Venous valve stent and venous valve prosthesis

Abstract

The present invention provides a venous valve stent and a venous valve prosthesis. The venous valve stent includes a stent body and a sinus cavity frame; the stent body is in a hollow cylindrical structure and is radially expandable and contractible; a window is provided on the side of the stent body; the sinus cavity frame has a relative fixed end and a free end; the fixed end is connected to the window; the free end extends outside the stent body; a sinus area is formed inside the sinus cavity frame, and the sinus area communicates with the inside of the stent body through the window. The venous valve prosthesis includes a valve and the venous valve stent, the valve is fixed inside the stent body and covers at least part of the area of the sinus area, and the side of the valve facing away from the sinus area is a free edge. The present invention can improve the reliability of the one-way conduction function, avoid excessive stimulation to blood vessels, and is also convenient for manufacturing.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a venous valve stent and a venous valve prosthesis. Background Art

[0002] Venous surgical diseases are common surgical diseases, mostly occurring in the lower extremities. Their main clinical manifestations are varicose veins, limb swelling, and trophic lesions of the skin in the gaiter area, such as dermatitis, pigmentation, and ulcer formation. The main pathological reason is that under the action of pathogenic factors, the venous valves lose their basic function of one-way opening. Venous diseases can, to a lesser extent, interfere with the ability to live and work, and to a greater extent, can cause varying degrees of disability. Therefore, the treatment of lower extremity venous valve diseases has been increasingly emphasized. Currently, most of these diseases are still treated conservatively in clinical practice, such as drug treatment, pressure pumps, etc., and surgical treatments such as femoral vein valve repair and reconstruction surgery, etc., and the clinical effects are not ideal. Especially for patients with severely damaged venous valves or congenital valveless disease, venous valve transplantation seems to be the only available method.

[0003] Currently, autologous valved iliac vein prosthesis or popliteal vein prosthesis transplantation is commonly used in clinical practice. The prosthesis is implanted into the venous blood vessel, the stent of the prosthesis fits with the blood vessel, and a blood passage is constructed inside the stent. The valve located inside the stent can open or close the passage to achieve the one-way opening function. However, in such a structure, local thrombosis is likely to form between the valve and the stent. In addition, the valve is also prone to degeneration and insufficient anti-reflux ability. In the long term, the effect is not ideal. Summary of the Invention

[0004] The purpose of the present invention is to provide a venous valve stent and a venous valve prosthesis with better reliability.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] According to one aspect of the present invention, the present invention provides a venous valve stent, including a stent body and a sinus cavity frame; the stent body is in a hollow cylindrical structure and can be radially expanded and contracted; a window is provided on the side of the stent body; the sinus cavity frame has a fixed end and a free end opposite to each other; the fixed end is connected to the window; the free end extends outside the stent body; a sinus area is formed inside the sinus cavity frame, and the sinus area communicates with the inside of the stent body through the window.

[0007] In some embodiments, in the radial direction of the stent body, the free end does not extend beyond the outermost side of the remaining part of the sinus cavity frame except the free end.

[0008] In some embodiments, in the direction from the fixed end to the free end along the axis of the stent body, the sinus cavity frame includes a first extension section and a second extension section. The distance from the first extension section to the central axis of the stent body gradually increases. The junction of the first extension section and the second extension section is the outermost side of the sinus cavity frame, and the end of the second extension section is the free end.

[0009] In some embodiments, in the direction from the outermost side to the free end, the distance from the second extension section to the central axis of the stent body gradually decreases.

[0010] In some embodiments, in the direction from the outermost side to the free end, the decreasing speed of the distance from the second extension section to the central axis of the stent body gradually increases.

[0011] In some embodiments, the second extension section extends linearly.

[0012] In some embodiments, the distance from the second extension section to the central axis of the stent body remains unchanged.

[0013] In some embodiments, in the direction from the fixed end to the outermost side, the increasing speed of the distance from the first extension section to the central axis of the stent body gradually decreases.

[0014] In some embodiments, the first extension section extends linearly.

[0015] In some embodiments, the sinus cavity frame includes a first strut and a second strut. The first ends of the first strut and the second strut are separated and serve as the fixed ends respectively connected to the fenestration. The second ends of the first strut and the second strut are joined to form the free end.

[0016] In some embodiments, the second ends of the first strut and the second strut are directly connected.

[0017] In some embodiments, the sinus cavity frame further includes a cross bar. The cross bar extends circumferentially along the stent body, and the two ends of the cross bar are respectively connected to the second ends of the first strut and the second strut.

