A new type of valve stent and artificial heart valve

Abstract

This invention discloses a novel valve stent and artificial heart valve, belonging to the field of medical device technology. The valve stent has a hollow, symmetrical, mesh-like tubular structure, with a first layer of hexagonal mesh groups, a second layer of polygonal mesh groups, and a third layer of polygonal mesh groups arranged sequentially from the outflow end to the inflow end. The stent has a small overall mesh count and symmetrical structure, resulting in uniform deformation during compression and expansion. It exhibits excellent radial support and minimal expansion rebound, significantly reducing the risk of paravalvular leakage. While maintaining radial support, this invention can reduce the stent strut width to 0.2–0.4 mm, and the minimum outer diameter of the valve after compression can reach 2.5–4.5 mm. Simultaneously, the overall length change during stent compression and expansion is minimal, greatly improving the smoothness of vascular delivery and the accuracy of valve implantation positioning. This meets the clinical needs of transcatheter aortic valve replacement surgery, enhancing the safety and effectiveness of artificial heart valve implantation.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, specifically to a novel valve stent and artificial heart valve. Background Technology

[0002] With the increasing aging of the population, the proportion of age-related aortic valve disease is rising. Traditional treatment for aortic valve disease involves open-chest surgery to replace the valve with a mechanical or bioprosthetic valve. This type of surgery causes significant damage to the patient's body, and patients with mechanical valves need to take anticoagulants for life. Bioprosthetic valves have a relatively short lifespan and will gradually deteriorate, leading to problems such as valvular stenosis or insufficiency, potentially requiring a second open-chest surgery for valve replacement.

[0003] Transcatheter aortic valve replacement (TAVR) is a valve replacement technique that has been actively developed both domestically and internationally in recent years. This technique involves delivering an artificial heart valve to the diseased site via vascular intervention to replace the original valve. Compared to traditional surgery, TAVR does not require open-chest surgery, resulting in less surgical trauma, shorter operation time, and faster postoperative recovery. It is suitable for elderly patients and high-risk patients who cannot tolerate traditional surgical methods. The TAVR procedure uses a delivery system to deliver the compressed artificial heart valve to the diseased site, expands the valve stent by inflating a balloon, and then implants and fixes the valve to the original valve annulus.

[0004] Currently, transcatheter aortic valves still have many shortcomings in actual clinical use: After a valve is implanted in the human body, the metal rebounds after the stent expands and is also squeezed by the original valve annulus. Gaps can easily form between the valve and the original valve annulus, and the fabric skirt cannot completely fit and fill them, which can lead to paravalvular leakage complications. Existing transcatheter aortic valve stents have a long length and a large clamping diameter after compression, which is not conducive to the delivery of the valve in tortuous blood vessels, increasing the difficulty of the operation and the risk of vascular damage. When the valve expands radially within the valve annulus, the length of the stent changes significantly, which can easily lead to deviation of the final implantation position of the valve, affecting the surgical outcome and the long-term lifespan of the valve. Existing stent structures cannot balance radial support and gripping performance: stents with quadrilateral grid structures are easy to deform and easy to grip and expand, but the deformation is uneven during compression and expansion, which can easily lead to bone-like deformation and cause perivalvular leakage; stents with hexagonal or polygonal grid structures have excellent radial support, but the gripping diameter is large, which increases the risk of obstruction during delivery, and both types of structures have the problem of large length changes during compression and expansion.

[0005] To address the aforementioned issues, existing technologies have made relevant improvements. Chinese patent CN216535665U discloses a balloon-expandable stent and an artificial aortic valve. The stent has multiple sets of mesh groups arranged sequentially from the outflow end to the inflow end. By adjusting the mesh size difference between different mesh groups, the mesh group in contact with the human aortic valve tissue has a larger mesh size, improving sealing and reducing the valve's outer diameter under compression. However, in this solution, a larger mesh size reduces the stent's radial support force, affecting sealing under compression from the original valve annulus. Furthermore, simply increasing the mesh size of a single mesh group cannot effectively reduce the overall compressed outer diameter of the valve.

[0006] Chinese patent CN114469446B discloses a valve stent and valve prosthesis. By adjusting the number of wave rod units in different layers of wave rod unit groups, multiple large grids are formed between layers, reducing the risk of the original leaflet obstructing the coronary ostium. Simultaneously, no straight rods are added within the large grids to reduce the stent's gripping diameter, and the radial support force is improved through continuous and uniform multi-layered grids. However, in this design, the large grid structure without straight rods still leads to a decrease in the stent's radial support force, failing to address the core issues of large length changes and implantation positioning misalignment during stent compression and expansion.

