Valve stent and heart valve replacement device

Abstract

The invention relates to a valve stent and a heart valve replacement device. The heart valve replacement device comprises a valve support and a valve prosthesis, the valve support comprises a support body and a plurality of flange extension sections, the support body is used for bearing the valve prosthesis, and the projection contour of the support body is non-circular on a projection plane perpendicular to the central axis. The flange extending sections are arranged on at least part of the edge of the blood input end of the support body at intervals. Therefore, when the valve stent is anchored on a native valve ring of a heart, the stent main body can be matched with the contour shape of the native valve ring, so that the interaction between the valve stent and a weak tissue part of the native valve ring is smaller; and the damage risk of the heart valve device implanted into the human heart to the weak part of the ventricle or the atrial wall tissue is reduced. Compared with the stent main body, the flange extension section has better compliance, so that the fitting degree of the stent and the atrial wall can be improved, and the risk of perivalvular leakage after the stent is implanted into the heart is reduced.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a valve stent and a heart valve replacement device. Background Art

[0002] The heart is a very important organ in the human body, which provides power for the blood circulation of the human body. The human heart is divided into two parts, the left and the right, each part contains a ventricle and an atrium respectively. The ventricles are separated from each other and the atria are separated from each other by the interventricular septum and the interatrial septum. There are valves between the atria, ventricles, and arteries to prevent blood from flowing back. Among them, the mitral valve and the tricuspid valve are important heart valves. Taking the mitral valve as an example, it is located between the left atrium and the left ventricle. The mitral valve opens during diastole, and blood flows from the left atrium into the left ventricle. During systole, the valve leaflets close to prevent blood from flowing back from the left ventricle to the left atrium, acting as a one-way valve. The leaflets of a normal mitral valve or tricuspid valve can close tightly when the ventricle is in the systolic state, thus completely blocking the blood from flowing back from the ventricle to the atrium. However, the leaflets of a diseased mitral valve or tricuspid valve often cannot close tightly, resulting in mitral regurgitation or tricuspid regurgitation. In order to treat patients with heart valve diseases, especially those with severe heart valve diseases, in recent years, a heart valve replacement device is often implanted into the native mitral valve or tricuspid valve of the heart through minimally invasive interventional surgery to replace the diseased native valve.

[0003] Generally, a heart valve replacement device includes a valve stent and artificial valve leaflets disposed within the stent. The valve stent is used to be positioned at the native mitral valve or tricuspid valve of the heart, and the artificial valve leaflets are used as a one-way "valve" to prevent blood from flowing back. Existing valve stents usually have a circular profile, and the radial supporting force for anchoring to the native tissue comes from the circumferential extrusion between the circular profile of the stent and the native tissue, and this force is evenly distributed in the circumferential direction. However, the native mitral valve annulus has a three-dimensional saddle shape, and its profile is not a standard circle. Therefore, a stent with a circular profile has a strong extrusion effect on the tissue structure on the anterior leaflet side of the mitral valve. Since the myocardial tissue on the anterior leaflet side of the mitral valve is relatively weak, there is a risk that the heart valve replacement device may damage the native annulus tissue and the aortic sinus, and it may also hinder the ventricular remodeling after minimally invasive surgery. Summary of the Invention

[0004] Based on this, it is necessary to provide a valve stent and a heart valve replacement device including the valve stent to solve the problem that the existing heart valve replacement device is prone to damage the native annulus tissue and the aortic sinus.

[0005] According to one aspect of the present application, there is provided a valve stent, comprising:

[0006] The stent body is used to carry the valve prosthesis. The stent body is arranged around a central axis. In a projection plane perpendicular to the central axis, the projection profile of the stent body is non-circular; in the axial direction defined by the central axis, the stent body has a blood input end and a blood output end arranged oppositely.

[0007] A plurality of flange extension segments are arranged at the edge of the stent body at the blood input end. The plurality of flange extension segments are spaced apart in the circumferential direction defined by the central axis.

[0008] In one embodiment, the stent body includes an outer stent and an inner stent connected to each other. The outer stent is sleeved outside the inner stent. The outer stent and / or the inner stent includes at least one set of grid groups in the axial direction. Each set of grid groups includes a plurality of grids connected end to end in sequence in the circumferential direction.

[0009] In one embodiment, the outer stent includes a flange section, an outer main body section, and an outer outflow section connected in sequence in the axial direction. One end of the flange section away from the outer main body section forms the blood input end, and one end of the outer outflow section away from the outer main body section forms the blood output end.

[0010] The inner stent includes an inner main body section and an inner outflow section connected in sequence in the axial direction. The inner outflow section is connected to the outer outflow section.

[0011] In one embodiment, the outer diameters of the flange section, the outer main body section, and the outer outflow section in the radial direction defined by the central axis decrease in sequence; the outer diameter of the inner main body section in the radial direction is greater than or equal to the outer diameter of the inner outflow section.

[0012] In one embodiment, the projection profile of the flange section in the projection plane is non-circular, or the projection profiles of the flange section and the outer main body section in the projection plane are both non-circular.

[0013] In one embodiment, the flange section includes a plurality of flanges connected end to end in sequence in the circumferential direction. Adjacent two of the flange extension segments are connected by one or more flanges. Each flange is in a Y shape, a rhombus shape, a pentagon shape, or a hexagon shape.

