Heart valve stent and artificial heart valve structure composed of the same

Abstract

The present invention relates to a heart valve stent and a prosthetic heart valve structure comprising the same. The heart valve stent comprises a stent body (1), a fixed portion, an elastically expandable portion connected to the fixed portion, and a joining member (2) whose end remote from the fixed portion is a movable end. By optimizing the design of the stent structure, it is possible to extend the service life of the prosthetic heart valve attached to the stent, and to use a material with a relatively low elasticity to achieve the same performance as valves made of higher elasticity materials in the prior art. Furthermore, it is possible to close the leaflet unit (31) more quickly with less external force, which is a significant advantage.

Description

[Technical field]

[0001] This application relates to the field of medical devices, and more particularly to heart valve stents and prosthetic heart valve structures constructed therefrom. [Background technology]

[0002] Most artificial heart valve stents delivered through catheters are composed only of metal elements, which are cut by laser from thin-walled tubing or made from thin metal wires, and the metal elements are used to further construct the desired shape. By fixing and assembling the heart valve to the artificial heart valve stent, an artificial heart valve structure is obtained, and by assembling the stent to the heart valve as described above, the heart valve can also be delivered with a small catheter with an inner diameter as small as 14Fr, and further effectively realize the effective implementation of transcatheter aortic valve replacement (TAVR).

[0003] In the assembly of prosthetic heart valve structures, animal-derived tissues are typically used as substitutes for leaflets to construct tissue heart valves, as they have similar elastic properties to natural valve tissues. However, animal-derived tissues, typically considered "natural" materials, have limitations in terms of long-term durability, and these limitations are fully documented in the academic literature and in clinical use practices and datasets. Therefore, transcatheter aortic valve replacement (TAVR) using animal-derived tissue heart valves is generally not recommended for patients under the age of 60.

[0004] To overcome the limitations of long-term durability, one solution is to use synthetic materials instead of leaflet materials, which are known to have high durability and biocompatibility. However, compared to alternative materials based on animal-derived tissues, most materials have low elasticity, although their high strength and fatigue life make them ideal materials, and the low elasticity of these materials limits their use in cardiac leaflet applications. In particular, the majority of leaflet designs considered in the prior art are all aimed at replicating the anatomical shape and function of natural valves, with the leaflet unit having two states, open and closed, and the cardiac valve stent being stiffer than the leaflet material. Therefore, when the leaflet unit is in the closed state, the interconnected leaflet junction between the leaflet unit and the cardiac valve stent experiences a certain cyclic load, which affects its service life.

[0005] For example, the heart valve disclosed in US Patent US10524902 B2 discloses a leaflet material that has an elasticity obviously less than that of natural tissue. The assembly method between the leaflet unit and the heart valve stent is specifically as follows: the leaflet unit is constructed by integrally molding a number of leaflets and a sewing ring, and there is a leaflet joint between two adjacent leaflets in the leaflet unit, and the leaflet joint is directly fixed to the sewing ring and fixed to the heart valve stent through the sewing ring. The above structure only imitates and replicates the anatomical shape and function of the natural valve, in this case, in all the designs described in this document US10524902 B2, there exists a stress concentration at the fixing position between the leaflet joint and the sewing ring, which greatly limits the service life of the valve. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the technical problem to be solved by the present application is to provide a stent and an artificial heart valve structure constituted therewith, which effectively reduces the stress concentrated at the fixing positions between the leaflet junctions and the sewing ring, thereby extending the service life of the valve, in order to eliminate the defects of the structural designs of the prior art that significantly limit the service life of the valve. [Means for solving the problem]

[0007] 1. A heart valve stent comprising: A stent body; The joint member includes a fixed portion and an elastically expandable portion connected to the fixed portion, with one end of the elastically expandable portion remote from the fixed portion being a movable end.

[0008] The joining member is elongated.

[0009] When the elastic joining member is in its original position, the central axis of the joining member is parallel to the central axis of the stent body.

[0010] The elastic elastic portion is connected to a leaflet junction, which is a connection between two adjacent leaflets of a prosthetic heart valve; The length of the elastically stretchable portion is the same as the length of the leaflet joints, and / or the number of joint members is the same as the number of leaflet joints, with one joint member fixed to each leaflet joint.

[0011] The joining member is made of a biocompatible elastic material.

