Valve stent and artificial heart valve

Abstract

The invention discloses a valve stent and an artificial heart valve. The valve stent comprises four layers of grids, and any layer of grid comprises a plurality of grid frames which are sequentially connected in the circumferential direction of the valve stent; the layer of grid frame on one side of the outflow end and the two layers of grid frames on one side of the inflow end are hexagonal hollow frames, and the rest layer of grid frame is a quadrilateral hollow frame; the area of one layer of grid frame on one side of the outflow end is the largest, the areas of the other three layers of grid frames are sequentially increased in the direction from the outflow end to the inflow end, and the area difference is reduced. The structural design is easy to press and hold, the diameter is small after pressing and holding, and a conveyor can convey the stent to a lesion position. Deformation is uniform in the valve compression and expansion process, the balloon is stressed uniformly during pressurization and expansion, and the conveying and expansion process of the valve in a human body is smoother. The whole valve uniformly deforms, a bone-shaped structure with a thin middle part and two open ends is not easy to appear, the radial supporting force is good, and the use safety and effectiveness of the valve are improved.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a valve stent and an artificial heart valve. Background Technology

[0002] Transcatheter aortic valve replacement (TAVR) is a minimally invasive surgical procedure that replaces diseased aortic valves via vascular intervention. It is primarily used to treat elderly patients with severe aortic stenosis or regurgitation, or those at high surgical risk. During the procedure, a delivery system is used to transport a crimped artificial heart valve to the diseased site. A balloon is then inflated to expand the valve stent, which is then placed and fixed to the aortic annulus. However, some problems still exist in the practical use of TVRs. The crimped valve stent experiences greater pressure in the middle, and during balloon expansion, the stent expands unevenly, becoming thicker at both ends and thinner in the middle, resembling a bone-like structure. After implantation, gaps exist between the valve and the original annulus, increasing the probability of paravalvular leakage. Excessively large gaps can even lead to valve detachment, seriously endangering the patient's life.

[0003] Traditional treatment for aortic valve disease involves open-heart surgery to replace the valve with a mechanical or bioprosthetic valve. However, such surgeries are highly invasive, and patients require lifelong anticoagulant medication after implantation of a mechanical valve. Bioprosthetic valves have a relatively short lifespan and gradually deteriorate, leading to problems such as valvular stenosis or insufficiency, potentially requiring a second open-heart surgery for valve replacement, which is often unacceptable for elderly patients. Transcatheter aortic valve replacement (TAVR) is a valve replacement technique that has been actively developed both domestically and internationally in recent years. This technique delivers an artificial heart valve to the diseased site via vascular intervention to replace the original valve. Compared to traditional surgery, TAVR is less invasive, has a shorter operation time, and allows for faster recovery, making it suitable for patients who cannot tolerate traditional surgical methods.

[0004] Chinese patent document CN113855326B discloses an artificial heart valve, which includes multiple leaflets and an artificial heart valve stent, with the leaflets connected to the stent. The stent is a radially contractible and expandable annular stent, including an inflow end and an outflow end. Multiple interconnected inflow end frame units are gyroscope-shaped hollow frame units, and multiple interconnected outflow end frame units are hexagonal hollow frame units. This invention improves the safety of valve use by adjusting the size of the stent connecting rods (described in paragraph

[0065] of the specification) and the angle of adjacent connecting rods (described in paragraph

[0068] of the specification) and designing the top protrusion of the stent as an arc or ellipse, thereby avoiding the stent's inability to expand smoothly due to excessive pressure, puncturing the external balloon, and uneven stent expansion. Chinese patent document number CN11358825B discloses an interventional valve stent and a valve. The valve stent includes a body part with multiple valve orifices. By setting a support part inside the valve orifices of the valve stent and designing the support part to be protruding or concave, the support part can improve the support performance of the valve stent and reduce the risk of the valve dislodging from the diseased valve site. Artificial heart valves with this stent structure have good support and fixation performance and can effectively prevent valve dislodging.

[0005] In the existing valve stent solutions described above, adjusting the size of the stent connecting rods and the angle of adjacent connecting rods to avoid uneven stent expansion is difficult in practice and requires repeated verification. Furthermore, if there are significant differences in stent rod width and structural strength, uneven mesh deformation may occur during stent compression and expansion. While adding a support portion within the valve orifice to improve the stent's support performance may result in a larger stent diameter after compression, which is detrimental to valve delivery within the blood vessel. Therefore, this invention addresses this issue. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, the objective of this invention is to provide a valve stent and an artificial heart valve. This valve stent has a rational structural design, is easy to grip, provides uniform compression and expansion force, good radial support, effectively avoids the formation of bone-like structures, and ensures a tight fit between the valve and the valve annulus tissue, significantly reducing the risk of paravalvular leakage or valve detachment, and improving the safety and effectiveness of valve implantation in the human body.

[0007] The technical solution of this invention is:

[0008] One object of the present invention is to provide a valve stent, which is implemented as a radially compressible and expandable hollow grid tubular structure, including an inflow end at one axial end and an outflow end at the other axial end and a transition section between the two, extending from the outflow end to the inflow end along its axial direction. The valve stent includes four grid layers, and each grid layer includes multiple grid frames connected sequentially along the circumferential direction of the valve stent.

[0009] The first layer of the grid frame on the outflow side and the two layers of the grid frame on the inflow side are both implemented as hexagonal hollow frames, and the remaining layer of the grid frame is implemented as a quadrilateral hollow frame.

