An artificial venous valve

Abstract

The present application provides an artificial venous valve, comprising a stent, a leaflet structure, and a sealing membrane; the stent is elastic and can be radially expanded to be positioned in a venous vessel; the leaflet structure is sutured to the stent, and can be expanded under the action of blood pressure flowing in the positive direction, and can be closed under the action of blood pressure flowing in the reverse direction; the sealing membrane is sutured to the stent, and the sealing membrane is sleeved on the periphery of the leaflet structure and is sealed to the leaflet structure, and the sealing membrane can be expanded by the stent to seal against the inner wall of the venous vessel. The artificial venous vessel of the present application, through the arrangement of the stent, the leaflet structure, and the sealing membrane, enables it to be inserted into or implanted in the venous blood of the human body to replace the native venous valve, thereby achieving the purpose of treating venous reflux.

Description

Technical Field

[0001] The present application belongs to the field of medical device technology, and more specifically, relates to an artificial venous valve. Background Art

[0002] Chronic venous disease (CVD) often occurs in the lower extremities. It is caused by damaged venous valves, leading to venous backflow and venous hypertension. Data shows that the current prevalence of lower extremity venous disease in my country is 8.89%, representing nearly 100 million patients.

[0003] There are three types of blood vessels in the human body: veins, arteries, and capillaries. Only veins have valves. Veins are responsible for carrying blood from all parts of the body back to the heart. To prevent blood from flowing back into the veins, they have valves. When blood flows toward the heart, the valves open, allowing blood to flow toward the heart. Once the blood flows away, the valves close. In summary, venous valves are the "one-way valves" that ensure the veins transport blood back to the heart. Damage to the venous valves can cause venous blood to flow back, leading to venous hypertension and, in turn, CVD.

[0004] Sustained venous hypertension in CVD patients can trigger the extravasation of inflammatory cells and factors within the blood vessels, leading to local inflammation and skin nutritional disorders. Clinical manifestations include superficial varicose veins, tissue edema, and venous ulcer formation.

[0005] Currently, there are two types of treatments for CVD: surgical and non-surgical.

[0006] Treatment options include: Compression stockings, which are elastic stockings designed to squeeze the veins and prevent excessive backflow, and patients need to wear them for life; Sclerotherapy, in which chemicals are injected into the malfunctioning veins. The chemicals damage the abnormal veins, forcing blood to take an alternative, normal venous route, where it is then absorbed by the body; Medication, which can treat some skin problems caused by CVD with anti-inflammatory drugs and control high venous blood pressure with diuretics, but medications do not address the underlying cause of CVD; Surgical ablation, which, like sclerotherapy, destroys the veins from the inside, but uses a catheter with electrodes instead of chemicals; Bypass surgery, in patients with extensive valve damage, surgeons connect an artificial or grafted vein to a healthy vein, bypassing the damaged area. This procedure is often used in more severe cases; Valve repair, in which surgeons typically shorten the valve flap to improve valve function. A sleeve is often placed over the newly fixed vein to help press the vein walls together, preserving the valve's function.

[0007] Conventional treatments fail to fundamentally address the problems of venous valve dysfunction and venous reflux, and suffer from drawbacks such as high recurrence rates and low ulcer healing rates. Furthermore, surgical procedures such as ablation and bypass surgery are associated with lengthy procedures, high operational difficulty, significant trauma, and a high risk of postoperative venous thrombosis. To prevent deep vein thrombosis, large amounts of anticoagulants are often required during and after surgery, potentially leading to complications such as hematoma and bleeding. Summary of the Invention

[0008] The purpose of the embodiments of the present application is to provide an artificial venous valve to solve the technical problem that traditional treatment methods in the prior art cannot fundamentally solve the loss of venous valve function and venous reflux.

[0009] To achieve the above-mentioned purpose, the technical solution adopted in the present application is: to provide an artificial venous valve, including a stent, a leaflet structure and a sealing membrane; the stent is elastic, and the stent can be radially expanded to be positioned in the venous blood vessel; the leaflet structure is sutured to the stent, and the leaflet structure can be opened under the action of blood pressure flowing in the positive direction, and can be closed under the action of blood pressure flowing in the reverse direction; the sealing membrane is sutured to the stent, and the sealing membrane is sleeved on the periphery of the leaflet structure and is sealed with the leaflet structure, and the sealing membrane can be expanded by the stent to seal against the inner wall of the venous blood vessel.

[0010] In a possible design, the leaflet structure includes at least two leaflets, and at least two of the leaflets are an integrally connected structure;

[0011] At least two of the leaflets can be separated from each other under the action of blood pressure flowing in the positive direction, and can be closed to each other under the action of blood pressure flowing in the reverse direction.

[0012] In a possible design, at least two of the leaflets are formed by sewing a closed annular elastic membrane onto the stent at different circumferential positions.

