Valve stents and valve prostheses

Abstract

The present invention provides a valve stent and a valve prosthesis, wherein the valve stent is in the shape of a net tube, and a plurality of grid units are arranged circumferentially at the distal end, and the grid units include a four-layer structure connected in sequence along the axial direction, wherein the first layer includes four first wave-rod units connected in sequence; the second layer includes four second wave-rod units connected in sequence, and the four first wave-rod units are respectively arranged opposite to and connected to the four second wave-rod units; the third layer includes two unconnected third wave-rod units, wherein one of the third wave-rod units is respectively connected to two adjacent second wave-rod units, and the other third wave-rod unit is respectively connected to the other two adjacent second wave-rod units; the fourth layer includes a fourth wave-rod unit, and one fourth wave-rod unit is respectively connected to two third wave-rod units. The present invention can solve the problem that the existing valve stent squeezes the leaflets during use, thereby causing the 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 surgery, 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 net tube, and a plurality of grid units are arranged circumferentially at the distal end thereof, wherein the grid units include a four-layer structure connected in sequence along the axial direction, wherein:

[0007] The first layer includes four first wave-bar units connected in sequence;

[0008] The second layer includes four second wave-rod units connected in sequence, and the four first wave-rod units are respectively arranged opposite to and connected to the four second wave-rod units;

[0009] The third layer includes two unconnected third wave-rod units, wherein one of the third wave-rod units is respectively connected to two adjacent second wave-rod units, and the other third wave-rod unit is respectively connected to another two adjacent second wave-rod units;

[0010] The fourth layer includes a fourth wave-bar unit, and each of the fourth wave-bar units is connected to two of the third wave-bar units.

[0011] Optionally, in the above-mentioned valve stent, a plurality of the grid units are continuously distributed along the circumferential direction, the first layers of two adjacent grid units are directly connected, and the fourth layers of two adjacent grid units are connected through another fourth wave rod unit.

[0012] Optionally, in the above-mentioned valve stent, the number N of the grid units has a value range of 3≤N≤6.

[0013] Optionally, in the above-mentioned valve stent, the plurality of grid units are distributed discontinuously along the circumferential direction.

[0014] Optionally, in the above-mentioned valve stent, the first wave rod unit has a V-shape, and the second wave rod unit, the third wave rod unit, and the fourth wave rod unit have an inverted V-shape.

[0015] Optionally, in the above-mentioned valve stent, the fourth wave rod unit is connected to the third wave rod unit through an axial straight rod.

[0016] Optionally, in the above-mentioned valve stent, the number of the axial straight rods is greater than or equal to 3.

[0017] Optionally, in the above-mentioned valve stent, the total number of layers of the valve stent is 4 or 5.

[0018] Optionally, in the above valve stent, when the total number of layers of the valve stent is 4, the two-layer wave-rod unit group at the distal end of the valve stent is the coronary segment, and the two-layer wave-rod unit group at the proximal end is the anchoring segment;

[0019] When the total number of layers of the valve stent is 5, the two-layer wave-rod unit group at the distal end of the valve stent is the coronary segment, and the three-layer wave-rod unit group at the proximal end is the anchoring segment.

[0020] Optionally, in the above-mentioned valve stent, the anchoring section at the proximal end of the valve stent includes a multi-layer wave rod unit group, and the wave rod unit group includes circumferentially connected wave rod units. The number and size of the wave rod units in each layer of the wave rod unit group are the same, and two adjacent layers of the wave rod unit groups form a layer of circumferentially continuously distributed grid.

[0021] 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.

