Valve stent

Abstract

The present invention discloses a valve stent, comprising: an outer layer stent, a tubular stent body with proximal and distal openings, the tubular stent body comprising a uniform grid area and a special-shaped grid area arranged circumferentially; the uniform grid area comprises a plurality of basic grid units arranged in sequence along the circumference, each basic grid unit comprising at least a first medium grid; the special-shaped grid area comprises at least a supporting grid unit and an avoidance grid unit, the area of ​​the avoidance grid unit being greater than the area of ​​at least two first medium grids; the plurality of basic grid units and the supporting grid units and the avoidance grid units of the special-shaped grid area constitute a radial support portion of the outer layer stent; an inner layer stent is placed within the outer layer stent and maintains a predetermined radial gap with the distal portion of the outer layer stent; the proximal end of the inner layer stent is connected to the proximal end of the outer layer stent so that the two are relatively fixed; and the leaflet is fixedly connected to the side wall of the inner layer stent. This application achieves bionic avoidance of specific areas by specializing the grid locally.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a valve stent for reducing conduction block. Background Art

[0002] Heart valve disease is a common cardiovascular condition, primarily affecting the aortic, mitral, and tricuspid valves. Currently, surgical valve replacement and repair are the primary treatment options, but they are associated with significant trauma, high risk, and a high incidence of complications. In recent years, transcatheter valve replacement has emerged as a new approach to treating valvular disease, offering advantages such as minimal invasiveness and the absence of extracorporeal circulation.

[0003] Existing artificial valves implanted through catheters mostly use self-expanding valve stents with a continuous and uniform grid structure. After the self-expanding valve stent is fully expanded, the radial support force it generates will apply uniform pressure to the entire valve annulus area, which may directly compress the atrioventricular node area, thereby causing atrioventricular conduction block and affecting the normal conduction function of the heart.

[0004] To address the potential conduction block associated with valve implantation, existing technologies have proposed a pressure-dividing stent configuration. Specifically, the valve stent utilizes a dual-layer design: a flexible outer stent secured to the valve leaflets via barbs, while an inner functional stent maintains hemodynamics. Simultaneously, a "champagne cork" configuration (narrow neck, wide body) balances radial support and flexibility. The ventricular segment is rigid to resist displacement, while the atrial segment is flexible to reduce pressure on the atrioventricular node. However, while this pressure-dividing stent design can avoid conduction block, it can sacrifice radial stability and increase the risk of paravalvular leak.

[0005] Therefore, it is necessary to provide an artificial valve that can better fit the human valve ring and avoid conduction block at the same time. Summary of the Invention

[0006] In order to achieve the above objectives, one aspect of the present invention provides a valve stent, comprising:

[0007] An outer layer stent having a tubular stent body with proximal and distal openings, the tubular stent body comprising a uniform grid area and a special-shaped grid area arranged circumferentially; the uniform grid area comprises a plurality of basic grid units arranged in sequence along the circumference, each of the basic grid units comprising at least a first medium grid; the special-shaped grid area comprises at least a supporting grid unit and an avoiding grid unit, the area of ​​the avoiding grid unit being greater than the area of ​​at least two first medium grids; the plurality of basic grid units and the supporting grid units and avoiding grid units of the special-shaped grid area together constitute a radial support portion of the outer layer stent; the radial support portion of the outer layer stent provides substantially the same radial support performance as a valve stent consisting only of basic grid units;

[0008] An inner stent is placed inside the outer stent and maintains a predetermined radial gap with the distal portion of the outer stent; the proximal end of the inner stent is connected to the proximal end of the outer stent to achieve relative fixation between the two;

[0009] The leaflets are fixedly connected to the side walls of the inner support.

[0010] In one embodiment, the basic grid unit includes two circumferentially adjacent first middle grids and a first small grid; the first small grid is located at the distal end of the two first middle grids and in the middle between the two first middle grids;

[0011] The special-shaped grid area includes a large grid, a second medium grid, and two second small grids; the large grid and the second medium grid are arranged adjacent to each other along the circumferential direction, and the two second small grids are located at the distal ends of the large grid and the second medium grid and arranged at intervals; the second medium grid constitutes the supporting grid unit, and the large grid constitutes the avoiding grid unit;

[0012] A plurality of first middle grids, a second middle grid and a large grid constitute a radial support portion of the valve stent;

[0013] The radial supporting force missing from the blank area in the avoidance grid unit is provided by the edge of the avoidance grid unit.

[0014] In one embodiment, the first grid and the second grid have the same shape.