[0013] In a possible design, the stent also includes at least two suture beams, and different circumferential positions of the elastic membrane are correspondingly sutured on at least two of the suture beams to form suture edges of at least two of the leaflets; the suture edges extend along a curve, and the opposite ends of the suture edges extend to an axial end surface of the elastic membrane, and a movable edge is connected between the opposite ends of the suture beam; at least two of the leaflets can produce elastic deformation under the action of blood pressure and drive at least two of the movable edges to press against each other or separate from each other.

[0014] In one possible design, the leaflet has a bottom end farthest from the active edge and a top end located on the active edge;

[0015] The distance from the side wall of the support to each leaflet gradually increases from zero from the bottom end to the top end; so that the distance from the side wall of the sealing membrane to the corresponding leaflet gradually increases from zero from the bottom end to the top end.

[0016] In one possible design, the stent is designed in a grid shape, and the stent includes a blood inflow section, an intermediate section and a blood outflow section connected in sequence along the axial direction, and the blood inflow section and the blood outflow section are both cylindrical and have equal diameters; the intermediate section is provided with a telescopic beam at least toward the position of each leaflet, and the telescopic beam is connected between the blood inflow section and the blood outflow section, and the telescopic beam is arranged in an arc-shaped outward protrusion relative to the blood inflow section and the blood outflow section; the distance from the telescopic beam to the central axis of the stent gradually increases from the bottom end to the top end, and gradually decreases from the top end to the blood outflow section.

[0017] In a possible design, the leaflet structure includes two symmetrically arranged leaflets; the radial cross-section of the middle section is elliptical, and the short axis of the ellipse coincides with the symmetry line of the two leaflets.

[0018] In one possible design, the leaflet structure includes a leaflet, which is formed by sewing the circumferential side wall of a closed annular elastic membrane onto the stent; the leaflet can move away from the side wall of the elastic membrane opposite to the leaflet under the action of blood pressure flowing in the positive direction; and the leaflet can radially press against the side wall of the elastic membrane opposite to the leaflet under the action of blood pressure flowing in the reverse direction.

[0019] In a possible design, the elastic membrane is made of animal pericardium;

[0020] Alternatively, the elastic film is made of high molecular polymer material.

[0021] In a possible design, the leaflet structure includes at least two leaflets, at least two leaflets are split structures, and at least two leaflets are sutured to the stent respectively.

[0022] The beneficial effects of the artificial venous valve provided by the present application are as follows: the artificial venous valve provided by the embodiment of the present application, through the provision of a stent, and the stent is elastic and can be radially expanded to be positioned in the venous blood vessel, thereby realizing the introduction of the artificial venous valve into the human venous blood vessel and the positioning in the human venous blood vessel; at the same time, by suturing the leaflet structure and the sealing membrane to the stent with sutures, the stent also has the function of supporting the leaflet structure and the sealing membrane. By providing the leaflet structure, the leaflet structure can open under the action of the blood pressure flowing in the positive direction, and can close under the action of the blood pressure flowing in the reverse direction, thereby realizing the unidirectional flow of blood in the venous blood vessel, avoiding the need for backflow. In addition, by providing the sealing membrane, and the sealing membrane being sealedly connected to the leaflet structure, the sealing membrane can be expanded by the stent to seal with the inner wall of the venous blood vessel, so that blood cannot flow from the position between the leaflet structure and the inner wall of the venous blood vessel, avoiding the occurrence of paravalvular leakage. To sum up, the artificial venous blood vessel of the present application can be inserted into or implanted into the human body's venous blood through the arrangement of the above-mentioned stent, leaflet structure and sealing membrane to replace the native venous valve, thereby achieving the purpose of treating venous reflux and fundamentally solving the problem of venous reflux. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 A schematic three-dimensional diagram of an artificial venous valve provided in an embodiment of the present application;

[0025] Figure 2 for Figure 1 Schematic side view of the middle venous prosthesis;

[0026] Figure 3 for Figure 1 Schematic diagram of the top view of the artificial venous valve;

[0027] Figure 4 for Figure 1 Schematic diagram of the state of the artificial venous valve after intervention in the venous blood vessel;

[0028] Figure 5 for Figure 4 Schematic diagram of the closed state of the artificial venous valve;

[0029] Figure 6 for Figure 5 Schematic diagram of blood flowing around the bottom of the valve leaflet and sealing membrane;

[0030] Figure 7 for Figure 2 AA cross-sectional view of ;

[0031] Figure 8 for Figure 2 BB cross-sectional diagram;

[0032] Figure 9 for Figure 2 Schematic diagram of CC cross-section;

[0033] Figure 10 for Figure 1 A three-dimensional schematic diagram of the middle bracket;

[0034] Figure 11 for Figure 10 Schematic diagram of the state after the middle bracket is folded;

[0035] Figure 12 for Figure 10 Schematic diagram of the state after the middle bracket is expanded;

[0036] Figure 13 for Figure 10 Schematic diagram of the state after the middle bracket is deployed;

[0037] Figure 14 is a three-dimensional schematic diagram of an elastic membrane;

[0038] Figure 15 It is a schematic diagram of the structure in which the elastic membrane is arranged in the bracket;

[0039] Figure 16 This is a three-dimensional schematic diagram of the elastic membrane being sutured into the stent to form a leaflet structure;

[0040] Figure 17 It is a three-dimensional schematic diagram of the leaflet structure;

[0041] Figure 18 16 is a side view diagram;

[0042] Figure 19 The leaflet structure in this application includes a schematic structural diagram of a leaflet;

[0043] Figure 20 This is a schematic diagram of the structure in which two leaflets in the leaflet structure of this application are independently arranged.