[0014] The outer main body section includes a plurality of outer grid units connected end to end in sequence in the circumferential direction. Each outer grid unit is connected to a corresponding one of the flanges, and each outer grid unit includes at least one outer grid in the axial direction. A single outer grid is in a rhombus shape, a pentagon shape, or a hexagon shape.

[0015] The outer outflow section includes a plurality of outer outflow units that are sequentially connected end to end in the circumferential direction. Each outer outflow unit is connected to a corresponding one of the outer grid units. A single outer outflow unit is one of a V shape, a rhombus shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a rhombus and a straight rod.

[0016] In one embodiment, the inner main body section includes a plurality of inner grid units that are sequentially connected end to end in the circumferential direction. Each inner grid unit includes at least one inner grid in the axial direction. A single inner grid is in a rhombus shape, a pentagon shape, or a hexagon shape.

[0017] The inner outflow section includes a plurality of inner outflow units that are sequentially connected end to end in the circumferential direction. Each inner outflow unit is connected to a corresponding one of the inner grid units. A single inner outflow unit is one of a V shape, a rhombus shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a rhombus and a straight rod.

[0018] In one embodiment, the flange extension section is in a straight rod structure, a serpentine curved rod structure, or a combined structure of a straight rod and a serpentine curved rod; the stiffness of the flange extension section is less than the stiffness of the outer bracket; and / or the stiffness of the outer bracket is less than the stiffness of the inner bracket.

[0019] In one embodiment, the outer side of the bracket main body includes two valve leaf joint sides that are oppositely arranged in the radial direction defined by the central axis, and a front leaf side and a rear leaf side that are oppositely arranged in the radial direction. The connection line of the two valve leaf joint sides in the projection plane is defined as the first connection line, the connection line of the front leaf side and the rear leaf side in the projection plane is defined as the second connection line. The first connection line and the second connection line are perpendicular to each other, and the length of the first connection line is greater than the length of the second connection line.

[0020] In one embodiment, in the direction from the blood input end to the blood output end, the outer diameter of the bracket main body gradually decreases in the radial direction; the reduction amplitude of the distance between the outer side of the front leaf side and the central axis in the axial direction is greater than the reduction amplitude of the distance between the outer side of the rear leaf side and the central axis in the axial direction.

[0021] In one embodiment, the plurality of flange extension sections are spacedly arranged on the edge of the blood input end on the side of and / or close to the front leaf side.

[0022] In one embodiment, the bracket main body is provided with a plurality of barbed structures on the outer side. Each barbed structure extends obliquely from the outer side of the bracket main body towards the blood output end or towards the blood input end.

[0023] According to another aspect of the present application, there is provided a heart valve replacement device, comprising:

[0024] The valve stent as described above;

[0025] A valve prosthesis, connected to the valve stent, and the valve prosthesis is used to replace the native valve of the heart.

[0026] In one embodiment, the valve stent includes an outer stent and an inner stent that are nested and connected to each other. The outer stent is sleeved on the outside of the inner stent. The valve prosthesis includes an outer skirt, an inner skirt, and valve leaflets. The outer skirt and the inner skirt are connected to each other. The outer skirt covers the inside and / or outside of the outer stent. The inner skirt covers at least the inside of the inner stent. The valve leaflets are connected to the inside of the inner skirt.

[0027] For the above-mentioned valve stent and heart valve replacement device, on the one hand, by designing the stent body of the valve stent as an irregular shape surrounding a central axis, so that the projection profile of the stent body on the projection plane perpendicular to the central axis is non-circular. When the valve stent is anchored on the native annulus of the mitral valve or tricuspid valve of the human heart, it can match the contour shape of the native annulus, so that the interaction between the valve stent and the weak tissue part of the native annulus is small, reducing the risk of damage to the weak parts of the ventricular or atrial wall tissue after the heart valve device is implanted into the human heart, and reducing the mechanical hindrance to ventricular remodeling or recovery after minimally invasive surgery. On the other hand, by arranging a plurality of flange extension segments spaced around the central axis at least on part of the edge of the stent body at the blood input end, the contact area between the stent and the atrial wall can be reduced, avoiding damage to the atrial wall and the aorta, and since the flange extension segments are spaced, they have better compliance compared to the stent body, so that the fitting degree between the stent and the atrial wall can be improved to reduce the risk of paravalvular leakage after the stent is implanted into the heart. Description of the Drawings

[0028] Figure 1 Is an axonometric view of a heart valve replacement device provided by an embodiment of the present application.

[0029] Figure 2 Is an axonometric view of a valve stent provided by an embodiment of the present application Figure 1 .

[0030] Figure 3 Is an axonometric view of a valve stent provided by an embodiment of the present application Figure 2 (The inner stent is hidden).

[0031] Figure 4 Is an axonometric view of the inner stent provided by an embodiment of the present application.

[0032] Figure 5 Partial structural schematic diagram of the flange section in the outer stent provided by an embodiment of the present application.

[0033] Figure 6 Partial structural schematic diagram of the outer main body section in the outer stent provided by an embodiment of the present application.

[0034] Figure 7 Partial structural schematic diagram of the outer main body section in the outer stent provided by another embodiment of the present application.

[0035] Figure 8 Partial structural schematic diagram of the outer outflow section in the outer stent provided by an embodiment of the present application.

