Valve stent and prosthetic heart valve

Abstract

The application discloses a valve stent and an artificial heart valve. The valve stent comprises four layers of grids, and each layer of grid comprises a plurality of grid frames connected in sequence along the circumferential direction of the valve stent. One layer of grid frame on the outflow end side and two layers of grid frames on the inflow end side are implemented as hollow hexagonal frames, and the remaining one layer of grid frame is implemented as a hollow quadrilateral frame. The area of the one layer of grid frame on the outflow end side is the largest, and the areas of the remaining three layers of grid frames gradually increase in the direction from the outflow end to the inflow end, and the area difference gradually decreases. The structure is easy to compress and has a small diameter after compression, which is beneficial to the delivery of the stent to the lesion position by a delivery device. During the compression and expansion of the valve, the deformation is uniform, the stress of the balloon expansion is uniform, and the valve is more smoothly delivered and expanded in the human body. The overall deformation is uniform, the bone-like structure with thin middle and open ends is not prone to occurring, the radial support force is good, and the use safety and effectiveness of the valve are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a valve stent and an artificial heart valve. BACKGROUND

[0002] Transcatheter aortic valve replacement is a minimally invasive surgery for replacing the diseased aortic valve through vascular intervention, mainly used for treating severe aortic valve stenosis or insufficiency in elderly and high-risk patients. During the surgery, the artificial heart valve after being pressed is delivered to the diseased site by a delivery device, the valve stent is expanded by a pressurized expansion balloon, and then the valve is placed and fixed at the aortic valve annulus. However, there are still some problems in the actual use of the transcatheter aortic valve. The middle part of the valve stent after being pressed is subjected to greater pressure, and during the process of expanding the stent by the balloon, the overall expansion of the stent is uneven, the two ends are thick and the middle is thin, showing a bone-like structure. After being implanted into the human body, there is a gap between the valve and the native valve annulus, the probability of paravalvular leakage increases, and if the gap is too large, the valve may even fall off, which seriously endangers the life and health of the patient.

[0003] The traditional treatment method for aortic valve disease is to replace mechanical or biological valves through surgical operation, but such operation causes greater damage to the patient's body. After implanting a mechanical valve, the patient needs to take anticoagulant drugs for life, and the service life of a biological valve is relatively short and will gradually deteriorate, causing problems such as valve stenosis or insufficiency, and there is a possibility of revalve replacement through a second thoracotomy, which is unacceptable for elderly patients. Transcatheter aortic valve replacement (TAVR) is a valve replacement method actively developed at home and abroad in recent years. This technology delivers an artificial heart valve to the diseased site to replace the original valve through vascular intervention. Compared with traditional surgical operation, TAVR does not require thoracotomy, has small trauma, short operation time, and faster postoperative recovery, and is suitable for patients who cannot tolerate traditional surgical methods.

[0004] The patent for invention with the patent document number CN113855326B discloses an artificial heart valve. The artificial heart valve comprises a plurality of valve leaves and an artificial heart valve support. The valve leaves are connected with the artificial heart valve support. The support is a ring-shaped support that can be radially contracted and expanded, and comprises an inflow end and an outflow end. A plurality of mutually connected inflow end frame units are hollow frame units in a gyroscopic shape, and a plurality of mutually connected outflow end frame units are hollow frame units in a hexagonal shape. The support top protrusion is designed in a circular arc shape or an elliptical shape to avoid the phenomenon that the support cannot be smoothly expanded due to excessive compression, the external balloon is punctured, and the support is unevenly expanded, thereby improving the use safety of the valve. The patent for invention with the patent document number CN11358825B discloses an interventional valve support and valve. The valve support comprises a body part provided with a plurality of valve ports. A support part is arranged in the valve port of the valve support and designed in a form of outward protrusion or inward concave. The support part can improve the support performance of the valve support and reduce the risk of the valve falling off from the diseased valve part. The artificial heart valve with the support structure has good support and fixing performance, and can effectively prevent the valve from falling off.

