Valve-in-valve stent and valve

Abstract

Provided are a valve-in-valve stent and a valve. A valve-in-valve stent (1) is of a cylindrical structure and comprises an inflow section stent (16), a middle section stent (15), and an outflow section stent (14) connected in sequence. The range of the height ratio of the inflow section stent (16) to the middle section stent (15) is 1:1 to 1.15:1, and the range of the height ratio of the outflow section stent (14) to the middle section stent (15) is 1.15:1 to 1.5:1. A cutting blade array (13) is arranged on an outer side of the outflow section stent (14), and a cutting edge direction of the cutting blade array (13) is parallel to a tangential direction of a corresponding position of the outflow section stent (14).

Description

Valve-in-valve stent and valve

[0001] This application claims priority to the Chinese patent application No. 202410444788.9 filed on April 15, 2024 with the Chinese Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the technical field of medical devices, and relates to a valve stent and a valve, for example, to a valve-in-valve stent and a valve. BACKGROUND

[0003] The human heart has four heart chambers: left atrium, right atrium, left ventricle and right ventricle. The atrium is connected to the corresponding ventricle, and the atrium is connected to the large blood vessels. The heart valve is arranged at the connection, which functions as a one-way valve to ensure one-way blood flow.

[0004] The heart valve includes the aortic valve, the mitral valve, the tricuspid valve and the pulmonary valve. Factors such as rheumatic fever, degenerative deformation, congenital malformation disease, infection or trauma can cause heart valve disease, thereby causing abnormal heart function. Since the 1990s, domestic and foreign have treated aortic valve and mitral valve by replacing the valve through surgical operation, and the number of implants is increasing.

[0005] The service life of early biological valves is 5-15 years. The implanted valves have reached the service limit, but older patients are not suitable for open chest surgery. Therefore, a minimally invasive valve-in-valve valve treatment method is needed.

[0006] In the conventional technology, the products for valve-in-valve treatment are mostly balloon dilatation type transcatheter aortic valve products. The valve stent will shrink after the balloon is depressurized, which is easy to form paravalvular regurgitation with the biological valve, or the valve is displaced due to the influence of scar tissue. Therefore, a valve-in-valve stent and valve with good adhesion and stable anchoring are needed.

[0007] SUMMARY

[0008] In a first aspect, the present application provides a valve-in-valve stent, which is in a cylindrical structure and includes an inflow segment stent, a middle segment stent and an outflow segment stent connected in sequence.

[0009] The height ratio of the inflow segment stent to the middle segment stent is in the range of 1:1 to 1.15:1.

[0010] The height ratio of the outflow segment stent to the middle segment stent is in the range of 1.15:1 to 1.5:1.

[0011] The outflow segment stent is provided with a row of knives on the outer side.

[0012] The blade direction of the row of blades is parallel to the tangent direction at the corresponding position of the outflow section support frame.

[0013] The outer side of the outflow section support frame in the present application refers to the side of the outflow section support frame away from the shaft center.

[0014] As an optional technical solution, the length of the row of blades is the same as the height of the outflow section support frame.

[0015] In the valving-in-valving stent provided by the present application, the height ratio of the inflow section support frame to the middle section support frame is in the range of 1:1 to 1.15:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.12:1 or 1.15:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0016] In the valving-in-valving stent provided by the present application, the height ratio of the inflow section support frame to the middle section support frame is in the range of 1.15:1 to 1.5:1, for example, it can be 1.15:1, 1.2:1, 1.25:1, 1.3:1, 1.35:1, 1.4:1 or 1.5:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0017] Optionally, the inflow section support frame comprises a single-layer rhombic lattice structure.

[0018] In the single-layer rhombic lattice structure of the inflow section support frame, the connecting nodes of adjacent rhombic lattices are round corner structures.

[0019] Optionally, the middle section support frame comprises a single-layer rhombic lattice structure.

[0020] In the single-layer rhombic lattice structure of the middle section support frame, the connecting nodes of adjacent rhombic lattices are round corner structures.

[0021] The middle section support frame is connected with the inflow section support frame to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are round corner structures.

[0022] Optionally, the outflow section support frame comprises an outflow section support frame.

[0023] The outflow section support frame is connected with the middle section support frame to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are round corner structures.

