A valve stent applied to bicuspid aortic valve stenosis and its usage method

Abstract

The present invention provides a valve stent and a usage method thereof for bicuspid aortic valve stenosis, comprising an ascending aorta contact area, a connecting body, a valve support area and a valve prosthesis suture part; the ascending aorta contact area is in an annular shape, a honeycomb-like structure formed by arranging and connecting a plurality of regular hexagons; the valve support area is in an elliptical annular shape, a grid structure formed by arranging and connecting a plurality of rhombuses. The present invention enhances the radial stiffness of the stent, thereby improving its radial support capacity; the valve support area is designed as an elliptical ring structure, and when implanting the artificial heart valve stent, the long-axis implantation angle of the valve stent is kept perpendicular to the long axis of the valve annulus, and by using the mutual coupling effect between the two, the cross-sectional shape of the expanded valve stent is finally circular, which improves the problem of poor expansion during the implantation of the valve stent and the elliptization after the valve stent is implanted, thereby reducing the occurrence of paravalvular leakage, with uniform stress and extended service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a valve stent for bicuspid aortic valve stenosis and a using method thereof. Background Art

[0002] With the improvement of material living standards and the change of lifestyle, the incidence of cardiovascular diseases is also increasing, and it has become one of the main diseases endangering human life, health and safety. Among them, the incidence of heart valve diseases is relatively high. The transcatheter aortic valve replacement (TAVR) method is widely used due to its minimally invasive and efficient characteristics. The normal aortic valve has three valves in total. If there are only two valves in the aortic valve congenitally, it is called bicuspid aortic valve malformation, which is the most common congenital aortic valve stenosis malformation and is prone to complicated with infective endocarditis. Moreover, among TAVR patients, the proportion of bicuspid aortic valve patients in China is higher than that in foreign countries. Due to the characteristics of oval annulus, high degree of leaflet calcification and asymmetry of leaflets in patients with bicuspid aortic valve stenosis, it brings certain difficulties to the TAVR treatment method. In addition, due to the existence of the oval annulus, after the traditional artificial valve stent is implanted, there will be poor dilation and the valve stent will be ovalized after dilation, which will not only lead to clinical complications such as paravalvular leakage, but also cause uneven stress on the artificial biological leaflets in the valve stent, thus shortening its service life. Summary of the Invention

[0003] In view of the above technical problems, the present invention provides a valve stent for bicuspid aortic valve stenosis and a using method thereof.

[0004] The present invention includes an ascending aorta contact area and a valve support area. The ascending aorta contact area is a circular ring structure, and the unit form structure is a regular hexagon structure to enhance the radial stiffness and support performance of the stent. The valve support area is an elliptical ring structure to improve the elliptical shape of the artificial aortic valve after implantation at the bicuspid aortic valve, enhance the dilation performance of the valve stent during the implantation process, and extend the in-vivo durability of the valve stent after surgery. A valve prosthesis suture part is provided at the bottom of the valve support area to provide a suture site for the valve prosthesis. The present invention solves the technical problems that after the traditional artificial valve stent is implanted, there are problems such as poor dilation and the valve stent is ovalized after dilation, resulting in clinical complications such as paravalvular leakage, uneven stress on the artificial biological leaflets in the valve stent, and thus shortening its service life.

[0005] The technical solution of the present invention is: a valve stent for bicuspid aortic valve stenosis, including an ascending aorta contact area, a connecting body, a valve support area and a valve prosthesis suture part;

[0006] The ascending aorta contact area is circular and is a honeycomb-like structure formed by arranging and connecting multiple regular hexagons; the valve support area is elliptical and is a grid structure formed by arranging and connecting multiple rhombuses; one end of the connecting body is connected to one end of the ascending aorta contact area, the other end of the connecting body is connected to one end of the valve support area, and several valve prosthesis suture parts are provided at the other end of the valve support area.

[0007] In the above solution, the connecting body is a straight rod-shaped connecting body.

[0008] In the above solution, the diameter D1 of the ascending aorta contact area is larger than the major axis A2 of the valve support area.

[0009] Further, the diameter D1 of the ascending aorta contact area is 3 - 4 mm larger than the major axis A2 of the valve support area.

[0010] In the above solution, the height H1 of the ascending aorta contact area is one-third of the total height H of the stent; the sum of the heights H2 of the valve support area and the valve prosthesis suture part is one-half of the total height H of the stent.