[0005] In the valve support of the above-mentioned prior art solution, the size of the support connecting rod and the angle of adjacent connecting rods are adjusted to avoid uneven expansion of the support. The actual operation is difficult and needs to be verified repeatedly. If the width difference of the support rod is large, the structural strength is different, and the grid may be deformed unevenly during the compression and expansion of the support. The support part arranged in the valve port of the valve support can improve the support performance of the valve support, but the diameter of the support after compression is large, which is not conducive to the transportation of the valve in the blood vessel. Therefore, the present application is thus derived. SUMMARY

[0006] In view of at least one of the above-mentioned technical problems, the present application aims to provide a valve support and an artificial heart valve. The valve support has a reasonable structure design, is easy to compress, the compression and expansion of the support are uniformly stressed, the radial support force is good, the bone-like structure can be effectively avoided, the valve is closely attached to the periphery of the valve ring tissue, the risk of paravalvular leakage or valve falling off is greatly reduced, and the safety and effectiveness of the valve implanted in the human body are improved.

[0007] The technical solution of the present application is as follows:

[0008] The application aims to provide a valve support which is implemented as a radially compressible and expandable hollow mesh tube structure, comprising an inflow end at one axial end, an outflow end at the other axial end and a transition section between the two, along the axial direction from the outflow end to the inflow end, the valve support comprises four layers of meshes, each layer of mesh comprises a plurality of mesh frames connected in sequence along the circumferential direction of the valve support;

[0009] The mesh frame on the outflow end side and the two mesh frames on the inflow end side are implemented as hexagonal hollow frames, and the remaining mesh frame is implemented as a quadrilateral hollow frame;

[0010] The area of the mesh frame on the outflow end side is the largest, and the areas of the remaining three mesh frames increase in sequence along the direction from the outflow end to the inflow end, and the area difference decreases.

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

[0012] The area difference between any of the third mesh frame and any of the second mesh frame is 4.5-10mm 2 , and the area difference between any of the fourth mesh frame and any of the third mesh frame is 0.5-7mm 2 .

[0013] Preferably, the area of any of the second mesh frame is 8-20mm 2 , the area of any of the third mesh frame is 13-30mm 2 , and the area of any of the fourth mesh frame is 14-32mm 2 .

[0014] Preferably, the area of any of the first mesh frame is 25-55mm 2 .

[0015] Preferably, in the first layer of mesh, any of the first mesh frame comprises two first upper inclined rods intersecting at an angle and arranged obliquely on the outflow end side, two first lower inclined rods intersecting at an angle and arranged obliquely 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;

[0016] And in the first mesh, at least two fixing rods with openings are arranged in the circumferential direction and spaced apart, and the fixing rods of any two adjacent first mesh frames are implemented to share the first vertical rods.

[0017] In any of the first grid frames, the two first upper inclined rods and the two first lower inclined rods are non-straight lines;

[0018] In any of the first grid frames, the two first upper inclined rods and the two first lower inclined rods are non-straight lines;

[0019] Preferably, any of the second grid frames comprises two second upper inclined rods obliquely arranged at an angle and towards the outflow end, and two second lower inclined rods obliquely arranged at an angle and towards the inflow end, wherein the two second upper inclined rods are respectively implemented as the two mutually close first lower inclined rods of the two adjacent first grid frames connected with the second grid frame, and the second upper inclined rods and the second lower inclined rods are non-straight lines;

[0020] In any of the second grid frames, the two second upper inclined rods and the two second lower inclined rods are connected through a third transition part;

[0021] The end of any of the second upper inclined rods or the second lower inclined rods connected with 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 the second lower inclined rod is 0.85-0.95.

[0022] Preferably, any of the third grid frames comprises two third upper inclined rods obliquely arranged at an angle and towards the outflow end, two third lower inclined rods obliquely arranged at an angle and towards the inflow end, 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 of the third grid frames are implemented as the two mutually close second lower inclined rods of the two adjacent second grid frames connected therewith, and the third upper inclined rods and the third lower inclined rods are non-straight lines;

[0023] The two mutually close second vertical support rods of any of the two adjacent third grid frames are connected through a fourth transition part to form a second vertical rod;