[0024] Optionally, the inner diameters of the inflow section support frame and the outflow section support frame are independently 18-32mm, for example, it can be 18mm, 20mm, 24mm, 25mm, 28mm, 30mm or 32mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0025] The total height of the valve-in-valve stent is 18-25mm, for example, it can be 18mm, 20mm, 21mm, 24mm or 25mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0026] The wall thickness of the inflow section stent, the middle section stent and the outflow section stent is independently 0.3-0.55mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or 0.55mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] Optionally, the ratio of the inner diameter of the middle section stent to the inner diameter of the inflow section stent is 1:1 to 1.2:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0028] The ratio of the inner diameter of the middle section stent to the inner diameter of the outflow section stent is 1:1 to 1.2:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0029] Optionally, the inflow section stent comprises a first support frame and a second support frame;

[0030] The middle section stent comprises a third support frame and a fourth support frame;

[0031] The first support frame and the second support frame form a single-layer rhombic lattice structure;

[0032] The second support frame and the third support frame form a single-layer rhombic lattice structure;

[0033] The third support frame and the fourth support frame form a single-layer rhombic lattice structure;

[0034] The fourth support frame and the outflow section support frame form a single-layer rhombic lattice structure.

[0035] In this application, the thickness of the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame is independently 0.3-0.55mm.

[0036] In this application, the height of the valve-in-valve stent refers to the distance from one end of the first support frame away from the middle section stent to one end of the outflow section support frame away from the middle section stent.

[0037] Optionally, the width of the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame is independently 0.2-0.35mm, for example, it can be 0.2mm, 0.25mm, 0.3mm or 0.35mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0038] The width of the outflow section support frame is 70-90% of the width of the fourth support frame, for example, it can be 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] Optionally, in the diamond lattice structure in the valve-in-valve stent, the angle of the other two corners of the diamond lattice is 50-100°, for example, it can be 50°, 60°, 80°, 90° or 100°, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0040] Optionally, the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently include a straight rod section and a connecting section;

[0041] The straight rod section is a tapered structure with a narrow middle and wide ends, and the width of the middle is 60-90% of the width of the two ends, for example, it can be 60%, 65%, 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0042] When the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently include a straight rod section and a connecting section, the width of the two ends of the straight rod section is referred to as the width of the corresponding support frame.

[0043] As a further optional technical solution, the valve-in-valve stent provided by the application further provides a connecting head at one end of the outflow section support frame away from the middle section support frame; the number of connecting heads is at least 3, and the connecting heads are uniformly arranged along the circumference of the outflow section support frame; the connecting head is connected to the conveying device through a clamping structure, facilitating the arrangement and recovery of the valve-in-valve stent.

[0044] In a second aspect, the application provides a valve-in-valve stent, which comprises a valve leaflet, a skirt and the valve-in-valve stent of the first aspect.

[0045] The skirt is arranged on the outside of the valve-in-valve stent.

[0046] The number of valve leaflets is at least 3, and the valve leaflets are arranged on the inside of the valve-in-valve stent.

[0047] The material of the frame of the valve-in-valve stent includes, but is not limited to, nickel-titanium memory alloy.

[0048] The material of the leaflets includes, but is not limited to, biological materials, and exemplary includes bovine pericardium materials.

[0049] The material of the skirt includes, but is not limited to, polyethylene terephthalate (PET).

[0050] Exemplarily, the connection method of the skirt and the frame of the valve-in-valve stent includes sewing, and the connection method of the leaflets and the frame of the valve-in-valve stent includes sewing. In the case of at least 3 leaflets, the leaflets are connected to the inner side of the valve-in-valve stent by sewing, and the edges of the non-sewn parts are sequentially butted and gathered to form a valve structure. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a structural schematic diagram of the valve-in-valve stent provided by the present application;

[0052] Fig. 2 is a structural schematic diagram of the valve-in-valve stent provided by the present application;

[0053] Fig. 3 is a cross-sectional schematic diagram of the valve-in-valve stent matched with a biological valve provided by the present application;

[0054] Fig. 4 is a schematic diagram of the valve-in-valve stent applied to an aortic valve biological valve provided by the present application;

[0055] Fig. 5 is a schematic diagram of the valve-in-valve stent applied to a mitral valve biological valve provided by the present application;

[0056] Fig. 6 is a structural schematic diagram of a straight line segment;

[0057] Figs. 7, 8 and 9 are structural schematic diagrams of a connecting head, respectively.

[0058] Wherein: 1, valve-in-valve stent; 111, outflow segment support frame; 112, fourth support frame; 113, third support frame; 114, second support frame; 115, first support frame; 12, connecting head; 13, row cutter; 14, outflow segment support frame; 15, middle segment support frame; 16, inflow segment support frame;

[0059] 2, valve-in-valve stent; 3, leaflet; 4, skirt; 5, aortic valve biological valve; 6, mitral valve biological valve;

[0060] a is the included angle of the support frame of the diamond grid;

[0061] K2 is the width of the middle of the straight line segment; K1 and K3 are the widths of the two ends of the straight line segment. DETAILED DESCRIPTION

[0062] The technical solutions of the present application are further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are only used for understanding the present application and should not be regarded as specific limitations of the present application.

