement of the native valve during the beating of the heart, thereby affecting the service life and ventricular remodeling.

[0038] The valve prosthesis provided by the present invention is applicable to the mitral valve or the tricuspid valve, and the following embodiments are described by taking the application scenario of 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 valve leaflet 120 , and a skirt 130 .

[0040] The artificial valve leaflet 120 is fixed in the inner cavity of the stent 110. The artificial valve leaflet 120 includes at least two valve leaflets. The artificial valve leaflet 120 dynamically switches between the open and closed states. When the artificial valve leaflet 120 is in the closed state, the valve leaflet is tightened or converged in a sealed abutment manner. The artificial valve leaflet 120 can be selected from biological tissues such as chemically stable tissues from the heart valves of animals (such as pigs), or pericardial tissues of animals such as cows (bovine pericardium) or sheep (sheep pericardium) or pigs (pig pericardium) or horses (equine pericardium), preferably bovine pericardial tissue. The artificial valve leaflet 120 can also be made of submucosal tissue of the small intestine. The artificial valve leaflet 120 is used to replace the native valve to perform opening and closing movements and control the direction of blood flow.

[0041] The skirt 130 may cover the inner surface of the stent 110, or cover the outer surface of the stent 110, or both the inner surface and the outer surface of the stent 110 are covered with the skirt 130. The skirt 130 has a sealing function, which can prevent paravalvular leakage and better ensure that the single channel of blood flows from the inflow end of the valve prosthesis 100 to the outflow end of the valve prosthesis 100. The inflow end of the valve prosthesis 100 is usually set to adapt to the shape of the native tissue, and the skirt 130 is set circumferentially on the outer side of the inflow end where it fits with the native tissue, which can effectively prevent paravalvular leakage. The skirt 130 is made of biological materials, specifically, it can be made of knitted, woven, braided polyester fabrics, or polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), and animal pericardial materials.

[0042] The stent 110 has a contracted state for delivery and an expanded state for deployment, and can dynamically switch between the contracted state and the expanded state. The stent 110 is a cylindrical structure that can provide several functions for the valve prosthesis 100, including: serving as the main structure of the artificial valve leaflet 120, carrying the internal valve leaflet; being able to be connected to the delivery system so as to be manipulated to achieve functions such as delivery and release, and the stent body 110 can be detachably connected to the delivery system through its own connection structure such as a hanging ear or a fixing ear. 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, etc., or other biocompatible metals known to those skilled in the art, preferably nickel titanium material, and elastic or plastically deformable polymer materials, such as balloon expandable materials, can also be selected to prepare the stent 110.

[0043] like Figure 2a and Figure 2b As shown, the stent 110 has different heights in its own circumference, so that the shape of the stent 110 imitates the native valve ring. In view of the saddle-like shape of the native valve ring, in order to enhance the fit between the valve prosthesis 100 and the native valve ring, the stent 110 is set to a three-dimensional D-shaped shape to imitate the shape of the native valve ring to the greatest extent. In this regard, the stent 110 includes a first leaflet portion 111, a commissure portion 112, and a second leaflet portion 113 distributed along its own circumference, and the commissure portion 112 is located between the first leaflet portion 111 and the second leaflet portion 113, and the commissure portion 112 corresponds to the position where two adjacent leaflets are joined.

[0044] In one aspect, Figure 2aAs shown, the height of the first leaflet portion 111 is H1, the height of the commissure portion 112 is H2, and the height of the second leaflet portion 113 is H3. The relationship among H1, H2, and H3 is H1≥H3>H2, so that the stent 110 presents a shape with high ends and low middle. On the other hand, the first leaflet portion 111, the commissure portion 112, and the second leaflet portion 113 form a contour adapted to the original valve ring in the circumferential direction of the stent 110, that is, a D-shaped contour, which is basically consistent with the outer contour of the original valve ring. Specifically, as Figure 2b As shown, viewed along the axial direction, the profile of the bracket 110 along the circumferential direction is generally D-shaped.

