An artificial heart valve prosthesis and its stent

Abstract

The present invention discloses an artificial heart valve prosthesis and its stent. The artificial heart valve stent includes an outer stent and an inner stent; the inner stent and the outer stent are fixedly connected; the outer stent has an outer inflow channel structure and an outer outflow channel structure that are axially connected; the inner stent has an inner inflow channel structure and an inner outflow channel structure that are axially connected and are located inside the outer stent in the radial direction, and an anchoring structure is provided on the outer side of the inner stent. For the artificial heart valve prosthesis and its stent provided by the present invention, the inner stent bears the artificial valve leaflets and has high stiffness and small diameter, which can reduce the area of the artificial valve leaflets, lower the height required for the opening and closing movement of the valve leaflets, and improve the lifespan of the valve leaflets; the outer stent has relatively low stiffness and large diameter, which can prevent paravalvular leakage. The anchoring structure is connected to the inner stent, and the anchoring force for preventing the movement of the prosthetic valve is mainly borne by the inner stent with stronger stiffness, thereby improving the lifespan of the stent.

Description

Technical Field

[0001] The invention relates to an interventional medical prosthesis, in particular to an artificial heart valve prosthesis and a bracket thereof. 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 structure is formed between the atrium and the ventricle, the left ventricle and the aorta form the left ventricular outflow tract structure, and the right ventricle and the pulmonary artery form the right ventricular outflow tract structure. There are valves with "one-way valve" functions in the ventricular inflow tract structure and the ventricular outflow tract structure 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%. 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, the surgical risk is high, the surgical mortality rate is high, and some patients even lose the opportunity for surgery. Transcatheter valve implantation / repair has the advantages of no need for open-chest surgery, less trauma, and faster patient recovery.

[0004] The native heart valve structure is different, and the anatomical structure and pathological requirements that heart valve prostheses need to face during interventional treatment are also different.

[0005] The valves at the left ventricular inflow tract structure and the right ventricular inflow tract structure are the mitral valve and the tricuspid valve, respectively. Both valves are combined, including the valve ring, valve leaflets, chordae tendineae and papillary muscles, and some literature also includes the ventricular wall. The chordae tendineae are the supporting devices connecting the mitral valve leaflets and the myocardium, and are distributed between the leaflets and the ventricular wall. The subvalvular structure of the mitral valve (chordae tendineae, papillary muscles, ventricular wall, etc.) plays an important role in maintaining the structure and function of the left ventricle, and the native valve structure is preserved as much as possible during surgery. Therefore, when using transcatheter implantation of artificial valve prostheses to replace native valves, it is also necessary to adapt to the structure of the native valve as much as possible to reduce the damage of the prosthetic valve to the native valve structure.

[0006] The valves at the left ventricular outflow tract structure and the right ventricular outflow tract structure are the aortic valve and the pulmonary valve respectively. Unlike the valves at the inflow tract structure, the valves at the outflow tract structure only include leaflets and valve rings.

[0007] Existing prosthetic valves for transcatheter aortic valve replacement are mainly applicable to patients with aortic valve calcification. Their anchoring mechanism is that the prosthetic valve radially squeezes the annulus of the native valve to generate sufficient radial support force to increase the friction between the prosthetic valve and the native valve, prevent the prosthetic valve from shifting due to blood impact, and enable the prosthetic valve to function as a one-way valve at the position of the native valve. Currently, the transcatheter aortic valve replacements on the market are made of nitinol or other biocompatible materials. The support body contacts and fixes with the native valve, and the prosthetic leaflets are fixed inside the support body to achieve the design of unidirectional passive opening in the direction of blood flow and passive closing of the prosthetic leaflets in the reverse direction of blood flow. When the annulus of the native valve is larger, the size of the required support body is larger.

[0008] When an aortic valve prosthetic valve is implanted into the native mitral valve, due to the fact that the annulus size of the mitral valve in anatomy is much larger than that of the aortic valve annulus, the part of the support body of the prosthetic valve implanted in the mitral valve that matches the prosthetic leaflets requires larger sizes both in circumferential diameter and axial height. As a result, after the prosthetic valve is implanted in the mitral valve, the size of the prosthetic structure under the valve is relatively large, posing a greater risk of damage to the subvalvular structure of the native valve assembly. For some patients with mitral regurgitation, there is no calcified part on their valves, and the existing working principle of using the radial support force generated between the prosthetic valve and the native valve to prevent the prosthetic valve from shifting cannot be adopted.

[0009] The tricuspid valve, as the atrioventricular valve of the right heart, has a similar structure to the mitral valve and also includes leaflets, annulus, chordae tendineae, papillary muscles, and myocardium. The prosthetic valve used to replace the native mitral valve can also be applied to replace the native tricuspid valve. Different sizes of native valves result in different sizes of the prosthetic valves for transcatheter replacement.