[0063] Some embodiments of the present application provide a valve-in-valve stent 1 as shown in FIG. 1, which is in a cylindrical structure and comprises an inflow section stent 16, a middle section stent 15 and an outflow section stent 14 connected in sequence;

[0064] The height ratio of the inflow section stent 16 to the middle section stent 15 ranges from 1:1 to 1.15:1;

[0065] The height ratio of the outflow section stent 14 to the middle section stent 15 ranges from 1.15:1 to 1.5:1.

[0066] The valve-in-valve stent 1 provided by the present application is in a whole cylindrical structure, without the need to make the diameters of the inflow section stent 16, the middle section stent 15 and the outflow section stent 14 different, or to set a special-shaped structure on the inflow section stent 16 or the outflow section stent 14, thereby reducing the processing difficulty and processing cost of the valve-in-valve stent 1. The technical solutions provided by the present application provide strong support for the valve-in-valve stent 1 by controlling the proportions of the inflow section stent 16, the middle section stent 15 and the outflow section stent 14, thereby reducing the paravalvular regurgitation, effectively expanding the valve leaflet 3 which is calcified or cohered, increasing the effective opening area; and the height of the outflow section stent 14 is higher than that of the middle section stent 15 and the inflow section stent 16, thereby dispersing the stress at the suture when the valve leaflet 3 is closed, and making the valve have higher fatigue durability.

[0067] In some embodiments, the outflow section stent 14 is provided with a row of knives 13 on the outer side thereof;

[0068] The direction of the blade edge of the row of knives 13 is parallel to the tangent direction at the corresponding position of the outflow section stent 14.

[0069] The outer side of the outflow section stent of the present application refers to the side of the outflow section stent 14 away from the shaft.

[0070] When the valve leaflet 3 of the biological valve is cohered, the valve-in-valve stent 1 cannot be opened to a larger size due to the influence of the cohered valve leaflet 3, thereby affecting the effective opening area of the valve-in-valve and the transvalvular pressure difference. The present application provides a row of knives 13 on the outer side of the outflow section stent 14, which not only provides a larger support for the valve-in-valve stent 1, but also cuts and separates the cohered biological valve leaflet 3 by extruding the cohered biological valve leaflet 3, thereby making the valve-in-valve stent 1 be able to be opened to a larger size, increasing the opening area and reducing the transvalvular pressure difference.

[0071] In some embodiments, the length of the row of knives 13 is the same as the height of the outflow section stent 14.

[0072] In the valving-in-valving stent 1 provided by the present application, the height ratio of the inflow section stent 16 to the middle section stent 15 ranges from 1:1 to 1.15:1, for example, can be 1:1, 1.05:1, 1.1:1, 1.12:1 or 1.15:1, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0073] In the valving-in-valving stent 1 provided by the present application, the height ratio of the inflow section stent 16 to the middle section stent 15 ranges from 1:1 to 1.15:1, for example, can be 1:1, 1.05:1, 1.1:1, 1.12:1 or 1.15:1, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0074] In some embodiments, the inflow section stent 16 comprises a single-layer rhombic lattice structure;

[0075] In the single-layer rhombic lattice structure of the inflow section stent 16, the connecting nodes of adjacent rhombic lattices are round corner structures.

[0076] In some embodiments, the middle section stent 15 comprises a single-layer rhombic lattice structure;

[0077] In the single-layer rhombic lattice structure of the middle section stent 15, the connecting nodes of adjacent rhombic lattices are round corner structures.

[0078] The middle section stent 15 and the inflow section stent 16 are connected to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are round corner structures.

[0079] In some embodiments, the outflow section stent 14 comprises an outflow section support frame 111.

[0080] The outflow section support frame 111 and the middle section stent 15 are connected to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are round corner structures.

[0081] In some embodiments, the inner diameters of the inflow section stent 16 and the outflow section stent 14 are independently 18-32mm, for example, can be 18mm, 20mm, 24mm, 25mm, 28mm, 30mm or 32mm, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0082] The total height of the valve-in-valve stent 1 is 18-25 mm, for example, it can be 18 mm, 20 mm, 21 mm, 24 mm or 25 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0083] The wall thickness of the inflow section stent 16, the middle section stent 15 and the outflow section stent 14 is independently 0.3-0.55 mm, for example, it can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm or 0.55 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0084] In some embodiments, the ratio of the inner diameter of the middle section stent 15 to the inner diameter of the inflow section stent 16 is in the range of 1:1 to 1.2:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0085] The ratio of the inner diameter of the middle section stent 15 to the inner diameter of the outflow section stent 14 is in the range of 1:1 to 1.2:1, for example, it can be 1:1, 1.05:1, 1.1:1, 1.15:1 or 1.2:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0086] In some embodiments, the inflow section stent 16 comprises a first support frame 115 and a second support frame 114;

[0087] The middle section stent 15 comprises a third support frame 113 and a fourth support frame 112;

[0088] The first support frame 115 and the second support frame 114 form a single-layer diamond mesh structure;

[0089] The second support frame 114 and the third support frame 113 form a single-layer diamond mesh structure.