[0045] In addition, considering the dynamic changes of the native valve ring after implantation, the stiffness of the commissure 112 is greater than the stiffness of the first leaflet 111 and the second leaflet 113, so that during the contraction and relaxation of the heart, the dynamic changes of the commissure 112 are smaller than those of the first leaflet 111 and the second leaflet 113. In this way, the fit between the valve prosthesis 100 and the native valve ring is enhanced, and on this basis, it is ensured that the valve prosthesis 100 can dynamically adapt to the native valve ring during the contraction and relaxation of the heart, and the interaction force between the native tissue and the valve prosthesis 100 is reduced, which not only improves the service life of the valve prosthesis 100, but also reduces the impact of the valve prosthesis 100 on ventricular remodeling.

[0046] Also refer to Figure 3 Understand the dynamic changes of the native valve annulus. Figure 3 The diagram shows the motion of the native mitral valve ring during contraction and relaxation. A is the anterior leaflet, P is the posterior leaflet, and CC is the leaflet commissure of the native mitral valve ring. Figure 3 It can be seen that when the native valve changes from diastole to contraction, the native valve ring moves from the left atrium to the left ventricle, and the movement amplitude of the anterior valve leaflet A and the posterior valve leaflet P is larger than the movement amplitude of the valve leaflet commissure CC of the native mitral valve ring, and the anterior valve leaflet A and the posterior valve leaflet P contract toward each other, which is beneficial to the closure of the native valve and reduces regurgitation. However, in the prior art, the structure of the valve prosthesis fails to match the native valve ring well, and the dynamic movement process of the native valve ring is not considered. When the valve prosthesis 100 is implanted in the body, the compression of the artificial valve leaflets by the native tissue during the contraction and diastole of the heart can easily lead to premature failure of the artificial valve leaflets. At the same time, the reaction force of the artificial valve leaflets on the heart will also affect ventricular remodeling, making the ventricular compliance worse, leading to heart failure. However, the valve prosthesis 100 provided in the embodiment of the present invention can better overcome the defect that the existing valve prosthesis cannot dynamically adapt to the native valve ring.

[0047] Preferably, H1>H3>H2, which can better match the native valve ring and better adapt to the movement of the native valve, resulting in better effect.

[0048] It should be noted that there are multiple ways to make the bracket 110 have different stiffness in the circumferential direction, and at least one of them can be selected for implementation. In practice, the bracket 110 can be ensured to have different stiffness in the circumferential direction through materials and / or structures. The following is an exemplary description.

[0049] In one exemplary embodiment, at least one of the first lobe portion 111 and the second lobe portion 113 is Figure 4a The first structural unit 110a shown in the figure provides a smaller rigidity in the axial direction. The first structural unit 110a generally adopts a quadrilateral mesh, including a diamond mesh, which can be deformed better. The first structural unit 110a is set to multiple, and the multiple first structural units 110a are arranged in sequence along the circumference of the bracket 110.

[0050] In another exemplary embodiment, at least one of the first lobe portion 111 and the second lobe portion 113 is Figure 4b The spiral structure 110b shown can also provide a small rigidity in the axial direction. The spiral structure 110b is formed by spirally winding the primary structure and has scalability. A plurality of spiral units 110b are sequentially arranged along the circumference of the stent 110.

[0051] In one example, the joint 112 is formed by Figure 5a The grid structure 110c shown can provide greater rigidity in the axial direction. Usually, one grid structure 110c is provided, but it is not limited to more than one. The grid structure 110c is a grid structure composed of a series of strip materials intersecting vertically and horizontally.

[0052] In another example, the joint portion 112 is Figure 5b The second structural unit 110d shown in the figure, although the second structural unit 110d adopts diamond meshes, a structural reinforcement member is arranged in the axial direction and penetrates all the diamond meshes to enhance the rigidity. There is at least one second structural unit 110d.

[0053] However, it should be understood that the stiffness of each part of the bracket can be adjusted by changing the distribution density and size of the mesh, or it can be achieved by other methods recognized by technical personnel in the field, such as selecting materials with a small elastic modulus, etc., and this application is not limited to this.

[0054] The stent 110 may be manufactured in one piece, or the first leaflet portion 111, the second leaflet portion 113 and the connection portion 112 may be manufactured separately and then assembled together, or the stent 110 may be partially a split-molded structure.