[0010] The area of ​​the first layer of mesh frame on the outflow end side is the largest, and the areas of the other three layers of mesh frames increase sequentially from the outflow end to the inflow end, with the area difference decreasing.

[0011] Preferably, along the direction from the outflow end to the inflow end, the four mesh layers are sequentially a first mesh layer, a second mesh layer, a third mesh layer, and a fourth mesh layer, and the four mesh frames are sequentially a first mesh frame, a second mesh frame, a third mesh frame, and a fourth mesh frame;

[0012] The area difference between any of the third mesh frames and any of the second mesh frames is 4.5~10mm. 2 The area difference between any of the fourth grid frames and any of the third grid frames is 0.5~7mm. 2 .

[0013] Preferably, the area of ​​any of the second grid frames is 8~20 mm². 2 The area of ​​any of the third mesh frames is 13~30mm². 2 The area of ​​any of the fourth grid frames is 14~32mm². 2 .

[0014] Preferably, the area of ​​any of the first mesh frames is 25~55mm². 2 .

[0015] Preferably, in the first layer of grid, any one of the first grid frames includes two first upper inclined rods that intersect at an angle on the outflow side, two first lower inclined rods that intersect at an angle on the inflow side, and two opposing and spaced first vertical rods located between the first upper inclined rods and the first lower inclined rods, and any two adjacent first grid frames share the first vertical rods;

[0016] Furthermore, in the first grid, at least two fixing rods with openings in the middle are provided at intervals along its circumferential direction, and the fixing rods of any two adjacent first grid frames with fixing rods are implemented to share a first vertical rod;

[0017] In any of the first grid frames, both of the first upper diagonal braces and both of the first lower diagonal braces are non-linear;

[0018] In any two adjacent first grid frames without the fixed rod, the connection point of the two adjacent first upper inclined rods is implemented as a first transition portion protruding outward toward the inflow end and opening toward the outflow end. The connection point of the two adjacent first lower inclined rods is implemented as a second transition portion protruding outward toward the outflow end and opening toward the inflow end. A first vertical support rod is connected between the first transition portion and the second transition portion, and all three are implemented as sharing a first vertical rod. The ratio of the width of the widest part of the first transition portion and the second transition portion to the width of the first vertical support rod is 1.8 to 2.7.

[0019] Preferably, any second grid frame includes two second upper inclined rods that intersect at an angle and are inclined toward the outflow end and two second lower inclined rods that intersect at an angle and are inclined toward the inflow end, wherein the two second upper inclined rods are respectively implemented as two adjacent first grid frames connected to the second grid frame and are close to each other, and both the second upper inclined rods and the second lower inclined rods are non-linear;

[0020] In any two adjacent second grid frames, the two second upper diagonal bars and the two second lower diagonal bars that are close to each other are connected by a third transition section;

[0021] The end of any second upper or lower diagonal bar that connects to the corresponding third transition portion is implemented as a connecting end, and the ratio of the width of the connecting end to the width at other positions of the second upper or lower diagonal bar is 0.85 to 0.95.

[0022] Preferably, any of the third grid frames includes two third upper inclined rods that intersect at an angle and are inclined toward the outflow end, two third lower inclined rods that intersect at an angle and are inclined toward the inflow end, and two opposing and spaced second vertical supports located between the two third upper inclined rods and the two third lower inclined rods, wherein the two third upper inclined rods of any of the third grid frames are implemented as two adjacent second lower inclined rods of two adjacent second grid frames connected to them, and both the third upper inclined rods and the third lower inclined rods are non-linear;

[0023] Two adjacent second vertical supports of any two adjacent third grid frames are connected by a fourth transition section to form a second vertical support;

[0024] In any of the third grid frames, the ratio of the length of any of the third upper diagonal bars and the third lower diagonal bars to the length of any of the second vertical bars is 2 to 4, and the ratio of the width of any of the third upper diagonal bars and the third lower diagonal bars to the width of any of the second vertical bars is 0.3 to 0.5.

[0025] Preferably, any of the fourth grid frames includes two fourth upper inclined rods that intersect at an angle and are inclined toward the outflow end, two fourth lower inclined rods that intersect at an angle and are inclined toward the inflow end, and two opposing and spaced third vertical rods located between the two fourth upper inclined rods and the two fourth lower inclined rods. Each of the fourth upper inclined rods and the fourth lower inclined rods is non-linear, and any two adjacent fourth grid frames share the third vertical rod.

[0026] The two fourth upper diagonal bars of any of the fourth grid frames are implemented as two adjacent third lower diagonal bars of two adjacent third grid frames connected to them;

[0027] The connection between two adjacent fourth upper diagonal bars in any two adjacent fourth grid frames is implemented as a fifth transition section protruding outward toward the inflow end and opening toward the outflow end. The connection between two adjacent fourth lower diagonal bars is implemented as a sixth transition section protruding outward toward the outflow end and opening toward the inflow end. A third vertical support is connected between the fifth transition section and the sixth transition section, and the three together form a shared third vertical bar. The ratio of the width of the third vertical support to the width of the widest part of the fifth transition section and the sixth transition section is 0.5 to 0.7, and the ratio of the length of the third vertical support to the length of the third vertical bar is 0.2 to 0.5.

[0028] Preferably, in any of the first grid frames, the connection of the two first upper inclined rods is implemented as an arc protruding outward toward the outflow end, and the connection of the two first lower inclined rods is implemented as an arc protruding outward toward the inflow end.