[0044] Among them, the reference numerals in the figures are:

[0045] 100. Stent; 110. Blood inflow section; 111. Auxiliary beam; 112. Positioning beam; 120. Middle section; 121. Suture beam; 122. Telescopic beam; 130. Blood outflow section; 131. V-shaped beam; 141. First positioning ring; 142. Second positioning ring; 200. Leaflet structure; 210. Leaflet section; 211. Leaflet; 2111. Movable edge; 2112. Suture edge; 2113. Top end; 2114. Bottom end; 212. Spacer; 2121. Spacer edge; 220. Fixed section; 2000. Elastic membrane; 300. Sealing membrane; 310. First sealing part; 320. Second sealing part; 400. Vein. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0047] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0048] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0050] See also Figures 1 to 5 The artificial venous valve provided in the embodiment of the present application is now described. The artificial venous valve is used to intervene in or be implanted in a human vein to replace the native venous valve, thereby achieving the purpose of treating venous reflux.

[0051] See also Figures 1 to 5The artificial venous valve includes a stent 100, a leaflet structure 200 and a sealing membrane 300; the stent 100 is elastic and can be radially expanded to be positioned in the venous vessel 400; the leaflet structure 200 is sutured to the stent 100 by sutures, and the leaflet structure 200 can open under the action of blood pressure flowing in the positive direction and can close under the action of blood pressure flowing in the reverse direction; the sealing membrane 300 is sutured to the stent 100 by sutures, and the sealing membrane 300 is sleeved on the outer periphery of the leaflet structure 200 and is sealed with the leaflet structure 200, and the sealing membrane 300 can be expanded by the stent 100 to seal against the inner wall of the venous vessel 400.

[0052] Among them, see Figures 10 to 13 The stent 100 has a mesh structure and is arranged in a circumferential closed loop. The stent 100 is elastic and can be radially collapsed or expanded. For example, before being introduced into the vein 400, the stent 100 is radially collapsed and guided into the vein 400 via a catheter. Once the stent 100 reaches the correct position in the vein 400, the stent 100 is radially expanded and the sealing membrane 300 is pressed against the inner wall of the vein 400, thereby achieving positioning and circumferential sealing of the artificial venous valve.

[0053] Stent 100 is made of a shape-memory alloy, such as nickel-titanium alloy, and is formed by laser engraving. Shape-memory alloys are alloys that, upon heating, completely eliminate deformation incurred at lower temperatures and return to their original shape. This is known as an alloy exhibiting a "memory" effect. Therefore, after stent 100 is radially compressed and deformed outside the human body, when it is introduced into a vein 400, the temperature of stent 100 rises, causing it to return to its pre-compression state and expand to align with the inner wall of the vein 400.

[0054] It should be noted that the positive direction referred to in this application refers to the direction in which blood flows from the venous valve to the heart, specifically Figure 5 The Z1 direction in the figure is the reverse direction, which refers to the direction in which blood flows back from the heart to the venous valve. Figure 5 When the leaflet structure 200 is subjected to the pressure of blood flowing in the positive direction, the leaflet structure 200 opens, allowing blood to flow toward the heart through the leaflet structure 200. When the leaflet structure 200 is subjected to the pressure of blood flowing in the negative direction, the leaflet structure 200 is compressed and closed, preventing blood from flowing back from the heart through the leaflet structure 200 to the vein 400, thereby achieving the purpose of treating venous reflux.

[0055] The sealing membrane 300 is sealed to the leaflet structure 200, preventing blood from flowing through the gap between them. The sealing membrane 300 is then propped open by the stent 100 to seal against the inner wall of the vein 400, preventing blood from flowing between them. This prevents blood from flowing outside the leaflet structure 200, potentially leading to paravalvular leakage after implantation of the artificial venous valve. Furthermore, after prolonged use, the sealing membrane 300 can promote tissue proliferation within the vein 400, becoming integrated with the vein 400.

[0056] The artificial venous valve of the present application is provided with a stent 100, which is elastic and can be radially expanded to be positioned in a vein 400, thereby achieving the introduction of the artificial venous valve into and positioning in a human vein 400. At the same time, by suturing the leaflet structure 200 and the sealing membrane 300 to the stent 100 using sutures, the stent 100 also supports the leaflet structure 200 and the sealing membrane 300. The provision of the leaflet structure 200, which can open under the pressure of blood flowing in the forward direction and close under the pressure of blood flowing in the reverse direction, enables unidirectional blood flow in the vein 400, preventing blood backflow. In addition, by providing the sealing membrane 300 and sealingly connecting the sealing membrane 300 to the leaflet structure 200, the sealing membrane 300 can be expanded by the stent 100 to seal against the inner wall of the venous vessel 400, thereby preventing blood from flowing between the leaflet structure 200 and the inner wall of the venous vessel 400, thereby avoiding paravalvular leakage. In summary, the artificial venous vessel 400 of the present application, through the provision of the stent 100, leaflet structure 200, and sealing membrane 300, can be inserted into or implanted in the human venous blood to replace the native venous valve, thereby achieving the purpose of treating venous reflux and fundamentally solving the problem of venous reflux.