[0010] However, the existing prosthetic valves have the following problems:

[0011] 1. The opening area of the native mitral valve is relatively large. When replacing the prosthetic valve, after implantation in the mitral valve, the size of the prosthetic valve structure under the valve is relatively large, posing a greater risk of damage to the subvalvular structure of the native valve assembly;

[0012] 2. For some patients with mitral regurgitation, there is no calcified part on their valves, and the existing aortic valve prosthetic valve replacement method, which uses the radial support force generated between the prosthetic valve and the native valve to prevent the prosthetic valve from shifting, cannot be adopted. Summary of the Invention

[0013] The technical problem to be solved by the present invention is to provide an artificial heart valve prosthesis and its stent, aiming to solve the problems of a greater risk of damage to the subvalvular structure of the native valve assembly and the easy displacement of the prosthetic valve.

[0014] The technical solution adopted by the present invention to solve the above technical problems is to provide an artificial heart valve stent, which includes an outer stent and an inner stent; the inner stent and the outer stent are fixedly connected; the outer stent has an outer inflow channel structure and an outer outflow channel structure connected axially; the inner stent has an inner inflow channel structure and an inner outflow channel structure connected axially, and is located inside the outer stent in the radial direction, and an anchoring structure is provided on the inner stent.

[0015] Preferably, the inner stent and the outer stent are made of different biocompatible materials, and the stiffness of the inner stent is greater than that of the outer stent.

[0016] Preferably, the inner stent and the outer stent are made of the same biocompatible material, and different structures or heat treatment processes are used to make the stiffness of the inner stent greater than that of the outer stent.

[0017] Preferably, in the expanded state, the inner stent is tubular, and the maximum tubular outer diameter of the inner stent is less than 75 mm.

[0018] Preferably, the outer stent or / and the inner stent are composed of at least one row of mesh structure units connected to each other in the circumferential direction axially, and lugs are provided on the outer stent or / and the inner stent.

[0019] Preferably, the distal end of the inner outflow channel structure extends in a direction away from the axis of the inner stent.

[0020] Preferably, the inner stent and the outer stent are connected at the inner outflow channel structure, and the axial position of the connection point between the inner stent and the outer stent is higher than the connection point between the anchoring structure and the inner stent.

[0021] Preferably, the outer stent and the inner stent are connected by riveting, welding, suturing, animal pericardium or skirt.

[0022] Preferably, both the outer stent and the inner stent are composed of mesh structure units axially. The mesh structure unit has a mesh edge rod and a node. The node is a connection point formed by connecting adjacent mesh structure units, and the mesh edge rod is the mesh edge between adjacent nodes; the nodes of the mesh structure units on the outer stent and the nodes of the mesh structure units on the inner stent overlap to form a connection point; or the mesh edge rod on the inner stent overlaps with the node or mesh edge rod of the mesh unit structure on the outer stent to form a connection point; or the mesh edge rod on the outer stent overlaps with the node of the mesh unit structure on the inner stent to form a connection point.

[0023] Preferably, the proximal end of the outer inflow channel structure extends radially away from the inner stent, and the minimum diameter of the proximal end of the outer inflow channel structure is greater than 25 mm.

[0024] Preferably, the distal end of the outer outflow channel structure extends radially toward the inner stent side to form an adduction structure. One end of the adduction structure is adjacent to or connected to the inner stent, and the other end of the adduction structure is connected to the outer outflow channel structure.

[0025] Preferably, the main body of the outer outflow channel structure is cylindrical, conical, elliptical cylindrical, or a column with a D-shaped cross-section.

[0026] Preferably, at least two anchoring structures are distributed along the circumferential direction of the inner outflow channel structure.

[0027] Preferably, the anchoring structure has two ends, one of which is a fixed end fixed to the inner stent, and the other end is a free end.

[0028] Preferably, the anchoring structure is a rod-shaped structure. The fixed end of the rod-shaped structure has 1 fixed point with the inner stent, and the free end of the rod-shaped structure is spherical or ellipsoidal.

[0029] Preferably, the anchoring structure has two ends, and both ends are fixed on the mesh structure unit of the inner stent. The anchoring structure and the structural unit of the inner stent form a closed structure.

[0030] Preferably, small barbs are provided on the side of the anchoring structure facing the inner stent, or it is provided in a serrated shape.

[0031] Another technical solution adopted by the present invention to solve the above technical problems is to provide an artificial heart valve prosthesis, including the above artificial heart valve stent, and further including artificial valve leaflets and a skirt. The artificial valve leaflets are arranged inside the inner stent, and the skirt is arranged on the inner surface and / or outer surface of the outer stent and / or the inner stent. The area covered by the skirt at least includes the area covered by the artificial valve leaflets on the inner stent when the artificial valve leaflets perform opening and closing movements.