[0090] The third support frame 113 and the fourth support frame 112 form a single-layer diamond mesh structure;

[0091] The fourth support frame 112 and the outflow section support frame 111 form a single-layer diamond mesh structure.

[0092] In this application, the wall thickness of the valve-in-valve stent 1 is 0.3-0.55 mm, which means that the thickness of the first support frame 115, the second support frame 114, the third support frame 113, the fourth support frame 112 and the outflow section support frame 111 is independently 0.3-0.55 mm.

[0093] In the present application, the height of the valve-in-valve stent 1 refers to the distance between the end of the first support frame 115 away from the middle section stent 15 and the end of the outflow section support frame 111 away from the middle section stent 15.

[0094] In some embodiments, the widths of the first support frame 115, the second support frame 114, the third support frame 113 and the fourth support frame 112 are independently 0.2-0.35mm, for example, can be 0.2mm, 0.25mm, 0.3mm or 0.35mm, but are not limited to the listed values, and other values not listed in the value range are also applicable.

[0095] The width of the outflow section support frame 111 is 70-90% of the width of the fourth support frame 112, for example, can be 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0096] The technical solutions provided in the present application are based on the specific setting of the heights of the inflow section stent 16, the middle section stent 15 and the outflow section stent 14, and the widths of the first support frame 115, the second support frame 114, the third support frame 113, the fourth support frame 112 and the outflow section support frame 111 are also specifically set. Through the cooperation of width and height, paravalvular regurgitation is further reduced, and the valve-in-valve stent 1 has higher valve fatigue durability when applied.

[0097] In some embodiments, the diamond mesh structure in the valve-in-valve stent 1 has two other included angles of the diamond mesh except for the connection between the two adjacent diamond meshes, and the included angle a of the support frame is 50°-100°, for example, can be 50°, 60°, 80°, 90° or 100°, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0098] The greater the value of the included angle, the greater the supporting force of the valve-in-valve stent 1, but an excessively large included angle will cause serious size attenuation of the valve-in-valve stent 1 during assembly and will cause excessive stress concentration at the connection of the diamond mesh, increasing the risk of fracture. Therefore, in the present application, the angle of the two other included angles of the diamond mesh in the valve-in-valve stent 1 can be selected to be 75°-85° except for the connection between the two adjacent diamond meshes.

[0099] In some embodiments, the first support frame 115, the second support frame 114, the third support frame 113, the fourth support frame 112 and the outflow section support frame 111 each independently comprises a straight rod section and a connecting section.

[0100] The straight rod section is a tapered structure with the width of the middle part being narrower than the width of the two ends (see FIG. 6). The width of the middle part is 60-90% of the width of the two ends, for example, it can be 60%, 65%, 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0101] The straight rod section adopted in the present application is a tapered structure with the width of the middle part being narrower than the width of the two ends, which facilitates the transfer of the valve-in-valve stent 1 to the delivery system without squeezing the fabric of the skirt 4 and the leaflet 3, and reduces the resistance and folding tendency of the valve-in-valve stent 1 during recovery.

[0102] In some embodiments, the valve-in-valve stent 1 provided by the present application further comprises a connecting head 12 arranged at one end of the outflow section stent 14 away from the middle section stent 15; the number of the connecting head 12 is at least 3, and the connecting head 12 is uniformly arranged along the circumference of the outflow section stent 14; the connecting head 12 is connected with the delivery device through a clamping structure, which facilitates the arrangement and recovery of the valve-in-valve stent 1.

[0103] The connecting head 12 includes three parallel technical solutions, as shown in FIGS. 7, 8 and 9.

[0104] In some embodiments, the valve-in-valve stent 1 further comprises at least 3 stent barbs arranged on the middle section stent 15 or the inflow section stent 16.

[0105] The extension direction of the stent barb is away from the outflow section;

[0106] The outturn angle of the stent barb is 10°-70°, for example, it can be 10°, 20°, 30°, 40°, 50°, 60° or 70°, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0107] In the present application, the at least 3 stent barbs are uniformly arranged along the circumference of the valve-in-valve stent 1. Through the arrangement of the stent barbs, the stent barbs are pierced into the artificial biological valve during the arrangement of the valve-in-valve stent 1, thereby improving the stability of anchoring.