[0036] Figure 9 Partial structural schematic diagram of the inner main body section in the inner stent provided by an embodiment of the present application.

[0037] Figure 10 Partial structural schematic diagram of the inner outflow section in the inner stent provided by an embodiment of the present application.

[0038] Figure 11 Schematic cross-sectional view of the aorta and mitral valve in the human heart.

[0039] Figure 12 Bottom view of the valve stent provided by an embodiment of the present application.

[0040] Figure 13 Side view of the valve stent provided by an embodiment of the present application (the inner stent is hidden).

[0041] Figure 14 Structural schematic diagram of the flange extension section provided by an embodiment of the present application.

[0042] Figure 15 Structural schematic diagram of the flange extension section provided by another embodiment of the present application.

[0043] Figure 16 Structural schematic diagram of the flange extension section provided by yet another embodiment of the present application.

[0044] Explanation of reference numerals:

[0045] 10. Heart valve replacement device; 100. Valve stent; 110. Stent body; 110a. Blood input end; 110b. Blood output end; 110c. Blood channel; 110d. Cusp commissure side; 110e. Anterior cusp side; 110f. Posterior cusp side; 111. Outer stent; 1111. Flange section; 1111a. Flange; 1112. Outer main body section; 1112a. Outer grid; 1113. Outer outflow section; 1113a. Outer outflow unit; 112. Inner stent; 1121. Inner main body section; 1121a. Inner grid; 1122. Inner outflow section; 1122a. Inner outflow unit; 120. Flange extension section; 200. Valve prosthesis; 210. Skirt; 211. Outer skirt; 212. Inner skirt; 220. Cusp; 30. Central axis; 40. First connection line; 50. Second connection line. Detailed implementation manners

[0046] To make the above objects, features, and advantages of the present application more apparent and understandable, the following will describe in detail the specific implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0047] In the description of the present application, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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 cannot be understood as a limitation to the present application.

[0048] In addition, if terms such as "first" and "second" appear, these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0049] In this application, unless otherwise clearly specified or limited, if terms such as "installed", "connected", "linked", "fixed", etc. appear, these terms shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In this application, unless otherwise clearly specified or limited, if there is a description such as the first feature is "on" or "under" the second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath", and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal level than the second feature.

[0051] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right", and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0052] This application provides a valve stent and a heart valve replacement device. The heart valve replacement device includes a valve stent, which is used to, when the native valve of the human heart is diseased, enable the artificial valve carried on the valve stent to replace the native valve so that blood flows from the atrium to the ventricle during diastole and prevent blood from flowing back from the ventricle to the atrium during systole, so as to achieve the purpose of treating heart reflux diseases.

[0053] Taking the heart valve as the mitral valve located between the left atrium and the left ventricle, and taking the heart valve replacement device for replacing the native mitral valve as an example, the structures of the heart valve replacement device and the valve stent in this application will be described. It can be understood that in other embodiments, the heart valve replacement device of this application is not limited to only being used to replace the native mitral valve, and can also be used to replace the native tricuspid valve. Moreover, the heart valve replacement device of this application is not limited to only being used to replace the heart valves of the human body, and can also be used to replace the heart valves of certain animals, which is not limited here.

[0054] Refer to Figure 1 , Figure 1 which shows a schematic structural view of the heart valve replacement device 10 in an embodiment of the present application. The heart valve replacement device 10 provided in an embodiment of the present application includes a valve stent 100 and a valve prosthesis 200. The valve stent 100 is used to carry the valve prosthesis 200 and enable the heart valve replacement device 10 to be anchored on the native valve annulus of the heart. The valve prosthesis 200 is used to replace the diseased native valve of the heart and prevent blood from flowing back from the ventricle to the atrium during the systolic phase of the heart.

[0055] Refer to Figure 2 , in one embodiment, the valve stent 100 includes a stent main body 110 and a plurality of flange extension segments 120. The stent main body 110 has a net tubular structure and surrounds a central axis 30. The stent main body 110 has a relatively arranged blood input end 110a and a blood output end 110b in the axial direction defined by the central axis 30. As shown in Figure 2 , the upper end of the stent main body 110 is the blood input end 110a, and the lower end is the blood output end 110b. The inner peripheral surface of the stent main body 110 forms a blood channel 110c. The plurality of flange extension segments 120 are provided at at least part of the edge of the stent main body 110 at the blood input end 110a, and the plurality of flange extension segments 120 are circumferentially spaced apart by the central axis 30. Their function is to fit with the atrial wall to improve the fit degree of the valve stent 100 with the atrial wall, thereby reducing the risk of paravalvular leakage.

[0056] Specifically, the stent main body 110 includes an outer stent 111 and an inner stent 112 that are nested and connected to each other. The outer stent 111 is sleeved outside the inner stent 112. The outer stent 111 is in direct contact with the native valve annulus after the heart valve replacement device 10 is implanted, and plays a role in expanding the native valve annulus and anchoring. The inner stent 112 plays a role in carrying the valve prosthesis 200. And the height of the outer stent 111 is higher than or equal to the height of the inner stent 112, so that blood can flow more smoothly from the atrium into the ventricle.