[0057] In one embodiment, the leaflet structure 200 includes at least two leaflets 211, which are integrally connected. The at least two leaflets 211 can separate from each other under the pressure of blood flowing in the positive direction and can close together under the pressure of blood flowing in the negative direction.

[0058] The number of the leaflets 211 may be two or three. Of course, in some special design structures, the number of the leaflets 211 may be more than three.

[0059] At least two leaflets 211 are integrally connected, meaning they are made from the same base material and are inseparable. This integral connection ensures that the at least two leaflets 211 have identical performance, facilitating the designer's control over the material and dimensional design of the leaflets 211. This also facilitates the positioning and assembly of the entire leaflet structure 200, eliminating the need to reposition and install each leaflet 211. Furthermore, this ensures a good seal between the leaflets 211 and between the leaflets 211 and the sealing membrane 300, preventing leakage.

[0060] In a specific embodiment, see Figures 14 to 18 At least two leaflets 211 are sutured to the stent 100 at different circumferential positions of the closed annular elastic membrane 2000. Figure 14 , which is the shape of the elastic membrane 2000 before being installed on the bracket 100, is cylindrical. When the elastic membrane 2000 is sutured on the bracket 100, it forms Figure 17 The leaflet structure 200. When at least two leaflets 211 are sutured and formed, the at least two leaflets 211 can be radially separated from each other under the action of the blood pressure flowing in the positive direction to allow blood to flow, and the at least two leaflets 211 can be radially closed to each other under the action of the blood pressure flowing in the reverse direction to prevent blood flow. Such a configuration not only allows each leaflet 211 to be sealed and connected along the circumferential direction, thereby facilitating a sealed connection with the sealing membrane 300, but also eliminates the need to cut and produce each leaflet 211. Instead, the leaflets 211 only need to be sutured to the stent 100 at the position where they need to be sutured, resulting in a simple manufacturing process. In addition, a cylindrical elastic membrane can be directly selected for material selection. For example, animal pericardium can be directly selected to make the elastic membrane 2000, which simplifies material selection.

[0061] In a preferred embodiment, the elastic membrane 2000 is made of animal pericardium, such as bovine pericardium or porcine pericardium. The pericardial material can be selected from animal blood vessels, including the endothelium or adventitia of venous blood vessels or arterial blood vessels. Natural animal blood vessels have a three-layer structure, including the endothelium, the middle membrane and the adventitia. Among them, the endothelium and the adventitia have good toughness and elasticity. The present application can peel off the endothelium of blood vessels of the same specifications from the blood vessels, and use it as the material of the leaflet structure 200, thereby making the manufactured leaflet structure 200 have good toughness and elasticity. At the same time, it can also be close to the leaflet performance of the human venous valve, so that the therapeutic effect of the artificial venous valve made by the leaflet structure 200 is better.

[0062] In other embodiments of the present application, the elastic membrane 2000 may also be made of a polymer material, which has good elasticity and toughness. Furthermore, the elastic membrane 2000 may also be made of SEBS (Styrene-Ethylene-Butylene-Styrene; SEBS is a linear triblock copolymer with polystyrene as the terminal segment and ethylene-butylene copolymer obtained by hydrogenating polybutadiene as the middle elastic segment). SEBS has good rubber elasticity and is suitable for making the leaflets 211. Furthermore, the elastic membrane 2000 may also be made of PTFE (polytetrafluoroethylene), which has good toughness and is also suitable for making the leaflets 211. When the elastic membrane 2000 is made of other non-animal pericardial materials, since the non-animal pericardial material is planar after cutting, that is, the planar non-animal pericardial material needs to be formed into a cylindrical shape, and thus the cylindrical shape needs to be formed by the direction of suturing.

[0063] In one embodiment, see Figure 10 、 Figure 16 and Figure 18 The stent 100 includes at least two suture beams 121, and different circumferential positions of the elastic membrane 2000 are correspondingly sutured on the at least two suture beams 121 to form suture edges 2112 of at least two leaflets 211; the suture edges 2112 extend along a curve, and the opposite ends of the suture edges 2112 extend to an axial end surface of the elastic membrane 2000, specifically the axial end surface close to the heart, and a movable edge 2111 is connected between the opposite ends of the suture edge 2112; at least two leaflets 211 can produce elastic deformation under the action of blood pressure and drive at least two movable edges 2111 to press against each other or separate from each other.

[0064] The elastic membrane 2000 has a first end and a second end that are oppositely disposed. The first end is the end of the elastic membrane 2000 that is close to the heart, and the second end is the end of the elastic membrane 2000 that is away from the heart.