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

[0025] Preferably, any of the fourth grid frames comprises two fourth upper inclined rods obliquely arranged at an angle of intersection towards a side of the outflow end, two fourth lower inclined rods obliquely arranged at an angle of intersection towards a side of the inflow end, and two third vertical rods oppositely and spacedly arranged between the two fourth upper inclined rods and the two fourth lower inclined rods, any of the fourth upper inclined rods and the fourth lower inclined rods being non-linear, and any two adjacent fourth grid frames sharing the third vertical rods;

[0026] In any of the fourth grid frames, the two fourth upper inclined rods are implemented as the two third lower inclined rods of the two adjacent third grid frames connected thereto and approaching each other;

[0027] In any of the two adjacent fourth grid frames, a connection of the two fourth upper inclined rods approaching each other is implemented as a fifth transition portion protruding towards the side of the inflow end and opening towards the side of the outflow end, and a connection of the two fourth lower inclined rods approaching each other is implemented as a sixth transition portion protruding towards the side of the outflow end and opening towards the side of the inflow end, the fifth transition portion and the sixth transition portion are connected by a third vertical support rod, and the third vertical support rod, the fifth transition portion and the sixth transition portion together constitute the shared third vertical rods, a ratio of a width of the third vertical support rod to a width of the widest part of the fifth transition portion and the sixth transition portion is 0.5-0.7, and a ratio of a length of the third vertical support rod to a length of the third vertical rods is 0.2-0.5.

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

[0029] In any of the fourth grid frames, a connection of the two fourth lower inclined rods is implemented as a circular arc protruding towards the side of the inflow end, and a connection of the two fourth upper inclined rods is implemented as a circular arc protruding towards the side of the outflow end.

[0030] Another object of the present application also provides an artificial heart valve comprising the valve support according to any of the above.

[0031] Compared with the prior art, the present application has the following advantages:

[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 Structure diagram of one of the leaflets of the artificial heart valve of the embodiment of the present application;

[0042] Figure 9 Structure diagram of the artificial heart valve of the embodiment of the present application after the three leaflets are connected, folded and sutured;

[0043] Figure 10 Structure diagram of the skirt of the artificial heart valve of the embodiment of the present application.

[0044] In the drawings: 1, valve stent; 100, first layer of mesh; 110, fixed rod; 120, first mesh frame; 121, first upper inclined rod; 122, first vertical support rod; 123, first lower inclined rod; 124, first circular arc structure; 125, first transition part; 126, second transition part; 200, second layer of mesh; 220, second mesh frame; 221, second lower inclined rod; 222, third transition part; 2211, connecting end; 300, third layer of mesh; 320, third mesh frame; 321, third lower inclined rod; 322, fourth transition part; 323, second vertical support rod; 400, fourth layer of mesh; 420, fourth mesh frame; 421, fourth lower inclined rod; 422, third vertical support rod; 423, second circular arc structure; 424, fifth transition part; 425, sixth transition part; 2, leaflet; 21, leaflet main body; 22, fixed edge; 23, arc-shaped bottom edge; 3, skirt; 31, skirt main body; 32, sutured edge; 33, inner skirt edge; 34, outer skirt edge; 4, suture. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be given below in conjunction with specific embodiments and with reference to the drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of well-known structures and techniques is omitted to avoid unnecessary confusion of the concept of the present application.