[0011] In the above solution, the ellipticity of the valve support area is 1 - (minor axis B2 / major axis A2), and the value range of the ellipticity is 0.1 - 0.3.

[0012] In the above solution, the number of circumferential regular hexagon units in the ascending aorta contact area is the same as the number of circumferential rhombus grids in the valve support area; the circumferential number of the connecting body is half of the number of rhombus grids in the valve support area; the number of the valve prosthesis suture parts is the same as the number of rhombus units in the valve support area.

[0013] In the above solution, the minor axis B2 of the valve support area is larger than the major axis A3 of the elliptical valve annulus.

[0014] In the above solution, it further includes a radiopaque marker; the radiopaque marker is installed on the valve prosthesis suture part on the major axis of the valve support area.

[0015] A method for using a valve stent applied to bicuspid aortic valve stenosis according to the above, includes the following steps:

[0016] Position the implantation angle of the valve stent through the radiopaque marker on the valve prosthesis suture part on the major axis of the valve support area. By observing the radiopaque marker, rotate the valve stent until the major axis A2 of the valve support area is perpendicular to the major axis A3 of the elliptical valve annulus, so that the implantation angle of the major axis of the valve support area is perpendicular to the valve annulus of the bicuspid aortic valve, that is, the major axis A2 of the valve support area is perpendicular to the major axis A3 of the elliptical valve annulus.

[0017] In the above solution, the average diameter of the valve support area is 3 - 6 mm larger than the average diameter of the elliptical valve annulus, and the average diameter is one-half of the sum of the major axis and the minor axis.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention adopts a honeycomb-like regular hexagonal structure in the ascending aorta contact area to enhance the radial stiffness of the stent, thereby improving its radial support capacity; in the clinical treatment of bicuspid aortic valve stenosis, due to the presence of an elliptical valve ring, the traditional artificial valve stent will expand poorly after implantation and the stent will become elliptical after expansion. The present invention designs the valve support area as an elliptical ring structure, and when implanting the artificial heart valve stent, the long axis implantation angle of the valve stent is kept perpendicular to the long axis of the valve ring, and the mutual coupling effect of the two is utilized to finally achieve a circular cross-sectional shape of the valve stent after expansion, which improves the problems of poor expansion during the valve stent implantation process and the elliptical shape of the valve stent after implantation, restores the normal working environment of the valve prosthesis as much as possible, makes it evenly stressed, thereby reducing the occurrence of paravalvular leakage, and can effectively extend the service life of the artificial heart valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of a heart valve stent according to one embodiment of the present invention;

[0021] Figure 2 is a top view of a heart valve stent according to one embodiment of the present invention;

[0022] Figure 3 is a cross-sectional view of a bicuspid aortic valve stenosis according to an embodiment of the present invention;

[0023] Figure 4 is a bottom view of a bicuspid aortic valve stenosis according to an embodiment of the present invention;

[0024] Figure 5 Schematic diagram of a heart valve stent implantation according to one embodiment of the present invention;

[0025] Figure 6 yes Figure 5 Schematic diagram of implantation angle along the AA plane;

[0026] Figure 7 This is a rendering of the valve position after implantation of a heart valve stent according to one embodiment of the present invention.

[0027] In the figure: 1-ascending aorta contact area, 2-straight rod-shaped connector, 3-valve support area, 4-valve prosthesis suture part, 5-bicuspid aortic valve, 6-valve annulus, 7-autologous valve leaflets, 8-valve prosthesis, 9. Development landmark. DETAILED DESCRIPTION

[0028] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0030] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Figure 1 and 2 Shown is a preferred embodiment of the valve stent applied to bicuspid aortic valve stenosis according to the present invention. The valve stent applied to bicuspid aortic valve stenosis is a self-expanding stent. Preferably, the material of the valve stent is nitinol. The valve stent applied to bicuspid aortic valve stenosis includes an ascending aorta contact area 1, a connecting body, a valve support area 3, and a valve prosthesis suture part 4. The ascending aorta contact area 1 is circular and is a honeycomb-like structure formed by connecting a plurality of regular hexagons. The valve support area 3 is elliptical and is a grid structure formed by connecting a plurality of rhombuses. One end of the connecting body is connected to one end of the ascending aorta contact area 1, and the other end of the connecting body is connected to one end of the valve support area 3. A plurality of valve prosthesis suture parts 4 are provided at the other end of the valve support area 3.

