Valve stents and valve prostheses

Abstract

The present invention provides a valve stent and a valve prosthesis, wherein the valve stent is in a mesh tube shape, and comprises M layers of wave-rod unit groups connected in sequence along the axial direction, wherein the first layer of wave-rod unit groups is located at the inflow end, and the Mth layer of wave-rod unit groups is located at the outflow end, wherein the wave-rod unit groups comprise circumferentially connected wave-rod units, and the number of wave-rod units in the Mth layer of wave-rod unit groups is less than the number of wave-rod units in the M-1st layer of wave-rod unit groups. The present invention can solve the problem that the existing valve stent squeezes the valve leaflets during use, thereby causing the valve leaflets to block the coronary channel.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a valve stent and a valve prosthesis. Background Art

[0002] Interventional aortic valve replacement is a new minimally invasive valve replacement technology developed internationally in recent years. Its principle is that the valve prosthesis is loaded into the delivery system and delivered to the aortic root through a catheter. The release of the valve stent can ensure that the valve is fixed to the aortic valve ring, replacing the original valve with degraded function, so that the patient's heart function is improved. This technology can treat aortic valve disease without opening the chest and without stopping the heart, eliminating the huge trauma caused to patients by surgical thoracotomy and cardiac arrest in the past.

[0003] Interventional aortic valve replacement, under the premise of restoring the aortic valve function, needs to ensure that the implanted valve prosthesis has the lowest impact on the surrounding blood vessels, especially the coronary vessels at the aortic root. Under the current technical background, if the valve prosthesis cannot reserve a channel for the coronary artery, then the scope of indications can only be narrowed, leaving some patients' problems unsolved.

[0004] However, in existing valve prostheses, the valve stent is prone to push away the native valve leaflets when implanted in the aortic valve ring, causing the native valve leaflets to stick to the Valsalva sinus wall, thereby creating the risk of the native valve leaflets blocking the coronary artery orifice. Summary of the invention

[0005] The object of the present invention is to provide a valve stent and a valve prosthesis to solve the problem that the existing valve stent squeezes the valve leaflets during use, thereby causing the valve leaflets to block the coronary passage.

[0006] In order to solve the above technical problems, the present invention provides a valve stent, which is in the shape of a mesh tube, and includes M layers of wave rod unit groups connected in sequence along the axial direction, the first layer of wave rod unit group is located at the inflow end, the Mth layer of wave rod unit group is located at the outflow end, the wave rod unit group includes circumferentially connected wave rod units, and the number of wave rod units in the Mth layer of wave rod unit group is less than the number of wave rod units in the M-1th layer of wave rod unit group.

[0007] Optionally, in the above-mentioned valve stent, the number of the wave-rod units in the 1st to M-1th layers of wave-rod unit groups are the same, and two adjacent layers of wave-rod unit groups form a circumferentially continuously distributed grid.

[0008] Optionally, in the above-mentioned valve stent, the shape of the wave rod units in the 1st to M-1th layer wave rod unit groups is V-shaped or inverted V-shaped, and the two corresponding wave rod units in two adjacent layers of wave rod units are directly connected to form a diamond grid.

[0009] Optionally, in the above-mentioned valve stent, the shape of the wave rod units in the 1st to M-1th layer wave rod unit groups is V-shaped or inverted V-shaped, and the two corresponding wave rod units in two adjacent layers of wave rod units are connected by an axial connecting part to form a hexagonal grid.

[0010] Optionally, in the above-mentioned valve stent, the shape of the wave rod unit in the Mth layer wave rod unit group is an inverted V shape, having two free ends, and the two free ends are respectively connected to two target wave rod units in the M-1th layer wave rod unit group, wherein X wave rod units in the M-1th layer wave rod unit group are spaced between the two free ends.

[0011] Optionally, in the above-mentioned valve stent, 1≤X≤3.

[0012] Optionally, in the above valve stent, the wave-rod units in the Mth layer of the wave-rod unit group are connected to the wave-rod units in the M-1th layer of the wave-rod unit group via straight rods.

[0013] Optionally, in the above-mentioned valve stent, the number of the straight rods is greater than or equal to 3.

[0014] Optionally, in the above-mentioned valve stent, M≤5.