[0046] The current existing valve stents, the outflow end is generally a larger opening hexagonal mesh, the middle section and the inflow end mesh are generally quadrilateral, hexagonal or polygonal structure. As the above-mentioned patent literature No. CN113855326B invention patent valve stent outflow end is hexagonal, the middle section and the inflow end are quadrilateral. The patent literature No. CN11358825B valve stent outflow end is hexagonal, the middle section is quadrilateral, and the inflow end is hexagonal. Generally, quadrilateral is easy to deform, and the stent design quadrilateral structure is more prone to compression and expansion. While the hexagonal and polygonal structure is relatively more stable, the radial support force is better. Although the stent with quadrilateral structure is easy to deform, the entire stent is not uniform in deformation when compressed and expanded, and the bone-shaped structure with the middle thin and the two ends open is easy to appear, and there is a gap between the valve and the original valve ring after the valve is implanted. Perivalvular leakage and even valve shedding may occur, and the balloon may also rupture due to uneven stress during the pressurized expansion process, which seriously affects the surgical effect. While the hexagonal or polygonal structure can improve the radial support force of the valve, the stent with more hexagonal or polygonal structure has a large compression diameter, and the stent is not smooth when transported to the lesion site by the delivery device, which increases the difficulty of the operation. In order to solve the problems existing in the above-mentioned valve stent of the prior art, the valve stent of the present application is re-optimized and designed, specifically, see Figures 1 to 6 The valve stent 1 of the embodiment of the present application is a hollow mesh tubular structure that can be radially compressed and expanded. The material of the valve stent 1 is cobalt-chromium alloy or other metal material that can be plastically deformed, which is obtained by laser cutting of alloy pipe material. More specifically, the valve stent 1 of the present embodiment includes an inflow end at one axial end, i.e. the lower end as shown in Figure 1 Or Figure 2 The other axial end, i.e. the upper end as shown in Figure 1 Or Figure 2The upper end, the outflow end and the transition section therebetween are shown, and sequentially comprise four layers of meshes in the axial direction thereof from the outflow end to the inflow end, wherein the layer of meshes at the outflow end is implemented as the first layer of meshes 100, the layer of meshes at the inflow end is implemented as the fourth layer of meshes 400, and the transition section comprises two layers of meshes and is sequentially implemented as the second layer of meshes 200 and the third layer of meshes 300 in the direction from the outflow end to the inflow end. Any layer of meshes comprises a plurality of mesh frames sequentially connected in the circumferential direction of the valve stent 1. Among them, the mesh frame at one side of the outflow end, the mesh frame at one side of the inflow end and the mesh frame at one side of the transition section close to the inflow end are all implemented as hexagonal hollow frames, i.e. hexagonal structures, and the mesh frame at one side of the transition section close to the outflow end is implemented as a quadrilateral hollow frame, i.e. a quadrilateral structure. That is, the outflow end and the inflow end of the valve stent 1 adopt more stable hexagonal structures, and the transition section in the middle combines the characteristics of the quadrilateral structure being easier to compress and expand and the hexagonal structure being more stable, taking into account the requirements of easy deformation and good radial support force. In addition, in order to avoid the appearance of a bone-shaped stent structure with thick ends and a thin middle, the opening area of each layer of meshes is optimized in the embodiment of the present application. Specifically, in order to facilitate description and differentiation, the mesh frame on the first layer of meshes 100 is implemented as the first mesh frame 120, the mesh frame on the second layer of meshes 200 is implemented as the second mesh frame 220, the mesh frame on the third layer of meshes 300 is implemented as the third mesh frame 320, and the mesh frame on the fourth layer of meshes 400 is implemented as the fourth mesh frame 420. More specifically, the valve stent 1 of the embodiment of the present application, the opening area of the mesh frame at the outflow end, i.e. the first mesh frame 120, is the largest, and the opening areas of the mesh frames in 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, a total of three layers of mesh frames, more specifically, the areas of the mesh frames in the direction from the outflow end to the inflow end sequentially increase and the difference in area 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. In order to facilitate understanding and differentiation, the area of the first mesh frame 120 is expressed as S1, the area of the second mesh frame 220 is expressed as S2, the area of the third mesh frame 320 is expressed as S3, and the area of the fourth mesh frame 420 is expressed as S4. Thus, S1>S4>S3>S2 and (S3-S2)>(S4-S3). Such design is conducive to more uniform deformation of the stent as a whole, avoiding the appearance of a bone-shaped stent structure with thick ends and a thin middle.