[0022] Compared with the prior art, the valve stent and valve prosthesis provided by the present invention have the following beneficial effects:

[0023] The valve stent of the present invention is in the shape of a mesh tube, and a plurality of grid units are arranged circumferentially at the distal end, so as to form a plurality of gradually changing large grids in the coronary segment. When the valve stent is implanted in the aortic valve ring, the gradually changing large grid formed will not squeeze the native valve leaflets in the radial direction in the coronary segment due to its large area, thereby ensuring that the coronary blood flow is not affected. Even for some patients with poor coronary conditions (the height of the native valve leaflets is greater than the coronary artery orifice), radial space for the valve leaflets can be provided without squeezing the valve leaflets against the inner wall of the sinus to affect the coronary blood flow, thereby reducing the risk of the native valve leaflets blocking the coronary artery orifice; at the same time, the grid density of the coronary segment is sparse, and the sparse grid makes the radial stiffness of the valve stent lower. Under the traction of the valve leaflets, the valve stent can share a part of the traction deformation, thereby improving the life of the valve leaflets; in addition, the gradually changing large grid formed can provide a channel for the coronary blood flow, and can also provide a channel for later PCI;

[0024] 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

[0025] 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.

[0026] Figure 1 is a schematic structural diagram of a grid unit in an embodiment of the present invention;

[0027] Figure 2 is a front view of a valve stent in one embodiment of the present invention;

[0028] Figure 3 for Figure 2 A stereoscopic view of the valve stent shown. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The valve stent provided by the present invention is in the shape of a mesh tube, and 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). The inflow end corresponds to the direction of blood flow inflow, and the outflow end corresponds to the direction of blood flow outflow. The direction from the inflow end to the outflow end is the axial direction of the valve stent.

[0033] Specifically, a plurality of grid units are arranged circumferentially at the distal end of the valve stent. Figure 1 The structural diagram of the grid unit is schematically shown, as shown in FIG. Figure 1 As shown, the grid unit includes four layers of structures I to IV connected in sequence along the axial direction, wherein:

[0034] The first layer I comprises four first wave rod units 10 connected in sequence;

[0035] The second layer II includes four second wave-bar units 20 connected in sequence, and the four first wave-bar units 10 are arranged opposite to and connected to the four second wave-bar units 20 respectively;

[0036] The third layer III includes two unconnected third wave-bar units 30, wherein one of the third wave-bar units 30 is respectively connected to two adjacent second wave-bar units 20, and the other third wave-bar unit 30 is respectively connected to the other two adjacent second wave-bar units 20;

[0037] The fourth layer IV includes a fourth corrugated bar unit 40 , and each of the fourth corrugated bar units 40 is connected to two of the third corrugated bar units 30 .

[0038] It should be noted that the first, second, third and fourth here are only for distinguishing the wave-rod units in different layers, and do not limit the similarities and differences between these wave-rod units, that is, these wave-rod units can be the same or different.

[0039] The valve stent provided by the present invention has the above-mentioned grid units arranged at the distal end, and a large gradient grid A is formed in the grid unit structure, thereby forming multiple large gradient grids A at the distal end (i.e., corresponding to the coronary artery segment). In this way, when the valve stent is implanted in the aortic valve ring, the large gradient grid A formed will not squeeze the native valve leaflets in the radial direction in the coronary artery segment due to its large area, thereby ensuring that the coronary blood flow is not affected. Even for some patients with poor coronary artery conditions (the height of the native valve leaflets is greater than the coronary artery orifice), radial space for the valve leaflets can be provided without squeezing the valve leaflets against the inner wall of the sinus to affect the coronary blood flow, thereby reducing the risk of the native valve leaflets blocking the coronary artery orifice. At the same time, the grid density of the coronary artery segment is sparse, and the sparse grid makes the radial stiffness of the valve stent lower. Under the traction of the valve leaflets, the valve stent can share part of the traction deformation, thereby improving the life of the valve leaflets; in addition, the large gradient grid A formed can provide a channel for coronary blood flow and can also provide a channel for later PCI.