[0015] Based on the same inventive concept, the present invention further provides a valve prosthesis, comprising a valve leaflet and the valve support as described above, wherein the valve leaflet is fixed on the valve support.

[0016] Compared with the prior art, the valve stent and valve prosthesis provided by the present invention have the following beneficial effects:

[0017] The valve stent of the present invention, since the number of the second wave-rod units in the Mth layer is less than the number of the first wave-rod units in the M-1th layer, can form a plurality of large grids between the M-1th layer and the Mth layer. When the valve stent is implanted in the aortic valve ring, the formed large grids will not squeeze the native valve leaflets in the radial direction, thereby reducing the risk of the native valve leaflets blocking the coronary orifice; at the same time, the formed large grids can provide a channel for coronary blood flow and can also provide a channel for later PCI;

[0018] Since the valve prosthesis of the present invention has the above-mentioned valve stent, it also has all the advantages of the above-mentioned valve stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a front view of a valve stent in one embodiment of the present invention;

[0021] Figure 2 for Figure 1 A three-dimensional view of the valve stent shown;

[0022] Figure 3a A simplified schematic diagram of the connection relationship between the second wave-bar unit and the first wave-bar unit;

[0023] Figure 3b is another simplified schematic diagram of the connection relationship between the second wave-bar unit and the first wave-bar unit;

[0024] Figure 4 It is a structural diagram of a valve stent for comparative example. DETAILED DESCRIPTION

[0025] The following is a further detailed description of a valve stent and valve prosthesis proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0026] In this article, "proximal end, lower part or lower end" and "distal end, upper part or upper end" are viewed from the direction of heart blood flowing through the valve stent. Although "proximal end", "lower part" or "lower end" and "distal end", "upper part" or "upper end" are not restrictive, "proximal end", "lower part" or "lower end" generally refers to the end close to the blood flowing into the valve stent, and "distal end", "upper part" or "upper end" generally refers to the end close to the blood flowing out of the valve stent.

[0027] The core idea of ​​the present invention is to provide a valve stent and a valve prosthesis to solve the problem that the existing valve stent squeezes the valve leaflets during use, thereby causing the valve leaflets to block the coronary passage.

[0028] The valve stent provided by the present invention is in the shape of a mesh tube (the main contour of the stent can be a straight contour, or it can be provided with an inner concave or outer convex structure), and has an inflow end structure and an outflow end structure connected in sequence, the inflow end corresponds to the direction of blood flow inflow, the outflow end corresponds to the direction of blood flow outflow, and the direction from the inflow end to the outflow end is the axial direction of the valve stent. When the valve stent is implanted into the aortic valve, it includes an anchoring section and a coronary section, the anchoring section is located at the valve inflow end (i.e., the proximal end), and the coronary section is located at the valve outflow end (i.e., the distal end).

[0029] Specifically, the valve stent includes M layers of wave-rod unit groups connected in sequence along the axial direction, wherein the first layer is located at the inflow end and the Mth layer is located at the outflow end. In the second wave-rod unit group of the Mth layer, each second wave-rod unit is connected in sequence along the circumferential direction, and the number of the second wave-rod units is less than the number of the first wave-rod units in the first wave-rod unit group of the M-1th layer. This structure can form a plurality of large grids between the M-1th layer and the Mth layer wave-rod unit group. When the valve stent is implanted in the aortic valve ring, the large grid formed will not cause radial compression to the native leaflets in the coronary segment, thereby reducing the risk of the native leaflets blocking the coronary orifice. At the same time, the large grid formed can provide a channel for coronary blood flow and a channel for later PCI. It can be understood that the "wave-rod unit" described herein refers to the smallest structural unit composed of the wave rods in each layer of the structure in the valve stent. Each layer of the structure in the valve stent is a wave-rod unit group, and the wave-rod unit group is composed of a plurality of wave-rod units. For the convenience of distinction and description, the wave-rod unit group in the 1st to M-1th layer structures is referred to as the first wave-rod unit group, and the wave-rod unit group in the Mth layer structure is referred to as the second wave-rod unit group.