[0032] Preferably, the skirt extends from the inner side of the proximal end of the outer inflow channel structure of the outer stent to the connection point of the inner stent and the outer stent, and then extends along the outer side of the inner stent toward the inner inflow channel structure direction.

[0033] The present invention has the following beneficial effects compared with the prior art: 1. The artificial heart valve stent provided by the present invention is a double-layer stent, including an inner stent and an outer stent. The inner stent bears the artificial valve leaf with high stiffness and a relatively small diameter matching the prosthesis valve leaf, which can reduce the area of the artificial valve leaf, lower the height required for the opening and closing movement of the valve leaf, improve the service life of the valve leaf, and reduce the sub-valve height. The outer stent has relatively low stiffness and fits with the native tissue to achieve a sealing effect, which can prevent paravalvular leakage; although the stent diameter of the outer stent is large, it does not bear the pulling force when the prosthesis valve leaf closes, and the risk of local large stress on the stent during the working state is relatively low, and the service life is relatively high; 2. An anchoring structure is arranged on the outer side of the inner stent. Since the anchoring structure is stably connected to the inner stent, the anchoring force to prevent the prosthesis valve from moving is mainly borne by the inner stent with stronger stiffness, achieving a higher structural service life; 3. The sub-valve structure height of the prosthesis valve is low, reducing the risk of interference with the native heart sub-valve structure and the risk of obstruction of the ventricular outflow tract structure; 4. In particular, the inner stent and the outer stent are integrally cut from the same biocompatible material, and there is no need to connect each structure through later processing. The relative positions of each structure are stable and accurate, avoiding functional defects caused by position deviation between each structure due to various later factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the overall structure of the stent of the artificial heart valve in the embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the structure of the inner stent of the artificial heart valve in the embodiment of the present invention;

[0036] Figure 3 Schematic diagram of the position structure of the stent of the artificial heart valve in the heart in the embodiment of the present invention;

[0037] Figure 4 Schematic diagram of the position structure of another artificial heart valve in the heart in the embodiment of the present invention;

[0038] Figure 5 Schematic diagram of the connection between the stent and the anchoring structure of the artificial heart valve in the embodiment of the present invention;

[0039] Figure 6 Schematic diagram of the integrally formed structure of the inner stent and the outer stent of the artificial heart valve in the embodiment of the present invention;

[0040] Figure 7 Schematic diagram of the formation of a single blood flow channel by the stent, skirt and prosthesis valve leaf of the artificial heart valve in the embodiment of the present invention;

[0041] Figure 8 Schematic diagram of the distribution of the skirt on the inner stent and the outer stent in the embodiment of the present invention;

[0042] Figures 9a - 9d This is a schematic structural view of an artificial heart valve or an inner stent with different anchoring structures in an embodiment of the present invention.

[0043] Reference numerals:

[0044] Detailed implementation manners

[0045] In the following description, in order to provide a thorough understanding of the present invention, many specific details are set forth. However, the present invention may be practiced without these specific details, which will be apparent to those of ordinary skill in the art. Therefore, the specific details set forth are merely exemplary, and the specific details may vary according to the spirit and scope of the present invention and are still considered to be within the spirit and scope of the present invention.

[0046] The present invention provides a transcatheter implantable artificial heart valve prosthesis (also referred to as a "prosthetic valve") for replacing a heart valve, mainly the mitral valve or the tricuspid valve, including an artificial heart valve stent. The artificial heart valve stent is a double-layer stent. The inner stent has high stiffness and bears the tensile force of the prosthetic valve leaflets. The outer stent has relatively low stiffness and fits with the native tissue, mainly realizing the function of preventing paravalvular leakage of the prosthesis. The anchoring structure is stably connected to the inner stent.

[0047] Specifically, in combination with Figures 1 to 8 As shown, a preferred embodiment of the present invention provides an artificial heart valve prosthesis, including a stent 100, a valve 200, and a skirt 300. The stent 100 includes an inner stent 110, an outer stent 120, an anchoring structure 130, and a delivery device connection structure (ear 140). The inner stent 110 is radially located inside the outer stent 120. The stent 100 is defined as an inflow channel structure and an outflow channel structure according to the direction of blood flow. The double-layer stent respectively has an inflow channel structure and an outflow channel structure, that is, the inner stent 110 has an axially connected inner inflow channel structure 1110 and an inner outflow channel structure 1120, and the outer stent 120 has an axially connected outer inflow channel structure 1210 and an outer outflow channel structure 1220. The stent 100 has two forms: a crimped state and an expanded state, that is, both the inner stent 110 and the outer stent 120 have these two states. In the present invention, unless otherwise emphasized, the descriptions are all about the characteristics of the stent in the expanded state.

