Integrated interventional venous valve and preparation method thereof

Abstract

The invention discloses an integrated interventional venous valve and a preparation method thereof. The integrated interventional venous valve comprises a valve stent, a valve leaflet and a skirt; the valve stent comprises a first annular grid stent, a second annular grid stent and a straight rod for connecting the first annular grid stent and the second annular grid stent; the skirt edge covers the inner and outer surfaces of the first annular grid bracket and the second annular grid bracket; the valve leaflet is arranged on the straight rod, one side of the valve leaflet is connected with the skirt edge, and the free surface of the other side of the valve leaflet is arc-shaped; according to the integrated interventional venous valve, the valve leaflet and the skirt edge cover the inner surface and the outer surface of the valve support, so that the valve support, the valve leaflet and the skirt edge do not need to be fixed through sewing, the problems of complexity and potential tearing risk of split type processing are solved, and by arranging the material and the structure of the valve support, the integral interventional venous valve can be manufactured. And the valve leaflet free surface has a bionic arc shape, so that the integrated interventional vein valve can adapt to the diameter change of a blood vessel.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to an integrated interventional venous valve and a preparation method thereof. Background Art

[0002] For severe deep vein valve insufficiency, conventional treatment methods include valve repair and plasty and venous wall circumference reduction, but the effects of these two treatment methods are not good; while valve replacement therapy is one of the treatment methods with clinical prospects, but there is no marketed product.

[0003] In addition, currently clinically used transcatheter artificial (heart) valves generally adopt a split design. The valve leaflets mostly use biological materials such as bovine pericardium, with poor durability. The valve leaflets are fixed to the metal stent by suturing. The preparation process is complex and time-consuming, and it causes early tearing at the suture site due to interfacial stress concentration after implantation. Under long-term cyclic loading, it is easy to cause suture breakage, resulting in valve leaflet prolapse and accelerated interfacial calcification and structural degradation.

[0004] For example, the Chinese patent application with the patent application number CN202221974757.7 discloses a valve leaflet structure and an artificial venous valve. Specifically, it discloses that the artificial venous valve includes a stent, a sealing membrane and a valve leaflet structure. The suture edge of the valve leaflet structure is sutured and fixed to the stent, the sealing membrane is sutured to the stent, the sealing membrane is sleeved on the outer periphery of the valve leaflet structure, and the sealing membrane is hermetically connected to the valve leaflet structure; it can be seen that the above artificial venous valve needs to suture the valve leaflet structure and the sealing membrane to the stent, there is a problem of suture breakage resulting in prolapse of the valve leaflet and the sealing membrane, and the free surface of the valve leaflet of the above artificial venous valve cannot be biomimetic to be arc-shaped. At the same time, the stent structure is complex and inelastic, cannot adapt to the change of blood vessel diameter, and is easy to damage the blood vessel.

[0005] Another example is the Chinese patent application with the patent application number CN200520039624.0, which discloses a venous valve substitute. Specifically, it discloses that the venous valve substitute is composed of an artificial valve and a wire stent, and the wire stent is sutured and fixed to the outside of the body of the artificial valve; it can be seen that the artificial valve in the above venous valve substitute needs to be sutured to the wire stent, and there is also a problem of suture breakage resulting in prolapse of the artificial valve.

[0006] The US patent applications with patent application numbers US20230363901A1 and US20230363914A1 disclose a transcatheter anti-reflux venous valve system, specifically disclosing the valve frame, valve leaflets and skirt structure. The valve involves suture operations at multiple sites. The valve leaflets of this system are made of continuous biological tissue, usually porcine pericardial tissue, formed into a single-valve shape through a folding process, with the edges sutured. The inflow skirt is connected to the valve wall, using the same biological tissue material as the valve leaflets, mostly in the shape of a rectangle or square. In addition, the connection between the valve leaflets and the stent requires suturing. It can be seen that the above artificial venous valve needs to suture the valve leaflet structure and the sealing membrane to the stent, and there is also the problem of prolapse of the valve leaflets and the sealing membrane caused by suture breakage; moreover, the valve leaflets of the above artificial venous valve are single-leaf, with a large morphological difference from the human venous valve; at the same time, the valve leaflet material is porcine pericardial tissue, which also has the disadvantages of high thrombus and calcification risks and limited sources.