[0030] Please refer to Figure 1 and Figure 2 , which schematically shows a schematic diagram of the structure of a valve stent provided by an embodiment of the present invention. In this embodiment, the valve stent includes 4 layers of wave-rod unit groups, which are the 1st to 4th layers from the inflow end to the outflow end, and the 1st to 3rd layer structures all include the first wave-rod unit group, and the 4th layer structure includes the second wave-rod unit group. Figure 1 , 2As shown, the 4th layer second wave bar unit group includes 6 second wave bar units 20, each second wave bar unit 20 is connected in sequence along the circumferential direction, the 3rd layer first wave bar unit group includes 12 first wave bar units 10, and 6 large grids A are formed between the 3rd layer and the 4th layer wave bar unit groups. The 2nd layer and the 1st layer first wave bar unit groups both include 12 first wave bar units, the 1st layer and the 2nd layer first wave bar unit groups form a first layer of diamond grids, and the 2nd layer and the 3rd layer first wave bar unit groups form a second layer of diamond grids. The coronary segment and the anchoring segment are separated by the node a where the 2nd layer first wave bar unit group and the 3rd layer first wave bar unit group are connected, so when implanted, the node a needs to be lower than the coronary ostium.

[0031] It is understandable that the total number of layers of the valve stent in this embodiment is 4, but the present invention is not limited thereto. In the present invention, the total number of layers is preferably no more than 5, so that the height of the valve stent in the axial direction can be lower, and a lower valve stent can reduce the impact on coronary blood flow.

[0032] However, the valve stent has a small number of wave rod unit layers in the axial direction, which will cause the defect of insufficient radial support force. Therefore, in actual clinical practice, this is a set of contradictory factors, which requires both ensuring the radial support force of the valve stent and ensuring that the height is not too high to affect coronary blood flow. Based on this, in an embodiment of the present invention, each first wave rod unit 10 in each layer of the first wave rod unit group is sequentially connected along the circumferential direction, so that a multi-layer complete grid can be formed, and the grid is continuously distributed along the circumferential direction, so that the valve stent can provide a larger radial support force. Preferably, the number of first wave rod units 10 in each layer of the first wave rod unit group is the same, so that the multi-layer grid can be evenly distributed to further improve the radial support force of the valve stent.

[0033] like Figure 1 , 2 As shown, each first wave rod unit 10 in the 1st to 3rd layer first wave rod unit group is connected in sequence along the circumferential direction, and the number of first wave rod units 10 in each layer of the first wave rod unit group is 12. The 1st and 2nd layer first wave rod unit groups form a first layer of grid, and the 2nd and 3rd layer first wave rod unit groups form a second layer of grid. Both layers of grids contain 12 grids, thus forming a uniform and complete grid. The grid is continuously and evenly distributed along the circumferential direction, thereby improving the radial supporting force of the valve stent.

[0034] In this embodiment, the height of the node a where the second layer first wave rod unit group is connected to the third layer first wave rod unit group is lower than the coronary artery orifice, so that the coronary artery channel will not be blocked. Under the premise of ensuring radial support force, the height of the valve stent can be greatly reduced, thereby reducing the risk to the coronary artery.

[0035] Specifically, Figure 1 ,2 As shown, the shape of the first wave bar unit 10 can be V-shaped. For example, the V-shaped structure of the first wave bar unit 10 can be composed of two wave bars, or a V-shaped bar can be formed in one piece. The present invention does not limit this. In the first wave bar unit group of the same layer, the free ends of each first wave bar unit 10 are connected in sequence to form a ring-shaped first wave bar unit group. For the first wave bar unit group of adjacent layers, the corresponding two first wave bar units 10 are directly connected to form a diamond grid (such as Figure 1 or, two correspondingly arranged first wave bar units 10 are connected via an axial connection portion 30 to form a hexagonal grid (such as Figure 1 The connection method of the first wave rod unit 10 in the first wave rod unit group of the 1st and 2nd layers).

