An integrated interventional venous valve and its preparation method

Abstract

The present invention discloses an integrated interventional venous valve and a preparation method thereof, wherein the integrated interventional venous valve includes a valve support, leaflets and a skirt; the valve support includes a first annular grid support, a second annular grid support and a straight rod connecting the first annular grid support and the second annular grid support; the skirt covers the inner and outer surfaces of the first annular grid support and the second annular grid support; the leaflets are arranged on the straight rod, and one side of the leaflets is connected to the skirt, and the free surface of the other side is arc-shaped; in the integrated interventional venous valve of the present invention, the leaflets and the skirt cover the inner and outer surfaces of the valve support, so that the valve support and the leaflets and the skirt do not need to be sutured and fixed, thereby solving the tediousness of split processing and the potential risk of tearing, and through the setting of the material and structure of the valve support, and combined with the bionic arc shape of the free surface of the leaflets, the integrated interventional venous valve can adapt to changes in blood vessel diameter.

Description

Technical Field

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

[0002] For severe deep vein valvular insufficiency, conventional treatments include valvuloplasty and venous wall circumference reduction surgery, but these two treatments are not very effective. Valve replacement therapy is one of the treatments with clinical prospects, but there is no marketed product.

[0003] Furthermore, current transcatheter prosthetic heart valves in clinical use generally adopt a split design, with leaflets often made of biomaterials such as bovine pericardium, which have poor durability. The leaflets are secured to the metal stent via sutures, a complex and time-consuming preparation process. This can also lead to premature tearing at the suture site after implantation due to interfacial stress concentration. Under long-term cyclic loading, suture breakage can easily cause leaflet prolapse, and interfacial calcification can accelerate structural degradation.

[0004] For example, the Chinese patent application with patent application number CN202221974757.7 discloses a leaflet structure and an artificial venous valve, specifically disclosing that the artificial venous valve includes a stent, a sealing membrane and a leaflet structure, the suture edge of the leaflet structure is sutured and fixed to the stent, the sealing membrane is sutured to the stent, the sealing membrane is sleeved on the periphery of the leaflet structure, and the sealing membrane is sealed and connected to the leaflet structure; it can be seen that the above-mentioned artificial venous valve requires the leaflet structure and the sealing membrane to be sutured to the stent, and there is a problem of suture line breakage leading to prolapse of the leaflet and the sealing membrane, and the free surface of the leaflet of the above-mentioned artificial venous valve cannot be biomimetic into an arc shape, and the stent structure is complex and inelastic, and cannot adapt to changes in blood vessel diameter, which can easily cause damage to the blood vessel.

[0005] For example, Chinese patent application number CN200520039624.0 discloses a venous valve substitute, which specifically 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 outer side of the artificial valve body. It can be seen that in the above-mentioned venous valve substitute, the artificial valve needs to be sutured to the wire stent, and there is also the problem of suture line breakage leading to artificial valve prolapse.

[0006] For example, the U.S. patent applications with patent application numbers US20230363901A1 and US20230363914A1 disclose a transcatheter anti-reflux venous valve system, which specifically discloses a valve frame, leaflets and skirt structure, and the valve involves suturing operations in multiple locations. The leaflets of this system are made of continuous biological tissue, usually porcine pericardial tissue, and are formed into a single-cusp valve shape through a folding process. The edges are sutured, and the inflow skirt is connected to the valve wall. The same biological tissue material as the leaflets is used, and the shape is mostly rectangular or square. In addition, the connection between the leaflets and the stent requires suturing. It can be seen that the above-mentioned artificial venous valve requires suturing the leaflet structure and the sealing membrane to the stent, and there is also the problem of suture line breakage causing the leaflet and sealing membrane to prolapse; and the leaflets of the above-mentioned artificial venous valve are single leaflets, which are very different from the morphology of human venous valves; at the same time, the leaflet material is porcine pericardial tissue, which also has the disadvantages of high risk of thrombosis and calcification and limited source.