[0029] In any of the fourth grid frames, the connection between the two fourth lower diagonal bars is implemented as an arc protruding outward toward the inflow end, and the connection between the two fourth upper diagonal bars is implemented as an arc protruding outward toward the outflow end.

[0030] Another object of the present invention is to provide an artificial heart valve, comprising the valve stent described in any of the preceding claims.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] The valve stent and artificial heart valve of the present invention have four layers of mesh arranged sequentially from the outflow end to the inflow end. One layer of mesh on the outflow end side is the outflow section, and one layer of mesh on the inflow end side is the inflow section. The two middle layers of mesh serve as transition sections. Among them, three layers of mesh on the outflow end side, the inflow end side, and the transition section near the inflow end side are hexagonal, and the one layer of mesh on the transition section near the outflow end side is quadrilateral. In this way, it combines the advantages of quadrilateral structure, which is easier to compress and expand, and hexagonal structure, which is relatively more stable, while taking into account the requirements of easy deformation in the middle of the stent and good radial support. Meanwhile, the area relationship of each layer of grid was optimized. The grid opening area of ​​the outflow section is the largest. After the valve is implanted with the stent, the opening grid will not squeeze the original leaflet, reducing the risk of the leaflet blocking the coronary artery ostium, and can provide a channel for the smooth entry of coronary interventional devices into the coronary artery. The grid area of ​​the intermediate transition section to the inflow section increases sequentially and the difference in area between two adjacent grids decreases. This design is conducive to more uniform overall stent deformation and avoids the bone-like stent structure that is thick at both ends and thin in the middle. It solves the problems of uneven grid deformation caused by changing the size of the stent connecting rod and the angle of adjacent connecting rods in the existing technology, as well as the problems of valve delivery caused by adding support parts. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Figure 1 This is a three-dimensional structural diagram of the valve stent according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the front view of the valve stent according to an embodiment of the present invention;

[0036] Figure 3 This is a partial structural diagram of the valve stent after deployment according to an embodiment of the present invention;

[0037] Figure 4 for Figure 3 A schematic diagram of the first grid frame of the first layer of the middle valve stent;

[0038] Figure 5 for Figure 3 A schematic diagram of the structure of a portion of the second and third mesh frames of the second and third mesh layers of the middle valve stent;

[0039] Figure 6 for Figure 3 A schematic diagram of the fourth grid frame of the fourth layer of the middle valve stent;

[0040] Figure 7 This is a schematic diagram of the structure of the artificial heart valve according to an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram of the structure of one leaflet of an artificial heart valve according to an embodiment of the present invention;

[0042] Figure 9 This is a schematic diagram of the structure of the artificial heart valve after the three leaflets of the present invention are connected, folded, sutured, and assembled.

[0043] Figure 10 This is a schematic diagram of the valve skirt of the artificial heart valve according to an embodiment of the present invention.