[0036] like Figure 1 , 2 As shown, the shape of the second wave rod unit 20 can be an inverted V-shape. For example, the inverted V-shaped structure of the second wave rod unit 20 can be composed of two wave rods, or it can be an inverted V-shaped rod formed in one piece, and the present invention does not limit this. The two free ends b1 and b2 of the second wave rod unit 20 are respectively connected to the two first wave rod units 10 in the first wave rod unit group of the third layer after being separated by X first wave rod units 10. It can be understood that the second wave rod unit 20 is an inverted V-shaped structure, and the two free ends correspond to the two vertices of the inverted V-shaped structure. Interval of X first wave rod units 10 means that there are X first wave rod units 10 between the two free ends b1 and b2 of the second wave rod unit 20. The number of intervals X can be set according to actual conditions, preferably 1 to 3, and the present invention does not limit this. Figure 3a The schematic diagram shows that the two free ends of the second wave rod unit 20 are connected to the two first wave rod units 10 in the first wave rod unit group of the upper layer after being separated by one first wave rod unit 10, which is similar to Figure 1 The valve stents shown are connected in the same manner; Figure 3b A simplified schematic diagram is schematically shown in which two free ends of the second wave bar unit 20 are respectively connected to two first wave bar units 10 in the first wave bar unit group of the upper layer after being separated by two first wave bar units 10 .

[0037] As mentioned above, since the number of wave rod unit groups in the 1st to M-1st layers does not exceed 4 layers, in order to avoid the problem that insufficient leaflet height affects the normal operation of the leaflet, the second wave rod unit 20 in the Mth layer can be connected to the first wave rod unit 10 in the first wave rod unit group in the M-1th layer through the straight rod 40. Figure 1 , 2As shown, the two free ends of the second wave bar unit 20 of the fourth layer are connected to the first wave bar unit 10 of the first wave bar unit group of the third layer through a straight rod 40. It can be seen that in this embodiment, at each connection point between the second wave bar unit 20 and the first wave bar unit 10, the straight rod 40 is continuously arranged, that is, 6 straight rods 40 are arranged. It can be understood that in other embodiments, the straight rods 40 can also be arranged at intervals, that is, the number of straight rods 40 is less than 6. At the same time, the number of straight rods 40 is greater than or equal to 3, and 3 straight rods 40 can be selected as leaflet suturing rods. The leaflet suturing rods can be provided with suturing holes, and the shape of the suturing holes can be rectangular. Figure 1 As shown, the second wave rod unit 20, the first wave rod unit 10 and the straight rod member 40 connected therebetween, which are arranged opposite to each other up and down, form a closed large grid A, and no straight rod member 40 is added to the large grid A to reduce the crimping diameter of the valve stent after loading.

[0038] The valve stent provided by the present invention can be applied to a ball-expandable stent or a self-expanding stent. When applied to a self-expanding stent, corresponding structures can be set at both ends of the valve stent as required to achieve connection with the delivery system, for example, ears, pull wire holes, etc. can be added, which will not be elaborated here.

[0039] Please refer to Figure 1 and Figure 4 , according to Figure 1 The valve support of the present invention is shown Figure 4 The existing valve stents shown are compared to analyze the advantages and disadvantages of the two.

[0040] exist Figure 1 In the valve stent of this embodiment, in the fourth layer, there is only one V-shaped wave rod unit between two adjacent straight rods. Figure 4 In the comparative valve stent, in the fourth layer, there are two V-shaped wave rod units between two adjacent straight rods, such as Figure 1 and 4 As shown, the valve stent of the comparative example has the same structure as other parts of the valve stent of this embodiment.

[0041] First, from Figure 1 and Figure 4 It can be seen from the figure that compared with the comparative example, the valve stent of this embodiment has no grid stent blocking the large grid A, and the free edge of the valve leaflet can move freely in this area. Figure 4 In the comparative valve stent shown, due to the existence of the free end b from the outflow end toward the inflow end (i.e., the portion where the two V-shaped wave rod units between two adjacent straight rod members are connected), the native leaflets will be squeezed in the radial direction, thereby increasing the risk of the native leaflets sticking to the wall and blocking the coronary artery orifice.

[0042] Secondly, in terms of loading and recyclability, in the valve stent of this embodiment, the two free ends of each second wave rod unit 20 are connected to the stent body, which is conducive to the loading of the stent; for the valve stent of the comparative example, the free ends of the wave rod unit where the outflow end is located are not all connected to the stent body (that is, there is a free end b). When the apex of the valve stent is subjected to axial tension, due to the existence of the free free end b, the valve stent undergoes severe deformation, affecting the performance of the stent. Therefore, the valve stent of this embodiment can be applied to both ball-expandable stents and self-expandable stents.

[0043] In addition, from the perspective of the unilateral force in the section near the outflow end, the unilateral force of the open-loop structure is smaller than that of the closed-loop structure. The valve stent in the comparative example has an open-loop structure due to the presence of the free end b, while the valve stent in this embodiment does not have the above-mentioned free end b, so it is a closed-loop structure with a large unilateral force, which is more suitable for the actual aortic root working conditions.