[0007] Although there have been some studies on artificial venous valves, such as autologous valved segment grafts, allogeneic valved grafts, and metal and bioprosthetic venous valve grafts, most of these have not achieved satisfactory results and have not entered clinical application. These materials still face several technical challenges, such as thrombosis, intimal hyperplasia, leaflet stiffness, device collapse and embolism, vessel diameter mismatch, bleeding problems caused by anticoagulants, graft tilting and migration, and other serious complications, which limit their widespread clinical application and long-term effectiveness. Currently, only one foreign venous valve (VenoValve, patent number US11872126B2) has entered the clinical trial stage. This valve is a surgically implanted valve with a single leaflet that needs to be sutured to a metal frame. Currently, there are no reports of venous valve products in China. Summary of the Invention

[0008] The purpose of the present invention is to provide an integrated interventional venous valve and a preparation method thereof. In the integrated interventional venous valve of the present invention, the leaflets and skirt are covered on the inner and outer surfaces of the valve stent, and through chemical bonding and high-temperature sintering, the valve stent and the leaflets and skirt do not need to be sutured and fixed, thereby solving the cumbersomeness of split processing and the potential risk of tearing. Moreover, through the setting of the material and structure of the valve stent, and combined with the bionic arc shape of the free surface of the leaflets, the integrated interventional venous valve can adapt to changes in blood vessel diameter.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0010] A first aspect of the present invention provides an integrated interventional venous valve, which includes a valve stent, a leaflet and a skirt; the valve stent includes a first annular grid stent, a second annular grid stent and a straight rod 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 properties and can self-expand from a compressed state within a blood vessel; the skirt covers the inner and outer surfaces of the first annular grid stent and the second annular grid stent; the leaflet is arranged on the straight rod, and one side of the leaflet is connected to the skirt, and the free surface of the other side is arc-shaped.

[0011] In the present invention, there is no specific limitation on the mesh shapes of the first annular mesh stent and the second annular mesh stent. Conventional shapes in the art may be used, such as a diamond shape or a V shape. Other mesh shapes that enable the first annular mesh stent and the second annular mesh stent to contract and expand (compress and release) may also be used.

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

[0013] Preferably, the first annular grid support and the second annular grid support are made of shape memory alloy.

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

[0015] A second aspect of the present invention provides a method for preparing an integrated interventional venous valve, the method comprising the following steps:

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

[0017] (2) Conductive treatment is performed on the cylindrical receiver, and then an inner layer film is formed on the surface of the receiver with a polymer solution.

[0018] (3) The valve stent is placed on the surface of the inner film, and then a polymer solution is used to form an outer film on the surface of the valve stent.

[0019] (4) The valve stent covered with the inner film and the outer film is removed and bonded to fuse the inner film and the outer film, and then cut to obtain the integrated interventional venous valve.

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

[0021] A polymer solution is used to form a tube around the cut valve stent, and then the skirt on the valve stent is bonded to the tube.

[0022] Preferably, the inner film, the outer film and the pipeline are formed by any one of electrospinning, 3D printing, spin coating, dip coating, spraying and casting.

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

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

[0025] The cutting method is laser cutting.

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

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

[0028] In the integrated interventional venous valve of the present invention, the leaflets and skirt are covered on the inner and outer surfaces of the valve stent, so that the valve stent, the leaflets and the skirt do not need to be fixed by suturing and no metal stent is exposed, which solves the problem of the leaflets and the valve stent being fixed by suturing in the prior art, which has a complex and time-consuming preparation process, and leads to early tearing of the suture site after implantation due to interface stress concentration and avoids thrombosis caused by metal; in addition, the present invention makes the valve stent radially adaptable by setting the material and structure of the valve stent, and combines the free surface of the leaflet with a bionic arc shape, so that the compliance can be improved, thereby enabling the integrated interventional venous valve of the present invention to adapt to changes in blood vessel diameter; in addition, the leaflets and skirt of the present invention are made of polymer materials with a wide range of raw material sources, and the preparation process is simple, with a low risk of decay and calcification; the integrated interventional venous valve of the present invention is suitable for interventional operations, avoiding traditional surgical incision and suturing, and improving the success rate of surgery and patient acceptance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0030] Figure 1 This is a structural side view of a valve stent according to an embodiment of the present invention;

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

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

[0033] Figure 4 This is a side view of the integrated single-leaflet interventional venous valve in Example 1 of the present invention;

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

[0035] Figure 6 This is a side view of the integrated bileaflet interventional venous valve in Example 2 of the present invention;

[0036] Figure 7 1. A top view of the integrated bileaflet interventional venous valve according to Example 2 of the present invention;

[0037] Figure 8 This is a schematic structural diagram of an integrated bileaflet interventional venous valve with a conduit in Example 3 of the present invention;

[0038] Figure 9 These are the experimental results of pulsating flow and steady-state flow in the experimental examples of the present invention.