[0007] In light of the problems mentioned above, we propose a novel valve stent and artificial heart valve. Summary of the Invention

[0008] The purpose of this invention is to provide a novel valve stent and artificial heart valve to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A novel valve stent, wherein the valve stent is a hollow mesh tubular symmetrical structure, and the stent consists of a first mesh group, a second mesh group, and a third mesh group in sequence from the outflow end to the inflow end; The first layer of mesh group is distributed at the outlet end of the support. Its mesh frame is a hexagonal structure, and there are three fixing rods evenly distributed in the circumference for fixing the leaflets. The second layer of mesh is distributed in the middle transition section of the support, and the third layer of mesh is distributed at the inflow end of the support. The mesh frames of the second layer of mesh and the third layer of mesh are both symmetrically distributed polygonal structures. The support has a small number of overall grids, a uniform and symmetrical structure, uniform deformation during compression and expansion, excellent radial support force, and small rebound after expansion.

[0010] Preferably, the grid frame units of the first layer of grid group are symmetrically distributed except for the structure at the fixed rod, and are composed of a first layer of diagonal rods, a first layer of vertical rods or fixed rods, and a second layer of diagonal rods; A circular arc transition section is provided between the symmetrically distributed first layer of diagonal bars, and the circular arc transition section is the top end of the outlet end of the support; A circular arc transition section is set between the second layer of diagonal bars, the width of which is 1.5 to 2.5 times the width of the circular arc transition section at the top of the outflow end.

[0011] Preferably, a U-shaped transition section is provided between the first layer of diagonal braces and the first layer of vertical braces, and the ratio of the width of the widest part of the transition section to the width of the first layer of vertical braces is 2 to 3.5. A tree-branch-shaped intersection is provided between the first layer of vertical bars and the second layer of diagonal bars to enhance the stability of the grid structure during the deformation of the support.

[0012] Preferably, the grid frame units of the second layer grid group are symmetrically distributed polygonal structures, consisting of a second layer of diagonal bars, a second layer of vertical bars, and a third layer of diagonal bars. The second layer of diagonal bars and the third layer of diagonal bars have the same structure and are nearly parallel to each other. An arc transition section is provided between the third layer of diagonal braces, and a tree branch-shaped intersection section is provided between the second layer of vertical braces and the third layer of diagonal braces.

[0013] Preferably, the grid frame unit of the third layer grid group is a symmetrically distributed polygonal structure, consisting of a third layer of diagonal bars, a third layer of vertical bars, and a fourth layer of diagonal bars. The third layer of diagonal bars and the fourth layer of diagonal bars have the same structure and are distributed in a mirror image symmetrically. An arc transition section is provided between the fourth layer of diagonal braces, and a tree branch-shaped intersection section is provided between the third layer of vertical braces and the fourth layer of diagonal braces.

[0014] Preferably, the fixing rod has a gap in the middle, and the gap is rectangular, has two rows of rectangular holes, or has two rows of circular holes, with 2 to 4 holes in a single row.

[0015] An artificial heart valve includes a novel valve stent as described above, and further includes leaflets, a skirt, and sutures, wherein the leaflets and skirt are fixed to the valve stent by the sutures.

[0016] Preferably, a single artificial heart valve comprises three identical fan-shaped leaflets, each leaflet including a leaflet body, a first fixing plate, a second fixing plate, and an arc-shaped bottom edge; The second fixation piece of the adjacent leaflet is connected by suture. After being connected, the second fixation piece passes through the gap of the fixation rod from the inside of the valve stent, folds to both sides of the fixation rod and aligns with the first fixation piece, and is fixed to the fixation rod by suture. The curved bottom edge is sewn and fixed to the petal skirt.

[0017] Preferably, the valve skirt includes a valve skirt body and a suture edge, wherein the suture edge is serrated and its shape matches the mesh shape of the valve stent; The petal-shaped roll is cylindrical and fixed to the inside of the support with stitching to form an inner skirt edge, and then folded from the inside to the outside and fixed to the outside of the support to form an outer skirt edge.

[0018] Preferably, the material of the petal skirt is polyethylene terephthalate or polyurethane foam; The skirt is either a one-piece structure or a separate inner and outer skirt structure, with the outer skirt being a three-dimensional structure with protrusions.