[0040] Preferably, Figure 1As shown, the shape of the first wave rod unit 10 is V-shaped, and the shape of the second wave rod unit 20, the third wave rod unit 30, and the fourth wave rod unit 40 is inverted V-shaped. Specifically, it can be a V-shaped or inverted V-shaped structure composed of two straight rods, or it can be a V-shaped or inverted V-shaped wave rod, which is not limited by the present invention. The number of first wave rod units 10 in the first layer I is the same as the number of second wave rod units 20 in the second layer II, and the corresponding first wave rod units 10 and second wave rod units 20 are connected to achieve the connection between the first layer I and the second layer II, and a diamond grid B is formed between the first wave rod units 10 and the second wave rod units 20 that are arranged opposite to each other. One third wave rod unit 30 in the third layer III is connected to two adjacent second wave rod units 20, and another third wave rod unit 30 is respectively connected to the other two adjacent second wave rod units 20, so as to achieve the connection between the third layer III and the second layer II, and a diamond grid B' is formed between each third wave rod unit 30 and the two adjacent second wave rod units 20 connected thereto. The fourth wave-rod unit 40 in the fourth layer IV is respectively connected to the two third wave-rod units 30 in the third layer III, thereby realizing the connection between the fourth layer IV and the third layer III, and a gradient large grid A is formed between the fourth wave-rod unit 40 and the two third wave-rod units 30 .

[0041] Preferably, Figure 2 , 3 In the valve stent shown, the fourth wave rod unit 40 is connected to the third wave rod unit 30 through an axial straight rod member 50. Specifically, the two third wave rod units 30 of the third layer III are respectively connected to the second wave rod unit 20 of the second layer II to form two diamond grids B', and the vertices of the two diamond grids B' close to the outflow end respectively extend an axial straight rod member 50 toward the outflow end, and the fourth wave rod unit 40 of the fourth layer IV is connected to the axial straight rod member 50 to achieve connection with the third wave rod unit 30 of the fourth layer IV. Generally speaking, the number of the axial straight rod members 50 is greater than or equal to 3, and some of the axial straight rod members 50 can be used as leaflet suturing rods. For example, 3 axial straight rod members 50 are selected as leaflet suturing rods for fixing the skirt and / or leaflets when making a valve prosthesis later.

[0042] The plurality of grid units may be distributed continuously or discontinuously in the circumferential direction. Continuous distribution refers to two adjacent grid units. Figure 1 The first layer I of the grid cells shown is directly connected, and the discontinuous distribution refers to the adjacent two Figure 1 Other grids are arranged between the first layer I of the grid units shown, but are not directly connected. Preferably, the plurality of grid units are continuously distributed along the circumference, and the number of the distributed grid units is greater than or equal to 3 and less than or equal to 6, so that the diameter after crimping can be reduced, and the diameter of the delivery system can be further reduced, thereby reducing complications. Figure 3It is shown that three grid units are arranged continuously, and another fourth wave-rod unit 40 is arranged between each of the three fourth wave-rod units 40 of the IV layer, and a large grid A' identical to the large grid A is formed between the other fourth wave-rod unit 40 and two adjacent grid units, and the large grid A' is a common grid between two adjacent grid units. It can be understood that when the number of the grid units is 3, it can be ensured that the three grid units are arranged symmetrically in the circumferential direction of the valve stent in three equal parts, so as to facilitate the subsequent suturing of three leaflets to form a valve prosthesis, and at the same time, it can be ensured that the number of circumferential grids in the coronary segment is small.