[0044] Among them, 1. Valve stent; 100. First layer of mesh; 110. Fixing rod; 120. First mesh frame; 121. First upper inclined rod; 122. First vertical support rod; 123. First lower inclined rod; 124. First arc structure; 125. First transition section; 126. Second transition section; 200. Second layer of mesh; 220. Second mesh frame; 221. Second lower inclined rod; 222. Third transition section; 2211. Connecting end; 300. Third layer of mesh; 320. Third mesh frame 321. Third lower diagonal bar; 322. Fourth transition section; 323. Second vertical support bar; 400. Fourth layer of mesh; 420. Fourth mesh frame; 421. Fourth lower diagonal bar; 422. Third vertical support bar; 423. Second arc structure; 424. Fifth transition section; 425. Sixth transition section; 2. Petal leaf; 21. Petal leaf body; 22. Fixed edge; 23. Arc-shaped bottom edge; 3. Petal skirt; 31. Petal skirt body; 32. Seam edge; 33. Inner skirt edge; 34. Outer skirt edge; 4. Seam thread. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0046] Currently available valve stents typically feature a large-aperture hexagonal mesh at the outflow end, while the meshes at the middle and inflow ends are generally quadrilateral, hexagonal, or polygonal. For example, the valve stent in patent CN113855326B has a hexagonal outflow end and quadrilateral middle and inflow ends. Similarly, the valve stent in patent CN11358825B has a hexagonal outflow end, a quadrilateral middle section, and a hexagonal inflow end. Generally, quadrilaterals are more easily deformed, making quadrilateral stent designs easier to compress and expand. Hexagonal and polygonal structures, on the other hand, are relatively more stable and offer better radial support. While quadrilateral stents are easily deformable, uneven deformation during compression and expansion can lead to a bone-like structure that is narrow in the middle and wide at both ends. This can result in gaps between the implanted valve and the original valve annulus, potentially causing paravalvular leakage or even valve detachment. Furthermore, the balloon may rupture during inflation due to uneven stress, severely impacting surgical outcomes. While hexagonal or polygonal structures can enhance the radial support of the valve, stents with more hexagonal or polygonal structures have a larger clamping diameter, making delivery to the lesion site via a delivery system more difficult and increasing the complexity of the procedure. To address these problems with existing valve stent technologies, the valve stent of this invention has been redesigned and optimized. For details, please refer to... Figures 1 to 6 The valve stent 1 in this embodiment of the invention is a hollow, grid-like tubular structure that can be radially compressed and expanded. The valve stent 1 is made of cobalt-chromium alloy or other malleable metal materials, obtained by laser cutting of the alloy tubing. More specifically, the valve stent 1 in this embodiment includes an axial end, i.e., as shown... Figure 1 or Figure 2 The lower inflow end and the other axial end shown are also as follows Figure 1 or Figure 2The upper outflow end and the transition section between them are shown, and along their axial direction from the outflow end to the inflow end, they include four layers of mesh. The first layer of mesh at the outflow end is implemented as the first mesh 100, the first layer of mesh at the inflow end is implemented as the fourth mesh 400, and the transition section includes two layers of mesh, which are implemented as the second mesh 200 and the third mesh 300 along the direction from the outflow end to the inflow end. Each layer of mesh includes multiple mesh frames connected sequentially along the circumferential direction of the valve stent 1. Among them, the mesh frame on the outflow end side, the mesh frame on the inflow end side, and the mesh frame near the inflow end side in the transition section are all implemented as hexagonal hollow frames, i.e., hexagonal structures, while the mesh frame near the outflow end side in the transition section is implemented as a quadrilateral hollow frame, i.e., a quadrilateral structure. That is, the outflow and inflow ends of the valve stent 1 adopt a more stable hexagonal structure, while the intermediate transition section combines the advantages of a quadrilateral structure (easier to grip and expand) and a hexagonal structure (more stable), taking into account both ease of deformation and good radial support. Furthermore, to avoid a bone-like stent structure that is thick at both ends and thin in the middle, the opening area of ​​each mesh layer in this embodiment of the invention has been optimized. Specifically, for ease of description and distinction, the mesh frame on the first mesh layer 100 is implemented as a first mesh frame 120, the mesh frame on the second mesh layer 200 is implemented as a second mesh frame 220, the mesh frame on the third mesh layer 300 is implemented as a third mesh frame 320, and the mesh frame on the fourth mesh layer 400 is implemented as a fourth mesh frame 420. More specifically, in the valve stent 1 of this embodiment, the opening area of ​​the mesh frame at the outflow end, i.e., the first mesh frame 120, is the largest. The three-layer mesh frame—the transition section and the inflow end—i.e., the second mesh frame 220, the third mesh frame 320, and the fourth mesh frame 420, are further specifically defined as follows: the area of ​​the mesh frames increases sequentially from the outflow end to the inflow end, and the area difference decreases. That is, the area of ​​the second mesh frame 220 is smaller than the area of ​​the third mesh frame 320, the area of ​​the third mesh frame 320 is smaller than the area of ​​the fourth mesh frame 420, and the difference between the area of ​​the third mesh frame 320 and the area of ​​the second mesh frame 220 is greater than the difference between the area of ​​the fourth mesh frame 420 and the area of ​​the third mesh frame 320. For ease of understanding and distinction, the area of ​​the first mesh frame 120 is denoted as S1, the area of ​​the second mesh frame 220 as S2, the area of ​​the third mesh frame 320 as S3, and the area of ​​the fourth mesh frame 420 as S4. Thus, S1 > S4 > S3 > S2 and (S3-S2) > (S4-S3). This design helps the overall deformation of the scaffold to be more uniform, avoiding a bone-like scaffold structure that is thick at both ends and thin in the middle.

[0047] Furthermore, the applicant discovered that the area difference between each layer of the grid frame should not be too large. If the area of ​​the second grid frame 220 is too small and the area of ​​the third grid frame 320 is too large, resulting in a large area difference, the middle section of the support will not easily deform. During the pressing and expansion process, the grid deformation will be uneven, potentially leading to a bone-like structure. If the area difference between the fourth grid frame 420 and the third grid frame 320 is large, and the area of ​​the third grid frame 320 is too small, the structure of the third grid frame 320 will reduce its effect on improving the radial support force, thus affecting the radial support force of the support. Therefore, to avoid the above phenomena, the applicant, through repeated experiments, optimized and obtained the area range of each layer of the grid frame, as well as the area difference range between the third grid frame 320 and the second grid frame 220, and the area difference range between the fourth grid frame 420 and the third grid frame 320. Specifically, in this embodiment of the invention, all first grid frames 120 have the same area, all second grid frames 220 have the same area, all third grid frames 320 have the same area, and all fourth grid frames 420 have the same area. The area of ​​any first grid frame 120 is 25~55mm². 2 The area of ​​any second grid frame 220 is 8~20 mm². 2 The area of ​​any third grid frame 320 is 13~30mm². 2 The area of ​​any fourth grid frame 420 is 14~32mm². 2 Furthermore, the area difference between any third grid frame 320 and any second grid frame 220 is 4.5~10mm. 2 The area difference between any fourth grid frame 420 and any third grid frame 320 is 0.5~7mm. 2 .