[0012] The fixed portion and the elastically expandable portion are integrally formed.

[0013] The elastically expandable portion extends outside the stent body in the axial direction of the stent body.

[0014] The elastically stretchable portion has a rectangular cross section.

[0015] 1. A prosthetic heart valve structure comprising: The heart valve stent as described above; a prosthetic heart valve comprising a leaflet unit and a sewing ring that secures the leaflet unit together, the connection between two adjacent leaflets of the leaflet unit being a leaflet junction of the prosthetic heart valve, and the elastic elastic part is connected to the leaflet junction.

[0016] 1. A prosthetic heart valve structure comprising: A stent body; a prosthetic heart valve including a leaflet unit and a sewing ring that secures the leaflet unit together, the connection between two adjacent leaflets of the leaflet unit being a leaflet joint of the prosthetic heart valve; The joint member includes a fixing portion and an elastically stretchable portion connected to the fixing portion, the fixing portion being connected to the sewing ring, and the elastically stretchable portion being connected to the leaflet joint portion.

[0017] The artificial heart valve is a knitted fabric, and the joining members are disposed within the knitted fabric.

[0018] The anchoring portion of the joining member is located between the stent body and the sewing ring.

[0019] The joining member is elongated, its central axis is parallel to the central axis of the stent body, and the length of the elastically expandable portion is the same as the length of the leaflet joining portion.

[0020] The number of said joining members is the same as the number of leaflet joining portions, one joining member being fixed to each leaflet joining portion.

[0021] The joining member is made of a biocompatible elastic material. Effect of the Invention

[0022] The technical solution of this application has the following advantages:

[0023] 1. In the heart valve stent according to the present application, a joining member is added, the fixed part of the joining member is fixed to the stent body, and the elastic part of the joining member has one end connected to the fixed part and one end remote from the fixed part as a movable end, which is intended to be connected to the leaflet joining part of the artificial heart valve. According to the above-mentioned structure, when the stent of this embodiment is used, a certain movement margin can be provided for the leaflet joining part of the artificial heart valve connected to the stent body, thereby reducing the stress concentrated at the fixing position between the sewing ring fixed to the stent body and the leaflet joining part, dispersing the stress at the fixing position to the entire joining member, and greatly extending the service life of the artificial heart valve attached to the heart valve stent.

[0024] The structure of the present application also makes it possible to offset the elastic expansion and contraction section between the leaflet joint and the joint member towards the centre of the valve, which not only reduces stress and extends the service life but also enables the leaflet unit to be manufactured using a less elastic material, achieving valve performance equivalent to that achieved by leaflet units manufactured from more elastic materials in the prior art, and also enables the leaflet unit to be closed more quickly with less external force, which is a significant advantage.

[0025] 2. The present application further provides an artificial heart valve structure that includes the improved heart valve stent of the present application and can achieve the same effects as the above-mentioned heart valve stent.

[0026] 3. The present application provides another artificial heart valve structure, specifically, by directly knitting or sewing a joining member to the leaflet junction of the leaflet unit during the knitting and molding process of the artificial heart valve, when fixed to a stent body of a conventional structure, it not only achieves the above-mentioned effects of the heart valve stent in the present application, but also effectively increases the thickness of the leaflet junction, thereby making it easier to position the artificial heart valve on the stent body, bringing convenience to the subsequent assembly work, reducing the time required for assembly, and improving the assembly efficiency. [Brief description of the drawings]

[0027] In order to more clearly describe the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly describe the drawings that need to be used in the description of the specific embodiments or the prior art. It is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained based on these drawings without creative efforts by those skilled in the art.

[0028] [Figure 1] FIG. 2 is a structural schematic diagram of the prosthetic heart valve in the present application when the prosthetic heart valve is in an open state after the prosthetic heart valve is attached to a stent. [Diagram 2] FIG. 2 is a top view of the structure shown in FIG. [Diagram 3] FIG. 2 is a structural schematic diagram of the prosthetic heart valve of the present application when the prosthetic heart valve is in a closed state after the prosthetic heart valve is attached to a stent. [Figure 4] FIG. 4 is a top view of the structure shown in FIG. [Diagram 5] FIG. 2 is a schematic structural diagram of the present application when the joining member is coated on the leaflet joining portion of the artificial heart valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The following clearly and completely describes the technical solutions of the present application with reference to the drawings, but it is clear that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without making creative efforts belong to the patent scope of the present application.