[0015] In one embodiment, the area of ​​the avoidance grid unit is n times the area of ​​the first grid, where 2≤n≤4.

[0016] In one embodiment, the distal ends of the first small grid and the second small grid are both provided with connecting claws; the outer layer stent and the inner layer stent are fixedly connected by the connecting claws;

[0017] The radial supporting portion of the outer layer stent transmits the radial force borne by the radial supporting portion to the inner layer stent through the first small grid, the second small grid and the connecting claws.

[0018] In one embodiment, the outer contour of the avoidance grid unit is heart-shaped.

[0019] In one embodiment, the avoidance grid unit includes a left bottom bar, a right bottom bar, a left support bar, a right support bar and multiple connecting rods; the left support bar, the left bottom bar, the right bottom bar, the right support bar and the multiple connecting rods are connected head to tail in sequence to form a heart-shaped outline; the multiple connecting rods provide radial support for the upper periphery of the avoidance grid unit, and the left bottom bar and the right bottom bar provide radial support for the lower periphery of the avoidance grid unit.

[0020] In one embodiment, the first grid is a closed hexagonal grid consisting of a V-shaped rod, an inverted V-shaped rod, and two parallel rods;

[0021] The multiple connecting rods are arranged in a zigzag manner to form multiple sharp corners facing the distal end and multiple suspended corners facing the proximal end.

[0022] In one embodiment, an auxiliary fixing hole is provided on each of the suspended corners.

[0023] In one embodiment, the included angle of the V-shaped rod is 60°-90°, the included angle of the inverted V-shaped rod is 60°-90°; the angle of the sharp angle is 60°-90°;

[0024] The included angle between the left bottom bar and the right bottom bar is 120°-160°;

[0025] The included angle between the left support rod and the left bottom rod is 110°-140°.

[0026] According to another aspect of the present application, a valve stent is provided, comprising:

[0027] The uniform grid area and the special-shaped grid area are arranged circumferentially to form a tubular stent body with proximal and distal openings;

[0028] The uniform grid area includes a plurality of basic grid units sequentially arranged along the circumferential direction, and each of the basic grid units includes at least a first medium grid;

[0029] The special-shaped grid area includes at least a supporting grid unit and an avoiding grid unit, and the area of ​​the avoiding grid unit is larger than the area of ​​at least two first medium grids; the plurality of basic grid units and the supporting grid units and the avoiding grid units of the special-shaped grid area together constitute the radial support portion of the valve stent;

[0030] The radial support portion of the valve stent provides substantially the same radial support performance as a valve stent composed only of basic grid units.

[0031] Compared with the prior art, the valve stent described in this application has the following beneficial effects:

[0032] 1. Local grid specialization is performed at the location where conduction block is prone to occur in the valve stent body, and a larger avoidance area is constructed to form a bionic avoidance, thereby reducing pressure on the atrioventricular node area and effectively reducing the risk of conduction block.

[0033] 2. The special-shaped grid area adopts an asymmetric design, and the avoidance grid units and the supporting grid units are arranged. For the structure of a single-layer valve stent, the radial support force of the special-shaped grid area is provided by both the avoidance grid units and the supporting grid units. The central area of ​​the avoidance grid unit is left empty, and its edges increase the structural strength and rigidity. The force originally concentrated in the avoidance area is dispersed to the surrounding area by "stress redistribution" to make up for the lack of radial support force in the empty area. The supporting grid units further compensate for the radial support force of the avoidance area, ensuring that the overall radial support performance of the special-shaped grid area is almost equivalent to that of a traditional uniform stent composed only of basic grid units.

[0034] 3. When the valve stent adopts a double-layer structure with an outer stent and an inner stent, the radial support force of the valve stent is provided by the radial support portion of the outer stent and the inner stent. The outer stent in the double-layer stent structure has better adaptability to the native valve annulus.

[0035] 4. While taking into account the streamlined structure of the valve stent as a whole, this application allows the valve stent to be retracted into the delivery system during the release process to cope with possible accidents during the operation and reduce surgical risks.