[0048] Furthermore, such as Figures 2 to 4 As shown, for the first layer of grid 100, any first grid frame 120 includes two first upper diagonal braces 121, two first lower diagonal braces 123, and two first vertical braces. The two first upper diagonal braces 121, the two first lower diagonal braces 123, and the two first vertical braces enclose a hexagonal frame structure with a hollow center. More specifically, the two first upper diagonal braces 121 intersect at an angle (e.g., 120°) and are inclined (i.e., as shown). Figure 4 As shown, the two sides slope downwards to the left and right on the outflow side, that is, as... Figure 4 The upper side is shown. The two first lower diagonal bars 123 are also intersecting and inclined at an angle (e.g., 120°). Figure 4The first vertical bars are arranged with one bar tilted upwards to the left and one to the right, and are spaced apart vertically from the two first upper diagonal bars 121. The two first vertical bars are also spaced apart vertically to the left and right and are connected to the two first upper diagonal bars 121 and the first lower diagonal bars 123 respectively. Any two adjacent first grid frames 120 share one first vertical bar, i.e., as shown... Figure 4 Taking the first complete first grid frame 120 on the left as an example, this first grid frame 120 shares its left first vertical bar with the first grid frame 120 on its left side and shares its right first vertical bar with the first grid frame 120 on its right side. The remaining first grid frames 120 follow the same pattern. However, in this embodiment of the invention, to facilitate the fixing of the leaflets 2, the first layer of grid 100 also includes multiple ( Figure 2 Three fixing rods 110 are provided circumferentially, corresponding one-to-one with the three corners of the leaf 2. Each fixing rod 110 is a structure with a hollow center forming a square opening (not shown). As an alternative embodiment, there can be multiple openings, such as one column and multiple rows or multiple columns and multiple rows. The openings can be square or other shapes such as circles. When fixing rods 110 are formed between two adjacent first grid frames 120, the fixing rods 110 are implemented as a shared first vertical rod. That is, the left and right sides of the fixing rod 110 are two adjacent first vertical rods of the left and right first grid frames 120, respectively. In other words, the fixing rod 110 is composed of two adjacent first vertical rods of two adjacent first grid frames 120 and two horizontal rods (not shown) arranged vertically and horizontally between the two first vertical rods. The length of the horizontal rods is less than the length of the first vertical rods. The specific length is not limited. For example, the length of the horizontal rods is one-fifth of the length of the first vertical rods or other ratios. The first upper inclined rod 121 and the first lower inclined rod 123 are both non-linear. For example, Figure 4 The upper end of the first upper inclined rod 121 on the right side of the diagram bends upward and to the right, the lower end bends downward and to the left, and the middle section is approximately straight. In any two adjacent first grid frames 120 without a fixed rod 110, the connection point of the two adjacent first upper inclined rods 121 is positioned facing the inflow end, i.e. Figure 4 As shown, the lower side protrudes outward and the opening faces the outlet side, i.e. Figure 4 The connection point of the two adjacent first lower inclined rods 123 on the upper side of the first transition section 125 shown is configured to face the outflow end side, i.e. Figure 4 As shown, the upper side protrudes outward and the opening faces the inflow end, i.e. Figure 4The second transition section 126 shown on the lower side, that is, both the first transition section 125 and the second transition section 126 are U-shaped structures. The U-shaped structure helps to eliminate stress concentration at the intersection of the diagonal bars during the clamping and expansion process of the support, resulting in more uniform deformation of the support. A first vertical support rod 122 connects the first transition section 125 and the second transition section 126, and all three are implemented as sharing a first vertical rod. That is, the first transition section 125 and the second transition section 126 are symmetrically designed about the first vertical support rod 122. The width of the first transition section 125 and the second transition section 126 is not the same at every point; the width is approximately widest at the middle position and narrowest at the end connected to the first vertical support rod 122. Furthermore, the ratio of the width of the widest point (the middle position) of the first transition section 125 and the second transition section 126 to the width of the first vertical support rod 122 is 1.8 to 2.7. This design further helps to eliminate stress concentration, resulting in more uniform deformation of the support.

[0049] like Figure 5 As shown, any second grid frame 220 includes a side facing the outflow end, i.e., as... Figure 5 The second upper inclined rod, which is inclined at an angle (120° for example) to the two intersecting upper sides shown, and the side facing the inflow end, that is, as Figure 5 The two lower diagonal bars 221 shown intersect at an angle (120° in an example) on the lower side, forming a roughly hollowed-out rhomboid structure for the second grid frame 220. The two upper diagonal bars are respectively implemented as two adjacent lower diagonal bars 123 of two adjacent first grid frames 120 connected to the second grid frame 220, i.e., arranged as follows... Figure 5Taking the second grid frame 220 on the left as an example, its two second upper diagonal rods are the first lower diagonal rod 123 of the first grid frame 120 above its left and the first lower diagonal rod 123 of the first grid frame 120 above its right. Both the second upper diagonal rods and the second lower diagonal rods 221 are non-linear. Similar to the first upper diagonal rod 121 and the first lower diagonal rod 123, in this embodiment of the invention, the upper and lower ends of the second upper diagonal rods and the second lower diagonal rods 221 are arc-shaped curved structures, and the middle section is approximately straight. In any two adjacent second grid frames 220, the two second upper diagonal rods and the two second lower diagonal rods 221 that are close to each other are connected by a third transition portion 222. The end of any second upper diagonal rod or second lower diagonal rod 221 that connects to the corresponding third transition portion 222 is implemented as a connecting end 2211. The ratio of the width of the connecting end 2211 to the width at other positions of the second upper diagonal rod or second lower diagonal rod 221 is 0.85 to 0.95. In other words, the end of any second upper or lower inclined rod 221 is thinner than the middle section. By optimizing the ratio between the two, the stent can be bent more easily when compressed, resulting in a smaller diameter stent after compression, which is beneficial for the delivery device to transport the stent to the lesion site. The ratio of the length of the connecting end 2211 to the length of the second upper or lower inclined rod 221 is not limited and can be, for example, one-tenth.