[0044] In summary, the valve stent provided by the present invention has an overall shorter height. Through different structural designs of the stent grids at the inflow end and the outflow end, different sections on the valve stent can realize different structural functions, thereby better achieving clinical effects. The height of the section near the inflow end (i.e., the anchoring section) is effectively reduced (even to below the coronary artery opening), thereby reducing the risk of coronary artery obstruction.

[0045] In addition, compared with the comparative example, the valve stent of the present invention has a larger area of ​​large grid A in the section near the outflow end (i.e., the coronary artery section), which can provide a channel for coronary blood flow and also provide a channel for later PCI; there is no free end of the grid pointing downward in the section near the outflow end, which will not cause squeezing of the leaflets, reducing the risk of the leaflets themselves sticking to the wall and blocking the coronary artery opening; the radial supporting force of the anchoring section is better, which is more conducive to expanding the native valve tissue; it can be applied to self-expanding stents and ball-expandable stents, expanding the scope of use of the stent.

[0046] Based on the same inventive concept, the present invention also provides a valve prosthesis, including a valve leaflet and a valve stent as described above, wherein the valve leaflet is fixed on the valve stent. The specific fixing method can be referred to the prior art and will not be described in detail here.

[0047] Since the valve prosthesis of the present invention has the above-mentioned valve stent, it also has all the advantages of the above-mentioned valve stent, that is, multiple large grids are formed in the coronary segment. When the valve prosthesis is implanted in the aortic valve ring, the large grids formed will not squeeze the native valve leaflets in the radial direction, thereby reducing the risk of the native valve leaflets blocking the coronary orifice; at the same time, the large grids formed can provide a channel for coronary blood flow and can also provide a channel for later PCI.

[0048] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0052] The above description is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims. Obviously, a person skilled in the art may make various changes and modifications to the invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A valve stent, characterized in that: The valve stent is in the shape of a net tube, including M layers of wave rod unit groups connected in sequence along the axial direction, M≤5, the first layer of wave rod unit group is located at the inflow end, the Mth layer of wave rod unit group is located at the outflow end, the wave rod unit group includes circumferentially connected wave rod units, the number of wave rod units in the Mth layer of wave rod unit group is less than the number of wave rod units in the M-1th layer of wave rod unit group, and a plurality of large grids can be formed between the Mth layer of wave rod unit group and the M-1th layer of wave rod unit group; the shape of the wave rod unit in the Mth layer of wave rod unit group is an inverted V shape, having There are two free ends, and the two free ends are respectively connected to two target wave rod units in the M-1 layer wave rod unit group, wherein the two free ends are separated by X wave rod units in the M-1 layer wave rod unit group, and the wave rod units in the M-1 layer wave rod unit group are connected to the wave rod units in the M-1 layer wave rod unit group through straight rods, wherein 2≤X≤3; when the valve stent is implanted in the aortic valve ring, the multiple large grids are located in the coronary artery segment, and the multiple large grids will not cause radial compression to the native valve leaflet in the coronary artery segment.

2. The valve stent according to claim 1, characterized in that: The numbers of the wave-rod units in the 1st to M-1th layers of wave-rod unit groups are all the same, and two adjacent layers of wave-rod unit groups form a layer of circumferentially continuously distributed grid.

3. The valve stent according to claim 1, characterized in that: The shape of the wave-rod units in the wave-rod unit groups of the 1st to M-1th layers is V-shaped or inverted V-shaped, and two corresponding wave-rod units in two adjacent layers of wave-rod units are directly connected to form a diamond grid.

4. The valve stent according to claim 1, characterized in that: The shape of the wave-rod units in the 1st to M-1th layers of the wave-rod unit group is V-shaped or inverted V-shaped, and two corresponding wave-rod units in two adjacent layers of the wave-rod units are connected through an axial connection portion to form a hexagonal grid.

5. The valve stent according to claim 1, characterized in that: The number of the straight rods is greater than or equal to 3.

6. A valve prosthesis, characterized in that: It comprises a valve leaflet and a valve support as described in any one of claims 1 to 5, wherein the valve leaflet is fixed on the valve support.

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