[0036] 5. The outer layer of the single-layer valve stent or the double-layer valve stent adopts an egg-shaped contour design. Through bionic morphological matching, it better fits the anatomical characteristics of the human valve ring, greatly reducing the risk of paravalvular leakage and improving the sealing of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of a valve stent according to an embodiment of the present application;

[0038] Figure 2 for Figure 1 A top view of the valve stent shown;

[0039] Figure 3 This is an expanded view of a partial main structure design of a valve stent according to an embodiment of the present application;

[0040] Figure 4 1 is a partial structural expansion diagram of a valve stent consisting only of a first middle grid according to an embodiment of the present application;

[0041] Figure 5 This is a partial structural expansion diagram of a valve stent according to an embodiment of the present application;

[0042] Figure 6 1 is a partial structural expansion diagram of another valve stent according to an embodiment of the present application;

[0043] Figure 71 is a partial structural expansion diagram of another valve stent according to an embodiment of the present application;

[0044] Figure 8 Schematic diagram of the structure of a valve stent constituting a control group according to an embodiment of the present application;

[0045] Figure 9 Schematic diagram of the position of the intersection of two connecting rods in an avoidance grid unit after recovery according to an embodiment of the present application;

[0046] Figure 10 Schematic diagram of the structure of a valve stent according to an embodiment of the present application;

[0047] Figure 11 Schematic diagram comparing the radial support forces of the valve stent according to an embodiment of the present application and a traditional uniform valve stent. Reference numerals

[0048] 10-outer support; 20-inner support; 100-uniform grid area; 110-basic grid unit; 111-first middle grid; 112-first small grid; 200-special-shaped grid area; 210-support grid unit; 220-avoidance grid unit; 221-large grid; 222-second middle grid; 223-second small grid; 224-connecting claw; 510-left bottom rod; 520-right bottom rod; 530-left support rod; 540-right support rod; 550-connecting rod; 560-overhang angle; 570-auxiliary fixing hole. DETAILED DESCRIPTION

[0049] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0050] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0051] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0052] The orientations or positional relationships indicated by terms such as “bottom”, “proximal end”, “lower”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0053] Unless otherwise specified or limited, the terms "connected" and "connection" should be understood broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0054] As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "or" is generally used in a sense including "and / or" unless the context clearly dictates otherwise.

[0055] As used herein, the term "axial" refers to the axial direction of the stent body. The proximal end refers to the side closer to the heart center (e.g., atrium or ventricle) or upstream of the blood flow, also known as the inflow end. The distal end refers to the side farther from the heart center or downstream of the blood flow, also known as the outflow end.

[0056] Traditional single-layer valve stents or pressure-dividing double-layer valve stents both use a uniform grid to achieve radial support. However, the uniform grid will apply continuous high pressure to the atrioventricular node area, which cannot avoid compressing the atrioventricular node. The valve stent of the present invention adopts a zoning design with uniform grid areas and special-shaped grid areas. While maintaining the overall radial support force, it achieves local area optimization and avoids rigid compression. The specific working principle is as follows:

[0057] In one embodiment, the valve stent includes an outer stent, an inner stent and leaflets. Figure 1 Schematic diagram of the structure of a valve stent according to an embodiment of the present application. Figure 2 for Figure 1 A top view of the valve stent is shown. Figure 1 and Figure 2The outer stent 10 in the valve stent comprises a tubular stent body with open proximal and distal ends. The tubular stent body includes a circumferentially arranged uniform mesh region 100 and a shaped mesh region 200. The inner stent 20 is positioned within the outer stent 10, maintaining a predetermined radial gap with the distal portion of the outer stent. The proximal end of the inner stent 20 is connected to the proximal end of the outer stent 10 to secure the inner stent 20 relative to the outer stent 10. The valve leaflets (not shown) are fixedly attached to the sidewalls of the inner stent 20.

[0058] Figure 3 This is a partial main structure design diagram of an outer layer support according to an embodiment of the present application. Figure 3 The uniform grid area 100 in the outer support comprises a plurality of basic grid units 110 arranged in sequence along the circumferential direction, and each basic grid unit 110 comprises at least a first middle grid 111. It should be noted that, for the sake of convenience, Figure 1 Only a portion of the uniform grid area is shown in the figure. The special-shaped grid area 200 includes at least a supporting grid unit 210 and an avoiding grid unit 220, and the area of ​​the avoiding grid unit 220 is larger than the area of ​​at least two first middle grids 111. A plurality of basic grid units 110 and the supporting grid units 210 and the avoiding grid units 220 of the special-shaped grid area 200 together constitute the radial support portion of the outer layer stent. The radial support portion of the outer layer stent provides substantially the same radial support performance as the outer layer stent composed only of basic grid units. The valve stent composed of basic grid units can be seen in Figure 4 The expanded view of the partial structure of the valve stent shown in FIG. 1 is composed only of the first grid.