[0048] The inner stent 110 is located radially inside the outer stent 120, and the inner stent 110 has high stiffness and is used to bear the blood force acting on the artificial valve leaflet of the prosthetic valve during movement. The relative stiffness of the outer stent 120 is relatively weak, and it can fit with the native tissue to achieve the function of preventing paravalvular leakage of the prosthesis. Although the diameter of the outer stent 120 is larger, since it does not bear the pulling force when the prosthetic valve leaflet closes, the risk of local high stress on the outer stent 120 in the working state is relatively low, so the outer stent 120 has a longer service life. The inner stent 110 that bears the artificial valve leaflet has a smaller radial dimension, so the radial dimension of the artificial valve leaflet can also be set smaller. As a result, the axial dimension occupied by the artificial valve leaflet during the opening and closing movement is small, and the overall axial height of the prosthetic valve also becomes smaller. The sub-valvular dimension of the entire prosthetic valve after implantation is lower, reducing the risk of interfering with the native tissue structure. In addition, since the area of the artificial valve leaflet is small, the fatigue resistance of the artificial valve leaflet is greatly improved, and the service life of the artificial valve leaflet is extended.

[0049] Since the anchoring structure 130 of the artificial heart valve prosthesis in this preferred embodiment is connected to the inner stent 110 rather than the outer stent 120, the anchoring force to prevent the movement of the prosthetic valve is mainly borne by the inner stent 110 with higher stiffness, and a higher structural life can be achieved.

[0050] The inner stent 110 is tubular, and the outer diameter of the tube of the inner stent 110 is smaller than the diameter of the native valve. Generally, the diameter range of the native valve annulus is 25 - 75 mm, and the outer diameter of the tube of the inner stent 110 is less than 75 mm. Usually, the outer diameter of the tube of the inner stent 110 is 20 - 35 mm. The inner stent 110 has significant radial and axial stiffness and can bear the pulling of the valve leaflet. The inner side of the inner stent 110 is stably connected to the prosthetic valve leaflet.

[0051] The inner stent 110 can be made of nitinol or other biocompatible materials with shape memory characteristics and is made by processes such as cutting followed by heat treatment, sandblasting, polishing, or other processes for processing stents. As an option, the inner stent 110 can also be made of biocompatible materials such as cobalt-chromium alloy and stainless steel and functions by balloon dilation to a specified shape during implantation.

[0052] The inner inflow tract structure 1110 is cylindrical, and the maximum outer diameter of the outside is not greater than the diameter of the native valve it replaces. The inner outflow tract structure 1120 is a cylinder with the same inner and outer diameters as the inner inflow tract structure 1110. The proximal end 1121 of the inner outflow tract structure and the distal end 1112 of the inner inflow tract structure are connected and have the same size. In another embodiment, the distal end 1122 of the inner outflow tract structure can also be set to extend along the direction away from the axis of the inner stent 110, making the inner stent 110 in a trumpet shape (not shown in the figure).

[0053] The inner stent 110 has a plurality of reticular structure units or wavy structure units, and the plurality of reticular structure units or wavy structure units are connected to each other in the circumferential direction along the axial direction of the inner stent 110.

[0054] In a specific implementation, as Figure 3 shown, after the valve prosthesis is implanted into the human body, the proximal end 1111 of the inner inflow tract structure and the distal end 1212 of the outer inflow tract structure are approximately the same in height along the axial direction of the inner stent 110, or the proximal end 1111 of the inner inflow tract structure is lower than the distal end 1212 of the outer inflow tract structure along the axial direction towards the outflow tract structure, so that there is no obvious blood stasis during the process of blood flowing from the atrium into the ventricle. That is, in terms of the axial height, the proximal end 1111 of the inner inflow tract structure and the distal end 1212 of the outer inflow tract structure are approximately the same in height, or the proximal end 1111 of the inner inflow tract structure is lower than the distal end 1212 of the outer inflow tract structure (on the central axis of the stent, the end close to the left atrium is high and the end close to the left ventricle is low). At this time, the entire axial height of the inner stent 110 is covered with the valve 200.

[0055] In another specific implementation, as Figure 4 shown, after the prosthetic valve is implanted into the human body, the proximal end 1111 of the inner inflow tract structure is higher than the distal end 1212 of the outer inflow tract structure along the axial direction away from the outflow tract structure. On the basis of ensuring the total design height required for fixing the prosthetic leaflets, the sub-valvular height of the inner stent 110 is minimized, thereby reducing the overall sub-valvular height of the stent and reducing the risk of obstruction of the blood outflow tract structure. That is, when the total height of the inner stent 110 remains unchanged, the inner stent 110 can be appropriately moved towards the left atrium end, so that the proximal end 1111 of the inner inflow tract structure is higher than the distal end 1212 of the outer inflow tract structure in the axial height of the stent. At this time, the proximal end of the valve 200 on the inner stent 110 is lower than the distal end 1212 of the outer inflow tract structure, or in the axial direction, the two are approximately the same in height, that is, the proximal end 1111 of the inner inflow tract structure of the inner stent 110 is not completely covered by the valve 200.