[0039] In the accompanying drawings, 1-valve stent, 11-first annular grid stent, 12-second annular grid stent, 13-straight rod; 2-leaflet; 3-skirt; 4-pipe. DETAILED DESCRIPTION

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

[0041] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common 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 to 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 a straight rod 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 from a compressed state in the blood vessel; 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 rod 13, and one side of the leaflet 2 is connected to the skirt 3, and the free surface of the other side is arc-shaped.

[0043] In the integrated interventional venous valve of the present invention, the leaflets 2 and the skirt 3 are covered on the inner and outer surfaces of the valve stent 1, so that the valve stent 1 and the leaflets 2 and the skirt 3 do not need to be fixed by suturing and no metal stent is exposed, thereby solving the problem of complex and time-consuming preparation process in the prior art of fixing the leaflets 2 and the valve stent 1 by suturing, and causing early tearing due to interface stress concentration at the suture site after implantation, and avoiding thrombosis caused by metal; in addition, the present invention makes the valve stent 1 deformable by setting the material and structure of the valve stent 1, and combines the free surface of the leaflet 2 with a bionic arc shape, so that the valve stent 1 can improve compliance, thereby enabling the integrated interventional venous valve of the present invention to adapt to changes in blood vessel diameter.

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

[0045] The present invention does not specifically limit the material of the leaflet 2 and the skirt 3, and conventional polymer materials in the field can be used. In one embodiment, the material of the leaflet 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 leaflet 2 and the skirt 3 are made of polymer materials, which have a wide range of raw material sources, and the preparation process is simple and reduces the risk of decline and calcification; the integrated interventional venous valve of the present invention is suitable for interventional operations, avoiding traditional surgical incision and suturing, and improving the success rate of the operation and patient acceptance.

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

[0048] The present invention does not specifically limit the number of leaflets 2 in the integrated interventional venous valve, and those skilled in the art can make routine selections based on actual needs. Specifically, in one embodiment, if there are two straight rods 13, the corresponding integrated interventional venous valve prepared can have one leaflet 2 (that is, the film on one side between the two straight rods 13 is cut into a leaflet 2), or two leaflets 2 (that is, the film on both sides between the two straight rods 13 is cut into leaflets 2 respectively); in one embodiment, if there are three straight rods 13, the corresponding integrated interventional venous valve prepared has three leaflets 2 (that is, the film between two adjacent straight rods 13 is cut into leaflets 2).

[0049] In one embodiment, the first annular lattice support 11 and the second annular lattice support 12 are made of a shape memory alloy, specifically nickel-titanium alloy.

[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 the range of (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 the range of (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 method for preparing the above-mentioned integrated interventional venous valve, the method comprising the following steps:

[0052] (1) The polymer is dissolved in an organic solvent to obtain a polymer solution.

[0053] (2) Conductive treatment is performed on the cylindrical receiver, and then an inner layer film is formed on the surface of the receiver with a polymer solution.

[0054] (3) The valve stent 1 is placed on the surface of the inner film, and then a polymer solution is used to form an outer film on the surface of the valve stent.

[0055] (4) The valve stent 1 covered with the inner film and the outer film is removed and bonded to fuse the inner film and the outer film, and then cut to obtain an integrated interventional venous valve.

[0056] The above-mentioned preparation method of the present invention covers the leaflets 2 and skirt 3 on the inner and outer surfaces of the valve stent 1, so that the valve stent 1 and the leaflets 2 and skirt 3 do not need to be fixed by suturing and no metal stent is exposed, thereby solving the problem in the prior art that the leaflets 2 and the valve stent 1 are fixed by suturing, the preparation process is complicated and time-consuming, and the problem that the suture site after implantation causes early tearing due to interface stress concentration.