[0018] In some embodiments, in the direction from the first end to the second end, the first strut and the second strut gradually approach each other.

[0019] In some embodiments, the included angle between the first strut and the second strut is 30° - 90°.

[0020] In some embodiments, the first strut and the second strut are symmetric.

[0021] In some embodiments, the window is located in the axial middle region of the stent body.

[0022] In some embodiments, the length of the sinus cavity support along the axial direction of the stent body is greater than half of the length of the window along the axial direction of the stent body.

[0023] In some embodiments, the bracket body includes two support bodies arranged at intervals and a plurality of columns connected between the two support bodies; the support body is in the shape of a circumferentially closed cylinder; the two support bodies are coaxially arranged and spaced opposite to each other along the axial direction; the plurality of columns are circumferentially spaced around the central axis of the support body; the window is formed in the interval between two adjacent columns.

[0024] In some embodiments, the support body includes a plurality of axially connected wave circles; each wave circle has staggered crests and troughs along the circumferential direction, and the crests and troughs of two adjacent wave circles are connected to form a grid; the column is connected to the opposite crests and troughs of the two support bodies.

[0025] In some embodiments, the column is linear and extends along the axial direction of the bracket body.

[0026] In some embodiments, the support body is an integrated structure, the entire peripheral wall thereof is mesh-shaped, and the window is provided on the peripheral wall.

[0027] In some embodiments, the number of the windows is multiple and distributed along the circumference of the stent body; the sinus cavity stents are multiple and connected to the windows one by one.

[0028] According to another aspect of the present invention, the present invention provides a venous valve prosthesis, comprising a valve and a venous valve stent as described above; the valve is fixed in the stent body and covers at least a portion of the sinus area; the valve has a free edge, and the free edge is located on the side of the valve away from the sinus area.

[0029] In some embodiments, the venous valve prosthesis further comprises a film, which covers the entire circumferential wall of the venous valve stent.

[0030] It can be seen from the above technical scheme that the present invention has at least the following advantages and positive effects: in the venous valve stent of the present invention, the stent body is a radially retractable cylindrical structure, so the venous valve stent can be placed in a delivery catheter in a contracted state before being implanted in the human body, so that it can be delivered to the vein by the delivery catheter, and the surgical incision is small. After being implanted in the human body, the stent body is radially expanded and anchored in the blood vessel by self-expansion, and a channel for blood to pass through is constructed in the stent body, and it can cooperate with the valve loaded in the venous valve stent to reconstruct the unidirectional conduction function of the vein and prevent venous blood from flowing back.

[0031] In particular, the venous valve stent has a sinus cavity frame that protrudes outward relative to the stent body, and a sinus region is formed inside the sinus cavity frame. The venous valve stent is loaded with a valve, and a vortex can be formed in the sinus region during blood reflux. Based on the vortex formed in the sinus region, when the blood flows in the forward direction, the acting force of the forward-flowing blood on the valve is balanced with the pressure generated by the vortex, enabling the valve leaflets to float without contacting the venous valve stent, reducing the risk of leaflet adhesion; and when the blood flows in the reverse direction, the reverse-flowing blood impacts the floating leaflets rather than the leaflets that are in contact with the venous valve stent, making it easier for the leaflets to deform in the direction of closing the blood flow channel and quickly closing the channel, improving the sensitivity and reliability of the one-way opening function. At the same time, under the action of the vortex in the sinus region, the reverse-flowing blood can be guided to flow back towards the heart direction, effectively avoiding blood accumulation and reducing the risk of local thrombus formation.

[0032] Furthermore, in this solution, the free end of the sinus cavity frame extends outside the stent body, making the sinus cavity frame elastic in the radial direction, which can avoid excessive stimulation of the blood vessel by the sinus cavity frame, reduce damage to the blood vessel, and prevent excessive proliferation of the vascular intima. At the same time, the sinus cavity frame is connected to the window opening of the stent body through its fixed end, and the structural shape of the sinus cavity frame is not restricted by the stent body, facilitating the manufacture of the sinus cavity frame and its connection with the stent body, and also facilitating maintaining the structural form of the sinus cavity frame protruding outside the stent body to maintain the stability of the sinus region after implantation in the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of the first embodiment of the venous valve prosthesis of the present invention.