[0056] As Figure 5As shown, the outer stent 120 is connected to the inner stent 110 on the outflow tract structure side. In the axial height of the stent, the connection point of the inner stent 110 and the outer stent 120 is higher than the connection point of the anchoring structure 130 and the inner stent 110. The distal end 1222 of the outer outflow tract structure is directly or indirectly connected to the outside of the inner stent 110. At the connection point between the two, the mesh structure units of the whole or part of the outer stent 120 are connected to the inner stent 110. Both the outer stent 120 and the inner stent 110 are composed of mesh structure units in the axial direction. The mesh structure unit has a mesh edge rod and a node. The mesh edge rod is the rod forming the mesh structure unit, and the node is the connection point formed by the connection of at least two mesh edge rods. For example, the inner stent 110 and the outer stent 120 are connected by welding node to node. At the connection, the outer stent 120 has 18 nodes and the inner stent 110 has 18 nodes. The 18 nodes of each can be welded one by one in sequence, or several corresponding nodes can be uniformly selected circumferentially for welding. The number of nodes at the connection of the inner stent 110 and the outer stent 120 can be the same or different, and an appropriate number of corresponding nodes can be selected for connection according to actual needs. The connection point can be various suitable connection forms such as node-to-node connection (that is, the nodes of the mesh structure unit on the outer stent 120 and the nodes of the mesh structure unit on the inner stent 110 overlap to form a connection point), node-to-mesh edge rod connection, and mesh edge rod-to-mesh edge rod connection, that is: the mesh edge rod on the inner stent 110 overlaps with the node or mesh edge rod of the mesh unit structure on the outer stent 120 to form a connection point; or the mesh edge rod on the outer stent 120 overlaps with the node of the mesh unit structure on the inner stent 110 to form a connection point. The connection points can be circumferentially distributed on the grids at the same axial height, which can be uniform or non-uniform, or can be appropriately staggered from each other, that is, several adjacent connection points are respectively located on the grids at different axial heights above and below. The connection method can be various suitable connection methods such as riveting, welding, and suture connection, or can also be connected through animal pericardium and skirt.

[0057] The outer inflow tract structure 1210 extends away from the inner stent 110 in a trumpet shape. The inflow tract structure of the outer stent 120 covers the atrioventricular orifice. The diameter at the proximal end 1211 of the outer inflow tract structure is larger than the diameter of the native valve. The diameter at the proximal end 1211 of the outer inflow tract structure can be 25 - 75 mm.

[0058] The proximal end 1221 of the outer outflow tract structure is adjacent to the outer inflow tract structure 1210. The outer outflow tract structure 1220 is adjacent to the inner outflow tract structure 1120. The maximum dimension of the main body of the outer outflow tract structure 1220 is larger than the diameter of the native valve. The main body of the outer outflow tract structure 1220 can be cylindrical or conical, and can effectively fit with the native valve leaflets without circumferential alignment. Preferably, the main body of the outer outflow tract structure 1220 is elliptical cylindrical or columnar with a D-shaped cross-section, which can better adapt to the shape of the native valve. The distal end 1222 of the outer outflow tract structure extends radially inward to the inner stent 110 to form an adduction structure. One end of the adduction structure is adjacent to or connected to the inner stent 110, and the other end of the adduction structure is connected to the main body of the outer inflow tract structure 1210.

[0059] The outer stent 120 is composed of structural units such as reticular structural units or wavy structural units whose axial morphology can be changed. Axially, the outer stent 120 is composed of at least one row of structural units that are circumferentially connected to each other. The multiple rows of units in the outer stent 120 can be directly or indirectly connected to each other axially. The outer stent 120 has two forms: a crimped state and an expanded state. In the crimped state, the axial dimension of the structural unit increases while the circumferential diameter decreases. Conversely, in the expanded state, the axial dimension decreases while the circumferential diameter increases. The reticular structural units can be diamond-shaped, pentagonal, hexagonal, etc., which can form closed shapes.

[0060] The material of the outer stent 120 is nitinol or other biocompatible materials with shape memory properties. The outer stent 120 can be manufactured by wire braiding, or by cutting process, or by using both. It is manufactured through processes such as heat treatment, sandblasting, and polishing, or can also be manufactured by other processes for manufacturing stents, such as 3D printing, etc.

[0061] The outer stent 120 can also be manufactured by wire braiding process, braided from one or more wires. The inner stent 110 is manufactured by cutting a pipe. At the connection point between the two, holes are provided in the inner stent 110, and the outer stent 120 is fixed after passing through these holes during the braiding process, or the two are connected by wires or other materials.