[0047] Further, the applicant finds that the area difference of 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, the area difference is too large, the middle section of the support is not easy to deform, and the grid is not uniformly deformed during the compression and expansion process, which may easily present a bone-like structure. If the area difference between the fourth grid frame 420 and the third grid frame 320 is large, the area of the third grid frame 320 is small, and the structure of the third grid frame 320 reduces the effect of improving the radial support force, thereby affecting the radial support force of the support. Therefore, in order to avoid the above phenomenon, the applicant optimizes the area range of each layer of the grid frame and 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 through repeated tests. Specifically, in the embodiment of the application, the areas of all the first grid frames 120 are the same, the areas of all the second grid frames 220 are the same, the areas of all the third grid frames 320 are the same, and the areas of all the fourth grid frames 420 are the same. The area of any first grid frame 120 is 25-55 mm 2 . The area of any second grid frame 220 is 8-20 mm 2 , the area of any third grid frame 320 is 13-30 mm 2 , and the area of any fourth grid frame 420 is 14-32 mm 2 . The area difference between any third grid frame 320 and any second grid frame 220 is 4.5-10 mm 2 , and the area difference between any fourth grid frame 420 and any third grid frame 320 is 0.5-7 mm 2 .

[0048] Further, as shown in Figures 2 to 4 , for the first layer of the grid 100, any first grid frame 120 includes two first upper inclined rods 121, two first lower inclined rods 123, and two first vertical rods. The two first upper inclined rods 121, the two first lower inclined rods 123, and the two first vertical rods form an intermediate hollow hexagonal frame structure. More specifically, the two first upper inclined rods 121 are arranged at an angle (for example, 120°) and inclined (i.e., as shown in Figure 4 , one left and one right downwardly inclined) on the outflow end side, i.e., as shown in Figure 4 , the upper side. The two first lower inclined rods 123 are also arranged at an angle (for example, 120°) and inclined (as shown in 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 part 126 on the lower side is also U-shaped, which is beneficial to eliminate stress concentration at the intersection of the inclined rods during the compression and expansion of the stent, and the stent deforms more uniformly. The first transition part 125 and the second transition part 126 are connected by the first vertical support rod 122, and the three are collectively implemented as a common first vertical rod. That is, the first transition part 125 and the second transition part 126 are designed symmetrically above and below the first vertical support rod 122. The width of the first transition part 125 and the second transition part 126 is not the same at every position. The width is the widest at the middle position, the width of the end connected to the first vertical support rod 122 is the smallest, and the ratio of the width of the widest part of the first transition part 125 and the second transition part 126, that is, the middle position, to the width of the first vertical support rod 122 is 1.8-2.7. This design is more beneficial to eliminate stress concentration and make the stent deform more uniformly.

[0049] As shown in Figure 5 Any second grid framework 220 includes two second upper inclined rods inclined at an angle (exemplarily 120°) toward the outflow end side, that is, the upper side as shown in Figure 5 Two second lower inclined rods 221 inclined at an angle (exemplarily 120°) toward the inflow end side, that is, the lower side as shown in Figure 5 That is, the second grid framework 220 has a roughly hollow diamond structure in the middle. The two second upper inclined rods are respectively implemented as two first lower inclined rods 123 of two adjacent first grid frameworks 120 connected to the second grid framework 220 and approaching each other, that is, as shown in 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 5In the diagram, the two third upper diagonal members of a complete third grid frame 320 in the middle are the second lower diagonal members 221 of a second grid frame 220 located to its upper left and upper right, respectively. Both the third upper and lower diagonal members 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 member. In any third grid frame 320, the ratio of the length of any third upper and lower diagonal member 321 to the length of any second vertical member is 2 to 4, and the ratio of the width of any third upper and lower diagonal member 321 to the width of any second vertical member is 0.3 to 0.5. By optimizing the ratio of the width and length of the second upper and lower diagonal members 321 to the second vertical member, 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 end of the first grid frame 120 and the bottom end of the fourth grid frame 420 are both implemented as a circular arc structure. For the convenience of description and differentiation, the circular arc structure of the first grid frame 120 is described as a first circular arc structure 124, and the circular arc structure of the fourth grid frame 420 is described as a second circular arc structure 423. In this way, the stent can be prevented from damaging the balloon during expansion. It should be noted that the specific radian of the first circular arc structure 124 and the second circular arc structure 423 is not the innovation of the present application, and the person skilled in the art can select and design according to the actual needs. Any two adjacent fourth grid frames 420 share a third vertical rod. The two fourth upper inclined rods of any fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two adjacent third grid frames 320 that are close to each other, and vice versa. For example, as shown in the figure, the two fourth upper inclined rods of the fourth grid frame 420 on the left side of the fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two third grid frames 320 on the left side of the fourth grid frame 420 that are close to each other. Figure 6 For example, as shown in the figure, the two fourth upper inclined rods of the fourth grid frame 420 on the left side of the fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two third grid frames 320 on the left side of the fourth grid frame 420 that are close to each other. Figure 6 For example, as shown in the figure, the two fourth upper inclined rods of the fourth grid frame 420 on the left side of the fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two third grid frames 320 on the left side of the fourth grid frame 420 that are close to each other. Figure 6 For example, as shown in the figure, the two fourth upper inclined rods of the fourth grid frame 420 on the left side of the fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two third grid frames 320 on the left side of the fourth grid frame 420 that are close to each other. Figure 6 For example, as shown in the figure, the two fourth upper inclined rods of the fourth grid frame 420 on the left side of the fourth grid frame 420 are implemented as the two third lower inclined rods 321 of the two third grid frames 320 on the left side of the fourth grid frame 420 that are close to each other. 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 required fan-shaped shape is shown, and adjacent leaflets 2 are fixed on the valve support 1 by sutures 4. The skirt 3 is sutured and fixed on the inner and outer sides of the inflow end of the valve support 1 by sutures 4, and the outer skirt edge 34 is tightly filled in the gap between the valve and the native valve annulus after implantation in the lesion site, which can effectively reduce the occurrence of paravalvular leakage. The material of the skirt 3 can be selected from polyethylene terephthalate (PET) or polyurethane foam material, and the material of the suture 4 can be selected from polyester, ultra-high molecular weight polyethylene or polytetrafluoroethylene.