[0050] like Figure 5 As shown, any third grid frame 320 includes a side facing the outflow end, i.e. Figure 5 The third upper inclined rod, which is set at an angle (e.g., 120°) between the two intersecting upper members on the side facing the inflow end, is as shown. Figure 5 The two lower inclined rods 321 shown are intersecting at an angle (e.g., 120°) and inclined, and the two upper inclined rods and the two lower inclined rods 321 are located between them. Figure 5 The second vertical supports 323 shown are arranged opposite each other and spaced apart. The lengths of the two second vertical supports 323 are less than those of the third upper diagonal members and the third lower diagonal members 321. The two third upper diagonal members of any third grid frame 320 are implemented as two adjacent second lower diagonal members 221 of two adjacent second grid frames 220 connected to it, for example, as shown... Figure 5The two third upper diagonal bars of the complete third grid frame 320 shown are the second lower diagonal bars 221 of a second grid frame 220 located to its upper left and upper right, respectively. Both the third upper and lower diagonal bars 321 are non-linear; similarly, their ends are curved arcs, while their middle sections are approximately straight. Two adjacent second vertical supports 323 of any two adjacent third grid frames 320 are connected by a fourth transition section 322 to form a second vertical bar. In any third grid frame 320, the ratio of the length of any third upper and lower diagonal bar 321 to the length of any second vertical bar is 2 to 4, and the ratio of the width of any third upper and lower diagonal bar 321 to the width of any second vertical bar is 0.3 to 0.5. By optimizing the ratio of the width and length of the second upper and lower diagonal bars 321 to the second vertical bars, the radial support force of the support structure can be improved.

[0051] like Figure 6 As shown, any fourth grid frame 420 includes a side facing the outflow end, i.e. Figure 6 The upper side shows two fourth upper diagonal bars that intersect at an angle (e.g., 120°) and are inclined, with two bars facing the inflow end, i.e. Figure 6 The diagram shows two lower inclined fourth bars 421 intersecting at an angle (e.g., 120°) on the lower side, and two opposing and spaced third vertical bars located between the two upper and lower fourth inclined bars 421. Both upper and lower fourth inclined bars 421 are non-linear; similarly, both upper and lower fourth inclined bars 421 have curved ends and are roughly straight in the middle. That is, in any first grid frame 120, the connection point of the two upper first inclined bars 121 is an arc protruding outward toward the outflow end, and the connection point of the two lower first inclined bars 123 is an arc protruding outward toward the inflow end. In any fourth grid frame 420, the connection point of the two lower fourth inclined bars 421 is an arc protruding outward toward the inflow end, and the connection point of the two upper fourth inclined bars is an arc protruding outward toward the outflow end. In other words, at both ends of the first grid frame 120 and the fourth grid frame 420, as shown... Figure 2 and Figure 6The top of the first grid frame 120 and the bottom of the fourth grid frame 420 shown are both implemented as arc structures. For ease of description and distinction, the arc structure of the first grid frame 120 is described as a first arc structure 124, and the arc structure of the fourth grid frame 420 is described as a second arc structure 423. This design can avoid damage to the balloon by the stent during expansion. It should be noted that the specific curvature of the first arc structure 124 and the second arc structure 423 in this embodiment is not an innovation of this invention, and those skilled in the art can choose to design according to actual needs. Any two adjacent fourth grid frames 420 share a third vertical bar. The two fourth upper diagonal bars of any fourth grid frame 420 are implemented as two adjacent third lower diagonal bars 321 of the two adjacent third grid frames 320 connected to it, and similarly, as shown in the figure. Figure 6 Taking a complete fourth grid frame 420 as an example, the two fourth upper diagonal bars of this fourth grid frame 420 are the third lower diagonal bars 321 of the third grid frame 320 to its upper left and upper right, respectively. The connection point of the two adjacent fourth upper diagonal bars in any two adjacent fourth grid frames 420 is implemented facing the inflow end side, i.e., as shown... Figure 6 As shown, the lower side protrudes outward and the opening faces the outlet side, i.e. Figure 6 The connection between the upper fifth transition section 424 and the two adjacent fourth lower inclined rods 421 is implemented facing the outflow end side, i.e. Figure 6 As shown, the upper side protrudes outward and the opening faces the inflow end, i.e. Figure 6The sixth transition section 425 is shown on the lower side. Both the fifth transition section 424 and the sixth transition section 425 are U-shaped structures and symmetrically arranged vertically. A third vertical support rod 422 connects the fifth transition section 424 and the sixth transition section 425, and the three together form a shared third vertical rod. That is, the shared third vertical rod in this embodiment of the invention has a structure that is thinner in the middle and thicker at both ends, similar to the first shared vertical rod. Similarly, the width of the fifth transition section 424 and the sixth transition section 425 is widest at the end opposite to the connection with the third vertical support rod 422, and the width is smallest at the end connected to the third vertical support rod 422. Specifically, the ratio of the width of the third vertical support rod 422 to the width at the widest point of the fifth transition section 424 and the sixth transition section 425 is 0.5 to 0.7, and the ratio of the length of the third vertical support rod 422 to the length of the third vertical rod is 0.2 to 0.5. The U-shaped structure helps eliminate stress concentration at the intersection of diagonal braces, enhancing the stability of the grid structure and providing better radial support. The thinner third vertical support 422 in the middle makes the grid structure more prone to deformation. Furthermore, since both the third and fourth grid frames 320 are hexagonal structures with relatively large opening areas, the valve skirts 3 sewn onto the grid will not be excessively stretched or compressed during the clamping and expansion process of the stent. This reduces the risk of excessive stretching of the valve skirts 3 leading to breakage or failure, lowering the risk of paravalvular leakage or valve detachment, and improving the safety and effectiveness of the valve.