[0065] Specifically, the movable edge 2111 is located on the end surface of the first end of the elastic membrane 2000, and the sewing edge 2112 is located on the side wall of the elastic membrane 2000. The sewing edge 2112 extends along a curve from one end of the movable edge 2111 to the other end of the movable edge 2111; the sewing edge 2112 is sewn to the bracket 100.

[0066] In this embodiment, the elastic membrane 2000 is sewn to the stent 100 along at least two suture edges 2112 at different circumferential positions, thereby dividing at least two leaflets 211 on the elastic membrane 2000; when blood flows through the leaflet structure 200 in the positive direction, the blood flows from the center of the second end of the elastic membrane 2000 to between the leaflets 211, squeezing the leaflets 211 from the inner side walls of the leaflets 211, thereby separating the leaflets 211 radially outward, and blood flows toward the heart; when blood flows through the leaflet structure 200 from the heart in the reverse direction, the blood squeezes the leaflets 211 from the outer side walls of the leaflets 211, causing the leaflets 211 to deform and drive the movable edges 2111 to approach each other and close, thereby preventing blood from flowing back into the vein 400.

[0067] Among them, the suture beam 121 can extend along an elliptical curve, an arc curve, a hyperbola or a spline curve, so that the formed suture edge 2112 can also extend along an elliptical curve, an arc curve, a hyperbola or a spline curve, thereby limiting the shape of the leaflet 211.

[0068] See also Figure 16 and Figure 17 A spacer 212 is connected between two adjacent leaflets 211 , and the spacer 212 is sutured to the stent 100 . The spacer 212 has a spacer edge 2121 located on the axial end surface of the elastic membrane 2000 , and the two adjacent movable edges 2111 are connected by the spacer edge 2121 .

[0069] In one embodiment, see Figure 16 and Figure 17 The leaflet structure 200 includes a fixing section 220 and a leaflet section 210, which are integrally connected along an axis. The fixing section 220 and the leaflet section 210 are two parts of the elastic membrane 2000 connected along the axial direction. The fixing section 220 is cylindrical and sutured to the stent 100. The sealing membrane 300 is positioned in a manner corresponding to the fixing section 220 and is disposed in contact with the fixing section 220. At least two leaflets 211 are formed on the leaflet section 210. In this embodiment, by providing the fixing section 220 on the basis of the leaflet section 210, the leaflet structure 200 can be stably mounted on the stent 100 through the fixing section 220. At the same time, the fixing section 220 is cylindrical and is also disposed in contact with the sealing membrane 300, thereby ensuring good sealing between the leaflet structure 200 and the sealing membrane 300.

[0070] In one embodiment, see Figure 3The stent 100 is provided with a plurality of positioning rings, which are spaced apart along the axial and circumferential directions of the stent 100. Each positioning ring is used to be sutured and connected to the leaflet structure 200 at different positions along the axial and circumferential directions to achieve the axial and circumferential positioning of the leaflet structure 200 on the stent 100. In the present application, the leaflet structure 200 needs to be sutured to the stent 100 by sutures, and the leaflets 211 in the leaflet structure 200 have suture edges 2112. The suture edges 2112 need to be sutured to the stent 100 so that the leaflets 211 can play a role. Therefore, the suture position of the leaflets 211 on the stent 100 cannot be wrong. In the present application, the leaflet structure 200 can be preliminarily positioned on the stent 100 by using a plurality of positioning rings, and then sutured corresponding to each leaflet 211, thereby reducing the difficulty of suturing the leaflets 211 and improving the suturing accuracy of the leaflets 211.

[0071] In a specific embodiment, see Figure 16 and Figure 18 The leaflet structure 200 includes two leaflets 211, and the stent 100 is provided with four positioning rings, namely two first positioning rings 141 and two second positioning rings 142. The two first positioning rings 141 and the two second positioning rings 142 are arranged at intervals along the axial direction, the two first positioning rings 141 are arranged at intervals along the circumferential direction, and the two second positioning rings 142 are arranged at intervals along the circumferential direction. The two first positioning rings 141 and the two second positioning rings 142 are arranged at equal intervals along the circumferential direction, and a second positioning ring 142 is provided between the two first positioning rings 141 along the circumferential direction; the two first positioning rings 141 are used to connect with the leaflet segment 210, specifically, the two first positioning rings 141 are used to be sutured and connected with the two spacers 212, and the two second positioning rings 142 are used to connect with the fixed segment 220.

[0072] During actual installation, the elastic membrane 2000 is first sutured and positioned in the stent 100 using the positioning rings, and then the positions on the elastic membrane 2000 corresponding to the suture beams 121 are sutured along the extension trajectory of the suture beams 121 to form suture edges 2112, thereby forming leaflets 211. By providing suture beams 121 on the stent 100, the installer only needs to sew the positions on the elastic membrane 2000 corresponding to the suture beams 121 along the suture beams 121 to form suture edges 2112 and leaflets 211. The operation is simple and error-prone. The design of the suture beams 121 can reduce errors during the suturing process and simplify the suturing process.