[0034] Figure 2 is Figure 1 the front view of

[0035] Figure 3 is Figure 1 the top view of

[0036] Figure 4 is Figure 1 the schematic structural diagram after removing the film.

[0037] Figure 5 is Figure 1 the front view of the venous valve stent in

[0038] Figure 6 is Figure 5 the side view of

[0039] Figure 7 and Figure 8 is Figure 1 the schematic cross-sectional view after implanting into the human blood vessel, showing the opened and closed states of the valve respectively in the figure.

[0040] Figure 9 It is a schematic structural diagram of the second embodiment of the venous valve prosthesis of the present invention.

[0041] Figure 10 It is Figure 9 the top view of.

[0042] Figure 11 It is Figure 9 the schematic internal structure diagram of.

[0043] Figure 12 It is Figure 9 the schematic structural diagram of the venous valve stent in.

[0044] Figure 13 It is a schematic structural diagram of the third embodiment of the venous valve prosthesis of the present invention.

[0045] Figure 14 It is Figure 13 the top view of.

[0046] Figure 15 It is a schematic structural diagram of the fourth embodiment of the venous valve prosthesis of the present invention.

[0047] Figure 16 It is Figure 15 the schematic structural diagram of the venous valve stent in.

[0048] Figure 17 It is a schematic structural diagram of the fifth embodiment of the venous valve prosthesis of the present invention.

[0049] Figure 18 It is Figure 17 the front view of.

[0050] Figure 19 It is a schematic structural diagram of the sixth embodiment of the venous valve prosthesis of the present invention.

[0051] Figure 20 It is Figure 19 the side view of the venous valve stent in.

[0052] Figure 21 It is Figure 20 the front view of.

[0053] Figure 22 It is a schematic structural diagram of the seventh embodiment of the venous valve prosthesis of the present invention.

[0054] Figure 23 It is Figure 22 the front view of.

[0055] The description of the reference numerals is as follows:

[0056] 100 / 100a / 100b / 100c / 100d / 100e / 100f, venous valve prosthesis; 500, blood vessel;

[0057] 1 / 1a / 1b / 1c / 1d / 1e / 1f, venous valve stent; 101 / 101a, channel; 102 / 102a / 102b, sinus region;

[0058] 11 / 11a / 11c / 11d / 11e / 11f, stent body; 111 / 111e, support body; 1111 / 1111f, corrugated ring; 1115, wave crest; 1116, wave trough; 1112, radiopaque rod; 112 / 112a / 112b / 112e, column; 115 / 115f, fenestration;

[0059] 12 / 12a / 12b / 12c / 12d / 12e / 12f, sinus cavity frame; 1201 / 1201c, first extension segment; 1202 / 1202c, second extension segment; 1203 / 1203c, free end; 1204 / 1204c, outermost side; 121 / 121d / 121e, first strut; 122 / 122d / 122e, second strut; 123d, cross bar;

[0060] 2 / 2a / 2b, valve; 201, fixed edge; 202 / 202a, free edge; 21, valve body; 22, valve leaflet;

[0061] 3 / 3a / 3d, membrane. Detailed implementation manners

[0062] Typical implementation manners embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different implementation manners, all of which do not depart from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes and not for limiting the present invention.

[0063] The present invention provides a venous valve stent and a venous valve prosthesis for interventional treatment of venous valve insufficiency. The venous valve prosthesis includes the venous valve stent and a valve connected within the venous valve stent. The venous valve prosthesis is delivered to the diseased vein through a delivery catheter by means of percutaneous puncture and accurately positioned and released to prevent venous blood reflux.

[0064] For the convenience of description, in this article, "proximal end" is defined as the end close to the heart, and "distal end" is defined as the end far from the heart. The normal blood flow direction in the human vein is towards the heart, that is, from the distal end to the proximal end.

[0065] The following is a specific introduction through several embodiments of the venous valve prosthesis.

[0066] First embodiment, refer to Figures 1 to 8 the shown structure and usage state.

[0067] First, refer to Figures 1 to 4 , the venous valve prosthesis 100 of this embodiment includes a venous valve stent 1, a valve 2, and a thin film 3.

[0068] Among them, the venous valve stent 1 is a bare stent, and a channel 101 for blood to pass through is formed inside it in the deployed state, communicating the distal end and the proximal end. In this embodiment, a convex sinus region 102 is also formed on the side of the venous valve stent 1. The thin film 3 can be sutured to the inner side of the venous valve stent 1 or to the outer side of the venous valve stent 1, covering the entire circumferential wall of the venous valve stent 1. The thin film 3 and the venous valve stent 1 are combined as a whole to increase the contact area between the venous valve prosthesis 100 and the human blood vessel. The valve 2 is a single-valve structure, located inside the venous valve stent 1, connected and fixed to the venous valve stent 1, and covering at least part of the sinus region 102, playing a role of one-way conduction.