[0007] Although there have been some studies on artificial venous valves, such as autologous valved segment vascular transplantation, allogeneic valves, and metal and bioprosthetic venous valve vascular grafts, most of them have unsatisfactory effects and have not entered clinical application. These materials still face some technical challenges, such as thrombosis, intimal hyperplasia, leaflet stiffness, device collapse and embolism, vascular diameter mismatch, bleeding problems caused by anticoagulant drugs, graft tilt and displacement and other serious complications, which limit the wide range of their clinical application and long-term effects. Currently, only a foreign venous valve (VenoValve, patent number US11872126B2) has entered the clinical trial stage. This valve is a surgically implanted valve under direct vision, and the valve leaflets are single-leaf valves, and the valve leaflets need to be sutured to the metal frame. There is currently no report on domestic venous valve products. Summary of the Invention

[0008] The purpose of the present invention is to provide an integrated interventional venous valve and its preparation method. In the integrated interventional venous valve of the present invention, the valve leaflets and the skirt are coated on the inner and outer surfaces of the valve stent, and through chemical bonding and high-temperature sintering and other methods, the valve stent is not required to be sutured and fixed to the valve leaflets and the skirt, solving the cumbersome problem of split processing and potential tearing risks. Moreover, through the setting of the material and structure of the valve stent, combined with the bionic arc of the free surface of the valve leaflets, the integrated interventional venous valve can adapt to changes in blood vessel diameter.

[0009] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0010] In the first aspect of the present invention, an integrated interventional venous valve is provided. The integrated interventional venous valve includes a valve stent, valve leaflets, and a skirt; the valve stent includes a first annular grid stent, a second annular grid stent, and straight rods connecting the first annular grid stent and the second annular grid stent; there are 2 to 3 straight rods; the first annular grid stent and the second annular grid stent have shape memory characteristics and can self-expand in a blood vessel from a compressed state; the skirt covers the inner and outer surfaces of the first annular grid stent and the second annular grid stent; the valve leaflets are arranged on the straight rods, and one side of the valve leaflets is connected to the skirt, and the free surface on the other side is arc-shaped.

[0011] In the present invention, the grid shapes of the first annular grid stent and the second annular grid stent are not specifically limited, and conventional shapes in the art can be adopted, such as a rhombus or a V shape; other grid shapes that can enable the first annular grid stent and the second annular grid stent to contract and expand (compress and release) can also be used.

[0012] Preferably, the integrated interventional venous valve further includes a pipeline arranged on the outer periphery of the valve stent.

[0013] Preferably, the materials of the first annular grid stent and the second annular grid stent are shape memory alloys.

[0014] Preferably, the ratio of the maximum height of the valve leaflets to the inner diameter of the first annular grid stent is (1 to 3):1; the ratio of the minimum height of the valve leaflets to the inner diameter of the first annular grid stent is (1 to 6):2.

[0015] In the second aspect of the present invention, a preparation method of an integrated interventional venous valve is provided. The preparation method includes the following steps:

[0016] (1) Dissolve a polymer in an organic solvent to obtain a polymer solution.

[0017] (2) Conduct electroconductive treatment on a cylindrical receiver, and then form an inner layer film on the surface of the receiver with the polymer solution.

[0018] (3) Put the valve stent on the surface of the inner layer film, and then form an outer layer film on the surface of the valve stent with the polymer solution.

[0019] (4) Take off the valve stent covered with the inner layer film and the outer layer film and conduct bonding treatment for the fusion of the inner layer film and the outer layer film, and then cut it to obtain the integrated interventional venous valve.

[0020] Preferably, the step (4) further includes:

[0021] A pipeline is formed by a polymer solution around the outer periphery of the trimmed valve stent, and then, the skirt on the valve stent is adhesively treated with the pipeline.

[0022] Preferably, the forming methods of the inner layer film, the outer layer film and the pipeline are respectively selected from any one of electrospinning, 3D printing, spin coating, dip coating, spraying and casting.

[0023] Preferably, in the step (1), the polymer is selected from at least one of polyurethane, polycaprolactone, polystyrene, polytetrafluoroethylene and polyethylene glycol.

[0024] Preferably, in the step (4), the adhesive treatment method is sintering treatment or chemical bonding treatment;

[0025] The cutting method is laser cutting.