[0108] In some embodiments, the number of the stent barbs is at least 3, for example, it can be 3, 5, 8, 10 or 12, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0109] In some embodiments, the length of the stent barb is 1-5 mm, for example, it can be 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0110] Some embodiments of the present application provide a valve-in-valve valve 2 as shown in FIG. 2, which comprises leaflets 3, a skirt 4, and a valve-in-valve stent 1;

[0111] The skirt 4 is arranged on the outside of the valve-in-valve stent 1;

[0112] The number of leaflets 3 is at least 3, which are arranged on the inside of the valve-in-valve stent 1.

[0113] The material of the valve-in-valve stent 1 in the valve-in-valve valve 2 provided by the second aspect of the present application includes but is not limited to nickel-titanium memory alloy.

[0114] The material of the leaflets 3 includes but is not limited to biological materials, and exemplary includes bovine pericardium material.

[0115] The material of the skirt 4 includes but is not limited to polyethylene terephthalate (PET).

[0116] Exemplarily, the connection method of the skirt 4 and the valve-in-valve stent 1 includes suturing, and the connection method of the leaflets 3 and the valve-in-valve stent 1 includes suturing. In the case of at least 3 leaflets 3, the leaflets 3 are connected to the inside of the valve-in-valve valve 2 by suturing, and the edges of the non-sutured parts are sequentially butted and gathered to form a valve structure.

[0117] Exemplarily, the cross-sectional view of the valve-in-valve valve 2 used in matching with a biological valve is shown in FIG. 3, the schematic diagram of the valve-in-valve valve 2 applied to an aortic valve biological valve 5 is shown in FIG. 4, and the schematic diagram of the valve-in-valve valve 2 applied to a mitral valve biological valve 6 is shown in FIG. 5.

[0118] Embodiment 1

[0119] The present embodiment provides a valve-in-valve stent, which is integrally carved and cut from a nickel-titanium memory alloy;

[0120] The valve-in-valve stent has a cylindrical structure, which comprises an inflow segment stent, a middle segment stent, and an outflow segment stent connected in sequence; the inner diameters of the inflow segment stent and the outflow segment stent are independently 32 mm; the total height of the valve-in-valve stent is 25 mm; and the wall thicknesses of the inflow segment stent, the middle segment stent, and the outflow segment stent are independently 0.55 mm;

[0121] The ratio of the inner diameter of the middle segment stent to the inner diameter of the inflow segment stent is 1.1:1, and the ratio of the inner diameter of the middle segment stent to the inner diameter of the outflow segment stent is 1.1:1;

[0122] The height ratio of the inflow segment stent to the middle segment stent is 1.1:1, and the height ratio of the outflow segment stent to the middle segment stent is 1.3:1;

[0123] The inflow section stent comprises a single-layer rhombic lattice structure; in the single-layer rhombic lattice structure of the inflow section stent, the connecting nodes of adjacent rhombic lattices are in a round corner structure;

[0124] The middle section stent comprises a single-layer rhombic lattice structure; in the single-layer rhombic lattice structure of the middle section stent, the connecting nodes of adjacent rhombic lattices are in a round corner structure; the middle section stent is connected with the inflow section stent to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are in a round corner structure;

[0125] The outflow section stent comprises an outflow section support frame; the outflow section support frame is connected with the middle section stent to form a single-layer rhombic lattice structure, and the connecting nodes of adjacent rhombic lattices are in a round corner structure;

[0126] The inflow section stent comprises a first support frame and a second support frame; the middle section stent comprises a third support frame and a fourth support frame; the first support frame and the second support frame form a single-layer rhombic lattice structure; the second support frame and the third support frame form a single-layer rhombic lattice structure; the third support frame and the fourth support frame form a single-layer rhombic lattice structure; and the fourth support frame and the outflow section support frame form a single-layer rhombic lattice structure;

[0127] The width of the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame is 0.35 mm.

[0128] In the rhombic lattice structure in the valve-in-valve stent, in addition to the connecting position of the two adjacent rhombic lattices, the other two included angles of the rhombic lattice are defined as support frame included angle a, and the angle of the support frame included angle a is 80°.

[0129] The valve-in-valve stent further comprises a connecting head arranged at the end of the outflow section stent away from the middle section stent, the number of the connecting head is six, and the connecting head is uniformly arranged along the circumference of the outflow section stent; the connecting head is connected with a matching conveying device through a clamping structure as shown in FIG. 7.