[0057] Correspondingly, the valve prosthesis 200 includes a skirt 210 and valve leaflets 220. In Figure 1In the embodiment shown, the skirt 210 has a double-layer structure, including an outer skirt 211 and an inner skirt 212. The outer skirt 211 covers the outer stent 111, specifically covering one or both of the inner and outer sides of the outer stent 111. The inner skirt 212 covers the inner side of the inner stent 112, or covers both the inner and outer sides of the inner stent 112 simultaneously. The advantage of only covering the inner side is that since less material is required for the skirt 210, the radial dimension of the heart valve replacement device 10 can be made smaller, thus avoiding damage to the native annulus tissue. The advantage of covering both the inner and outer sides simultaneously is that it can reduce blood leakage, which can be specifically set according to needs. Further, since the valve prosthesis 200 is used to replace the native mitral valve, and the native mitral valve includes an anterior leaf and a posterior leaf, optionally, the valve leaflets 220 have at least two pieces. In this embodiment, the valve leaflets 220 have three pieces, and the three valve leaflets 220 are arranged in sequence along the circumferential direction of the native annulus (i.e., a structure similar to trisecting the cross-section of the native annulus), so that the valve leaflets 220 have better fatigue resistance. Furthermore, the material of the valve leaflets can be animal pericardium or other biocompatible polymer materials. One end of each valve leaflet 220 is connected to the inner skirt 212, so that it can be stably fixed on the valve stent 100, and the other end is a free end, whose function is to replace the diseased native valve leaflets to open and close the blood passage 110c in the working state.

[0058] It can be understood that in other embodiments, the stent body 110 can also be a single-layer structure. For example, it only includes the outer stent 111, and the skirt 210 correspondingly has a single-layer structure and covers the inner side of the outer stent 111, which is not limited here. However, the embodiment in which the stent body 110 is designed as a double-layer structure inside and outside is obviously a better embodiment because the outer diameter of the outer stent 111 is larger, and placing it at the native annulus can better play a role in fixing and supporting. Since the outer diameter of the inner stent 112 is smaller, the valve leaflets 220 are indirectly fixed on the inner stent 112 through the inner skirt 212, so that the size of the valve leaflets 220 in the radial direction defined by a central axis 30 can be reduced, and the fatigue resistance of the valve leaflets 220 can be significantly improved. And since the outer stent 111 and the inner stent 112 are of a split structure, compared with the stent body 110 of a single-layer structure, the diameter of the sheath tube used to load the valve stent 100 is also smaller, reducing the delivery difficulty of the valve stent 100 and the risk of damaging blood vessels in the native tissue.

[0059] Specifically in terms of the materials and structures of the outer stent 111 and the inner stent 112, refer to Figure 3 and Figure 4, in order to enable the outer stent 111 and the inner stent 112 to have better stiffness to better conform to the structure of the native tissue in the heart, the materials of the outer stent 111 and the inner stent 112 can optionally be nitinol alloy materials. This is because nitinol alloy has a unique shape memory function, and both the outer stent 111 and the inner stent 112 are in a net tubular structure, that is, the outer stent 111 and the inner stent 112 respectively include one or more groups of grid groups in the axial direction, and each group of grid groups includes a plurality of grids that are sequentially connected end to end in the circumferential direction.

[0060] Refer to Figure 3 , the outer stent 111 includes a flange section 1111, an outer main body section 1112, and an outer outflow section 1113 that are sequentially connected in the axial direction. One end of the flange section 1111 away from the outer main body section 1112 forms a blood input end 110a, and one end of the outer outflow section 1113 away from the outer main body section 1112 forms a blood output end 110b. A plurality of flange extension sections 120 are arranged at one end of the flange section 1111 away from the outer main body section 1112; Refer to Figure 4 , the inner stent 112 includes an inner main body section 1121 and an inner outflow section 1122 that are sequentially connected in the axial direction, and the inner outflow section 1122 is connected to the outer outflow section 1113. Optionally, the inner stent 112 and the outer stent 111 can be connected at any position of the two stents by connection means such as welding, riveting, or using sutures or skirts 210 for sewing. The number of connection points can be 3 to 20, and there is no special limitation here.

[0061] Optionally, in order to make the contour outside the stent main body 110 match the contours of the native valve annulus and the atrial wall, as Figure 3 shown, in the direction from the blood input end 110a to the blood output end 110b, the size of the stent main body 110 gradually decreases in the radial direction, that is, the radial size of the stent main body 110 at the blood input end 110a is greater than the radial size of the stent main body 110 at the blood output end 110b. Specifically, the outer diameters of the flange section 1111, the outer main body section 1112, and the outer outflow section 1113 of the outer stent 111 gradually decrease in the radial direction, as Figure 4 shown, the outer diameter of the inner main body section 1121 of the inner stent 112 in the radial direction can be equal to the outer diameter of the inner outflow section 1122, or can be slightly larger than the outer diameter of the inner outflow section 1122. Optionally, between the flange section 1111 and the outer main body section 1112, between the outer main body section 1112 and the outer outflow section 1113, and between the inner main body section 1121 and the inner outflow section 1122, laser cutting technology can be used for integral molding, and then the diameter is expanded and shaped through a heat treatment shaping process, so that the valve stent 100 is finally shaped to form the above-mentioned net tubular structure.

[0062] It can be understood that in the direction from the blood input end 110a to the blood output end 110b, the radial dimension of the stent body 110 can decrease first, then increase, and then decrease again, as long as the radial dimension of the stent body 110 at the blood input end 110a is greater than the radial dimension of the stent body 110 at the blood output end 110b, and no further limitation is made here.