[0055] Furthermore, in view of the problem that the existing valve prosthesis is easy to change the intraventricular hemodynamics after implantation, the present invention also proposes an improved solution. For ease of understanding, the intraventricular blood flow state is first described.

[0056] like Figure 7a As shown, for the native mitral valve, since the native mitral valve is a dynamic saddle-shaped valve ring and the two leaflets are asymmetrically designed, with the anterior leaflet larger than the posterior leaflet, when the mitral valve opens, it is conducive to the formation of a flow vortex A1 toward the aortic valve. The formation of vortex A1 can maintain the kinetic energy of the blood flow, and during the ventricular contraction, it is ejected from the heart, thereby 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, the bileaflet mechanical valve has 3 openings, and the blood flow velocity at the opening position close to the aortic valve is faster, forming a vortex A2 toward the mechanical valve, which is exactly opposite to the direction of vortex A1 formed by the native mitral valve, thereby changing the intraventricular hemodynamics, increasing the blood kinetic energy consumption, increasing the cardiac load, and increasing the risk of heart failure.

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

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

[0060] Accordingly, if Figure 8a to Figure 8b and Fig. 9 As shown, in a preferred embodiment of the present invention, the artificial valve leaflet 120 is an asymmetric structure. After being fixedly connected to the stent 110, blood flow channels of different sizes can be formed, thereby obtaining a vortex similar to the original blood flow condition of the human body, reducing the dissipation of blood flow energy, 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 connection portion, a leaflet fixing portion and a leaflet free portion, one end of the leaflet free portion is connected to one end of the leaflet fixing portion through the leaflet connection portion, and the other end of the leaflet free portion is connected to the other end of the leaflet fixing portion through another leaflet connection portion. The leaflet fixing portion is basically arc-shaped or arc-like. Multiple leaflets are always in contact with each other at the leaflet connection portion. The leaflet free portion is an arc that bulges away from the leaflet fixing portion, or an arc that bulges toward the leaflet fixing portion, or is straight. The leaflet connection portion and the leaflet fixing portion of the leaflet both need to be fixedly connected to the stent 110. When the artificial leaflet 120 is closed, the leaflet free portions of each leaflet are closed or met in a sealed abutment manner. When the artificial leaflet 120 is opened, the leaflet free portions of each leaflet are opened in a manner away from each other to allow blood to pass through.

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

[0063] like Figure 8b As shown, the artificial valve leaflet 120 adopts an asymmetric valve leaflet, including a first valve leaflet 121 and a second valve leaflet 122. The size of the first valve leaflet 121 is larger than the size of the second valve leaflet 122. It can also be understood that after the valve leaflet is flattened, the plane size of the first valve leaflet 121 is larger than the plane size of the second valve leaflet 122. After such a setting, when the artificial valve leaflet 120 is opened, the size of the blood flow channel formed by the first valve leaflet 121 is larger than the size of the blood flow channel formed by the second valve leaflet 122, so that the blood flow can form a vortex (A1) toward the aortic valve, which is similar to the original blood flow of the human body, and can reduce the dissipation of blood kinetic energy and improve the efficiency of heart pumping.

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

[0065] like Figure 8a and Figure 8bAs shown, similar to the stent 110, the distance from the first leaflet 121 to the center of the commissure 112 is L1, the distance between the first leaflet 121 and the second leaflet 122 is L2, and L1 / L2 is greater than 1 / 2. At this time, the distance from the second leaflet 122 to the center of the commissure 112 is less than L1, and when the artificial leaflet 120 is closed, the first leaflet 121 and the second leaflet 122 are equal in height in the axial direction of the stent 110. In this way, the asymmetric design of the artificial leaflet 120 can be achieved, so that after the artificial leaflet 120 is opened, the blood flow channel of the first leaflet 121 is larger than that of the second leaflet 122.