[0130] The embodiment of the present application is provided with a cutter on the outside of the outflow section stent, the direction of the cutter blade is parallel to the tangent direction at the corresponding position of the outflow section stent; and the length of the cutter is the same as the height of the outflow section stent.

[0131] The embodiment of the present application provides greater support for the valve-in-valve stent through the arrangement of the cutter, the cutter also extrudes and cuts the adhered biological valve leaflets, thereby separating the adhered biological valve leaflets, so that the valve-in-valve stent can be opened to a larger size, the opening area is increased, and the transvalvular pressure difference is reduced.

[0132] Embodiment 2

[0133] The embodiment of the present application provides a valve-in-valve stent, which is integrally carved and cut from a nickel-titanium memory alloy;

[0134] The valve-in-valve stent is in a cylindrical structure, comprising an inflow section stent, a middle section stent and an outflow section stent connected in sequence; the inner diameters of the inflow section stent and the outflow section stent are independently 32 mm; the total height of the valve-in-valve stent is 25 mm; the wall thicknesses of the inflow section stent, the middle section stent and the outflow section stent are independently 0.55 mm;

[0135] The ratio of the inner diameter of the middle section stent to the inner diameter of the inflow section stent is 1:1, and the ratio of the inner diameter of the middle section stent to the inner diameter of the outflow section stent is 1:1;

[0136] The height ratio of the inflow section stent to the middle section stent is 1:1, and the height ratio of the outflow section stent to the middle section stent is 1.15:1;

[0137] The inflow section stent comprises a single-layer rhombic grid structure; in the single-layer rhombic grid structure of the inflow section stent, the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0138] The middle section stent comprises a single-layer rhombic grid structure; in the single-layer rhombic grid structure of the middle section stent, the connecting nodes of adjacent rhombic grids are in a round corner structure; the middle section stent is connected with the inflow section stent to form a single-layer rhombic grid structure, and the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0139] The outflow section stent comprises an outflow section support frame; the outflow section support frame is connected with the middle section stent to form a single-layer rhombic grid structure, and the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0140] The inflow section stent comprises a first support frame and a second support frame; the middle section stent comprises a third support frame and a fourth support frame; the first support frame and the second support frame form a single-layer rhombic grid structure; the second support frame and the third support frame form a single-layer rhombic grid structure; the third support frame and the fourth support frame form a single-layer rhombic grid structure; and the fourth support frame and the outflow section support frame form a single-layer rhombic grid structure;

[0141] The widths of the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame are 0.2 mm.

[0142] In the rhombic grid structure of the valve-in-valve stent, except for the connecting position of adjacent two rhombic grids, the other two included angles of the rhombic grid are defined as support frame included angle a, and the angle of the support frame included angle a is 50°.

[0143] The valve-in-valve stent further comprises a connecting head arranged at the end of the outflow section stent away from the middle section stent, the number of the connecting head is 6, and the connecting head is uniformly arranged along the circumference of the outflow section stent; the connecting head is connected with a matching conveying device through a clamping structure as shown in FIG. 8.

[0144] The embodiment sets a row cutter outside the outflow section support, the cutter edge direction is parallel to the tangent direction at the corresponding position of the outflow section support; and the length of the row cutter is the same as the height of the outflow section support.

[0145] The embodiment provides a larger support force for the valve-in-valve support through the setting of the row cutter, the row cutter also extrudes and cuts the adhered biological valve leaflets, separates the adhered biological valve leaflets, so that the valve-in-valve support can be opened to a larger size, increases the opening area, and reduces the transvalvular pressure difference.

[0146] Embodiment 3

[0147] The embodiment provides a valve-in-valve support which is integrally carved and cut from a nickel-titanium memory alloy;

[0148] The valve-in-valve support is in a cylindrical structure, comprising a flow-in section support, a middle section support and a flow-out section support connected in sequence; the inner diameters of the flow-in section support and the flow-out section support are independently 32 mm; the total height of the valve-in-valve support is 25 mm; and the wall thicknesses of the flow-in section support, the middle section support and the flow-out section support are independently 0.55 mm;

[0149] The height ratio of the flow-in section support to the middle section support is 1.15:1, and the height ratio of the flow-out section support to the middle section support is 1.5:1;

[0150] The inner diameter ratio of the middle section support to the flow-in section support is 1.2:1, and the inner diameter ratio of the middle section support to the flow-out section support is 1.2:1;

[0151] The flow-in section support comprises a single-layer rhombic grid structure; in the single-layer rhombic grid structure of the flow-in section support, the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0152] The middle section support comprises a single-layer rhombic grid structure; in the single-layer rhombic grid structure of the middle section support, the connecting nodes of adjacent rhombic grids are in a round corner structure; the middle section support is connected with the flow-in section support to form a single-layer rhombic grid structure, and the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0153] The flow-out section support comprises a flow-out section support frame; the flow-out section support frame is connected with the middle section support to form a single-layer rhombic grid structure, and the connecting nodes of adjacent rhombic grids are in a round corner structure;