[0032] The main structure of the ascending aorta contact area 1 is a honeycomb-like structure composed of a number of regular hexagons closely arranged. This not only enhances the radial strength of the stent but also increases the contact area with the aortic wall, further strengthening the support performance. Starting from Figure 2 As can be seen, the overall structure of the ascending aorta contact area 1 is circular. The diameter D1 of the ascending aorta contact area is larger than the major axis A2 of the valve contact area. Preferably, it is 3 - 4 mm larger, which increases the anchoring property of the stent during use, reduces the occurrence of displacement, and better protects the aorta. The height H1 of the ascending aorta contact area 1 is one-third of the total height H of the stent, ensuring the anchoring property of the stent during use and reducing the occurrence of displacement. The sum of the heights H2 of the valve support area 3 and the valve prosthesis suture part 4 is one-half of the total height H of the stent, ensuring the working stability of the valve prosthesis 8. The valve support area 3 is arranged by a number of rhombic units, and the overall structure of the valve support area 3 is elliptical when viewed from Figure 2 above. The present invention uses the ellipticity as a measure of the elliptical degree of the valve support area 3. The ellipticity is defined as 1 - (minor axis / major axis). Preferably, the value range of the ellipticity of the valve support area 3 is 0.1 - 0.3, which improves the elliptical characteristics presented after the stent implantation, enhances the expansion performance of the valve stent after implantation, and reduces the occurrence of paravalvular leakage. The number of circumferential regular hexagon units in the ascending aorta contact area 1 is the same as the number of circumferential rhombic meshes in the valve support area 3, maintaining the stiffness of the stent.

[0033] According to this embodiment, preferably, the connecting body is a straight rod-shaped connecting body 2, which is a rigid connecting body. Preferably, the circumferential number of the connecting body is half of the number of rhombic meshes in the valve support area 3. The straight rod-shaped connecting bodies 2 are arranged at circumferential intervals, and there is a certain gap between adjacent connecting bodies, ensuring the reliability of the connection between the valve support area 3 and the ascending aorta contact area 1 and leaving a treatment space for treating coronary artery occlusion.

[0034] The valve prosthesis suture part 4 is distributed below the valve support area 3, closely arranged, and the circumferential distribution number is the same as the number of rhombic units in the valve support area 3, ensuring the connection reliability of the valve prosthesis and the convenience of suturing. There are two circular small holes on the valve prosthesis suture part 4, facilitating the suturing of the prosthetic valve. And, a radiopaque marker 9 is placed on the valve prosthesis suture part 4 on the major axis of the valve support area 3.

[0035] Figure 3 、 Figure 4 This is a schematic diagram of a bicuspid aortic valve stenosis applicable to the present invention. Bicuspid aortic valve stenosis is mainly divided into three types: type 0, type 1, and type 2. Figure 3 and 4 As shown above is the structure of type 0 bicuspid aortic valve, that is, there are only two autologous valve leaflets 7 and the apposition angle of the two valve leaflets is close to 180°.

[0036] Since the valve support area 3 of the heart valve stent is elliptical, the commonly used heart valve stent selection strategies in clinical practice are not applicable to the heart valve stent of the present invention. Therefore, in terms of the heart valve stent selection strategy, the present invention uses the average diameter as a selection criterion. The average diameter is defined as half of the sum of the major axis and the minor axis. The average diameter of the valve support area 3 is 3-6 mm larger than the average diameter of the elliptical valve annulus, which improves the elliptical characteristics presented after the stent implantation, enhances the expansion performance of the valve stent after implantation, and reduces the occurrence of paravalvular leakage. Moreover, during selection, the minor axis B2 of the valve support area should be larger than the major axis A3 of the elliptical valve annulus, which improves the elliptical characteristics presented after the stent implantation, enhances the expansion performance of the valve stent after implantation, and reduces the occurrence of paravalvular leakage.

[0037] The implantation position and implantation angle of the heart valve stent shown in the present invention are as Figure 5 , Figure 6 shown. The heart valve stent is compressed and loaded into the sheath, and then implanted into the aortic valve through the delivery device. Since the valve support area 3 of the heart valve stent is elliptical and the valve annulus 6 also has certain elliptical characteristics, the present invention determines the implantation angle of the heart valve stent. During implantation, through the imaging marker 9 placed at the major axis of the valve support area 3, the major axis A2 of the valve support area is made perpendicular to the major axis A3 of the elliptical valve annulus, so that the implantation angle of the valve stent is adjusted to form a perpendicular relationship with the valve annulus 6 of the bicuspid aortic valve 5.