[0019] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a composite structure design with three layers of differentiated grids, balancing the stent's deformability with radial support: the large-opening hexagonal grid at the outflow end prevents compression of the native leaflet, reduces the risk of coronary ostium obstruction, and provides a channel for coronary interventional devices; the symmetrical polygonal grid structure in the middle and inflow sections ensures the overall radial support of the stent, with minimal rebound after expansion, allowing the valve to fit tightly against the native annulus tissue, and significantly reducing the risk of paravalvular leakage when combined with the valve skirt structure.

[0020] The stent of this invention has a small overall mesh and a symmetrical structure. While ensuring radial support, the width of the support rod can be reduced to 0.2-0.4 mm. With the help of high-performance alloy materials such as rhenium alloy, the outer diameter of the valve after compression can be reduced to 2.5-4.5 mm. The outer diameter of the catheter of the matching delivery system can be reduced simultaneously, which greatly improves the smoothness of valve delivery in tortuous blood vessels and reduces the difficulty of surgical operation and the risk of vascular damage.

[0021] This invention achieves minimal axial length change during stent compression and expansion through a linked design of a grid structure: only the first grid layer experiences a small length change, while the second and third grid layers show no axial length change. The stent is shorter after compression and is easier to cross vascular access. The small size change during valve expansion and implantation effectively avoids implantation position deviation and significantly improves the accuracy of valve implantation positioning.

[0022] This invention effectively eliminates stress concentration at the intersection of diagonal bars during stent deformation through structural optimization of U-shaped transition sections, tree-branch-shaped intersecting sections, and multi-segment circular arc transitions. This avoids problems such as damage to the balloon at the top of the stent during expansion and damage to the valve skirt during compression expansion. At the same time, it enhances the stability of the grid structure, reduces the risk of stent displacement and deformation, and improves the long-term stability and service life of the valve after implantation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the artificial heart valve described in this invention; Figure 2 This is a three-dimensional structural diagram of the valve stent described in this invention; Figure 3This is a front view of the valve stent described in this invention; Figure 4 This is a schematic diagram of the unfolded leaflet described in this invention; Figure 5 This is a schematic diagram of the structure of the petal skirt described in this invention; Figure 6 This is a schematic diagram of the unfolded structure of the valve stent described in this invention; Figure 7 This is a schematic diagram showing the length change of the valve stent described in this invention during compression and expansion; Figure 8 This is a partially enlarged schematic diagram of the outflow end of the valve stent described in this invention; Figure 9 This is a partially enlarged schematic diagram of the intermediate transition section of the valve stent described in this invention; Figure 10 This is a partially enlarged schematic diagram of the inflow end of the valve stent described in this invention.

[0024] In the attached image: 1. Valve stent; 2. Leaflet; 3. Valve skirt; 4. Suture; 100. First layer mesh group; 110. Fixing rod; 120. First layer mesh frame; 121. First layer diagonal bar; 122. First layer vertical bar; 123. Second layer diagonal bar; 124. Arc transition section; 125. Transition section; 126. Cross section; 127. Arc transition section; 200. Second layer mesh group; 220. Second layer mesh frame; 221. Third layer diagonal bar; 222. Second layer vertical bar; 22 3. Arc transition section; 224. Cross section; 300. Third layer grid group; 320. Third layer grid frame; 321. Fourth layer diagonal bar; 322. Third layer vertical bar; 323. Arc transition section; 324. Cross section; 21. Leaflet body; 22. First fixing piece; 23. Second fixing piece; 24. Arc-shaped bottom edge; 31. Leaflet skirt body; 32. Seam edge; 33. Inner skirt edge; 34. Outer skirt edge; L1. Length of the support in expanded state; L2. Length of the support in compressed state. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, the artificial heart valve of the present invention is mainly composed of a valve stent 1, a leaflet 2, a skirt 3, and a suture 4.

[0027] The valve stent 1 is made of cobalt-chromium alloy, rhenium alloy or other malleable metal materials. In this embodiment, rhenium alloy is preferred because it has excellent ductility, tensile strength, yield strength and fatigue resistance, and can achieve smaller support rod size and better mechanical properties. The stent is integrally formed by laser cutting alloy tubing.

[0028] The valve leaflet 2 is made of high molecular polymer polyurethane, which is formed by dip coating and coating, and then cut into the required valve leaflet shape by carbon dioxide laser. The polymer valve leaflet has the characteristics of good biocompatibility, anti-calcification, anti-coagulation and excellent mechanical properties, which can effectively improve the service life of the valve.