[0026] Preferably, the sintering treatment temperature is 60~150°C and the time is 0.01~2h.

[0027] Compared with the prior art, the beneficial effects of the present invention at least include:

[0028] In the integrated interventional venous valve of the present invention, by covering the valve leaf and the skirt on the inner and outer surfaces of the valve stent, the valve stent, the valve leaf and the skirt do not need to be sutured and fixed and there is no exposure of the metal stent, solving the problems in the prior art that the valve leaf and the valve stent are sutured and fixed, the preparation process is complex and time-consuming, and the suture site after implantation causes early tearing due to interfacial stress concentration, and avoiding thrombus formation caused by metal; in addition, through the setting of the material and structure of the valve stent of the present invention, combined with the bionic arc of the free surface of the valve leaf, the valve stent has radial self-adaptability, can improve compliance, and further enables the integrated interventional venous valve of the present invention to adapt to the change of blood vessel diameter; in addition, the materials of the valve leaf and the skirt of the present invention are polymer materials, the raw material sources are wide, and the preparation process is simple, and the risks of decline and calcification are low; the integrated interventional venous valve of the present invention is suitable for interventional operations, avoiding traditional surgical incision and suture, and improving the surgical success rate and patient acceptance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0030] Figure 1 It is a structural side view of the valve stent in the embodiment of the present invention;

[0031] Figure 2Schematic three-dimensional structure diagram of the valve stent in the embodiment of the present invention;

[0032] Figure 3 Schematic three-dimensional structure diagram of the integrated single-leaf interventional venous valve in Embodiment 1 of the present invention;

[0033] Figure 4 Side view of the integrated single-leaf interventional venous valve in Embodiment 1 of the present invention;

[0034] Figure 5 Schematic three-dimensional structure diagram of the integrated two-leaf interventional venous valve in Embodiment 2 of the present invention;

[0035] Figure 6 Side view of the integrated two-leaf interventional venous valve in Embodiment 2 of the present invention;

[0036] Figure 7 Top view of the integrated two-leaf interventional venous valve in Embodiment 2 of the present invention;

[0037] Figure 8 Schematic structure diagram of the integrated two-leaf interventional venous valve with a pipeline in Embodiment 3 of the present invention;

[0038] Figure 9 Experimental results of pulsatile flow and steady flow in the experimental example of the present invention.

[0039] In the drawings, 1-valve stent, 11-first annular grid stent, 12-second annular grid stent, 13-straight rod; 2-valve leaf; 3-skirt; 4-pipeline. Detailed implementation manners

[0040] The embodiments of the technical solutions of the present invention will be described in detail below in conjunction with the embodiments. The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and therefore are only examples and cannot be used to limit the protection scope of the present invention.

[0041] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which the present invention belongs.

[0042] The embodiment of the present invention provides an integrated interventional venous valve, such as Figures 1 - 7As shown, the integrated interventional venous valve includes a valve stent 1, leaflets 2 and a skirt 3; the valve stent 1 includes a first annular grid stent 11, a second annular grid stent 12 and straight rods 13 connecting the first annular grid stent 11 and the second annular grid stent 12; there are 2 to 3 straight rods; the first annular grid stent 11 and the second annular grid stent 12 have shape memory properties and can self-expand in the blood vessel from the compressed state; the skirt 3 covers the inner and outer surfaces of the first annular grid stent 11 and the second annular grid stent 12; the leaflets 2 are arranged on the straight rods 13, and one side of the leaflets 2 is connected to the skirt 3, and the free surface on the other side is arc-shaped.

[0043] In the integrated interventional venous valve of the present invention, by covering the leaflets 2 and the skirt 3 on the inner and outer surfaces of the valve stent 1, the valve stent 1, the leaflets 2 and the skirt 3 do not need to be sutured and fixed and there is no exposure of the metal stent, which solves the problems in the prior art that the preparation process is complex and time-consuming when the leaflets 2 and the valve stent 1 are sutured and fixed, and the suture site after implantation causes early tearing due to interfacial stress concentration, and avoids thrombus formation caused by metal; in addition, through the setting of the material and structure of the valve stent 1 in the present invention, and combined with the bionic arc-shaped free surface of the leaflets 2, the valve stent 1 has deformability, can improve compliance, and further enables the integrated interventional venous valve of the present invention to adapt to the change of blood vessel diameter.