[0063] Thus, through the above settings, after the heart valve replacement device 10 is implanted into the human heart through a sheath tube, the valve stent 100 changes from a contracted state to an extended state after being released by the sheath tube. First, the flange section 1111 of the outer stent 111 is released first and becomes extended, and finally the outer main body section 1112 is released and becomes extended, so that the flange section 1111 with a larger diameter can be anchored to the native tissue first, and then the outer main body section 1112 and the outer outflow section with a smaller diameter are anchored to the native tissue, thereby avoiding the valve stent 100 from shaking randomly and accurately installing the valve stent 100 at a predetermined position.

[0064] More specifically, referring to Figure 3 and Figure 5 , the flange section 1111 includes a plurality of flanges 1111a that are sequentially connected end to end in the circumferential direction. Adjacent two flange extension sections 120 are connected by one or more flanges 1111a. Each flange 1111a is in the shape of a Y, a rhombus, a pentagon, a hexagon, etc., without special limitation. In the embodiment shown in Figure 5 , each flange 1111a ( Figure 5 the part within the dotted circle in

[0065] Referring to Figure 3 , Figure 6 and Figure 7 , the outer main body section 1112 includes a plurality of outer grid units that are sequentially connected end to end in the circumferential direction. Each outer grid unit is connected to a corresponding flange 1111a, and each outer grid 1112a unit includes at least one layer of outer grid 1112a in the axial direction. A single outer grid 1112a ( Figure 6 the part within the dotted circle in Figure 7 and the part within the dotted rectangle in Figure 6 can be in the shape of a rhombus, a pentagon or a hexagon. In the embodiment shown in Figure 7In the embodiment shown, each outer-layer grid 1112a unit includes two layers of outer-layer grids 1112a in the axial direction.

[0066] It should be noted that the number of outer-layer grid 1112a layers of the outer-layer main body section 1112 in the axial direction is not limited and can also be more layers, optionally 1 to 5 layers. And the circumferential distribution of each layer of outer-layer grid 1112a can be a uniform distribution or a non-uniform distribution. The number of the same layer of outer-layer grids 1112a is optionally between 3 and 18. And the widths and sizes of the same layer of outer-layer grids 1112a can be equal or unequal. And the grid heights of different outer-layer grids 1112a in the axial direction can be the same or different. The height range of a single layer of outer-layer grid 1112a is optionally between 3 mm and 20 mm.

[0067] Referring to Figure 3 and Figure 8 , the outer-layer outflow section 1113 includes a plurality of outer-layer outflow units 1113a that are sequentially connected end to end in the circumferential direction. Each outer-layer outflow unit 1113a ( Figure 8 the part within the dotted circle in Figure 8 the shown embodiment) is connected to a corresponding outer-layer grid unit. A single outer-layer outflow unit 1113a is one of a V shape, a diamond shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a diamond shape and a straight rod.

[0068] Similarly, referring to Figure 4 and Figure 9 , the inner-layer main body section 1121 of the inner-layer support 112 includes a plurality of inner-layer grid units that are sequentially connected end to end in the circumferential direction. Each inner-layer grid unit also includes at least one layer of inner-layer grid 1121a in the axial direction. A single inner-layer grid 1121a ( Figure 9 the part within the dotted ellipse in

[0069] the shown embodiment) can be in a diamond shape, a pentagon shape, or a hexagon shape. The number of layers of the inner-layer grid 1121a is optionally 1 - 5 layers. The number of the same layer of inner-layer grids 1121a is optionally 3 to 15. The height range of each inner-layer grid 1121a is optionally between 3 mm and 20 mm. Specifically, it can refer to the structure of the outer-layer main body section 1112 of the outer-layer support 111, which will not be elaborated here. Referring to Figure 4 and Figure 10 , the inner-layer outflow section 1122 of the inner-layer support 112 includes a plurality of inner-layer outflow units 1122a that are sequentially connected end to end in the circumferential direction. Each inner-layer outflow unit 1122a is connected to a corresponding inner-layer grid unit. A single inner-layer outflow unit 1122a is one of a V shape, a diamond shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a diamond shape and a straight rod. In Figure 10In the embodiment shown in Figure 10 the part within the dashed ellipse) has a structure combining an inverted V shape and a straight rod.

[0070] Thus, through the above design, both the outer stent 111 and the inner stent 112 are in the shape of a network tube structure respectively, so that the valve stent 100 can have a higher stiffness and a lower manufacturing cost.

[0071] It should be noted that the fewer the number of grid layers of the outer grid 1112a of the outer main body section 1112 in the outer stent 111 and the inner grid 1121a of the inner main body section 1121 in the inner stent 112, the lower the risk of damage to the ventricular structure. At the same time, combined with the structure in which the diameter of the outer stent 111 gradually decreases in the axial direction described in the above embodiment, it can not only ensure that the valve stent 100 matches the contours of the native annulus and the atrial wall, but also ensure that when the valve stent 100 is released from the sheath tube and changes from the contracted state to the expanded state, the diameter of the valve stent 100 will not suddenly change from a smaller diameter to a larger diameter, thus ensuring the release stability of the valve stent 100 when it is released into the heart.