[0066] like Fig. 9 As shown, in another example, L1 / L2=1 / 2, at this time, the distance from the second leaflet 122 to the center of the commissure 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, the height of the second leaflet 122 is h2, h1>h2, and the height difference between the two is h. In this way, the asymmetric design of the artificial leaflet 120 can also be achieved, so that after the artificial leaflet 120 is opened, the blood flow channel of the first leaflet 121 is larger than that of the second leaflet 122, which is equivalent to the first leaflet 121 having a height difference h more than the blood flow channel of the second leaflet 122.

[0067] Next reference Figure 6 In one exemplary embodiment, the inflow end of the stent 110 is connected to a flange 114. The flange 114 is used to be close to the native tissue when the valve prosthesis 100 is deployed, which can further prevent paravalvular leakage and improve the 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, so that the outer surface of the flange 114 can be close to the native valve ring and leaflet, and the edge of the flange 114 can be close to the inner wall of the left atrium, which plays a role of limiting and sealing, and prevents the valve prosthesis 100 from sliding toward 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 soft and easy to be compressed and deformed.

[0068] Continue to refer to Figure 6 In one exemplary embodiment, at least one anchor 115 is disposed on the outer surface of the stent 110 away from the inflow end. The anchor 115 can grab the native structure (such as the native leaflet) when the valve prosthesis 100 is deployed, which is conducive to fixing the valve and the native tissue. The specific position of the anchor 115 on the stent 110 is not limited, and the number of the anchor 115 is also not limited. The anchor 115 can have a variety of configurations, and at least one structure can be selected to achieve it, such as a barb, a hook, an anchor, a slender member, etc.

[0069] The delivery method of the valve prosthesis 100 of the embodiment of the present invention is not limited, and commonly used delivery methods may be delivery via the femoral artery, via the apical route, via the jugular vein route, and the like.

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

[0071] (1) A three-dimensional D-shaped stent is used to adapt the structure of the stent to the structure of the native valve annulus. Different parts of the stent have different stiffnesses to ensure that the valve prosthesis can dynamically adapt to the native valve annulus during cardiac contraction and relaxation, thereby increasing the life of the valve prosthesis and reducing the impact of the valve prosthesis on ventricular remodeling.

[0072] (2) An asymmetric artificial valve leaflet is used to form blood flow channels of different sizes, thereby obtaining a vortex similar to the original blood flow in the human body, thereby reducing the dissipation of blood flow energy, improving the heart's pumping efficiency, and reducing the risk of heart failure.

[0073] It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the disclosed content of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of the present invention, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A stent for a valve prosthesis, characterized in that: The stent has a contour adapted to the native valve ring, and includes a first leaflet portion, a connection portion, and a second leaflet portion distributed along its own circumference, the connection 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 both greater than the height of the connection 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 are both less than the stiffness of the connection portion.

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

3. The stent for valve prosthesis according to claim 1, characterized in that: The distance from the first lobe portion to the center position of the commissure is L1, the distance between the first lobe portion and the second lobe portion is L2, and L1 / L2≥0.

5.

4. The stent for valve prosthesis according to claim 3, characterized in that: L1 / L2≤0.

8.

5. The stent for valve prosthesis according to claim 4, characterized in that: L1 / L2=0.

75.

6. The stent for valve prosthesis according to claim 1, characterized in that: The bracket is an integrally formed structure or at least partially a split-formed structure.

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

8. A valve prosthesis, characterized in that: It comprises an artificial valve leaflet, a skirt and a stent for a valve prosthesis as described in any one of claims 1 to 7, wherein the artificial valve leaflet is fixed in the inner cavity of the stent, and the skirt covers the inner surface and / or outer surface of the stent.

9. The valve prosthesis according to claim 8, characterized in that: The artificial valve leaflet includes a first leaflet and a second leaflet, the size of the first leaflet is larger than the size of the second leaflet, and when the artificial valve leaflet is opened, 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.

10. The valve prosthesis according to claim 9, characterized in that: When the artificial leaflet is closed, the distance from the first leaflet to the center of the connection is greater than the distance from the second leaflet to the center of the connection, and the height of the first leaflet is equal to the height of the second leaflet; or, when the artificial leaflet is closed, the distance from the first leaflet to the center of the connection is equal to the distance from the second leaflet to the center of the connection, and the height of the first leaflet is greater than the height of the second leaflet.

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