[0044] In one embodiment, the first annular grid stent 11 and the second annular grid stent 12 have the same structure and size.

[0045] The present invention does not specifically limit the materials of the leaflets 2 and the skirt 3, and conventional polymer materials in the art can be used. In one embodiment, the materials of the leaflets 2 and the skirt 3 can be selected from at least one of polyurethane, polycaprolactone, polytetrafluoroethylene and polyethylene glycol.

[0046] In the present invention, the materials of the leaflets 2 and the skirt 3 are high molecular materials, the raw material sources are wide, the preparation process is simple, and the risks of decline and calcification are reduced; the integrated interventional venous valve of the present invention is suitable for interventional operations, avoids traditional surgical incision and suture, and improves the surgical success rate and patient acceptance.

[0047] In one embodiment, as Figure 8 shown, the integrated interventional venous valve further includes a conduit 4 arranged on the outer periphery of the valve stent 1.

[0048] In the present invention, the number of leaflets 2 in the integrated interventional venous valve is not specifically limited, and those skilled in the art can make a conventional selection according to actual needs. Specifically, in one embodiment, when there are 2 straight rods 13, the prepared integrated interventional venous valve can have 1 leaflet 2 (i.e., cutting one side of the film between the 2 straight rods 13 into a leaflet 2), or it can also be 2 leaflets 2 (i.e., cutting the films on both sides between the 2 straight rods 13 into leaflets 2); in one embodiment, when there are 3 straight rods 13, the prepared integrated interventional venous valve has 3 leaflets 2 (i.e., cutting the film between adjacent two straight rods 13 into a leaflet 2).

[0049] In one embodiment, the materials of the first annular grid stent 11 and the second annular grid stent 12 are shape memory alloys, specifically nickel-titanium alloys.

[0050] In one embodiment, the ratio of the maximum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 can be any value in (1 - 3):1; the ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 can be any value in (1 - 6):2; in the present invention, the maximum height of the leaflet 2 refers to the height of the highest point on the free surface of the leaflet 2, and the minimum height of the leaflet 2 refers to the height of the lowest point on the free surface of the leaflet 2.

[0051] Another embodiment of the present invention provides a preparation method of the above integrated interventional venous valve, and this preparation method includes the following steps:

[0052] (1) Dissolve the polymer in an organic solvent to obtain a polymer solution.

[0053] (2) Conduct electroconductive treatment on a cylindrical receiver, and then form an inner film on the surface of the receiver with the polymer solution.

[0054] (3) Put the valve stent 1 on the surface of the inner film, and then form an outer film on the surface of the valve stent with the polymer solution.

[0055] (4) Remove the valve stent 1 covered with the inner film and the outer film and conduct bonding treatment for the fusion of the inner film and the outer film, and then obtain the integrated interventional venous valve after cutting.

[0056] By coating the leaflet 2 and the skirt 3 on the inner and outer surfaces of the valve stent 1 in the above preparation method of the present invention, the valve stent 1 and the leaflet 2 and the skirt 3 do not need to be sutured and fixed and there is no exposed metal stent, solving the problems in the prior art that the preparation process is complex and time-consuming when the leaflet 2 and the valve stent 1 are sutured and fixed, and the suture site causes early tearing due to interfacial stress concentration after implantation.

[0057] In one embodiment, step (4) further includes:

[0058] A conduit 4 is formed around the outer periphery of the cut valve stent 1 with a polymer solution, and then, the skirt 3 on the valve stent 1 is adhesively treated with the conduit 4.

[0059] In the present invention, there are no strict limitations on the formation methods of the inner film, the outer film, and the conduit 4. Those skilled in the art can make conventional selections according to actual needs. In one embodiment, the formation methods of the inner film, the outer film, and the conduit 4 are respectively electrospinning, 3D printing, spin coating, dip coating, spraying, or casting.

[0060] In some embodiments, in step (1), the polymer is selected from at least one of polyurethane, polycaprolactone, polystyrene, polytetrafluoroethylene, and polyethylene glycol; preferably, in one embodiment, the polymer is composed of polyurethane and polycaprolactone, and the concentration of polyurethane in the polymer solution can be 5% - 7%, and the concentration of polycaprolactone can be 1% - 12%.