[0154] The inflow section stent comprises a first support frame and a second support frame; the middle section stent comprises a third support frame and a fourth support frame; the first support frame and the second support frame form a single-layer rhombic lattice structure; the second support frame and the third support frame form a single-layer rhombic lattice structure; the third support frame and the fourth support frame form a single-layer rhombic lattice structure; and the fourth support frame and the outflow section support frame form a single-layer rhombic lattice structure.

[0155] The width of the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame is 0.35 mm.

[0156] In the rhombic lattice structure in the valve-in-valve stent, except for the connection between two adjacent rhombic lattices, the other two angles of the rhombic lattice are defined as support frame angles a, and the angle of the support frame angle a is 100°.

[0157] The valve-in-valve stent further comprises a connector at one end of the outflow section support frame away from the middle section support frame, and the number of the connector is six, which are uniformly arranged along the circumference of the outflow section support frame; and the connector is connected with a matching delivery device through a clamping structure as shown in FIG. 9.

[0158] The present embodiment is provided with a cutter on the outside of the outflow section support frame, and the direction of the cutter blade is parallel to the tangent direction at the corresponding position of the outflow section support frame; and the length of the cutter is the same as the height of the outflow section support frame.

[0159] Through the arrangement of the cutter, the valve-in-valve stent is provided with greater support force, the cutter can extrude and cut the adhered biological valve leaflets, and the adhered biological valve leaflets are separated, so that the valve-in-valve stent can be opened to a larger size, the opening area is increased, and the transvalvular pressure difference is reduced.

[0160] Embodiment 4

[0161] The present embodiment provides a valve-in-valve stent, which is the same as embodiment 1 except that the width of the outflow section support frame is 80% of the width of the fourth support frame.

[0162] Embodiment 5

[0163] The present embodiment provides a valve-in-valve stent, which is the same as embodiment 1 except that the width of the outflow section support frame is 70% of the width of the fourth support frame.

[0164] Embodiment 6

[0165] The present embodiment provides a valve-in-valve stent, which is the same as embodiment 1 except that the width of the outflow section support frame is 90% of the width of the fourth support frame.

[0166] Embodiment 7

[0167] The embodiment provides a valve-in-valve stent, and the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently comprise straight rod sections and connecting sections in the embodiment.

[0168] The straight rod section is a tapered structure with the width of the middle part being smaller than the width of the two ends (see FIG. 6), and the width of the middle part is 75% of the width of the two ends.

[0169] Other parameters in the embodiment are the same as those in embodiment 4.

[0170] Embodiment 8

[0171] The embodiment provides a valve-in-valve stent, and the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently comprise straight rod sections and connecting sections in the embodiment.

[0172] The straight rod section is a tapered structure with the width of the middle part being smaller than the width of the two ends (see FIG. 6), and the width of the middle part is 60% of the width of the two ends.

[0173] Other parameters in the embodiment are the same as those in embodiment 4.

[0174] Embodiment 9

[0175] The embodiment provides a valve-in-valve stent, and the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently comprise straight rod sections and connecting sections in the embodiment.

[0176] The straight rod section is a tapered structure with the width of the middle part being smaller than the width of the two ends (see FIG. 6), and the width of the middle part is 90% of the width of the two ends.

[0177] Other parameters in the embodiment are the same as those in embodiment 4.

[0178] Comparative Example 1

[0179] The comparative example provides a valve-in-valve stent, and the height ratio of the inflow section support frame to the middle section support frame is 0.8:1, and the rest are the same as those in embodiment 7.

[0180] Comparative Example 2

[0181] The comparative example provides a valve-in-valve stent, and the height ratio of the inflow section support frame to the middle section support frame is 1.3:1, and the rest are the same as those in embodiment 7.

[0182] Comparative Example 3

[0183] The comparative example provides a valve-in-valve stent, and the height ratio of the outflow section support frame to the middle section support frame is 1:1, and the rest are the same as those in embodiment 7.

[0184] Comparative Example 4

[0185] The comparative example 7 provides a valve-in-valve stent, which is the same as the example 7 except that the height ratio of the outflow stent to the middle stent is 1.6:1.

[0186] Performance characterization

[0187] The support force and the chronic outward force of the valve-in-valve stents provided in the examples 1-9 and the comparative examples 1-4 are measured, and the results are shown in Table 1.