[0059] In the above technical solution, the uniform grid area 100 composed of multiple basic grid units 110 arranged continuously along the circumference provides basic radial support force to ensure that the valve frame can stably fit the main area of ​​the valve ring when it is deployed. The avoidance grid unit in the special-shaped grid area 200 is designed with a large avoidance area (area ≥ 2 first middle grids) at the position corresponding to the atrioventricular node area. By reducing the local grid and lowering the grid density of the area, the radial pressure on the atrioventricular node area is reduced or eliminated. At the same time, the avoidance grid unit transfers the radial support force to the edge rod ( Figure 3 The black thick rods in the middle form the avoidance grid units), ensuring that the overall radial support performance is comparable to that of the traditional uniform bracket composed of only basic grid units (see Figure 4 ) have almost the same supporting performance.

[0060] In some embodiments, see Figure 5 The basic grid unit includes two circumferentially adjacent first middle grids 111 and a first small grid 112 . The first small grid 112 is located at the distal end of the two first middle grids 111 and in the middle between the two.

[0061] In the traditional basic grid unit design, the radial support force is mainly provided by the first middle grids that are evenly arranged circumferentially. In the above embodiment, each basic grid unit includes two circumferentially adjacent first middle grids 111 and one first small grid 112. The first small grid 112 is located on the distal side of the two first middle grids 111 (i.e., the side away from the apex of the heart) and is located in the middle of the two. In this structure, the two first middle grids 111 are used to withstand the force of the native valve annulus, and the first small grid 112 provides a connection with the inner stent and transmits the force received to the inner stent when the outer stent is subjected to radial force, so as to maintain the structural stability of the outer stent.

[0062] The special-shaped grid area 200 includes a large grid 221, a second medium grid 222 and two second small grids 223. The large grid 221 and the second medium grid 222 are arranged adjacent to each other in the circumferential direction, and the two second small grids 223 are located on the distal side of the large grid 221 and the second medium grid 222 and arranged at intervals. The second medium grid 222 constitutes the support grid unit 210, and the large grid 221 constitutes the avoidance grid unit 220. Multiple first medium grids 111, one second medium grid 222 and one large grid 221 constitute the radial support portion of the valve stent. The radial support force missing from the blank area in the avoidance grid unit 220 is provided by the edge rods of the avoidance grid unit 220.

[0063] In the design of the special-shaped grid area 200, the radial support force is provided by a second middle grid 222 and a large grid 221. The large grid 221 constitutes the avoidance grid unit 220. The center area of ​​the large grid 221 is left empty, but its edge (the frame of the large grid 221) is designed to have a certain structural strength and rigidity, which can be seen in Figure 3 and / or Figure 5 , the rod width of the frame of the large grid 221 is greater than the rod width of the first medium grid 111 and the second medium grid 222. The frame of the large grid 221 is similar to "stress redistribution", which disperses the force originally concentrated in the atrioventricular node area to the surrounding area to make up for the lack of support in its empty area. The avoidance grid unit 220 in this application does not completely lose its support function, but contributes support force through the edge. The second medium grid 222, as a support grid unit 210, can concentrate support force in non-critical areas, that is, provide radial support force in areas that do not need to be avoided. The second small grid 223 is located on the distal side and is arranged at intervals. The second small grid 223 has the same working principle as the first small grid 112, that is, the second small grid 223 also provides a connection with the inner stent, and when the outer stent is subjected to radial force, the force received is transferred to the inner stent to maintain the structural stability of the outer stent. In Figure 5In the structure of the outer layer support shown, the supporting grid unit 210 and the avoiding grid unit 220 form a complete support structure through a second small grid 223 to maintain the structural integrity of the special-shaped grid area 200, and when the outer layer support is subjected to radial force, it can better withstand the force and transmit the force to the inner layer support to maintain the structural stability of the outer layer support.

[0064] In the above embodiment, the special-shaped grid area 200 forms a stable mechanical network through cross-connections between grids. Even if the avoidance grid unit 220 is partially left empty, the combination of the above-mentioned support grid unit 210 and the avoidance grid unit 220 can enable the special-shaped grid area 200 to achieve a balance between radial support force and avoidance requirements, thereby meeting mechanical requirements and better adapting to tissue morphology to achieve avoidance of key areas.