[0030] In the description of this application, the orientations or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the orientations or positional relationships shown in the drawings, and are merely for the purpose of facilitating and simplifying the description of this application, and do not indicate or imply that such devices or elements must have a specific orientation, be configured, or operate in a specific orientation, and therefore cannot be understood as limiting this application. Furthermore, the terms "first," "second," and "third" are used for explanatory purposes only, and cannot be understood as indicating or implying relative importance.

[0031] In the description of this application, unless otherwise expressly specified or limited, the terms "attach," "connect," and "connect" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, or may refer to a direct connection or an indirect connection via an intermediate medium. The specific meaning of the above terms in this application can be understood by those skilled in the art depending on the situation.

[0032] In addition, the technical features according to different embodiments of the present application described below may be combined with each other unless they are inconsistent with each other. Example 1

[0033] As shown in Figures 1 and 2, the cardiac valve stent includes a stent body 1 and a joining member 2. The joining member 2 includes a fixed part and an elastically expandable part, the elastically expandable part is connected to the stent body 1 by a fixed part, and one end of the elastically expandable part remote from the fixed part is a movable end, which is intended to be connected to a leaflet joining part of an artificial cardiac valve 3 for use. During use, the elastically expandable part has an original state and a tensioned state in which the movable end is offset toward the center part of the stent body.

[0034] In this embodiment, a joining member 2 is added, the fixed part of this joining member is fixed to the stent body, and the elastic part has one end connected to the fixed part and one end remote from the fixed part as a movable end, which is to be connected to the leaflet joint of the artificial heart valve. According to the above-mentioned structure, when the stent of this embodiment is used, a certain movement margin can be provided for the leaflet joint of the artificial heart valve connected to the stent body, thereby reducing the stress concentrated at the fixed position between the sewing ring fixed to the stent body and the leaflet joint, dispersing the stress at the fixed position to the entire joining member, and greatly extending the service life of the artificial heart valve attached to the heart valve stent.

[0035] Furthermore, by using the structure of this embodiment, in an artificial heart valve 3 formed of a leaflet material with a breaking elongation of less than 20%, 10% or 5%, when the leaflet unit is closed, the anchor point between the stent and the leaflet junction of the leaflet unit is the elastic junction member, so that the elastic stretchable part of the junction member between the leaflet junction and the junction member 2 can be offset towards the center of the valve, which not only reduces stress and extends the service life as shown in Figures 3 and 4, but also allows the use of a material with low elasticity to achieve the same effect as the performance of a valve made of a material with higher elasticity in the prior art, and also enables the leaflet unit to be closed more quickly with less external force, which is a significant effect.

[0036] In this embodiment, the fixing part may be an annular structure similar to the stent body, or may be a structure of another shape, as long as it can be fixedly connected to the stent body 1. The elastically stretchable part is for connection to the leaflet joint, and the connection method includes, but is not limited to, sewing, gluing, welding, or mechanical connection. In this embodiment, the elastically stretchable part is configured as a long structure and is provided along the seam between two adjacent leaflets, i.e., the elastically stretchable part is fixed to the leaflet joint, and the number of the elastically stretchable parts is the same as the number of leaflets in the leaflet unit. In a typical leaflet unit, the leaflets are two or three, and the number of the elastically stretchable parts is correspondingly two or three.

[0037] As one of the configurations, in this embodiment, the joining member 2 is elongated as a whole, that is, the fixing portion and the elastically expandable portion are integrally molded, one end of the joining member 2 is a fixing portion for being fixed and connected to the stent body 1, and the other end of the joining member 2 is an elastically expandable portion having a movable end, which is for being connected to the leaflet joint portion. Taking the case of use in the aorta as an example, the artificial heart valve 3 is a tricuspid valve having three leaflets, and in this case, in this embodiment, the number of joining members 2 of the stent body 1 is also three. One joining member 2 is fixed to each leaflet joint portion. The movable end of the elastically expandable portion may be lower than the position of the tip of the stent body 1 in the axial direction of the stent body 1, or may extend outside the stent body 1. In this embodiment, a configuration is used in which the elastically expandable portion extends outside the stent body in the axial direction of the stent body, and the length of the elastically expandable portion may be configured to be the same as the length of the leaflet joint portion, as shown in Figures 1 to 4.