[0073] In one embodiment, see Figure 6The leaflet 211 has a bottom end 2114 farthest from the active edge 2111 and a top end 2113 located on the active edge 2111; the distance from the side wall of the support 100 toward each leaflet 211 to the leaflet 211 gradually increases from zero from the bottom end 2114 to the top end 2113; so that the distance from the side wall of the sealing membrane 300 to the corresponding leaflet 211 gradually increases from zero from the bottom end 2114 to the top end 2113.

[0074] Taking two leaflets 211 as an example, Figure 6 The two leaflets 211 are symmetrically distributed on the left and right sides, and the distance from the left side wall of the stent 100 to the left leaflet 211 gradually increases from zero from the bottom end 2114 to the top end 2113; and the distance from the right side wall of the stent 100 to the right leaflet 211 gradually increases from zero from the bottom end 2114 to the top end 2113; thereby, the distance from the left and right side walls of the sealing membrane 300 to the left and right leaflets 211 gradually increases from zero from the bottom end 2114 to the top end 2113. Figure 6 It can be seen that such a design can make blood flow around the bottom end 2114 of the flow channel when the leaflet 211 is closed, which is beneficial to blood flow and prevents blood from being retained at the bottom of the leaflet 211 and forming thrombus. In addition, please refer to Figure 5 and Figure 6 Due to the outward convex setting of the stent 100, the vein 400 is also supported in an outward convex setting, so that the stent 100 and the vein 400 form an inclined abutment at the corresponding positions, thereby preventing the artificial venous valve from slipping and achieving effective fixation.

[0075] In one embodiment, see Figures 6 to 9 and Figure 16The stent 100 is designed as a grid as a whole, and the stent 100 can be axially and radially expanded and contracted. The stent 100 includes a blood inflow section 110, an intermediate section 120 and a blood outflow section 130 connected in sequence along the axial direction, wherein the blood inflow section 110 is a section away from the heart, and the blood outflow section 130 is a section close to the heart. The blood inflow section 110 and the blood outflow section 130 are both cylindrical and have equal diameters. The intermediate section 120 is provided with a telescopic beam 122 at least toward each leaflet 211. The telescopic beam 122 is connected between the blood inflow section 110 and the blood outflow section 130. The telescopic beam 122 is arranged in an arc-shaped outward protrusion relative to the blood inflow section 110 and the blood outflow section 130; the distance from the telescopic beam 122 to the central axis of the stent 100 gradually increases from the bottom end 2114 to the top end 2113, and gradually decreases from the top end 2113 to the blood outflow section 130, that is, the telescopic beam 122 is arranged in an arc-shaped outward protrusion relative to the blood inflow section 110 and the blood outflow section 130; The distance from the telescopic beam 122 to the leaflet 211 gradually increases from zero from the bottom end 2114 to the top end 2113, and then gradually decreases to zero from the top end 2113 to the blood outflow section 130. This arrangement not only enables the blood to flow around the bottom end 2114, which is beneficial to blood flow and prevents blood from being retained at the bottom of the leaflet 211 and producing thrombus; it also enables the diameter of the stent 100 to eventually return to the diameter of the blood outflow section 130 after passing through the telescopic beam 122, and the arc-shaped outward convexity is conducive to the positioning between the stent 100 and the vein 400.

[0076] Specifically, the telescopic beam 122 includes a plurality of S-shaped beam portions connected in sequence along the axial direction. Due to the design of the S-shaped beam portions, the telescopic beam 122 can be folded and stretched along the axial direction. Before intervention into the human body, the stent 100 is expanded, and the telescopic beam 122 is arranged in an arc-shaped outward protrusion relative to the blood inflow section 110 and the blood outflow section 130. When the stent 100 is folded in the radial direction, the entire stent 100 is also stretched in the axial direction, and the telescopic beam 122 is stretched accordingly. However, due to the design of the multiple S-shaped beam portions, the stretching of the telescopic beam 122 has no effect, and will not affect other parts of the stent 100.

[0077] See also Figure 16 Since the telescopic beam 122 is used to support the sealing membrane 300 so that a space for blood to flow around is formed between the sealing membrane 300 and the leaflet 211, the telescopic beam 122 is finally installed in the middle position of the leaflet 211 along the circumferential direction. One end of the telescopic beam 122 is connected to the bottom end 2114 of the suture beam 121, and the other end of the telescopic beam 122 is connected to the blood outflow section 130.

[0078] In this embodiment, one telescopic beam 122 is provided for each leaflet 211. It is understood that in other embodiments of the present application, two, three, or more telescopic beams 122 distributed along the circumference may be provided for each leaflet 211, thereby expanding the sealing membrane 300 more evenly. This is not intended to be a limitation.