[0054] As shown in Figure 9 Three fan-shaped leaflets 2 with the same shape are provided in a single artificial heart valve, and the leaflets 2 mainly include a leaflet body 21, a fixed edge 22 and an arc-shaped bottom edge 23. The fixed edges 22 of adjacent leaflets 2 are connected by sutures 4, and the connected fixed edges 22 pass through the gap in the fixed rod 110 from the inside to the outside of the valve support 1, and are then folded one or more times to the left and right and fixed on the fixed rod 110 by sutures 4. In order to ensure that the leaflets 2 are more firmly connected to the valve support 1, a gasket (not shown) can be placed on the outside after the fixed edge 22 is folded, and the fixed edge 22, the fixed rod 110 and the reinforcing gasket are connected together by the suture 4. In addition to the fixed edge 22, the arc-shaped bottom edge 23 on the leaflet 2 is also fixed on the valve support 1 by sutures 4.

[0055] As shown in Figure 7 and Figure 10 The skirt 3 includes a skirt body 31 and a suture edge 32, and the skirt 3 is rolled into a cylindrical structure and fixed inside the valve support 1 by sutures 4 to form an inner skirt edge 33. The skirt 3 is then sutured and fixed outside the support from the inside to the outside to form an outer skirt edge 34. The outer skirt edge 34 tightly fills the gap between the valve and the native valve annulus after implantation in the lesion site, 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 sawtooth-shaped suture edge 32, and the shape of the suture edge 32 matches the grid shape of the valve support 1. The skirt 3 can be fixed on the valve support 1 by repeatedly suturing multiple times with sutures 4. In addition to the single-layer skirt 3 structure, in order to better reduce the occurrence of paravalvular leakage, an elastomeric plastic such as polyurethane foam material can be used to make the outer skirt edge 34, and the outer skirt edge 34 is designed as a three-dimensional structure with protrusions, so that the valve and the valve annulus tissue are more tightly fitted around.

[0056] It should be understood that the foregoing detailed description of the application, rather than limiting the application, is intended to explain and describe the current implementation of the application. Therefore, any modification, equivalent replacement or improvement made without departing from the spirit and scope of the application should be included in the protection scope of the application. In addition, the appended claims of the application are intended to cover all changes and modifications falling within the scope and boundary of the appended claims, or the equivalent form of such scope and boundary.

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 25-55 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 through 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 rods; 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 rods are connected between the fifth transition portion and the sixth transition portion, and the third vertical support rods, the fifth transition portion and the sixth transition portion together constitute the shared third vertical rods, 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.

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