[0038] In this embodiment, the artificial heart valve 3 may be fixed to the joining member 2 from the inside of the stent body 1 or from the outside of the stent body 1. In this embodiment, the artificial heart valve 3 is fixed from the inside, which can minimize the profile of the artificial heart valve structure delivered through a catheter and reduce the wall thickness of the device. In this embodiment, the surface of a part of the joining member 2 may be exposed to the blood flow, and a part of the joining member 2 may be wrapped in the artificial heart valve 3. When handling it in a wrapping manner, the elastic stretchable part may be sewn to the leaflet joining part of the artificial heart valve 3 by sewing to wrap it, which increases the profile delivered through a catheter, but can further reduce the risk of potential tissue reaction, and is more effective.

[0039] In this embodiment, the joining member 2 is preferably made of a biocompatible elastic material, such as thermoplastic polyurethane rubber, and the material of the joining member 2 can be optimized through extrusion molding or injection molding, thereby effectively reducing tissue reactions such as collagen formation and leaflet layer thickening due to surface exposure.

[0040] If the cross section of the elastic elastic part is perpendicular to the central axis, when maintaining optimal valve dynamics, the cross-sectional shape of the elastic elastic part may change according to the different stent shapes and the connection manner between the leaflets of the prosthetic heart valve and the heart valve stent used, and the cross section of the elastic elastic part may be circular, angular, polygonal, irregular, etc. In this embodiment, the elastic elastic part has a rectangular cross-sectional shape and is adhesively connected to the leaflet junction of the prosthetic heart valve, thereby ensuring that the requirement of a minimum valve delivery profile is met. Example 2

[0041] An artificial heart valve structure, comprising the heart valve stent in Example 1 above and an artificial heart valve 3, wherein the artificial heart valve 3 comprises a leaflet unit 31 and a sewing ring 32 that fixes the leaflet unit 31 together, and the connection between two adjacent leaflets of the leaflet unit 31 is a leaflet junction of the artificial heart valve 3.

[0042] The connecting manner between the artificial heart valve 3 and the heart valve stent is as follows: the elastically elastic part of the heart valve stent is connected to the leaflet junction of the artificial heart valve 3, and the sewing ring 32 of the artificial heart valve 3 is fixed to the stent body 1 of the heart valve stent. The connecting manner between the elastically elastic part and the leaflet junction and the fixing manner between the sewing ring 32 and the stent body 1 include, but are not limited to, sewing, gluing, welding or mechanical connection. Example 3

[0043] The artificial heart valve structure includes a stent body 1, an artificial heart valve 3, and a joint member 2. The artificial heart valve 3 includes a leaflet unit 31 and a sewing ring 32 that fixes the leaflet unit 31 together, and the joint member 2 includes a fixed portion and an elastic stretchable portion. The connection portion between two adjacent leaflets of the leaflet unit 31 is the leaflet joint portion of the artificial heart valve 3. The fixed portion of the joint member 2 is connected to the sewing ring 32, and the elastic stretchable portion of the joint member 2 is connected to the leaflet joint portion.

[0044] In this embodiment, the fixing portion of the joining member 2 may be located between the stent body 1 and the sewing ring 32, and the sewing ring 32 may be provided between the fixing portion of the joining member 2 and the stent body 1, and then the elastic expansion portion and the leaflet joining portion of the artificial heart valve 3 may be connected.

[0045] Specifically, when the fixing part is located between the stent body 1 and the sewing ring 32, only the entire joining member 2 is exposed to the outside of the artificial heart valve 3, i.e., the joining member 2 can be fixed to the outer peripheral surface of the artificial heart valve 3, and it is only necessary to ensure that the fixing part is fixedly connected to the sewing ring 32 and the elastically stretchable part is fixedly connected to the leaflet joining part. In this case, when the artificial heart valve 3 and the stent body 1 are fixedly connected, it is possible to reliably realize that the joining member 2 is fixed to the stent body 1, and the elastically stretchable part may be embedded in the knitted fabric constituting the artificial heart valve 3, i.e., the elastically stretchable part may be knitted or sutured to the leaflet joining part of the artificial heart valve 3. In this case, in this embodiment, the joining member 2 may be made of a biocompatible elastic material, which effectively reduces tissue reaction in the valve caused by foreign bodies.