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

[0058] A polymer solution is used to form a tube 4 around the cut valve stent 1 , and then the skirt 3 on the valve stent 1 is bonded to the tube 4 .

[0059] In the present invention, there is no strict limitation on the formation methods of the inner film, the outer film and the tube 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 tube 4 are electrospinning, 3D printing, spin coating, dip coating, spraying or casting, respectively.

[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 consists of polyurethane and polycaprolactone, and the concentration of polyurethane in the polymer solution may be 5% to 7%, and the concentration of polycaprolactone may be 1% to 12%.

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

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

[0063] In the present invention, the thickness of the inner film and the outer film in the above-mentioned preparation method is not specifically limited. Those skilled in the art can make routine selections according to actual needs. Preferably, in one embodiment, in step (2), the thickness of the inner film can be any value between 30 and 200 μm; in one embodiment, in step (3), the thickness of the outer film can be any value between 30 and 200 μm.

[0064] The technical solution of the present invention is further described in detail below through specific embodiments.

[0065] Example 1

[0066] This embodiment is an integrated single-leaflet interventional venous valve. Figures 1 to 4 As shown, the integrated single-leaflet interventional venous valve includes a valve stent 1, a leaflet 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 from a compressed state within the blood vessel; there are two straight rods 13, each 25 mm long; the inner diameter of the first annular grid stent 11 and the second annular grid stent 12 is 12 mm, and the material is nickel-titanium alloy.

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

[0069] The leaflet 2 is one and is arranged on one side between the two straight rods 13, and 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 bracket 11 is 11:6; the ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid bracket 11 is 3:2.

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

[0071] (1) Polyurethane and polycaprolactone are dissolved in hexafluoroisopropanol to obtain a spinning solution, wherein the concentration of polyurethane in the spinning solution is 6% and the concentration of polycaprolactone is 3%.

[0072] (2) A layer of aluminum foil is covered on the electrospinning cylindrical receiver, and then the spinning solution is electrospun to form an inner film on the surface of the aluminum foil, wherein the thickness of the inner film can be 80 μm; the electrospinning parameters are as follows: 21G spinneret, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 16 °C.

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

[0074] (4) The valve stent 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 to produce an integrated single-leaflet interventional venous valve.

[0075] Example 2

[0076] This embodiment is an integrated bi-leaflet interventional venous valve. Figures 1 and 2 、 Figures 5-7As shown, the integrated bileaflet interventional venous valve includes a valve support 1, leaflets 2 and a skirt 3, and the total length of the valve support 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 from a compressed state within the blood vessel; there are two straight rods 13, each 25 mm long; the inner diameter of the first annular grid stent 11 and the second annular grid stent 12 is 12 mm, and the material is nickel-titanium alloy.

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

[0079] There are two leaflets 2, which are respectively arranged on both sides between the two straight rods 13, and one side of the leaflet 2 is connected to the skirt 3, and the free surface of 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 bracket 11 is 11:6; the ratio of the minimum height of the leaflet 2 to the inner diameter of the first annular grid bracket 11 is 1:1.

[0080] The preparation method of the above-mentioned integrated bileaflet interventional venous valve comprises the following steps:

[0081] (1) Polyurethane and polycaprolactone are dissolved in hexafluoroisopropanol to obtain a spinning solution, wherein the concentration of polyurethane in the spinning solution is 6% and the concentration of polycaprolactone is 3%.

[0082] (2) A layer of aluminum foil is covered on the electrospinning cylindrical receiver, and then the spinning solution is electrospun to form an inner film on the surface of the aluminum foil, wherein the thickness of the inner film can be 80 μm; the electrospinning parameters are as follows: 21G spinneret, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 16 °C.

[0083] (3) The valve stent 1 is placed on the surface of the inner film, and then the spinning solution is electrospun to form an outer film on the surface of the valve stent 1, wherein the thickness of the outer film is 80 μm; the electrospinning parameters are as follows: 21G spinneret, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 16 °C.

[0084] (4) The valve stent 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 to produce an integrated bileaflet interventional venous valve.