[0043] Preferably, in order to design a lower aortic valve stent, the total number of layers of the valve stent is 4 or 5, so that the height of the valve stent in the axial direction is lower, the lower valve stent is easier to transport, and the stent's arch performance and coaxiality with the native valve ring after implantation are improved. When the total number of layers is 4, the first layer I to the fourth layer IV of the grid unit are respectively located on the first layer to the fourth layer of the valve stent. When the total number of layers is 5, please refer to Figure 2 , 3 , the first layer I to the fourth layer IV of the grid unit are respectively located at the second layer to the fifth layer of the valve stent, and the wave rod unit is added to the inflow end of the first layer I of the grid unit to form the first layer of the valve stent. When the total number of layers of the valve stent is 4, the two layers of wave rod unit groups at the distal end of the valve stent are the coronary segments, and the two layers of wave rod unit groups at the proximal end are the anchoring segments. Figure 2 As shown, when the total number of layers of the valve stent is 5, the two-layer wave-rod unit group at the distal end of the valve stent is the coronary segment, and the three-layer wave-rod unit group at the proximal end is the anchoring segment. It can be understood that the "wave-rod unit group" mentioned here means that each layer of the valve stent is composed of multiple wave-rod units, and the shape of each wave-rod unit is V-shaped or inverted V-shaped.

[0044] However, when the number of axial layers of the valve stent is small, it will cause the defect of insufficient radial support force. Therefore, in actual clinical practice, this is a set of contradictory factors, which require 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, the anchoring section at the proximal end of the valve stent includes a multi-layer wave rod unit group, and the wave rod unit group includes circumferentially connected wave rod units. The number and size of the wave rod units in each layer of the wave rod unit group are the same, and two adjacent layers of the wave rod unit group form a layer of circumferentially continuously distributed grid. Please refer to Figure 2 , 3The anchoring section at the proximal end of the valve stent includes three layers of wave rod unit groups, the first layer of wave rod unit group is located at the inflow end, the wave rod units in the first layer of wave rod unit group, the second layer of wave rod unit group and the third layer of wave rod unit group are sequentially connected along the circumferential direction, and the wave rod units of two adjacent layers are connected, so that two layers of grids (i.e., continuous and uniformly distributed grids) can be formed at the proximal end of the valve stent. Figure 2 , 3 A layer of hexagonal grid C and a layer of diamond grid B are located at the bottom, so that the anchoring section at the proximal end of the valve stent can provide greater radial supporting force.

[0045] In this embodiment, the end point of the large grid A in the valve stent close to the inflow channel (i.e. Figure 2 The connection point a) between the first wave rod unit 10 of the first layer I and the second wave rod unit 20 of the second layer II of the grid unit shown is lower than the coronary artery opening, so that the coronary 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.

[0046] like Figure 2 , 3 The valve stent shown in the figure includes 12 hexagonal grids C in the anchoring section at the proximal end of the valve stent, and these 12 grids are continuously and evenly distributed in the circumferential direction. In other embodiments, the shape of the grid in the anchoring section at the proximal end of the valve stent can also be a rhombus (e.g., a rhombus grid B). The number of grids in the anchoring section in the circumferential direction can be determined according to the actual working conditions, and is generally composed of 9-24 (e.g., 12 / 15 / 18 / 24). In the axial direction, in order to avoid the high-density grid blocking the coronary artery, the height of the grid in the anchoring section is generally made below the coronary artery orifice. The grid of the coronary artery section is connected to the grid of the anchoring section, which can be an integral cutting, or other mechanical welding or matching connection. The grid density in the coronary artery section is lower than that in the anchoring section, and the grid area is large, so that enough space can be left for the coronary artery channel. In addition, if PCI surgery is required clinically, a channel can also be provided for the PCI catheter. In addition, when the height of the anchoring section is low, in order not to affect the opening and closing height of the leaflets, the free edges of the leaflets can be sutured to the coronary artery section, which will reduce the overall height of the valve.

[0047] 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.