[0038] Figure 7 This is the effect diagram of the valve position after the valve stent is implanted. After the valve stent is implanted, the valve stent will automatically return to the state before compression due to the shape memory effect of the nitinol alloy itself. Since the valve stent is vertically implanted into the bicuspid aortic valve, the major axis A2 of the valve stent is much larger than the minor axis B3 of the elliptical valve annulus. Therefore, there is a strong interaction between the major axis A2 of the valve stent and the minor axis B3 of the elliptical valve annulus. The reaction force of the aortic wall will compress the major axis of the valve stent and transfer the deformation to the minor axis of the stent. The final effect is to change the stent and the elliptical valve annulus from elliptical to circular or approximately circular.

[0039] In the ascending aorta contact area 1 of the present invention, a honeycomb-like regular hexagon structure is adopted to enhance the radial stiffness of the stent, thereby improving its radial support capacity. When treating bicuspid aortic valve stenosis clinically, due to the presence of an elliptical annulus, after the implantation of a traditional artificial valve stent, there will be poor dilation and the stent will become elliptical after dilation. However, in the present invention, the valve support area 3 is designed as an elliptical ring structure, and when implanting the artificial heart valve stent, the long-axis implantation angle of the valve stent is kept perpendicular to the long axis of the annulus. By utilizing the mutual coupling effect between the two, the cross-sectional shape of the valve stent after dilation is finally circular, which improves the problems of poor dilation during the implantation of the valve stent and the elliptical shape of the valve stent after implantation, and as much as possible restores the normal working environment of the valve prosthesis 8, making the force evenly distributed, thereby reducing or even avoiding the occurrence of paravalvular leakage, and being able to effectively extend the service life of the artificial heart valve. The valve stent described in the present invention is not only limited to the application in bicuspid aortic valve stenosis, but can also be used in tricuspid aortic valve stenosis with an elliptical annulus.

[0040] It should be understood that although this specification is described according to various embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0041] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or changes made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A valve stent applied to bicuspid aortic valve stenosis, characterized in that, It includes an ascending aorta contact area (1), a connecting body, a valve support area (3), and a valve prosthesis suture part (4); The ascending aorta contact area (1) is annular and is a honeycomb-like structure formed by arranging and connecting multiple regular hexagons; the valve support area (3) is elliptical annular and is a grid structure formed by arranging and connecting multiple rhombuses; one end of the connecting body is connected to one end of the ascending aorta contact area (1), the other end of the connecting body is connected to one end of the valve support area (3), and several valve prosthesis suture parts (4) are provided at the other end of the valve support area (3); The ellipticity of the valve support area (3) is 1 - (minor axis B2 / major axis A2), and the value range of the ellipticity is 0.1 - 0.3; The minor axis B2 of the valve support area (3) should be greater than the major axis A3 of the elliptical valve annulus.

2. The valve stent applied to bicuspid aortic valve stenosis according to claim 1, wherein The connecting body is a straight rod-shaped connecting body (2).

3. The valve stent applied to bicuspid aortic valve stenosis according to claim 1, wherein The diameter D1 of the ascending aorta contact area (1) is larger than the major axis A2 of the valve support area (3).

4. The valve stent applied to bicuspid aortic valve stenosis according to claim 3, characterized in that, The diameter D1 of the ascending aorta contact area (1) is 3 - 4 mm larger than the major axis A2 of the valve support area (3).

5. The valve stent applied to bicuspid aortic valve stenosis according to claim 1, characterized in that, The height H1 of the ascending aorta contact area (1) is one-third of the total height H of the stent; the sum of the heights H2 of the valve support area (3) and the valve prosthesis suture part (4) is one-half of the total height H of the stent.

6. The valve stent applied to bicuspid aortic valve stenosis according to claim 1, wherein The number of circumferential regular hexagon units in the ascending aorta contact area (1) is the same as the number of circumferential rhombus grids in the valve support area (3); the circumferential number of the connecting body is half of the number of rhombus grids in the valve support area (3); the number of the valve prosthesis suture parts (4) is the same as the number of rhombus units in the valve support area (3).

7. The valve stent applied to bicuspid aortic valve stenosis according to claim 1, characterized in that, It further includes a radiopaque marker (9); the radiopaque marker (9) is installed on the valve prosthesis suture part (4) on the major axis of the valve support area (3).

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