[0188] Table 1

[0189] The test method of the support force is as follows: the valve-in-valve stent is placed in a 37℃ environment for 2 min, and then the initial size is set as Dmax, and the termination size is set as Dmin, and the stent is run from Dmax to Dmin at a rate of 1 mm / s; wherein Dmax is the outer diameter + 2 mm, and Dmin is 5 mm.

[0190] The test method of the chronic outward force is as follows: the stent is recovered from Dmin to Dmax at a rate of 1 mm / s, and Dm (the maximum value of the valve application size range) is taken as the chronic outward force.

[0191] In summary, the valve-in-valve stent provided in the present application has a cylindrical structure as a whole, and does not need to make the diameters of the inflow stent, the middle stent and the outflow stent different, nor need to set a special-shaped structure in the inflow stent or the outflow stent, thereby reducing the processing difficulty and the processing cost of the valve-in-valve stent. The technical solution provided in the present application controls the ratio of the inflow stent, the middle stent and the outflow stent, thereby providing strong support force for the valve-in-valve stent, reducing the paravalvular regurgitation, effectively supporting the leaflets of the artificial biological valve which are calcified or adhered, and increasing the effective opening area; moreover, the height of the outflow stent is higher than that of the middle stent and the inflow stent in the present application, thereby dispersing the stress at the suture when the leaflets are closed, and making the valve have higher fatigue durability.

Claims

1. A paravalvular stent, which is in a cylindrical structure and comprises an inflow section stent, a middle section stent and an outflow section stent connected in sequence; a height ratio of the inflow section stent to the middle section stent ranges from 1:1 to 1.15:1; a height ratio of the outflow section stent to the middle section stent ranges from 1.15:1 to 1.5:1; an outer side of the outflow section stent is provided with a row of knives; a direction of a blade of the row of knives is parallel to a tangent direction at a corresponding position of the outflow section stent.

2. The valving-in-valving stent of claim 1, wherein, the inflow section stent comprises a single-layer rhombic lattice structure; in the single-layer rhombic lattice structure of the inflow section stent, a connecting node of adjacent rhombic lattices is a rounded structure.

3. The valving-in-valving stent of claim 2, wherein, the middle section stent comprises a single-layer rhombic lattice structure; in the single-layer rhombic lattice structure of the middle section stent, a connecting node of adjacent rhombic lattices is a rounded structure; the middle section stent is connected with the inflow section stent to form a single-layer rhombic lattice structure, and a connecting node of adjacent rhombic lattices is a rounded structure.

4. The valving-in-valving stent of claim 3, wherein, the outflow section stent comprises an outflow section support frame; the outflow section support frame is connected with the middle section stent to form a single-layer rhombic lattice structure, and a connecting node of adjacent rhombic lattices is a rounded structure.

5. The valving-in-valving stent of claim 1, wherein, an inner diameter of the inflow section stent and the outflow section stent is independently 18-32 mm; a total height of the paravalvular stent is 18-25 mm; a wall thickness of the inflow section stent, the middle section stent and the outflow section stent is independently 0.3-0.55 mm.

6. The valving-in-valving stent of claim 5, wherein, a ratio of the inner diameter of the middle section stent to the inner diameter of the inflow section stent ranges from 1:1 to 1.2:1, and a ratio of the inner diameter of the middle section stent to the inner diameter of the outflow section stent ranges from 1:1 to 1.2:

1.

7. The valve-in-valve stent of any of claims 2-6, wherein, the inflow section stent comprises a first support frame and a second support frame; the middle section stent comprises a third support frame and a fourth support frame; the first support frame and the second support frame form a single-layer rhombic lattice structure; the second support frame and the third support frame form a single-layer rhombic lattice structure; the third support frame and the fourth support frame form a single-layer rhombic lattice structure; the fourth support frame and the outflow section support frame form a single-layer rhombic lattice structure.

8. The valving-in-valving stent of claim 7, wherein, a width of the first support frame, the second support frame, the third support frame and the fourth support frame is independently 0.2-0.35 mm; a width of the outflow section support frame is 70-90% of the width of the fourth support frame.

9. The valving-in-valving stent of claim 7, wherein, the first support frame, the second support frame, the third support frame, the fourth support frame and the outflow section support frame independently comprise a straight rod section and a connecting section; the straight rod section is a tapered structure with a width gradually decreasing from both ends to a middle part, and a width of the middle part is 60-90% of the width of both ends. 10.A paravalvular valve, which comprises a leaflet, a skirt and the paravalvular stent of any one of claims 1-9; the skirt is arranged on an outer side of the paravalvular stent; a number of the leaflets is at least 3, and the leaflets are arranged on an inner side of the paravalvular stent.

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