[0062] The outer stent 120 can also be manufactured by cutting process and then through processes such as heat treatment, sandblasting, and polishing. It is directly or indirectly connected to the inner stent 110. The direct connection is a metal connection method such as welding, and the indirect connection is to use a third-party component, such as rivets to connect the two, or a polymer material between the outer stent and the inner stent.

[0063] Such as Figure 6As shown, preferably, in another preferred embodiment, the outer stent 120, the inner stent 110, and the anchoring structure 130 are manufactured by integral cutting, that is, the outer stent 120, the inner stent 110, and the anchoring structure 130 are integrally formed. After cutting, with a special stent design and heat treatment design, through processes such as sandblasting and polishing, the stent is formed with the characteristic that the inner stent 110 has strong stiffness and the outer stent 120 has weak stiffness. After integral cutting is completed, the structural units of the outer stent 120 extend radially away from the inner stent from their connection points with the inner stent 110, and then extend towards the inflow channel structure direction to form the structure of the outer stent 120. The stent 100 is manufactured by integral cutting. The inner stent 110, the outer stent 120, and the anchoring structure 130 are an integral whole in the initial state, and there is no need to connect the structures through post-processing. The relative positions of the structures are stable and precise, avoiding functional defects caused by position deviations between the structures due to various post-processing factors, such as positioning errors during connection processing and loosening between the structures caused by the force after the prosthetic valve is implanted.

[0064] In other embodiments, the outer stent 120 can also be manufactured by a combination of cutting and weaving processes. For example, the outer inflow channel structure 1210 is formed by a structure of braided wires, and the outer outflow channel structure 1220 is formed by a cutting process. The outer outflow channel structure side 1220 is directly or indirectly connected to the inner stent 110. There is a direct or indirect connection between the outer inflow channel structure 1210 and the outer outflow channel structure side 1220 of the outer stent 120. A direct connection means that there are connection points for the structural units in different parts, and the adoption method is such as welding. An indirect connection means that there are no connection points between the inflow channel structure side units and the outflow channel structure side units. For example, a third-party component is used for connection, such as using a rivet or the like to indirectly connect the outer stent 120 and the inner stent 110. In a specific implementation, the outer outflow channel structure 1220 and the inner stent 110 are integrally formed, and then directly or indirectly connected to the outer inflow channel structure 1210 manufactured by a weaving process.

[0065] As Figure 7 As shown, the valve 200 includes at least two prosthetic leaflets. The prosthetic leaflets are made of animal pericardium or other biocompatible polymer materials. The connection end 210 of the prosthetic leaflet is directly or indirectly stably connected to the inner stent 110, and the other end of the prosthetic leaflet is the free edge 220. In the working state of the prosthetic valve, the prosthetic leaflets replace the native leaflets to realize the function of opening and closing the blood channel.

[0066] The prosthetic leaflets of the valve are connected to the inner side of the inner stent 110, and the inner surface or the outer surface or both the inner and outer surfaces of the inner stent 110 are covered with a skirt 300. The area covered by the skirt 300 at least includes the area where the artificial leaflets cover the inner stent 110 during the opening and closing movement of the artificial leaflets, so as to realize the sealing function of the skirt 300 and ensure that the single blood channel is from the inflow channel structure end of the prosthetic leaflet to the outflow channel structure end of the prosthetic leaflet.

[0067] The outer stent 120 and the inner stent 110 are covered with a skirt 300 made of pericardium or other biocompatible polymer materials, and cooperate with the prosthetic leaflets to form a single blood flow channel. The skirt 300 extends from the inner side of the proximal end 1211 of the inflow channel structure to the connection point of the inner stent 110 and the outer stent 120, and then extends along the outer side of the inner stent 110 towards the inflow channel structure direction, covering the entire inner stent 110. The skirt 300 can also extend from the inner side of the proximal end 1211 of the inflow channel structure of the outer stent 120 to the connection point of the inner stent 110 and the outer stent 120, and then extend along the outer side of the inner stent 110 towards the inflow channel structure direction, covering part of the inner stent unit structure, that is, part of the unit near the proximal end 1111 of the inner inflow channel structure is not covered by the skirt. It is also possible that both the inner side and the outer side of the inner stent 110 are covered with the skirt 300, and at least one side of the skirt 300 covers the area on the inner stent when the artificial leaflet is opened.

[0068] The anchoring structure 130 radially extends away from the inner stent 110 from the side of the inner outflow channel structure 1120, and the free end 132 of the anchoring structure 130 is away from the fixed point 131 of the anchoring structure 130 and the inner stent 110 towards the inflow channel structure direction, and part of the outer stent 120 is located between the free end 132 and the fixed point 131. The fixed point 131 can be located at any position on the side of the inner outflow channel structure. Preferably, the fixed point is located at the distal end 1112 of the inner inflow channel structure.