[0065] In one embodiment, the area of ​​the avoidance grid unit 220 is n times the area of ​​the first middle grid 111, where 2≤n≤4. As a more preferred embodiment, when the first middle grid 111 and the second middle grid 222 have the same shape, the area of ​​the avoidance grid unit 220 is 3 times the area of ​​the first middle grid 111, that is, the area of ​​the avoidance grid unit 220 is equivalent to the area of ​​3 first middle grids 111. Since the larger the area of ​​the avoidance grid unit 220, the larger the blank area will be, the greater the radial support force dispersed to the surrounding frame will be. If the radial force support is to be balanced, the stress that the side rod of the avoidance grid unit 220 needs to withstand will be greater, and accordingly, the rod width of the avoidance grid unit 220 will be wider. In the above embodiment, the larger the value of n, the wider the rod width of the avoidance grid unit 220.

[0066] When n=2 or 4, the area of ​​the avoidance grid unit 220 is 2 or 4 times the area of ​​the first middle grid 111, see Figure 6 and Figure 7 The schematic diagram of the partial structure of the outer support in the corresponding embodiment is shown. Figure 6 and Figure 7 It can be seen that the avoidance grid unit 220 also includes a second middle grid 222. The purpose of setting the second middle grid 222 is to ensure that the avoidance grid unit 220 can form an even number of connection areas extending toward the distal side to couple exactly with the structure of the second small grid 223.

[0067] In some embodiments, the first middle grid 111 and the second middle grid 222 have the same shape. Using the same design, the support force lost in the avoidance zone of the large grid 221 in the radial support portion is compensated for by mechanical transmission and elastic deformation between the second middle grid 222 on one side and the first middle grid 111 on the other. Because the grid structures on both sides of the avoidance zone have the same shape, uniform radial support force is maintained in the local area of ​​the avoidance zone.

[0068] In some embodiments, see Figure 5-7 The distal ends of the first small grid 112 and the second small grid 223 are each provided with a connecting claw 224. The connecting claw 224 can serve as a traction point for transcatheter intervention, enabling operations such as traction and alignment of the valve stent. When the valve stent in this application is used to manufacture the outer stent of a pressure-dividing stent, the connecting claw is used to connect to the inner stent and to achieve traction of the pressure-dividing stent during delivery.

[0069] The valve stent described in the present application can be contracted and expanded in the radial direction. When the valve stent is transported through a catheter, the valve stent is in a contracted state. After the valve stent reaches a predetermined position, it expands and is supported at the native valve ring by the radial support portion of the outer stent. The special-shaped grid area 200 corresponds to the area to be avoided. The avoidance grid unit 220 uses "stress redistribution" to disperse the force originally concentrated in the avoidance area to the surrounding area to make up for the radial support force missing in its empty area. At the same time, the radial support force exerted on the outer stent is transmitted to the inner stent by the first small grid 112, the second small grid 223 and the connecting claw of the outer stent. Since the stiffness of the inner stent is greater than that of the outer stent, when it is subjected to the radial force transmitted by the outer stent, it can absorb the radial force transmitted by the outer stent and maintain its original contour state, thereby making the valve stent have better stability and preventing the outer stent from falling off.

[0070] In the embodiment, the outer contour of the avoidance grid unit 220 is heart-shaped. Figure 5 In one implementation of the heart-shaped outer contour, the avoidance grid unit 220 includes a left bottom bar 510, a right bottom bar 520, a left support bar 530, a right support bar 540, and a plurality of connecting rods 550. The left support bar 530, the left bottom bar 510, the right bottom bar 520, the right support bar 540, and the plurality of connecting rods 550 are sequentially connected end-to-end to form the heart-shaped contour. The plurality of connecting rods 550 provide radial support force for the upper perimeter of the avoidance grid unit 220, while the left bottom bar 510 and the right bottom bar 520 provide radial support force for the lower perimeter of the avoidance grid unit 220.

[0071] The outer stent described in this application can be contracted and expanded in the radial direction. When the outer stent is in an expanded state, the position of the intersection of the left bottom bar 510 and the right bottom bar 520 closest to the proximal end is substantially aligned with the position of the node closest to the proximal end of the first middle grid 111. When the outer stent is in a contracted state, the position of the intersection of the left bottom bar 510 and the right bottom bar 520 closest to the proximal end is lower than the position of the node closest to the proximal end of the first middle grid 111.

[0072] In the above-mentioned scheme of the heart-shaped outer contour, the left bottom rod 510 and the right bottom rod 520 are used to ensure that the deformation state of the large grid 221 is uniform during the implantation process, to ensure that the valve stent does not twist, and to form a radial support for the lower periphery of the avoidance grid unit 220. The left support rod 530 and the right support rod 540 serve as the boundary support points of the large grid 221, maintain the overall grid shape and support, and do not participate in deformation. Multiple connecting rods 550 are staggered and connected to provide the large grid 221 with the same order of magnitude of upper periphery radial support as the remaining grids. The area formed by the staggered multiple connecting rods 550 and the left bottom rod 510 and the right bottom rod 520 together provide the overall support stiffness of the avoidance grid unit 220. Relying on the same stiffness support, the overall radial support force of the valve stent is basically the same as the radial support force of the valve stent consisting of a uniform grid composed only of the first middle grid 111.