[0079] In a specific embodiment, the leaflet structure 200 includes two symmetrically arranged leaflets 211; the radial cross-section of the middle section 120 of the stent 100 is elliptical, and the minor axis of the ellipse coincides with the symmetry line of the two leaflets 211. Figure 2 and Figure 7 As shown, the two leaflets 211 are arranged symmetrically on the left and right sides, and the long axis of the ellipse extends in the left-right direction, and the two short axes extend in the front-back direction. In this arrangement, the positions of the stent 100 corresponding to the leaflets 211 are all convex to facilitate blood flow, while the positions of the stent 100 corresponding to the spacer 212 do not need to be convex. It is understandable that in other embodiments of the present application, the radial cross-section of the position of the stent 100 corresponding to the leaflet 211 along the axial direction can also be circular, that is, the position of the stent 100 facing the spacer 212 is also convex, and this is not the only limitation here.

[0080] Among them, see Figure 2 、 Figures 6 to 8 , assuming that the length of the minor axis of the ellipse is D1 and the length of the major axis is D2, then the ratio of D2 to D1 can range from 1 to 1.6.

[0081] Furthermore, assuming the diameter of the blood inflow section 110 and the blood outflow section 130 is D, the diameter range of D is 5-16 mm to accommodate veins of varying sizes. The ratio of D1 to D can therefore be in the range of 1-1.3. This means that the minor axis length D1 of the intermediate section 120 can be equal to or slightly greater than the diameter of the blood inflow section 110.

[0082] In one embodiment, see Figures 10 to 13 The stent 100 includes a plurality of V-shaped beams 131, wherein the blood outflow section 130 is formed by sequentially connecting the plurality of V-shaped beams 131. The blood outflow section 130 includes at least one circle of V-shaped beams 131 connected in sequence along the radial direction, wherein the topmost V-shaped beam 131 is arranged with its tip facing upward, and the second circle of V-shaped beams 131 is symmetrically connected to the first circle of V-shaped beams 131 along the axial and radial directions, thereby forming a plurality of diamond-shaped grids, and the other circles of V-shaped beams 131 are arranged similarly. The number of circles of the V-shaped beams 131 can be one, two, three, or more.

[0083] For the middle section 120, due to the arrangement of the suture beam 121 and the telescopic beam 122, each suture beam 121 is connected in sequence along the circumferential direction, and each telescopic beam 122 is arranged in the middle of the suture beam 121. However, since the axial length of the suture beam 121 along the axial direction of the stent 100 is smaller than the axial length of the telescopic beam 122 along the axial direction of the stent 100, the connection between the top ends 2113 of the two suture beams 121 and the blood outflow section 130 can also be connected through other V-shaped beams 131.

[0084] In one embodiment, see Figures 10 to 13 The stent 100 further includes an auxiliary beam 111. The auxiliary beam 111 is V-shaped, with opposite ends of the auxiliary beam 111 connected to positions between the top end 2113 and the bottom end 2114 of two adjacent suture beams 121. The auxiliary beam 111 is configured to be sutured to the fixed section 220 of the leaflet structure 200. The auxiliary beam 111 can secure the two suture beams 121, ensuring that the suture beams 121 maintain their original design shape when the stent 100 is compressed by a blood vessel.

[0085] See also Figures 10 to 13 The stent 100 further includes a positioning beam 112, one end of which is connected to the bottom end 2114 of the suture beam 121, and a second positioning ring 142 is provided on the other end of the positioning beam 112. The positioning beam 112 is provided between the two auxiliary beams 111, and not only serves to position the leaflet structure 200, but also provides support.

[0086] In one embodiment, the sealing film 300 can be installed on the inner side of the stent 100 or on the outer side of the stent 100. When the sealing film 300 is installed on the inner side of the stent 100, the sealing film 300 and the leaflet structure 200 are more closely attached, thereby achieving a better sealing effect between the sealing film 300 and the leaflet structure 200; when the sealing film 300 is installed on the outer side of the stent 100, the sealing film 300 and the leaflet structure 200 are sutured to the inner and outer sides of the stent 100 respectively, thereby making the suturing of the sealing film 300 and the leaflet structure 200 more convenient and achieving a better suturing effect, and also enabling the sealing film 300 to better integrate with the vein 400.

[0087] The sealing membrane 300 is used to prevent perivalvular reflux after valve implantation. The sealing membrane 300 can also promote tissue proliferation and fuse the valve and blood vessels in a short period of time.

[0088] Because the portion of the sealing membrane 300 corresponding to the telescopic beam 122 needs to be expanded, the sealing membrane 300 can be configured into two sections, a first sealing portion 310 and a second sealing portion 320, each having different diameters. The first sealing portion 310 is conical, and the second sealing portion 320 is cylindrical. The minimum diameter of the first sealing portion 310 is equal to the diameter of the second sealing portion 320. The first sealing portion 310 is sleeved over the middle section 120 of the stent 100, and the second sealing portion 320 is sleeved over the blood inflow section 110 of the stent 100. The first sealing portion 310 is sutured to the suture beam 121, and the second sealing portion 320 is sutured to the auxiliary beam 111.

[0089] The sealing membrane 300 can be made of PTFE, PET, or pericardial material. Similarly, when the sealing membrane 300 is made of a non-pericardial material, the sealing membrane 300 is planar and is sutured onto the stent 100. Two pieces of the sealing membrane 300 are joined together to form a curved surface, which is then placed over the lower end of the stent 100 and secured to the stent 100 with sutures.