[0052] In summary, the valve stent 1 of this invention features a structure design that facilitates easy gripping and has a small diameter after gripping, which is beneficial for the delivery device to the lesion site. The stent deforms uniformly during valve compression and expansion, resulting in uniform force during balloon inflation and expansion, thus facilitating smoother valve delivery and expansion within the body. The stent's uniform overall deformation reduces the likelihood of developing a bone-like structure that is thin in the middle and flared at both ends, and provides good radial support. After implantation at the lesion site, the valve adheres tightly to the surrounding annular tissue, reducing the risk of paravalvular leakage or valve dislodgement, and improving the safety and effectiveness of valve use.

[0053] This invention also provides an artificial heart valve, such as... Figures 1 to 10 As shown, the valve stent 1 of the above embodiment is included. It also includes other components found in conventional artificial heart valves, such as leaflets, leaflet skirts, and sutures. The leaflet 2 in this embodiment can be made of animal-derived tissue materials such as bovine pericardium or porcine pericardium, or polymer materials, and can be cut into the shape using methods such as carbon dioxide laser cutting. Figure 8The desired fan-shaped shape is shown, with adjacent leaflets 2 connected and fixed to the valve stent 1 by sutures 4. The valve skirt 3 is sutured and fixed to the inner and outer sides of the inflow end of the valve stent 1 by sutures 4. After implantation at the lesion site, the outer edge 34 of the valve skirt 3 tightly fills the gap between the valve and the original valve annulus, effectively reducing paravalvular leakage. The material of the valve skirt 3 can be polyethylene terephthalate (PET) or polyurethane foam, and the material of the sutures 4 can be polyester, ultra-high molecular weight polyethylene, or polytetrafluoroethylene.

[0054] like Figure 9 As shown, a single artificial heart valve has three identical fan-shaped leaflets 2. Each leaflet 2 mainly includes a leaflet body 21, a fixing edge 22, and an arc-shaped bottom edge 23. The fixing edges 22 of adjacent leaflets 2 are connected by sutures 4. The connected fixing edges 22 pass through the gap in the fixing rod 110 from the inside of the valve support 1, and are then folded to both sides once or multiple times before being connected and fixed to the fixing rod 110 by sutures 4. To ensure a more secure connection between the leaflets 2 and the valve support 1, a pad (not shown) can be placed on the outside of the folded fixing edge 22 for reinforcement. The fixing edge 22, the fixing rod 110, and the reinforcing pad are then connected and fixed together by sutures 4. In addition to the fixing edge 22, the arc-shaped bottom edge 23 on the leaflet 2 is also sequentially sewn to the valve support 1 by sutures 4.

[0055] like Figure 7 and Figure 10 As shown, the valve skirt 3 includes a valve skirt body 31 and a suture edge 32. The valve skirt 3 is rolled into a cylindrical structure and sutured and fixed inside the valve support 1 by sutures 4 to form an inner skirt edge 33. Then, the valve skirt 3 is folded from the inside out and sutured and fixed to the outside of the support to form an outer skirt edge 34. After the valve is implanted at the lesion site, the outer skirt edge 34 fits tightly and fills the gap between the valve and the original valve annulus, which can effectively reduce the occurrence of paravalvular leakage. One end of the inner skirt edge 33 and the outer skirt edge 34 is a serrated suture edge 32. The shape of the suture edge 32 matches the grid shape of the valve support 1. The valve skirt 3 can be fixed to the valve support 1 by repeated suturing with sutures 4. In addition to the single-layer valve skirt 3 structure, in order to better reduce the occurrence of paravalvular leakage, the outer skirt edge 34 can also be made of elastomeric plastics such as polyurethane foam. The outer skirt edge 34 is designed as a three-dimensional structure with protrusions, so that the valve fits more tightly around the valve annulus tissue.

[0056] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A valve stent implemented as a radially compressible and expandable hollow lattice tubular structure comprising an inflow end at one axial end and an outflow end at the other axial end and a transition section between the two, characterized in that, The valve stent comprises four layers of meshes along its axial direction from the outflow end to the inflow end, and each layer of mesh comprises a plurality of mesh frames connected in sequence along the circumferential direction of the valve stent; The mesh frame on one side of the outflow end and the mesh frames on two sides of the inflow end are implemented as hexagonal hollow frames, and the remaining mesh frame is implemented as a quadrilateral hollow frame; The area of the mesh frame on one side of the outflow end is the largest, and the areas of the remaining three layers of mesh frames gradually increase in the direction from the outflow end to the inflow end, and the area difference gradually decreases.

2. The valve support of claim 1, wherein, Let the four layers of meshes in the direction from the outflow end to the inflow end be the first layer of mesh, the second layer of mesh, the third layer of mesh and the fourth layer of mesh in sequence, and the four layers of mesh frames be the first mesh frame, the second mesh frame, the third mesh frame and the fourth mesh frame in sequence; The area difference between any of the third grid frames and any of the second grid frames is 4.5-10 mm 2 The area difference between any of the fourth grid frames and any of the third grid frames is 0.5-7 mm 2 .