[0069] Refer to Figure 5 and Figure 6 , the venous valve stent 1 includes a stent body 11 and a sinus cavity frame 12 connected to the side of the stent body 11. The stent body 11 is generally a hollow cylindrical structure, so the channel 101 is formed inside it. A window 115 is provided on the side of the stent body 11; the sinus cavity frame 12 is connected to the window 115 and protrudes outward relative to the stent body 11, so that the sinus region 102 is formed inside the sinus cavity frame 12, and the sinus region 102 is communicated with the channel 101 inside the stent body 11 through the window 115.

[0070] The stent body 11 of this embodiment mainly includes two support bodies 111 arranged at intervals and a plurality of columns 112 connected between the two support bodies 111.

[0071] The support body 111 is a self-expanding structure, in the shape of a circumferentially closed cylinder, and its central axis is on the same straight line as the central axis of the entire stent body 11, and this central axis is marked as L in Figure 6 . The two support bodies 111 are coaxially arranged and spaced apart axially relative to each other.

[0072] Each support body 111 has a plurality of corrugated rings 1111 connected axially. Each corrugated ring 1111 has alternately intersecting wave crests 1115 and wave troughs 1116 in the circumferential direction. Among them, the wave crest 1115 faces the proximal end, and the wave trough 1116 faces the distal end. The wave crests 1115 and wave troughs 1116 of two adjacent corrugated rings 1111 are connected to form a grid shape.

[0073] Between adjacent wave peaks 1115 and between adjacent wave valleys 1116 of each waveform loop 1111 can approach or move away from each other, so that the support body 111 and even the entire stent body 11 can expand and contract radially. The stent body 11 is in a contracted state before being implanted into the human body to be accommodated in a delivery catheter, and expands and anchors at a predetermined position of a human blood vessel through self-expansion after being implanted into the human body. In particular, it is mainly achieved by the support body 111 adhering to the wall of the human blood vessel after radially expanding to achieve anchoring.

[0074] Specifically, as Figure 5 shown in the structure, each support body 111 has two waveform loops 1111. Each waveform loop 1111 can be regarded as a closed-loop structure formed by a rod bent in a Z shape. Each waveform loop 1111 has a total of eight wave peaks 1115 and eight wave valleys 1116 arranged circumferentially and alternately. The wave valley 1116 of the proximal waveform loop 1111 is connected to the wave peak 1115 of the distal waveform loop 1111, forming eight successively connected rhombus-shaped meshes in the circumferential direction along the support body 111. The two waveform loops 1111 form a circumferential closed-loop structure, enabling the venous valve stent 1 to have high radial support force and better anchoring effect.

[0075] Two radiopaque rods 1112 protrude proximally on the support body 111 located at the proximal end, and two radiopaque rods 1112 protrude distally on the support body 111 located at the distal end. The two radiopaque rods 1112 on each support body 111 are opposite to each other in the circumferential direction, and the four radiopaque rods 1112 are staggered in the circumferential direction. Radiopaque marks can be provided on the radiopaque rods 1112 to facilitate showing the position of the venous valve stent 1 during implantation. The radiopaque marks are made of a radiopaque material and provided on the radiopaque rods 1112, and can be set to be dot-shaped, linear, etc. In this embodiment, the end of the radiopaque rod 1112 is annular and can be used to press dot-shaped radiopaque marks.

[0076] Each upright post 112 is linear and extends along the axial direction of the stent body 11. A plurality of upright posts 112 are arranged circumferentially and spaced apart around the central axis L of the support body 111. The cylindrical structure enclosed by the plurality of upright posts 112 is coaxial with the support body 111.

[0077] Both ends of the upright post 112 are respectively connected to the opposite wave peaks 1115 and wave valleys 1116 of the two support bodies 111. That is: the proximal end of the upright post 112 is connected to the wave valley 1116 of the proximal support body 111, and the distal end of the upright post 112 is connected to the corresponding wave peak 1115 of the distal support body 111.