[0090] In another embodiment of the present application, see Figure 19 The leaflet structure 200 may also include a leaflet 211, which is formed by sewing the circumferential sidewall of a closed annular elastic membrane 2000 onto the stent 100. Under the pressure of blood flowing in the positive direction, the leaflet 211 can move radially away from the sidewall of the elastic membrane 2000 opposite the leaflet 211. Under the pressure of blood flowing in the negative direction, the leaflet 211 can radially press against the sidewall of the elastic membrane 2000 opposite the leaflet 211. In other words, the leaflet 211 moves under the pressure of blood, while the sidewall of the elastic membrane 2000 opposite the leaflet 211 does not move. Thus, the leaflet structure 200 can be closed by the leaflet 211 approaching the sidewall of the elastic membrane 2000 opposite the leaflet 211, and opened by the leaflet 211 moving away from the sidewall of the elastic membrane 2000 opposite the leaflet 211.

[0091] Similarly, in this embodiment, a suture beam 121 needs to be provided at the position of the stent 100 corresponding to the leaflet 211, and a telescopic beam 122 may also be provided at the position of the stent 100 facing the leaflet 211 to facilitate blood flow.

[0092] In another embodiment of the present application, see Figure 20 The leaflet structure 200 includes at least two leaflets 211 , and at least two leaflets 211 are split structures, that is, each leaflet 211 is independently manufactured and then sutured to the stent 100 respectively.

[0093] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An artificial venous valve, characterized in that: The invention comprises a stent, a leaflet structure and a sealing membrane; the stent is elastic and can be radially expanded to be positioned in a venous blood vessel; the leaflet structure is sutured to the stent, and can be expanded under the action of blood pressure flowing in the positive direction and can be closed under the action of blood pressure flowing in the reverse direction; the sealing membrane is sutured to the stent, the sealing membrane is sleeved on the periphery of the leaflet structure and is sealingly connected to the leaflet structure, the sealing membrane can be expanded by the stent to seal against the inner wall of the venous blood vessel, the leaflet structure comprises at least two leaflets, at least two of the leaflets are an integrally connected structure, at least two of the leaflets can be separated from each other under the action of blood pressure flowing in the positive direction and can be closed with each other under the action of blood pressure flowing in the reverse direction, and at least two of the leaflets are respectively formed by suturing the closed annular elastic membrane to the stent at different circumferential positions through sutures.

2. The artificial venous valve according to claim 1, wherein: The stent also includes at least two suture beams, and different circumferential positions of the elastic membrane are correspondingly sutured on the at least two suture beams to form suture edges of at least two leaflets; the suture edges extend along a curve, and the opposite ends of the suture edges extend to an axial end surface of the elastic membrane, and a movable edge is connected between the opposite ends of the suture beam; at least two leaflets can produce elastic deformation under the action of blood pressure and drive at least two movable edges to press against each other or separate from each other.

3. The artificial venous valve according to claim 2, wherein: The leaflet has a bottom end farthest from the active edge and a top end located on the active edge; The distance from the side wall of at least the support toward each leaflet to the leaflet gradually increases from zero from the bottom end to the top end, so that the distance from the side wall of the sealing membrane to the corresponding leaflet gradually increases from zero from the bottom end to the top end.

4. The artificial venous valve according to claim 3, wherein: The stent is designed in a grid shape, and the stent includes a blood inflow section, an intermediate section and a blood outflow section connected in sequence along the axial direction, and the blood inflow section and the blood outflow section are both cylindrical and have equal diameters; the intermediate section is provided with a telescopic beam at least toward the position of each leaflet, and the telescopic beam is connected between the blood inflow section and the blood outflow section, and the telescopic beam is arranged in an arc-shaped outward protrusion relative to the blood inflow section and the blood outflow section; the distance from the telescopic beam to the central axis of the stent gradually increases from the bottom end to the top end, and gradually decreases from the top end to the blood outflow section.

5. The artificial venous valve according to claim 4, wherein: The leaflet structure includes two symmetrically arranged leaflets; the radial cross-section of the middle section is elliptical, and the short axis of the ellipse coincides with the symmetry line of the two leaflets.

6. The artificial venous valve according to claim 1, wherein: The leaflet structure includes a leaflet, which is formed by sewing the circumferential side wall of a closed annular elastic membrane onto the stent; the leaflet can move away from the side wall of the elastic membrane opposite to the leaflet under the action of blood pressure flowing in the positive direction; the leaflet can radially press against the side wall of the elastic membrane opposite to the leaflet under the action of blood pressure flowing in the reverse direction.

7. The artificial venous valve according to any one of claims 1 to 6, characterized in that: The elastic membrane is made of animal pericardium; Alternatively, the elastic film is made of high molecular polymer material.

8. The artificial venous valve according to claim 1, wherein: The leaflet structure includes at least two leaflets, at least two leaflets are split structures, and at least two leaflets are sutured to the stent respectively.

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