3. The valve support of claim 2, wherein, Any of the second grid frames has an area of 8 to 20 mm 2 Any of the third grid frames has an area of 13 to 30 mm 2 Any of the fourth grid frames has an area of 14 to 32 mm 2 .

4. The valve stent of claim 2 or 3, wherein, Any of the first grid frames has an area of 25 to 55 mm 2 .

5. The valve support of claim 2 or 3, wherein, In the first layer of mesh, any first mesh frame comprises two first upper inclined rods arranged obliquely at an included angle on the outflow end side, two first lower inclined rods arranged obliquely at an included angle on the inflow end side, and two first vertical rods arranged oppositely and spaced apart between the first upper inclined rods and the first lower inclined rods, and any two adjacent first mesh frames share the first vertical rods; And in the first mesh, at least two intermediate fixed rods with openings are arranged in the circumferential direction, and the fixed rods of any two adjacent first mesh frames are implemented as sharing the first vertical rods; In any first mesh frame, the two first upper inclined rods and the two first lower inclined rods are non-straight lines; In any two adjacent first mesh frames without the fixed rods, the connection of the two first upper inclined rods close to each other is implemented as a first transition part protruding outward toward the inflow end side with an opening facing the outflow end side, the connection of the two first lower inclined rods close to each other is implemented as a second transition part protruding outward toward the outflow end side with an opening facing the inflow end side, the first transition part and the second transition part are connected by a first vertical support rod, and the three together are implemented as sharing the first vertical rods, and the ratio of the width of the widest part of the first transition part and the second transition part to the width of the first vertical support rod is 1.8-2.

7.

6. The valve support of claim 5, wherein, Any second mesh frame comprises two second upper inclined rods arranged obliquely at an included angle toward the outflow end side and two second lower inclined rods arranged obliquely at an included angle toward the inflow end side, wherein the two second upper inclined rods are respectively implemented as two first lower inclined rods close to each other of two adjacent first mesh frames connected to the second mesh frame, and the second upper inclined rods and the second lower inclined rods are non-straight lines; In any two adjacent second mesh frames, the two second upper inclined rods and the two second lower inclined rods close to each other are connected by a third transition part; The end of any second upper inclined rod or second lower inclined rod connected to the corresponding third transition part is implemented as a connection end, and the ratio of the width of the connection end to the width of the rest of the second upper inclined rod or second lower inclined rod is 0.85-0.

95.

7. The valve support of claim 6, wherein, Any one of the third grid frames comprises two third upper inclined rods obliquely arranged at an angle and intersecting towards the outflow end side, two third lower inclined rods obliquely arranged at an angle and intersecting towards the inflow end side, and two second vertical support rods oppositely and spacedly arranged between the two third upper inclined rods and the two third lower inclined rods, wherein the two third upper inclined rods of any one of the third grid frames are implemented as the two mutually close second lower inclined rods of the two adjacent second grid frames connected thereto, and the third upper inclined rod and the third lower inclined rod are both non-straight lines; The two mutually close second vertical support rods of any two adjacent third grid frames are connected by fourth transition portions to form second vertical rods; In any one of the third grid frames, the ratio of the length of any one of the third upper inclined rod and the third lower inclined rod to the length of any one of the second vertical rods is 2-4, and the ratio of the width of any one of the third upper inclined rod and the third lower inclined rod to the width of any one of the second vertical rods is 0.3-0.

5.

8. The valve support of claim 7, wherein, Any one of the fourth grid frames comprises two fourth upper inclined rods obliquely arranged at an angle and intersecting towards the outflow end side, two fourth lower inclined rods obliquely arranged at an angle and intersecting towards the inflow end side, and two third vertical rods oppositely and spacedly arranged between the two fourth upper inclined rods and the two fourth lower inclined rods, any one of the fourth upper inclined rod and the fourth lower inclined rod is a non-straight line, and any two adjacent fourth grid frames share the third vertical rod; The two fourth upper inclined rods of any one of the fourth grid frames are implemented as the two mutually close third lower inclined rods of the two adjacent third grid frames connected thereto; The connection of the two mutually close fourth upper inclined rods in any two adjacent fourth grid frames is implemented as a fifth transition portion protruding towards the inflow end side and opening towards the outflow end side, and the connection of the two mutually close fourth lower inclined rods is implemented as a sixth transition portion protruding towards the outflow end side and opening towards the inflow end side, the third vertical support rod is connected between the fifth transition portion and the sixth transition portion, and the third vertical support rod, the fifth transition portion and the sixth transition portion together constitute the shared third vertical rod, the ratio of the width of the third vertical support rod to the width of the widest part of the fifth transition portion and the sixth transition portion is 0.5-0.7, and the ratio of the length of the third vertical support rod to the length of the third vertical rod is 0.2-0.

5.

9. The valve support of claim 8, wherein, In any one of the first grid frames, the connection of the two first upper inclined rods is implemented as a circular arc protruding towards the outflow end side, and the connection of the two first lower inclined rods is implemented as a circular arc protruding towards the inflow end side. In any one of the fourth grid frames, the connection of the two fourth lower inclined rods is implemented as a circular arc protruding towards the inflow end direction, and the connection of the two fourth upper inclined rods is implemented as a circular arc protruding towards the outflow end direction.

10. A prosthetic heart valve, comprising: The valve stent comprises any one of the valve stents according to claims 1-9.

Images