[0069] At least two anchoring structures 130 are circumferentially distributed, respectively anchoring the stent 100 to the two leaflets of the native valve. When the prosthetic valve stent is in the expanded state, the leaflets of the native valve are clamped between the anchoring structure 130 and the outer stent 120, preventing the valve prosthesis from being significantly displaced towards the inflow channel structure direction of the stent under the blood pressure. The anchoring structure 130 and the inner stent 110 can be integrally processed, or they can be connected by any stable connection method such as riveting, welding, or buckling.

[0070] In a specific implementation, such as Figure 9aAs shown, the anchoring structure 130 is a cantilever structure. The base of the cantilever is the fixed point 131, and the free end of the cantilever is 132. The prosthetic valve has 8 cantilever structures, and the 8 cantilever structures are evenly distributed along the circumferential direction on the inner stent 110. The cantilever structure can also be a rod-shaped structure. The fixed point of each cantilever structure and the inner stent 110 is one position, and its free end 132 is in a shape without obvious edges and corners such as spherical or ellipsoidal.

[0071] In a specific implementation, as Figure 9b shown, both the head and the end of the anchoring structure 130 are fixed on the mesh structure unit of the inner stent 110, so that the anchoring structure 130 and the structural unit of the inner stent 110 form a closed structure, and the fixed point of each anchoring structure and the inner stent 110 is at least two.

[0072] In a specific implementation, as Figure 9c shown, there are small barbs or serrations on the side of the anchoring structure facing the outer stent 120. In the expanded state, the small barbs or serrations penetrate into the valve leaflets, which can further increase the anchoring force.

[0073] In a specific implementation, as Figure 9d shown, on the side of the anchoring structure where it fits with the native valve leaflet, that is, on the side of the anchoring structure facing the outer stent 120, it presents a serrated shape, increasing the friction between the anchoring structure and the valve leaflet and improving the anchoring stability.

[0074] In a specific implementation, the lug 140 is a connection structure between the prosthetic stent 100 and the delivery system for transporting the prosthetic valve. The lug 140 can be manufactured on the inner stent 110, or on the outer stent 120, or both. Its position can be at the proximal end 1211 of the outer inflow tract structure, the distal end 1222 of the outer outflow tract structure, the proximal end 1111 of the inner inflow tract structure, or / and the distal end 1122 of the inner outflow tract structure. When the lug 140 is at the proximal end 1111 of the inner inflow tract structure, the prosthetic valve adopts a bilateral release method. Bilateral release means that before the prosthetic valve is completely released, both the inflow tract structure side and the outflow tract structure side can be detached from the delivery system. First, the anchoring structure 130 is released, and then a part of the outer outflow tract structure 1220 is released. After the native valve leaflet is located between the anchoring structure 130 and the outer stent 120, the outer inflow tract structure 1220 is gradually released, and finally the inner inflow tract structure 1110 is released.

[0075] The tricuspid valve, as the atrioventricular valve of the right heart, has a structure similar to that of the mitral valve and also includes valve leaflets, valve annulus, chordae tendineae, papillary muscles, and myocardium. The prosthetic valve used to replace the native mitral valve can also be applied to replace the native tricuspid valve. Due to the different sizes of the native valves, the sizes of the prosthetic valves for transcatheter replacement are different.

[0076] In summary, for the artificial heart valve prosthesis provided by the present invention, the sub-valve structure of the prosthesis valve has a low height, reducing the risk of interference with the native heart sub-valve structure and the risk of obstruction of the ventricular outflow tract structure; the double-layer stent design, the inner stent 110 has a high stiffness and a relatively small diameter matching the prosthesis leaflet, and the inner stent 110 and the prosthesis leaflet have a high service life; the outer stent 120 has a low stiffness and fits with the native tissue to achieve a sealing effect. Although the diameter of the outer stent 120 is large, it does not bear the pulling force when the prosthesis leaflet closes, and the risk of local large stress on the stent during the working state is relatively low, and the service life is relatively high; since the anchoring structure 130 is stably connected to the inner stent 110, the anchoring force for preventing the prosthesis valve from shifting is mainly borne by the inner stent 110 with strong stiffness, which can better resist the squeezing force of the heart, prevent the stent 100 from moving with the squeezing, and achieve a high structural service life; when the structures of the double-layer stent are integrally cut and manufactured, there is no need to connect the structures through post-processing. The relative positions of the structures are stable and precise, avoiding functional defects caused by position deviations between the structures due to various post-processing factors.

[0077] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the claims.