[0072] In an alternative embodiment, the stent body 110 is provided with barbed structures (not shown in the figure) on the outside (i.e., the outside of the outer stent 111). The barbed structures include multiple barbs. The multiple barbs are arranged circumferentially around the stent body 110 and can be distributed in a single layer or multiple layers. Each barb has an elongated rod-like structure and is connected to the grid nodes of the outer stent 111, and each barb extends obliquely from the outside of the stent body 110 towards the blood input end 110a or towards the blood output end 110b. Optionally, the length range of each barb is between 1 mm and 10 mm, and the angle range of each barb with the outside of the outer stent 111 is between 0° and 90°.

[0073] Thus, by setting the barbed structures, the barbs of the barbed structures can pierce into the native valve leaflets, and then fix the stent body 110 at the position of the native valve leaflets. It can be understood that the distribution positions of the multiple barbs in the barbed structures correspond to the native valve leaflets of the heart. For example, the density of the barbed structures arranged in the connecting area of the anterior and posterior leaflets of the valve leaflet 220 is less than the density of the barbed structures in the anterior leaflet area of the native valve leaflet and not greater than the density of the barbed structures in the posterior leaflet area of the native valve leaflet. By setting like this, the barbed structures can conform to the physiological and anatomical regions of the native valve leaflets, so that the degree of damage to the connecting area of the anterior and posterior leaflets of the native valve leaflets by the barbed structures is less than the degree of damage to the anterior and posterior leaflets of the native valve leaflets by the barbed structures, and it can also reduce the damage of the barbed structures to the surrounding tissues. Furthermore, on the premise of ensuring the normal opening and closing of the artificial valve leaflets and controlling that the native valve leaflets do not affect the blood flow, it can effectively reduce the damage of the barbed structures to the heart tissues, that is, achieve a better treatment effect with fewer barbed structures.

[0074] In another alternative embodiment, the outer stent 111 is provided with a plurality of lugs (not shown in the figure) at the blood output end 110b for connecting to the mitral valve delivery system or for connecting to the inner stent 112. The plurality of lugs are evenly or unevenly distributed in the circumferential direction of the outer stent 111, and the number can be 3 to 12.

[0075] Furthermore, as described in the background art, the commonly available valve stents 100 on the market usually have a circular profile. The radial supporting force for anchoring to the native tissue of the heart comes from the circumferential extrusion between the circular profile of the stent and the native tissue. This acting force is evenly distributed in the circumferential direction defined by the central axis 30. However, the native mitral valve annulus is a three-dimensional saddle shape, and its profile is not a standard circle. Therefore, the circular profile has a strong extrusion effect on some tissue structures of the mitral valve annulus. As Figure 11 shown, based on the internal structure of the heart, the anterior leaf side of the native mitral valve is close to the aortic valve annulus, and its myocardial tissue is relatively weak. The valve stent 100 with a circular profile has a risk of damaging the native annulus tissue and the aortic valve annulus, and hinders the remodeling of the ventricle after minimally invasive surgery.

[0076] To solve the above problems, the inventors of the present application thought that the structure of the valve stent 100 described in the above embodiments could be improved. Therefore, in an improved embodiment, as Figure 12 shown, the outer contour of the valve stent 100 is designed to match the contour of the native annulus, that is, it is designed as a non-cylindrical net-shaped tubular structure. In this way, on a virtual projection plane perpendicular to the central axis 30, the projection contour of the stent body 110 is non-circular, for example, a D shape or an ellipse similar to the contour of the native annulus. In the Figure 12 embodiment shown, the stent body 110 has an approximately D-shaped projection contour. For example, Figure 12 in, when observed from the upward view direction, the projection contour of the stent body 110 has a side with an approximately straight edge and a side with a larger bending arc. The side with the larger bending arc is located on the side close to the anterior leaf of the native valve leaf, so it is defined as the anterior leaf side 110e. The anterior leaf side 110e is located close to the aorta; the side with the approximately straight edge is close to the posterior leaf of the native valve leaf, so it is defined as the posterior leaf side 110f, and is oppositely arranged to the anterior leaf side 110e in the radial direction. The side where the connection between the approximately straight edge and the side with the larger bending arc is located is close to the area where the anterior leaf and the posterior leaf of the native valve leaf are connected, so it is defined as the leaflet commissure side 110d. There are two leaflet commissure sides 110d, and the two leaflet commissure sides 110d are oppositely arranged in the radial direction. And then combined with Figure 11As shown, the connection line of the two commissural sides 110d on the projection plane is defined as the first connection line 40, and the connection line of the anterior leaf side 110e and the posterior leaf side 110f on the projection plane is defined as the second connection line 50. The first connection line 40 is perpendicular to the second connection line 50, and the length of the first connection line 40 is greater than the length of the second connection line 50.

[0077] In order to make the projection contour of the stent body 110 on the projection plane non-circular and to reduce damage to tissues, the outer stent 111 needs to be designed as a non-standard cylindrical network tube structure. In order to make the inner skirt 212 easier to connect with the inner stent 112 and to increase the service life of the implant, optionally, the inner stent 112 can be designed as a relatively standard cylindrical network tube structure. Correspondingly, the outer outflow section 1113 of the outer stent 111 can be a cylindrical network tube structure corresponding to the contour shape of the inner outflow section 1122. This makes it possible for the contour shapes of the flange section 1111, the outer main body section 1112, and the outer outflow section 1113 in the outer stent 111 to be different from each other.