[0073] Various abnormalities may occur in the use of artificial valve products. The valve stent shown in this application can be recycled to stop the operation if it is not fully released. The valve stent in this application, the basic grid units of the uniform grid area 100, have the same structure and are evenly arranged adjacent to each other, which can ensure the streamline of the overall structure of the valve stent during the recycling process. The supporting grid unit 210 of the special-shaped grid area 200 has the same structure as the first middle grid 111, so it can be smoothly stored. The left bottom rod 510 and the right bottom rod 520 in the avoidance grid unit 220 are set at an obtuse angle, which can also achieve the smooth recycling of the valve stent during the secondary recycling process of the valve stent. The specific reasons are as follows:

[0074] In one embodiment of a valve stent, see Figure 8 In order to set up a blank area, the bottom structure of the avoidance grid unit 220 can adopt the same structural form as the multiple connecting rods 550, that is, the multiple connecting rods 550 are staggered. The bottom structure adopts the staggered arrangement of multiple connecting rods 550. Due to the symmetry of the upper and lower structures, the manufacturing process of the avoidance grid unit 220 will be relatively simple. However, when the valve stent is recycled for the second time, the avoidance grid unit 220 of this structure will squeeze each other due to the mutual compression between the connecting rods 550. The junction between the two connecting rods 550, that is, the sharp corner toward the distal end of the valve stent (see Figure 8 Due to the concentration of stress, the valve stent will move away from the axis of the stent, forming a side bending angle. Figure 9 (Left image) The vertical line in the figure represents the theoretical position of the intersection of the two connecting rods 550 after retraction, while the curved line represents the actual position of the intersection of the two connecting rods 550 after retraction. The angle α between the curved and straight lines is the lateral bend angle, which creates a retrieval barrier between the delivery device and the stent. This lateral bend angle prevents the stent from being properly retracted.

[0075] In the technical solution shown in the present application, the bottom structure of the avoidance grid unit 220 adopts a left bottom rod 510 and a right bottom rod 520 arranged at an obtuse angle, and the area spanned by the left bottom rod 510 and the right bottom rod 520 includes multiple connecting rods 550. During the recovery process of the valve stent, the left bottom rod 510 and the right bottom rod 520 are close to each other with their intersection as the fulcrum, and the distance between the two needs to reserve a circumferential space after the recovery of the multiple connecting rods 550. Therefore, the stress generated by the close squeezing of the left bottom rod 510 and the right bottom rod 520 during the contraction process will be concentrated at the connection between the left bottom rod 510 and the right bottom rod 520, with a downward angle. This angle conforms to the recovery direction of the conveying device, and even if a side bending angle occurs, it will not affect the recovery function, so that the valve stent can be evenly recovered. Figure 9 (Right image). This demonstrates that while this application takes into account the streamlined structure of the valve stent, the valve stent can be retracted into the delivery system after release to address potential accidents during surgery, significantly reducing surgical risks.

[0076] In one embodiment, see Figure 10 The first middle grid 111 is a closed hexagonal grid composed of V-shaped rods, inverted V-shaped rods, and two parallel rods; the second middle grid 222 has the same structure as the first middle grid 111. Multiple connecting rods 550 are arranged in a zigzag pattern, forming multiple sharp corners facing the distal end and multiple overhanging corners 560 facing the proximal end.

[0077] See also Figure 10 In the illustrated embodiment, auxiliary fixing holes 570 are provided at each overhang angle 560. During the valve stent manufacturing process, the valve stent body is expanded. During the expansion process, the auxiliary fixing holes 570 are used to secure the valve stent body to the expansion mold, thereby securing the valve stent body and ensuring accurate expansion of the valve body.

[0078] See Figure 10The first middle grid 111 and the second middle grid 222 both utilize hexagonal grids, forming a honeycomb constrained grid topology for the main body of the valve stent. A conventional circular outer layer stent can be understood as a valve stent with a circular projection formed by the first middle grid 111. However, in this application, the avoidance grid unit 220 of the special-shaped grid area 200 replaces three V-shaped rods with a deep V-shaped frame structure, allowing the stress transmission path to bypass the sensitive area of ​​the atrioventricular node, thereby avoiding compression of the atrioventricular node.