Claims

1. An artificial heart valve stent, characterized in that, It includes an outer support and an inner support; The inner layer support and the outer layer support are fixedly connected, and the rigidity of the inner layer support is greater than the rigidity of the outer layer support; The outer layer support comprises an outer layer inflow channel structure and an outer layer outflow channel structure which are axially connected; The inner layer support comprises an inner layer inflow channel structure and an inner layer outflow channel structure which are axially connected and are radially located on the inner side of the outer layer support. An anchoring structure is arranged on the inner layer support, and the anchoring structure is radially away from the inner layer support from the inner layer outflow channel structure side, and the free end of the anchoring structure is away from the fixing point between the anchoring structure and the inner layer support toward the inflow channel structure direction, and a part of the outer layer support is located between the free end and the fixing point, the inner layer support is connected to the outer layer support at the inner layer outflow channel structure, and the axial position of the connection point between the inner layer support and the outer layer support is higher than the connection point between the anchoring structure and the inner layer support; the proximal end of the inner layer inflow channel structure is axially higher than the distal end of the outer layer inflow channel structure along the direction away from the outflow channel structure.

2. The artificial heart valve stent according to claim 1, characterized in that, The inner layer stent and the outer layer stent are made of different biocompatible materials.

3. The artificial heart valve stent according to claim 1, wherein The inner layer support and the outer layer support are made of the same biocompatible material and adopt different structures or heat treatment processes so that the rigidity of the inner layer support is greater than that of the outer layer support.

4. The artificial heart valve stent according to claim 1, characterized in that, In the expanded state, the inner layer stent is tubular, and the maximum tubular outer diameter of the inner layer stent is less than 75 mm.

5. The artificial heart valve stent according to claim 1, characterized in that, The outer layer support and / or the inner layer support are composed of at least one row of mesh structure units connected to each other along the circumferential direction in the axial direction, and the outer layer support and / or the inner layer support are provided with hanging ears.

6. The artificial heart valve stent according to claim 1, wherein The distal end of the inner layer outflow channel structure extends radially toward an axial direction away from the inner layer support.

7. The artificial heart valve stent according to claim 1, wherein, The outer layer support and the inner layer support are both composed of mesh structure units in the axial direction, and the mesh structure units have mesh edge rods and nodes; the nodes of the mesh structure units on the outer layer support and the nodes of the mesh structure units on the inner layer support overlap with each other to form connection points; or the mesh edge rods on the inner layer support overlap with the nodes or mesh edge rods of the mesh unit structure of the outer layer support to form connection points; or the mesh edge rods on the outer layer support overlap with the nodes of the mesh unit structure of the inner layer support to form connection points.

8. The artificial heart valve stent according to claim 1, characterized in that, The proximal end of the outer layer inflow duct structure radially extends outward away from the inner layer stent, and the minimum diameter of the proximal end of the outer layer inflow duct structure is greater than 25 mm.

9. The artificial heart valve stent according to claim 1, wherein, The distal end of the outer outflow duct structure radially extends toward the inner support side to form an inward structure, one end of the inward structure is adjacent to or connected to the inner support, and the other end of the inward structure is connected to the outer outflow duct structure.

10. The artificial heart valve stent according to claim 1, characterized in that, The main body of the outer layer outflow channel structure is cylindrical, conical, elliptical, or a column with a D-shaped cross section.

11. The artificial heart valve stent according to claim 1, characterized in that, At least two anchoring structures are distributed along the circumferential direction of the inner layer outflow channel structure.

12. The artificial heart valve stent according to claim 1, characterized in that, The anchoring structure has two ends, one end of which is a fixed end fixed to the inner layer support, and the other end is a free end.

13. The artificial heart valve stent according to claim 12, characterized in that, The anchoring structure is a rod-shaped structure. The fixed end of the rod-shaped structure has one fixed point with the inner stent, and the free end of the rod-shaped structure is spherical or ellipsoidal.

14. The artificial heart valve stent according to claim 1, wherein The anchoring structure has two ends, both of which are fixed on the mesh structure unit of the inner stent, and the anchoring structure and the structural unit of the inner stent form a closed structure.

15. The artificial heart valve stent according to claim 1, characterized in that, On the side of the anchoring structure facing the inner stent, small barbs are provided or it is set in a serrated shape.

16. An artificial heart valve prosthesis, characterized in that, It includes the artificial heart valve stent according to any one of claims 1-15, and also includes an artificial valve leaf and a skirt. The artificial valve leaf is arranged on the inner side of the inner stent, and the skirt is arranged on the inner surface and / or outer surface of the outer stent or / and the inner stent. The area covered by the skirt at least includes the area covered by the artificial valve leaf on the inner stent when the artificial valve leaf opens and closes.

17. The artificial heart valve prosthesis according to claim 16, characterized in that, The skirt extends from the inner side of the proximal end of the outer inflow channel structure of the outer stent towards the connection point of the inner stent and the outer stent, and then extends along the outer side of the inner stent towards the inner inflow channel structure.

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