[0078] It can be understood that in some embodiments, it can be that the projection contour of the flange section 1111 on the projection plane is non-circular, while the projection contours of the outer main body section 1112 and the outer outflow section 1113 on the projection plane are circular, or it can be that the projection contours of the flange section 1111 and the outer main body section 1112 on the projection plane are non-circular, while the projection contour of the outer outflow section 1113 on the projection plane is circular.

[0079] Thus, through the above design, as Figure 11 shown, the distance between the two commissural sides 110d is longer, and the distance between the anterior leaf side 110e and the posterior leaf side 110f is shorter. Just because the distance between the two commissural sides 110d is longer, after the valve stent 100 is implanted into the heart, it mainly relies on the interaction between the two commissural sides 110d and the native mitral valve annulus to generate radial support force for anchoring. The interaction between the anterior leaf side 110e and the posterior leaf side 110f and the native mitral valve annulus is smaller, thereby reducing the risk of damage to the atrial and ventricular walls near the anterior leaf side 110e after the heart valve replacement device 10 and the mechanical obstruction to ventricular remodeling or recovery after minimally invasive surgery.

[0080] In a better embodiment, as Figure 12 shown, the projection contours of both the flange section 1111 and the outer main body section 1112 on the projection plane are approximately D-shaped, so that when observing the valve stent 100 from the side view direction (refer to Figure 13 ), the reduction amplitude of the distance between the outer side of the anterior leaf side 110e and the central axis 30 in the axial direction is greater than the reduction amplitude of the distance between the outer side of the posterior leaf side 110f and the central axis 30 in the axial direction.

[0081] Thus, as Figure 13 shown, the structures of the flange section 1111 and the outer main body section 1112 on the anterior leaflet side 110e are both such that the distance from the axial direction to the central axis 30 gradually decreases and the decreasing amplitude is greater. This can make the space occupied by the valve stent 100 on the side of the anterior leaflet of the native mitral valve close to the left ventricle smaller, thereby effectively reducing the blockage of the left ventricular outflow tract after the valve stent 100 is implanted into the heart. And based on the foregoing, the anterior leaflet side of the native mitral valve is close to the aortic valve annulus. The above design can further reduce the contact area between the anterior leaflet side 110e and the aorta and reduce the compression of the anterior leaflet side 110e on the aorta.

[0082] Optionally, in order to both reduce the contact area between the anterior leaflet side 110e and the aorta and ensure that the side of the valve stent 100 where the anterior leaflet side 110e is located can firmly adhere to the atrial wall to avoid paravalvular leakage, please continue to refer to FIGS. 12 and Figure 13 , the plurality of flange extension segments 120 are not uniformly arranged on the entire edge of the stent main body 110 at the blood input end 110a, but are arranged at intervals on the edge of the blood input end 110a on the side of the anterior leaflet side 110e and the side close to the anterior leaflet side 110e. Specifically, they are arranged on the side edge of the upper end of the outer stent 111 at and close to the anterior leaflet side 110e.

[0083] In other embodiments, it may also be that the flange extension segment 120 is only arranged on the edge of the blood input end 110a on the anterior leaflet side 110e, or arranged on the edge of the blood input end 110a close to the anterior leaflet side 110e. The number of the flange extension segments 120 can be 2 to 18, and the lengths of the respective flange extension segments 120 can be equal or unequal, and the length range can be 2 mm to 15 mm. None of the above is specifically limited. In the embodiment shown in the figure, the flange extension segment 120 is only arranged on the edge of the blood input end 110a on the anterior leaflet side 110e and the edge close to the anterior leaflet side 110e, and in the direction from the anterior leaflet side 110e to the posterior leaflet side 110f, the length of the flange extension segment 120 gradually decreases.

[0084] Furthermore, each flange extension segment 120 is a rod-shaped single-rod structure. Exemplarily, as Figures 14 to 16 shown, it can be the straight rod structure as Figure 14 shown, or the serpentine curved rod structure as Figure 15 shown, or also Figure 16The structure of the combination of the straight rod and the curved rod shown. Because the flange extension section 120 is a single-rod structure and the outer stent 111 is a mesh structure, the flange extension section 120 is more easily bent, so its stiffness is less than that of the outer stent 111. And because the size of each mesh of the outer stent 111 is larger than the size of each mesh of the inner stent, the stiffness of the outer mesh 1112a is less than the stiffness of the inner mesh 1121a.

[0085] Thus, as Figure 13 shown, when observing the valve stent 100 from the side shown in the figure, the height of the valve stent 100 on the side located at the anterior leaf side 110e is higher than the height on the side located at the posterior leaf side 110f. In this way, it can not only ensure that the auxiliary support part can be more effectively attached to the left atrial wall near the position of the anterior mitral leaf, but also ensure that the outer stent 111 can be better attached to the left atrial wall and the left ventricular wall near the posterior leaf side 110f, so as to effectively prevent paravalvular leakage, and can also ensure that the compression on the native mitral valve annulus at the positions near the anterior leaf side 110e and the posterior leaf side 110f is reduced. And because the inner stent 112 has a higher stiffness and better supporting force, it can ensure the normal operation of the valve leaf 220.

[0086] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered to be within the scope described in this specification.