[0029] The material of the petal skirt 3 is polyethylene terephthalate (PET) or polyurethane foam. In this embodiment, the inner skirt is made of PET woven fabric and the outer skirt is made of polyurethane foam, which can further improve the fit and sealing with the original petal ring.

[0030] The material of the suture 4 is polyester, ultra-high molecular weight polyethylene or polytetrafluoroethylene. In this embodiment, ultra-high molecular weight polyethylene suture is preferred because it has excellent tensile strength and biocompatibility.

[0031] like Figure 2 , Figure 3 , Figure 6 As shown, the main body of the valve stent 1 is a hollow grid tubular structure, and along the stent from the outflow end to the inflow end are the first grid group 100, the second grid group 200 and the third grid group 300 in sequence.

[0032] The first layer of mesh group 100 is distributed at the stent outlet end. The first layer of mesh frame 120 is a hexagonal structure with three fixing rods 110 evenly distributed circumferentially for fixing the leaflet 2. The gap in the middle of the fixing rod 110 is rectangular, or it can be designed as two rows of rectangular holes or two rows of circular holes. The number of holes in a single row is 2 to 4. In this embodiment, a structure with 3 rectangular holes in a single row is used to facilitate the suturing and fixing of the leaflet. The mesh opening area of ​​the first layer of mesh group 100 is the largest, ranging from 25 to 45 mm². After valve implantation, the large opening mesh will not compress the original leaflet, reducing the risk of the leaflet obstructing the coronary artery ostium. This facilitates the smooth entry of coronary interventional instruments into the coronary artery, is more favorable for patients with low coronary artery ostium positions, and can significantly reduce the risk of intraoperative coronary artery occlusion.

[0033] like Figure 8As shown, each grid frame unit of the first layer grid frame 120, except for the grid structure at the fixed rod 110, is symmetrically distributed and consists of a first layer of diagonal rods 121, a first layer of vertical rods 122 (or fixed rods 110), and a second layer of diagonal rods 123. Between the symmetrically distributed first layer of diagonal rods 121 is an arc transition section 124, which is the top of the stent's outflow end. This arc transition design prevents damage to the balloon at the top of the stent during expansion. Between the second layer of diagonal rods 123 is an arc transition section 127, the width of which is 1.5 to 2.5 times that of the arc transition section 124. This larger arc transition prevents damage to the valve skirt during compression or expansion of the stent and also helps reduce stress concentration during stent deformation.

[0034] The transition section 125 is between the first layer of diagonal braces 121 and the first layer of vertical braces 122. The transition section 125 has a U-shaped structure, and the width ratio between the widest part of the structure and the vertical brace 122 is between 2 and 3.5. The U-shaped structure can effectively eliminate stress concentration at the intersection of the diagonal braces during the deformation process of the support. The intersection section 126 is between the first layer of vertical braces 122 and the second layer of diagonal braces 123. The intersection section 126 has a tree branch-like structure, which can significantly enhance the stability of the grid structure during the deformation process of the support.

[0035] The second layer of grids 200 is distributed in the middle transition section of the stent, and the third layer of grids 300 is distributed at the inlet end of the stent. Both the second layer of grid frames 220 and the third layer of grid frames 320 are symmetrically distributed polygonal structures, which takes into account both the deformability of the stent and the radial support force. The stent has a small overall number of grids, a uniform and symmetrical structure, and is easy to deform. During compression and expansion, it can reduce local stress concentration, reduce the risk of stent displacement or deformation, and improve valve implantation stability.

[0036] like Figure 9 As shown, the frame units of the second-layer grid frame 220 are symmetrically distributed polygonal structures, consisting of second-layer diagonal braces 123, second-layer vertical braces 222, and third-layer diagonal braces 221. The second-layer diagonal braces 123 and the third-layer diagonal braces 221 have the same structure and are nearly parallel. Between the third-layer diagonal braces 221 is an arc transition section 223, which has the same structure as the arc transition section 127, preventing damage to the petal skirts during compression or expansion and reducing stress concentration during deformation. Between the second-layer vertical braces 222 and the third-layer diagonal braces 221 is an intersection section 224, with the same structure as the intersection section 126, used to enhance structural stability during deformation. The polygonal structure of the intermediate transition section is evenly distributed along the circumference of the support, making the structure easily deformable and reducing local stress concentration during support compression and expansion, thus lowering the risk of support displacement or deformation.