[0079] In one embodiment, the angle of the V-shaped rod is 60°-90°, the angle of the inverted V-shaped rod is 60°-90°; the angle of the sharp angle is 60°-90°. The angle between the left bottom rod 510 and the right bottom rod 520 is 120°-160°; the angle between the left support rod 530 and the left bottom rod 510 is 110°-140°. The left support rod 530 and the left bottom rod 510 are connected by a curve at the angle, and the bending radius is 0.5-3 mm. The valve stent formed by this structural parameter can conform to the recovery direction of the conveying device and realize uniform recovery of the valve stent.

[0080] The following simulation data is used to verify the radial support force provided by the valve stent of the structure described in this application and the traditional uniform valve stent (a valve stent consisting of only the first middle grid 111 arranged circumferentially) under the same load (the load is set according to the bionic data of the human body's native valve ring). Figure 11 .

[0081] Depend on Figure 11 It can be seen that the valve stent with the structure described in this application and the traditional uniform valve stent both have disordered radial support force in the initial stage (the adaptation period of the valve stent and the native valve ring at the beginning of support), but as time goes on, the radial support force of the valve stent provided by this application (line 2) is almost the same as the radial support force of the traditional uniform valve stent (line 1).

[0082] In the above embodiments of the different valve stents, the outer stent can be designed with a valve stent having an elliptical or egg-shaped projection profile, see Figure 2 . Through bionic morphological matching, the excessive local pressure caused by shape differences is reduced, and the direct pressure on the atrioventricular junction is reduced. In the preferred embodiment, the length-to-short diameter ratio of the elliptical or egg-shaped outer stent is 1.2:1. The valve stent with this ratio can better adapt to the shape of the native valve annulus, thereby reducing the negative impact of radial support on the native valve annulus and reducing direct pressure on the avoidance area. When the valve stent is adapted to the native valve annulus of the tricuspid valve, the valve stent and the valve annulus of this ratio interact with each other, providing the required radial support force while reducing pressure on the atrioventricular node and avoiding the occurrence of conduction block.

[0083] It can be seen from the above technical solutions that the valve stent in this application performs local grid specialization at the position where conduction block is prone to occur, achieving the effect of bionic avoidance, reducing pressure on the atrioventricular node area, and thus reducing the risk of conduction block.

[0084] According to another aspect of the present application, a valve stent is provided, comprising:

[0085] The uniform grid area 100 and the special-shaped grid area 200 are arranged circumferentially to form a tubular stent body with proximal and distal openings.

[0086] The uniform grid area 100 includes a plurality of basic grid units sequentially arranged along the circumferential direction, and each basic grid unit includes at least a first middle grid 111;

[0087] The special-shaped grid area 200 includes at least a supporting grid unit 210 and an avoiding grid unit 220, and the area of ​​the avoiding grid unit 220 is larger than the area of ​​at least two first middle grids 111; the plurality of basic grid units and the supporting grid units 210 and the avoiding grid units 220 of the special-shaped grid area 200 together constitute the radial support portion of the valve stent;

[0088] The radial support portion of the valve stent provides substantially the same radial support performance as a valve stent composed only of basic grid units.

[0089] The valve stent disclosed in this section is the same as the above Figure 1-10 The structure of the outer layer bracket shown in has the same various structural designs and working principles, which will not be repeated here.

[0090] The valve stent in this embodiment is a single-layer stent structure, which can be used as the outer layer stent of a pressure-dividing valve stent (a double-layer stent structure including an outer layer stent and an inner layer stent), and can also be used alone as a valve stent, for example, as an aortic valve stent. When used alone, the stiffness it has is greater than the stiffness of the outer layer stent used in the pressure-dividing valve stent, so as to provide sufficient radial support.