[0061] In one embodiment, in step (4), the adhesive treatment method is sintering treatment or chemical adhesive treatment; the cutting method is laser cutting.

[0062] In one embodiment, the sintering treatment temperature is 60 - 150 °C, and the time is 0.01 - 2 h.

[0063] In the present invention, there are no specific limitations on the thicknesses of the inner film and the outer film in the above preparation method. Those skilled in the art can make conventional selections according to actual needs. Preferably, in one embodiment, in step (2), the thickness of the inner film can be any value in the range of 30 - 200 μm; in one embodiment, in step (3), the thickness of the outer film can be any value in the range of 30 - 200 μm.

[0064] The technical solutions of the present invention are further described in detail below through specific examples.

[0065] Example 1

[0066] This example is an integrated single - leaf interventional venous valve. As Figures 1 - 4 shown, the integrated single - leaf interventional venous valve includes a valve stent 1, a valve leaf 2, and a skirt 3, and the total length of the valve stent 1 is 50 mm.

[0067] The valve stent 1 includes a first annular grid stent 11, a second annular grid stent 12, and a straight rod 13 connecting the first annular grid stent 11 and the second annular grid stent 12; the first annular grid stent 11 and the second annular grid stent 12 have shape memory properties and can self-expand in the blood vessel from a compressed state; the number of straight rods 13 is 2 and the length is 25 mm; the inner diameters of the first annular grid stent 11 and the second annular grid stent 12 are 12 mm, and the material is nitinol alloy.

[0068] The skirt 3 covers the inner and outer surfaces of the first annular grid stent 11 and the second annular grid stent 12.

[0069] There is one leaflet 2, which is arranged on one side between the two straight rods 13. One side of the leaflet 2 is connected to the skirt 3, and the free surface on the other side is arc-shaped; the ratio of the maximum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 11∶6; the ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 3∶2.

[0070] The preparation method of the above-mentioned integrated single-leaf interventional venous valve includes the following steps:

[0071] (1) Dissolve polyurethane and polycaprolactone in hexafluoroisopropanol to obtain a spinning solution. Among them, the concentration of polyurethane in the spinning solution is 6%, and the concentration of polycaprolactone is 3%.

[0072] (2) Cover a layer of aluminum foil paper on the electrostatic spinning cylindrical receiver, and then form an inner film on the surface of the aluminum foil paper by electrostatic spinning with the spinning solution. Among them, the thickness of the inner film can be 80 μm; the electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage is 14 kV, spinning speed is 2.4 mL / h, humidity is 40%, and temperature is 16 °C.

[0073] (3) Put the valve stent 1 on the surface of the inner film, and then form an outer film on the surface of the valve stent 1 by electrostatic spinning with the spinning solution. Among them, the thickness of the outer film is 80 μm; the electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage is 14 kV, spinning speed is 2.4 mL / h, humidity is 40%, and temperature is 16 °C.

[0074] (4) Take off the valve stent covered with the inner film and the outer film and place it in an oven, sinter at 85 °C for 1 h for the fusion of the inner film and the outer film, and then cut it to obtain an integrated single-leaf interventional venous valve.

[0075] Example 2

[0076] This example is an integrated two-leaf interventional venous valve, such as Figures 1 - 2 、 Figures 5 - 7As shown in the figure, the one-piece two-leaf interventional venous valve includes a valve stent 1, leaflets 2, and a skirt 3. The total length of the valve stent 1 is 50 mm.

[0077] The valve stent 1 includes a first annular grid stent 11, a second annular grid stent 12, and a straight rod 13 connecting the first annular grid stent 11 and the second annular grid stent 12. The first annular grid stent 11 and the second annular grid stent 12 have shape memory properties and can self-expand in the blood vessel from the compressed state. The number of straight rods 13 is 2, and the length is 25 mm. The inner diameters of the first annular grid stent 11 and the second annular grid stent 12 are 12 mm, and the material is nitinol.

[0078] The skirt 3 covers the inner and outer surfaces of the first annular grid stent 11 and the second annular grid stent 12.

[0079] There are two leaflets 2, which are respectively arranged on both sides between the two straight rods 13. One side of the leaflet 2 is connected to the skirt 3, and the free surface on the other side is arc-shaped. The ratio of the maximum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 11∶6. The ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 1∶1.