[0037] like Figure 10As shown, the frame units of the third-layer grid frame 320 are symmetrically distributed polygonal structures, consisting of third-layer diagonal braces 221, third-layer vertical braces 322, and fourth-layer diagonal braces 321. The third-layer diagonal braces 221 and the fourth-layer diagonal braces 321 have the same structure and are mirror-symmetrically distributed. The fourth-layer diagonal braces 321 are connected by an arc transition section 323, which has the same structure and function as the arc transition section 223. The third-layer vertical braces 322 and the fourth-layer diagonal braces 321 are connected by an intersection section 324, which has the same structure and function as the intersection section 224.

[0038] The stent's intermediate transition section and inlet end employ a homogeneous structural design, ensuring uniform deformation of the stent as a whole during compression and expansion. This reduces stress concentration at the intersection of the diagonal struts, increases the stability of the mesh structure, and provides better radial support for the implanted valve. The fewer mesh elements in the intermediate transition section and inlet end result in better stent ductility, lower radial resistance during expansion, and easier deformation. Furthermore, both the second and third mesh frames are polygonal symmetrical structures. During valve compression and expansion, the valve skirts sutured to the struts move accordingly without being subjected to excessive stretching or compression, effectively preventing paravalvular leakage due to valve skirt damage.

[0039] While ensuring radial support force, the present invention has a small number of stents. With the help of high-performance alloy materials, the width of the stents can be reduced to 0.2-0.4 mm, the outer diameter of the valve after compression can be reduced to 2.5-4.5 mm, and the outer diameter of the matching delivery system catheter can also be reduced accordingly, which is beneficial for the delivery of valves in tortuous blood vessels.

[0040] like Figure 7 As shown, L1 represents the length of the stent in the expanded state, and L2 represents the length of the stent in the compressed state. During stent compression or expansion, one end of the grid of the first-layer grid frame 120 moves towards the valve's outflow or inflow end, while the other end moves within the grid of the second-layer grid frame 220. The end of the grid of the second-layer grid frame 220 moves within its own grid and within the third-layer grid frame 320; the end of the grid of the third-layer grid frame 320 moves within its own grid. Regarding the length change, the stent's length change during compression and expansion is only reflected in the length change caused by the movement of the end of the first-layer grid frame 120. The movement of the end of the second-layer and third-layer grid frames 220 does not cause a change in grid length, therefore the overall length change of the stent is minimal. The shorter stent length after compression makes it easier to cross vascular access when loaded onto the delivery system. During valve expansion, the change in the grid length at the outflow end of the stent is small, and the change in the grid length at the inflow end is essentially unchanged, reducing potential positional displacement due to stent shrinkage and resulting in more accurate valve implantation positioning.

[0041] like Figure 4As shown, a single artificial heart valve has three identical fan-shaped leaflets 2. Each leaflet 2 mainly includes a leaflet body 21, a first fixing piece 22, a second fixing piece 23, and an arc-shaped bottom edge 24. During assembly, the first fixing piece 22 and the second fixing piece 23 are folded together and sewn together on the side closest to the leaflet body 21. The second fixing pieces 23 of adjacent leaflets are connected by sutures. The connected second fixing pieces 23 pass through the gap in the fixing rod 110 from the inside of the valve support 1, folding once or multiple times to both sides of the fixing rod 110 to align with the corresponding first fixing piece 22. The first fixing piece 22 and the second fixing piece 23 are then connected and fixed to the fixing rod 110 by sutures. To ensure a more secure connection between the leaflet 2 and the support, a pad can be placed on the outside of the folded second fixing piece 23 for reinforcement. The fixing pieces, fixing rod, and reinforcing pad are then connected and fixed together by sutures. The arc-shaped bottom edge 24 on the leaflet is sewn onto the leaflet skirt 3 for fixation.

[0042] like Figure 5 As shown, the valve skirt 3 includes a valve skirt body 31 and suture edges 32. The valve skirt is rolled into a cylindrical structure and sutured and fixed inside the valve stent 1 to form an inner skirt edge 33. Then, the valve skirt is folded from the inside out and sutured and fixed to the outside of the stent to form an outer skirt edge 34. After the valve is implanted at the lesion site, the valve skirt fills the gap between the valve and the original valve annulus, closely fitting the original valve annulus, which can effectively reduce the occurrence of paravalvular leakage. The two ends of the valve skirt 3 are serrated suture edges 32. The shape of the suture edges matches the grid shape of the valve stent 1. The valve skirt is fixed to the stent support by multiple sutures.