[0091] Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification in order to better explain the principles and practical applications of the present invention and thereby enable those skilled in the art to make good use of the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A valve stent, characterized in that: include: The outer layer stent has a tubular stent body with proximal and distal openings, and the tubular stent body includes a uniform grid area and a special-shaped grid area arranged around the circumference; The uniform grid area includes a plurality of basic grid units sequentially arranged along the circumferential direction, and each of the basic grid units includes at least a first medium grid; The special-shaped grid area includes at least a supporting grid unit and an avoidance grid unit, the area of ​​the avoidance grid unit is larger than the area of ​​at least two first medium grids; the central area of ​​the avoidance grid unit is left empty; the avoidance grid unit includes a left bottom rod, a right bottom rod, a left support rod, a right support rod and a plurality of connecting rods; the plurality of connecting rods constitute the upper radial support force of the avoidance grid unit, the left bottom rod and the right bottom rod are arranged at an obtuse angle and provide the lower radial support force of the avoidance grid unit; the structural strength and rigidity of the edge rods of the avoidance grid unit are greater than the structural strength and rigidity of the first medium grid and the supporting grid unit; The plurality of basic grid units and the supporting grid units and the avoiding grid units of the special-shaped grid area together constitute the radial supporting portion of the outer layer stent; the radial supporting portion of the outer layer stent provides substantially the same radial supporting performance as a valve stent composed only of basic grid units; An inner stent is placed inside the outer stent and maintains a predetermined radial gap with the distal portion of the outer stent; the proximal end of the inner stent is connected to the proximal end of the outer stent to achieve relative fixation between the two; The leaflets are fixedly connected to the side walls of the inner support.

2. The valve stent according to claim 1, characterized in that The basic grid unit includes two first medium grids adjacent to each other in the circumferential direction and a first small grid; the first small grid is located at the distal end of the two first medium grids and in the middle between the two; The special-shaped grid area includes a large grid, a second medium grid, and two second small grids; the large grid and the second medium grid are arranged adjacent to each other along the circumferential direction, and the two second small grids are located at the distal ends of the large grid and the second medium grid and arranged at intervals; the second medium grid constitutes the supporting grid unit, and the large grid constitutes the avoiding grid unit; A plurality of first middle grids, a second middle grid and a large grid constitute a radial support portion of the valve stent; The radial supporting force missing from the blank area in the avoidance grid unit is provided by the edge of the avoidance grid unit.

3. The valve stent according to claim 2, characterized in that: The distal ends of the first small grid and the second small grid are both provided with connecting claws; the outer layer stent and the inner layer stent are fixedly connected by the connecting claws; The radial supporting portion of the outer layer stent transmits the radial force borne by the radial supporting portion to the inner layer stent through the first small grid, the second small grid and the connecting claws.

4. The valve stent according to claim 2, characterized in that The first grid has the same shape as the second grid.

5. The valve stent according to claim 4, characterized in that: The area of ​​the avoidance grid unit is n times the area of ​​the first grid, where 2≤n≤4.

6. The valve stent according to any one of claims 1 to 5, characterized in that: The outer contour of the avoidance grid unit is heart-shaped.

7. The valve stent according to claim 6, characterized in that: The left support rod, the left bottom rod, the right bottom rod, the right support rod, and a plurality of connecting rods are sequentially connected end to end to form a heart-shaped outline.

8. The valve stent according to claim 7, characterized in that: The first grid is a closed hexagonal grid composed of V-shaped rods, inverted V-shaped rods and two parallel rods; The multiple connecting rods are arranged in a zigzag manner to form multiple sharp corners facing the distal end and multiple suspended corners facing the proximal end.

9. The valve stent according to claim 8, characterized in that: The included angle of the V-shaped rod is 60°-90°, the included angle of the inverted V-shaped rod is 60°-90°; the angle of the sharp angle is 60°-90°; The included angle between the left bottom bar and the right bottom bar is 120°-160°; The included angle between the left support rod and the left bottom rod is 110°-140°.

10. A valve stent, characterized in that: include: The uniform grid area and the special-shaped grid area are arranged circumferentially to form a tubular stent body with proximal and distal openings; The uniform grid area includes a plurality of basic grid units sequentially arranged along the circumferential direction, and each of the basic grid units includes at least a first medium grid; The special-shaped grid area includes at least a supporting grid unit and an avoiding grid unit, and the area of ​​the avoiding grid unit is larger than the area of ​​at least two first grids; The central area of ​​the avoidance grid unit is left empty; the avoidance grid unit includes a left bottom rod, a right bottom rod, a left support rod, a right support rod and a plurality of connecting rods; the plurality of connecting rods constitute the upper radial support force of the avoidance grid unit, the left bottom rod and the right bottom rod are arranged at an obtuse angle and provide the lower radial support force of the avoidance grid unit; the structural strength and rigidity of the edge rods of the avoidance grid unit are greater than the structural strength and rigidity of the first middle grid and the support grid unit; The plurality of basic grid units and the supporting grid units and the avoiding grid units of the special-shaped grid area together constitute the radial supporting portion of the valve stent; The radial support portion of the valve stent provides substantially the same radial support performance as a valve stent composed only of basic grid units.

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