[0080] The preparation method of the above one-piece two-leaf interventional venous valve includes the following steps:

[0081] (1) Dissolve polyurethane and polycaprolactone in hexafluoroisopropanol to obtain a spinning solution. Among them, the concentration of polyurethane in the spinning solution is 6%, and the concentration of polycaprolactone is 3%.

[0082] (2) Cover a layer of aluminum foil paper on the electrostatic spinning cylindrical receiver, and then form an inner layer film on the surface of the aluminum foil paper by electrostatic spinning with the spinning solution. Among them, the thickness of the inner layer film can be 80 μm. The electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 16 °C.

[0083] (3) Put the valve stent 1 on the surface of the inner layer film, and then form an outer layer film on the surface of the valve stent 1 by electrostatic spinning with the spinning solution. Among them, the thickness of the outer layer film is 80 μm. The electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 16 °C.

[0084] (4) Remove the valve stent covered with the inner layer film and the outer layer film and place it in an oven, sinter at 85 °C for 1 h for the fusion of the inner layer film and the outer layer film, and then cut it to obtain the one-piece two-leaf interventional venous valve.

[0085] Example 3

[0086] This embodiment is an integrated interventional venous valve with a conduit, as Figures 1 - 2 , Figures 5 - 8 shown. The above-mentioned integrated interventional venous valve with a conduit includes a valve stent 1, leaflets 2, a skirt 3, and a conduit 4. The total length of the valve stent 1 is 50 mm.

[0087] The valve stent 1 includes a first annular grid stent 11, a second annular grid stent 12, and straight rods 13 connecting the first annular grid stent 11 and the second annular grid stent 12; the first annular grid stent 11 and the second annular grid stent 12 have shape memory properties and can self-expand in the blood vessel from the compressed state; the number of straight rods 13 is 2, and the length is 25 mm; the inner diameters of the first annular grid stent 11 and the second annular grid stent 12 are 12 mm, and the material is nitinol.

[0088] The skirt 3 covers the inner and outer surfaces of the first annular grid stent 11 and the second annular grid stent 12.

[0089] There are two leaflets 2, which are respectively arranged on both sides between the two straight rods 13. One side of the leaflet 2 is connected to the skirt 3, and the free surface on the other side is arc-shaped; the ratio of the maximum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 11∶6; the ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid stent 11 is 1∶1.

[0090] The conduit 4 is arranged on the outer periphery of the leaflets 2 and the skirt 3 on the valve stent 1.

[0091] The preparation method of the above-mentioned integrated interventional venous valve with a conduit includes the following steps:

[0092] (1) Dissolve polyurethane and polycaprolactone in hexafluoroisopropanol to obtain a spinning solution. Among them, the concentration of polyurethane in the spinning solution is 6%, and the concentration of polycaprolactone is 3%.

[0093] (2) Cover a layer of aluminum foil on the electrostatic spinning cylindrical receiver, and then form an inner layer film on the surface of the aluminum foil by electrostatic spinning with the spinning solution. Among them, the thickness of the inner layer film can be 80 μm; the electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage is 14 kV, spinning speed is 2.4 mL / h, humidity is 40%, and temperature is 16°C.

[0094] (3) Put the valve stent 1 on the surface of the inner layer film, and then form an outer layer film on the surface of the valve stent 1 by electrostatic spinning with the spinning solution. Among them, the thickness of the outer layer film is 80 μm; the electrostatic spinning parameters are as follows: 21G spinneret needle, set voltage is 14 kV, spinning speed is 2.4 mL / h, humidity is 40%, and temperature is 16°C.

[0095] (4) The valve stent 1 covered with the inner film and the outer film is removed and placed in an oven, sintered at 85°C for 1 hour to fuse the inner film and the outer film, and then cut; then, the cut valve stent 1 is placed in an electrospinning conductive receiver, and then a peripheral channel 4 is formed on the surface of the valve stent 1 by electrospinning; aluminum foil is embedded between the channel 4 and the leaflet 2 to prevent the leaflet 2 and the channel 4 from fusing during the subsequent sintering process, and then placed in an oven and sintered at 85°C for 1 hour to fuse the skirt 3 on the valve stent 1 with the channel 4, thereby obtaining an integrated interventional venous valve with a channel.