[0048] In summary, the valve stent provided by the present invention has the following beneficial effects:

[0049] A plurality of large gradient grids are formed in the coronary segment. When the valve stent is implanted in the aortic valve ring, the large gradient grids formed will not squeeze the native valve leaflets in the radial direction in the coronary segment due to their large area, thereby ensuring that the coronary blood flow is not affected. Even for some patients with poor coronary conditions (the height of the native valve leaflets is greater than the coronary artery orifice), radial space for the valve leaflets can be provided without squeezing the valve leaflets against the inner wall of the sinus and affecting the coronary blood flow, thereby reducing the risk of the native valve leaflets blocking the coronary artery orifice; at the same time, the grid density of the coronary segment is sparse, and the sparse grid makes the radial stiffness of the valve stent lower. Under the traction of the valve leaflets, the valve stent can share a part of the traction deformation, thereby increasing the life of the valve leaflets; in addition, the large gradient grids formed can provide a channel for coronary blood flow and can also provide a channel for later PCI.

[0050] 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.

[0051] 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, a plurality of gradually changing large grids are formed in the coronary segment. When the valve stent is implanted in the aortic valve ring, the gradually changing 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 grid density of the coronary segment is sparse, and the sparse grid makes the radial stiffness of the valve stent lower. Under the traction of the valve leaflets, the valve stent can share part of the traction deformation, thereby increasing the life of the valve leaflets; in addition, the gradually changing large grids formed can provide a channel for coronary blood flow, and can also provide a channel for later PCI.

[0052] 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.

[0053] 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, and a plurality of grid units are arranged circumferentially at the distal end thereof. The grid units include four layers of structures connected in sequence along the axial direction, wherein: The first layer includes four first wave-bar units connected in sequence; The second layer includes four second wave-rod units connected in sequence, and the four first wave-rod units are respectively arranged opposite to and connected to the four second wave-rod units; The third layer includes two third wave-rod units that are not directly connected, wherein one of the third wave-rod units is respectively connected to two adjacent second wave-rod units, and the other third wave-rod unit is respectively connected to another two adjacent second wave-rod units; The fourth layer includes a fourth wave-rod unit, and one of the fourth wave-rod units is respectively connected to two of the third wave-rod units; The fourth wave rod unit is connected to the third wave rod unit via an axial straight rod; A gradient large grid is formed in each grid unit to form multiple gradient large grids in the coronary artery section at the distal end of the valve stent. When the valve stent is implanted in the aortic valve ring, the multiple gradient large grids will not squeeze the native valve leaflets in the radial direction in the coronary artery section.

2. The valve stent according to claim 1, characterized in that: The plurality of grid units are continuously distributed along the circumferential direction, the first layers of two adjacent grid units are directly connected, and the fourth layers of two adjacent grid units are connected via another fourth wave rod unit.

3. The valve stent according to claim 2, characterized in that: The value range of the number N of the grid units is 3≤N≤6.

4. The valve stent according to claim 1, characterized in that: The plurality of grid units are distributed discontinuously along the circumferential direction.

5. The valve stent according to claim 1, characterized in that: The first wave rod unit has a V-shape, and the second wave rod unit, the third wave rod unit, and the fourth wave rod unit have an inverted V-shape.

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

7. The valve stent according to any one of claims 1 to 6, characterized in that: The total number of layers of the valve stent is 4 or 5.

8. The valve stent according to claim 7, characterized in that: When the total number of layers of the valve stent is 4, the two layers of wave-rod unit groups at the distal end of the valve stent are coronary segments, and the two layers of wave-rod unit groups at the proximal end are anchoring segments; When the total number of layers of the valve stent is 5, the two-layer wave-rod unit group at the distal end of the valve stent is the coronary segment, and the three-layer wave-rod unit group at the proximal end is the anchoring segment.

9. The valve stent according to claim 7, characterized in that: The anchoring section at the proximal end of the valve stent includes a multi-layer wave rod unit group, which includes circumferentially connected wave rod units. The number and size of the wave rod units in each layer of the wave rod unit group are the same, and two adjacent layers of the wave rod unit group form a layer of circumferentially continuously distributed grid.

10. A valve prosthesis, characterized in that: It comprises a valve leaflet and a valve support as described in any one of claims 1 to 9, wherein the valve leaflet is fixed on the valve support.

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