[0087] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A valve stent, characterized in that, Comprising: A stent body for carrying a valve prosthesis, the stent body being arranged around a central axis, and in a projection plane perpendicular to the central axis, the projection profile of the stent body being non-circular; in the axial direction defined by the central axis, the stent body has a blood input end and a blood output end arranged oppositely. A plurality of flange extension segments provided at the edge of the stent body at the blood input end, the plurality of flange extension segments being spaced apart in the circumferential direction defined by the central axis.

2. The valve stent according to claim 1, wherein, The stent body includes an outer stent and an inner stent connected to each other, the outer stent being sleeved outside the inner stent, and both the outer stent and the inner stent include at least one set of mesh groups in the axial direction, and each set of mesh groups includes a plurality of meshes connected end to end in sequence in the circumferential direction.

3. The valve stent according to claim 2, wherein, The outer stent includes a flange segment, an outer main body segment, and an outer outflow segment connected in sequence in the axial direction, one end of the flange segment away from the outer main body segment forms the blood input end, and one end of the outer outflow segment away from the outer main body segment forms the blood output end. The inner stent includes an inner main body segment and an inner outflow segment connected in sequence in the axial direction, and the inner outflow segment is connected to the outer outflow segment.

4. The valve stent according to claim 3, characterized in that The outer diameters of the flange segment, the outer main body segment, and the outer outflow segment in the radial direction defined by the central axis decrease in sequence; the outer diameter of the inner main body segment in the radial direction is greater than or equal to the outer diameter of the inner outflow segment.

5. The valve stent according to claim 3, wherein, The projection profile of the flange segment in the projection plane is non-circular, or the projection profiles of the flange segment and the outer main body segment in the projection plane are both non-circular.

6. The valve stent according to claim 3, characterized in that, The flange segment includes a plurality of flanges connected end to end in sequence in the circumferential direction, and adjacent two flange extension segments are connected by one or more flanges, and each flange is in a Y shape, a rhombus shape, a pentagon shape, or a hexagon shape. The outer main body segment includes a plurality of outer mesh units connected end to end in sequence in the circumferential direction, each outer mesh unit is connected to a corresponding one of the flanges, and each outer mesh unit includes at least one outer mesh in the axial direction, and a single outer mesh is in a rhombus shape, a pentagon shape, or a hexagon shape. The outer outflow segment includes a plurality of outer outflow units connected end to end in sequence in the circumferential direction, each outer outflow unit is connected to a corresponding one of the outer mesh units, and a single outer outflow unit is in one of a V shape, a rhombus shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a rhombus and a straight rod.

7. The valve stent according to claim 5, wherein The inner main body segment includes a plurality of inner mesh units connected end to end in sequence in the circumferential direction, each inner mesh unit includes at least one inner mesh in the axial direction, and a single inner mesh is in a rhombus shape, a pentagon shape, or a hexagon shape. The inner outflow segment includes a plurality of inner outflow units connected end to end in sequence in the circumferential direction, each inner outflow unit is connected to a corresponding one of the inner mesh units, and a single inner outflow unit is in one of a V shape, a rhombus shape, a straight rod shape, a combined structure of a V shape and a straight rod, and a combined structure of a rhombus and a straight rod.

8. The valve stent according to claim 2, wherein, The flange extension section is in a straight rod structure, or a serpentine curved rod structure, or a structure combining a straight rod and a serpentine curved rod; the stiffness of the flange extension section is less than the stiffness of the outer stent; and / or the stiffness of the outer stent is less than the stiffness of the inner stent.

9. The valve stent according to claim 1, characterized in that, The outer side of the stent body includes two leaflet union sides oppositely arranged in the radial direction defined by the central axis, and a front leaflet side and a rear leaflet side oppositely arranged in the radial direction. The connection line of the two leaflet union sides in the projection plane is defined as the first connection line, and the connection line of the front leaflet side and the rear leaflet side in the projection plane is defined as the second connection line. The first connection line is perpendicular to the second connection line, and the length of the first connection line is greater than the length of the second connection line.

10. The valve stent according to claim 9, wherein, In the direction from the blood input end to the blood output end, the outer diameter of the stent body gradually decreases in the radial direction; the reduction amplitude of the distance between the outer side of the front leaflet side and the central axis in the axial direction is greater than the reduction amplitude of the distance between the outer side of the rear leaflet side and the central axis in the axial direction.

11. The valve stent according to claim 9, characterized in that, The plurality of flange extension sections are spacedly arranged at the edge of the blood input end on the side located at and / or near the front leaflet side.

12. The valve stent according to claim 1, characterized in that, The stent body is provided with a plurality of barbs on the outer side, and each barb extends obliquely from the outer side of the stent body towards the blood output end or towards the blood input end.

13. A heart valve replacement device, characterized in that, Comprising: The valve stent according to any one of claims 1-12; A valve prosthesis connected to the valve stent, the valve prosthesis being used to replace the native valve of the heart.

14. The heart valve replacement device according to claim 13, wherein The valve stent includes an outer stent and an inner stent that are nested and connected to each other, the outer stent is sleeved on the outer side of the inner stent, the valve prosthesis includes an outer skirt, an inner skirt and leaflets, the outer skirt and the inner skirt are connected to each other, the outer skirt covers the inner side and / or the outer side of the outer stent, the inner skirt at least covers the inner side of the inner stent, and the leaflets are connected to the inner side of the inner skirt.

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