[0085] Example 3

[0086] This embodiment is an integrated interventional venous valve with a pipeline, such as Figures 1 and 2 、 Figures 5-8 As shown, the above-mentioned integrated interventional venous valve with a pipeline includes a valve stent 1, leaflets 2, a skirt 3 and a pipeline 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 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 from a compressed state within the blood vessel; there are two straight rods 13, each 25 mm long; the inner diameter of the first annular grid stent 11 and the second annular grid stent 12 is 12 mm, and the material is nickel-titanium alloy.

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

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

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

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

[0092] (1) Polyurethane and polycaprolactone are dissolved in hexafluoroisopropanol to obtain a spinning solution, wherein the concentration of polyurethane in the spinning solution is 6% and the concentration of polycaprolactone is 3%.

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

[0094] (3) The valve stent 1 is placed on the surface of the inner film, and then the spinning solution is electrospun to form an outer film on the surface of the valve stent 1, wherein the thickness of the outer film is 80 μm; the electrospinning parameters are as follows: 21G spinneret, set voltage of 14 kV, spinning speed of 2.4 mL / h, humidity of 40%, and temperature of 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 the peripheral channel 4 is formed on the surface of the valve stent 1 by electrospinning; aluminum foil is pre-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 studies the performance of integrated 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 pulsatile flow experiment simulated the human body in three motion states of low, medium, and high intensity, 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 less than 20%, among which the venous valves with a minimum free surface height of 12 and 14 mm have better TRF performance.

[0101] All four valves opened normally at forward pressures below 5 mmHg. With increasing forward pressure, forward flow increased for all valves, but decreased as the lowest point of the valve arc increased. The valve closure time was less than 0.5 seconds for all four leaflet configurations.

[0102] Based on the results of pulsatile flow and steady-state flow tests, the curved leaflet with a minimum free surface height of 12~14mm and an interface height of 22mm has better hemodynamic characteristics, and 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. An integrated interventional venous valve, characterized in that: The integrated interventional venous valve comprises a valve support, a valve leaflet and a skirt: The valve stent comprises a first annular lattice stent, a second annular lattice stent, and straight rods connecting the first annular lattice stent and the second annular lattice stent; the straight rods are 2 to 3; the first annular lattice stent and the second annular lattice stent have shape memory properties and can self-expand from a compressed state within a blood vessel; The skirt is covered on the inner and outer surfaces of the first annular grid support and the second annular grid support; The leaflet is arranged on the straight rod, and one side of the leaflet is connected to the skirt, and the free surface of the other side is arc-shaped; The method for preparing the integrated interventional venous valve comprises the following steps: (1) dissolving the polymer in an organic solvent to obtain a polymer solution; (2) Conductive treatment is performed on the cylindrical receiver, and then an inner layer film is formed on the surface of the receiver with a polymer solution; (3) The valve stent is placed on the surface of the inner film, and then a polymer solution is used to form an outer film on the surface of the valve stent; (4) The valve stent covered with the inner film and the outer film is removed and bonded to fuse the inner film and the outer film, and then cut to obtain the integrated interventional venous valve.

2. The integrated interventional venous valve according to claim 1, characterized in that: The integrated interventional venous valve further includes a pipeline arranged on the periphery of the valve stent.

3. The integrated interventional venous valve according to claim 1, characterized in that: The first annular grid support and the second annular grid support are made of shape memory alloy.

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

2.

5. The integrated interventional venous valve according to claim 1, characterized in that: Said step (4) further comprises: A polymer solution is used to form a tube around the cut valve stent, and then the skirt on the valve stent is bonded to the tube.

6. The integrated interventional venous valve according to claim 1, characterized in that: In the step (1), the polymer is selected from at least one of polyurethane, polycaprolactone, polystyrene, polytetrafluoroethylene and polyethylene glycol.

7. The integrated interventional venous valve according to claim 1, characterized in that: In the step (4), the bonding treatment method is sintering treatment or chemical bonding treatment; The cutting method is laser cutting.

8. The integrated interventional venous valve according to claim 7, characterized in that: The sintering treatment temperature is 60-150° C., and the sintering time is 0.01-2 hours.

Images