[0096] Experimental example

[0097] This experimental case is a study on the performance of one-piece interventional venous valves with different leaflet morphologies:

[0098] Different venous valve leaflet morphologies were prepared according to the preparation method of the above embodiment, specifically four types of venous valves with an interface height (i.e., the highest point height on the leaflet free surface between the first mesh stent and the second mesh stent) of 22 mm and a minimum free surface height (i.e., the lowest point height on the leaflet free surface) of 10, 12, 14 and 16 mm, respectively, which were recorded as 1 to 4.

[0099] Pulsatile flow and steady-state flow experiments were used to study the effects of four leaflets with different free surface morphologies on venous valve performance. The pulsating flow experiment simulated the human body in three states of low, medium, and high intensity motion, and found the venous valve configuration with the best overall performance.

[0100] The results of the pulsating flow experiment are as follows Figure 9 As shown by Figure 9 It can be seen that the average effective opening area (EOA) of the four valves in the three states is greater than 40%, among which the venous valve with a minimum free surface height of 12 mm has the largest EOA; the average regurgitant fraction (TRF) of the four valves in the three states is lower than 20%, among which the venous valves with a minimum free surface height of 12 and 14 mm have better TRF performance.

[0101] The four valves can open normally under forward pressures below 5 mmHg. As the forward pressure increases, the forward flow of all valves gradually increases; as the height of the lowest part of the valve arc increases, the forward flow decreases. Under the four different leaflet configurations, the closing time of the valve is less than 0.5 seconds.

[0102] Based on the results of pulsatile flow and steady-state flow tests, the venous valve has a curved leaflet with a minimum free surface height of 12-14 mm and an interface height of 22 mm, and has more excellent hemodynamic characteristics. The performance of the venous valve is in line with the general consensus on venous valve preparation.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered within the scope of the claims and the description of the present invention.

Claims

1. An integrated interventional venous valve, characterized in that, The integrated interventional venous valve includes a valve stent, leaflets and a skirt; The valve stent includes a first annular grid stent, a second annular grid stent and straight rods connecting the first annular grid stent and the second annular grid stent; there are 2 to 3 straight rods; the first annular grid stent and the second annular grid stent have shape memory characteristics and can self-expand in the blood vessel from a compressed state; The skirt covers the inner and outer surfaces of the first annular grid stent and the second annular grid stent; The leaflets are arranged on the straight rods, and one side of the leaflets is connected to the skirt, and the free surface on the other side is arc-shaped.

2. The integrated interventional venous valve according to claim 1, wherein The integrated interventional venous valve further includes a conduit arranged on the outer periphery of the valve stent.

3. The one-piece interventional venous valve according to claim 1, characterized in that, The materials of the first annular grid stent and the second annular grid stent are shape memory alloys.

4. The one-piece interventional venous valve according to claim 1, characterized in that, The ratio of the maximum height of the leaflets to the inner diameter of the first annular grid stent is (1 to 3):1; the ratio of the minimum height of the leaflets to the inner diameter of the first annular grid stent is (1 to 6):

2.

5. A preparation method of an integrated interventional venous valve, characterized in that, The preparation method includes the following steps: (1) Dissolve the polymer in an organic solvent to obtain a polymer solution; (2) Conduct conductive treatment on a cylindrical receiver, and then form an inner layer film on the surface of the receiver with the polymer solution; (3) Put the valve stent on the surface of the inner layer film, and then form an outer layer film on the surface of the valve stent with the polymer solution; (4) Remove the valve stent covered with the inner layer film and the outer layer film and conduct bonding treatment for the fusion of the inner layer film and the outer layer film, and then cut to obtain the integrated interventional venous valve.

6. The preparation method according to claim 5, wherein The step (4) further includes: Form a conduit on the outer periphery of the cut valve stent with the polymer solution, and then bond the skirt on the valve stent to the conduit.

7. The preparation method according to claim 5, characterized in that In the step (1), the polymer is selected from at least one of polyurethane, polycaprolactone, polystyrene, polytetrafluoroethylene and polyethylene glycol.

8. The preparation method according to claim 5, characterized in that, In the step (4), the bonding treatment method is sintering treatment or chemical bonding treatment; The cutting method is laser cutting.

9. The preparation method according to claim 8, characterized in that, The sintering treatment temperature is 60 to 150 °C, and the time is 0.01 to 2 h.

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