[0043] In this embodiment, the valve skirt adopts a split design, with the inner skirt edge and outer skirt edge prepared and sewn separately. The outer skirt edge is designed as a three-dimensional structure with protrusions and is made of polyurethane foam elastomer material, which can make the valve and the valve annulus tissue fit more tightly and further reduce the risk of paravalvular leakage.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel valve stent, characterized in that, The valve stent is a hollow, symmetrical, grid-like structure, with a first grid group, a second grid group, and a third grid group arranged sequentially from the outflow end to the inflow end of the stent. The first layer of mesh group is distributed at the outlet end of the support. Its mesh frame is a hexagonal structure, and there are three fixing rods evenly distributed in the circumference for fixing the leaflets. The second layer of mesh is distributed in the middle transition section of the support, and the third layer of mesh is distributed at the inflow end of the support. The mesh frames of the second layer of mesh and the third layer of mesh are both symmetrically distributed polygonal structures. The support has a small number of overall grids, a uniform and symmetrical structure, uniform deformation during compression and expansion, excellent radial support force, and small rebound after expansion.

2. The novel valve stent according to claim 1, characterized in that, The grid frame units of the first layer of grid group are symmetrically distributed except for the structure at the fixed rod, and are composed of the first layer of diagonal rods, the first layer of vertical rods or fixed rods, and the second layer of diagonal rods. A circular arc transition section is provided between the symmetrically distributed first layer of diagonal bars, and the circular arc transition section is the top end of the outlet end of the support; A circular arc transition section is set between the second layer of diagonal bars, the width of which is 1.5 to 2.5 times the width of the circular arc transition section at the top of the outflow end.

3. A novel valve stent according to claim 2, characterized in that, A U-shaped transition section is provided between the first layer of diagonal braces and the first layer of vertical braces, and the ratio of the width of the widest part of the transition section to the width of the first layer of vertical braces is 2 to 3.

5. A tree-branch-shaped intersection is provided between the first layer of vertical bars and the second layer of diagonal bars to enhance the stability of the grid structure during the deformation of the support.

4. A novel valve stent according to claim 1, characterized in that, The grid frame units of the second layer of the grid group are symmetrically distributed polygonal structures, consisting of a second layer of diagonal bars, a second layer of vertical bars, and a third layer of diagonal bars. The second layer of diagonal bars and the third layer of diagonal bars have the same structure and are nearly parallel to each other. An arc transition section is provided between the third layer of diagonal braces, and a tree branch-shaped intersection section is provided between the second layer of vertical braces and the third layer of diagonal braces.

5. A novel valve stent according to claim 1, characterized in that, The grid frame unit of the third layer grid group is a symmetrically distributed polygonal structure, consisting of a third layer of diagonal bars, a third layer of vertical bars, and a fourth layer of diagonal bars. The third layer of diagonal bars and the fourth layer of diagonal bars have the same structure and are distributed in a mirror symmetrical manner. An arc transition section is provided between the fourth layer of diagonal braces, and a tree branch-shaped intersection section is provided between the third layer of vertical braces and the fourth layer of diagonal braces.

6. A novel valve stent according to claim 1, characterized in that, The fixing rod has a gap in the middle, which can be rectangular, two rows of rectangular holes, or two rows of circular holes, with 2 to 4 holes in a single row.

7. An artificial heart valve, characterized in that, The novel valve stent according to any one of claims 1-6 further includes leaflets, skirts and sutures, wherein the leaflets and skirts are fixed to the valve stent by the sutures.

8. An artificial heart valve according to claim 7, characterized in that, A single artificial heart valve comprises three identical fan-shaped leaflets, each leaflet including a leaflet body, a first fixing plate, a second fixing plate, and an arc-shaped bottom edge; The second fixation piece of the adjacent leaflet is connected by suture. After being connected, the second fixation piece passes through the gap of the fixation rod from the inside of the valve stent, folds to both sides of the fixation rod and aligns with the first fixation piece, and is fixed to the fixation rod by suture. The curved bottom edge is sewn and fixed to the petal skirt.

9. An artificial heart valve according to claim 8, characterized in that, The valve skirt includes a valve skirt body and a suture edge, wherein the suture edge is serrated and its shape matches the grid shape of the valve stent; The petal-shaped skirt roll is cylindrical and fixed to the inside of the support with stitching to form an inner skirt edge, and then folded from the inside to the outside and fixed to the outside of the support to form an outer skirt edge.

10. An artificial heart valve according to claim 9, characterized in that, The material of the petal skirt is polyethylene terephthalate or polyurethane foam. The skirt is either a one-piece structure or a separate inner and outer skirt structure, with the outer skirt being a three-dimensional structure with protrusions.

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