[0046] In the case where the sewing ring 32 is located between the fixing part and the stent body 1, in this embodiment, the structure in which the joining member 2 is connected to the stent body 1 via the sewing ring 32 will be described in detail. Specifically, the joining member 2 is first fixed to the leaflet junction of the artificial heart valve 3, and then connected to the stent body 1 via the sewing ring 32 of the artificial heart valve 3. More specifically, in this embodiment, the artificial heart valve 3 is a knitted fabric, the joining member 2 is elongated, and is sewn and wrapped inside the leaflet junction when the artificial heart valve 3 is knitted, or the joining member 2 is configured as a single fiber structure, and is woven into the leaflet junction as a weft when the artificial heart valve 3 is knitted, and this weft can be completely enclosed inside the leaflet junction of the leaflet unit with other fibers, thereby reducing tissue reaction in the valve caused by the high carbon material.

[0047] In this case, the leaflet joint of the artificial heart valve 3 is incorporated with the joint member 2, and the thickness of the leaflet joint is increased accordingly, as shown in Fig. 5, and the increased thickness makes it easier to assemble the artificial heart valve 3 to the stent, and effectively shortens the time required for assembly. Furthermore, the increased thickness of the leaflet joint can effectively shorten the time for positioning the artificial heart valve 3, and effectively promote the reduction of trimming and sewing work after assembly, and can also reduce the subsequent assembly work, and the effect is more significant.

[0048] 5, in this embodiment, the number of bonding members 2 is the same as the number of leaflet bonding portions, and one bonding member 2 is fixed to each leaflet bonding portion. Furthermore, the central axis of each bonding member 2 is parallel to the central axis of the stent body 1, and the length of the elastically expandable portion is the same as the length of a leaflet bonding portion.

[0049] Of course, the above examples are merely illustrative for the purpose of clarifying the description, and are not intended to limit the embodiments. Those skilled in the art can make various other changes or modifications based on the above description. We will not cover all the embodiments here, but this is impossible. Any obvious changes or modifications derived from these are also within the scope of the patent of this application. [Explanation of symbols]

[0050] 1-Stent body 2- Joint material 3-Artificial heart valve 31-Leaflet Unit 32-Suture ring

Claims

1. 1. A prosthetic heart valve structure comprising: a cardiac valve stent comprising a stent body (1) and a joint member (2), the joint member (2) comprising a fixing part and an elastically expandable part connected to the fixing part, the one end of the elastically expandable part remote from the fixing part being a movable end; an artificial heart valve (3) including a leaflet unit (31) and a sewing ring (32) that fixes the leaflet unit (31) together, and a connection between two adjacent leaflets of the leaflet unit (31) is a leaflet junction of the artificial heart valve (3), the elastic elastic part is connected to the leaflet junction, and the movable end of the elastic elastic part provides a certain movement margin with respect to the leaflet junction, the artificial heart valve (3) is a knitted fabric, the junction member (2) is provided within the knitted fabric, and when the artificial heart valve (3) is knitted, the junction member (2) is sewn and wrapped inside the leaflet junction, or the junction member (2) is knitted into the leaflet junction as a weft.

2. 2. The prosthetic heart valve structure of claim 1, wherein the anchoring portion is connected to a sewing ring (32).

3. 3. The prosthetic heart valve structure according to claim 2, characterized in that the fixing portion of the joining member (2) is located between the stent body (1) and a sewing ring (32).

4. 4. The artificial heart valve structure according to claim 1, wherein the joining member (2) is elongated, the central axis is parallel to the central axis of the stent body (1), and the length of the elastically expandable portion is the same as the length of the leaflet joining portion.

5. 4. The artificial heart valve structure according to claim 1, wherein the number of said joining members (2) is the same as the number of leaflet joining sections, one joining member (2) being fixed to each leaflet joining section.

6. 4. The artificial heart valve structure according to claim 1, wherein the joining member (2) is made of a biocompatible elastic material.

7. An artificial heart valve structure as described in any one of claims 1 to 3, characterized in that the fixed portion and the elastic stretchable portion are integrally molded.

8. An artificial heart valve structure as described in any one of claims 1 to 3, characterized in that the elastic expansion and contraction portion extends outside the stent body (1) in the axial direction of the stent body (1).

9. The artificial heart valve structure according to claim 1, wherein the cross section of the elastically expandable portion is rectangular.

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