[0078] Specifically, in this embodiment, the number of the columns 112 is four, which are circumferentially and uniformly arranged between the two support bodies 111, and one column 112 is connected at every other crest 1115 or trough 1116 along the circumferential direction. The interval between two adjacent columns 112 forms a window 115, and the distance between the two support bodies 111, or rather the length of the column 112, constitutes the axial length of the window 115.

[0079] For the structure of the stent body 11, the support bodies 111 in the form of a closed loop located at both ends can provide good radial support force, have the advantage of strong anchoring force, and are convenient for fitting and fixing with human blood vessels. The columns 112 located in the middle increase the axial stiffness of the venous valve stent 1, which is convenient for the venous valve stent 1 to maintain the shape stability. Preferably, the width of the column 112 is greater than the width of the rod of the corrugated ring 1111 of the support body 111.

[0080] Still referring to Figure 5 and Figure 6 , the sinus cavity frame 12 is correspondingly connected at the window 115 of the stent body 11. The sinus cavity frame 12 includes a first strut 121 and a second strut 122. The first ends, i.e., the distal ends, of the first strut 121 and the second strut 122 are separated from each other, and are respectively connected to a column 112 that defines the window 115. The second ends, i.e., the proximal ends, of the first strut 121 and the second strut 122 are joined together to form the free end 1203 of the sinus cavity frame 12; the free end 1203 extends outside the stent body 11. The space enclosed by the first strut 121, the second strut 122, and the two columns 112 to which they are connected forms the sinus region 102.

[0081] As Figure 5 shown, in this embodiment, in the direction from the distal end to the proximal end, the first strut 121 and the second strut 122 gradually approach each other. The proximal ends of the first strut 121 and the second strut 122 are directly connected, and the first strut 121 and the second strut 122 are connected to form a V shape. Preferably, the first strut 121 and the second strut 122 are symmetric. The included angle α formed by the first strut 121 and the second strut 122 preferably ranges between 30° and 90°. In this embodiment, the distal ends of the first strut 121 and the second strut 122 are respectively connected to the distal ends of the two columns 112, so that the relative positions of the first strut 121 and the second strut 122 can be maintained by the radial support force of the support body 111.

[0082] In the direction from the distal end to the proximal end along the axis of the stent body 11, the sinus cavity frame 12 starts at the distal end of the upright post 112 and extends proximally beyond the midpoint of the upright post 112, but there is a gap from the support body 111 at the proximal end. That is, the length of the sinus cavity frame 12 along the axis of the stent body 11 is greater than half of the axial length of the fenestration 115, which is convenient for guiding the blood flow and also convenient for arranging the film 3.

[0083] Refer to Figure 6 , in the direction from the distal end to the proximal end along the axis of the stent body 11, the sinus cavity frame 12 gradually extends outwardly and obliquely relative to the stent body 11 first, and then gradually extends inwardly and obliquely. That is, the free end 1203 of the sinus cavity frame 12 bends towards the inner side of the stent body 11. Thus, the free end 1203 of the sinus cavity frame 12 does not exceed the outermost side 1204 of the sinus cavity frame 12 in the radial direction of the stent body 11, which can effectively avoid the free end 1203 of the sinus cavity frame 12 damaging the vascular tissue when implanted into the human blood vessel.

[0084] For the convenience of description, along the axis of the stent body 11, the sinus cavity frame 12 is divided into a first extension section 1201 near the distal end and a second extension section 1202 near the proximal end. In the direction from the distal end to the proximal end, the distance Di from the first extension section 1201 to the central axis L of the stent body 11 gradually increases, and the distance Dj from the second extension section 1202 to the central axis L of the stent body 11 gradually decreases. The distal end of the first extension section 1201 is connected to the stent body 11. The junction of the first extension section 1201 and the second extension section 1202 constitutes the outermost side 1204 of the sinus cavity frame 12 relative to the stent body 11, and the end of the second extension section 1202 is the aforesaid free end 1203.

[0085] Judging from the appearance of the venous valve stent 1, the outer diameter of the support body 111 of the stent body 11 is D1, and the distance between the outermost side 1204 of the sinus cavity frame 12 and the side wall on the opposite side of the support body 111 is D2, and D2 > D1. The difference between D2 and D1 is the maximum distance by which the sinus cavity frame 12 protrudes outward.

[0086] Furthermore, in this embodiment, in the direction from the distal end to the proximal end, the increasing speed of the distance from the first extension section 1201 to the central axis L gradually decreases, while the decreasing speed of the distance from the second extension section 1202 to the central axis L gradually increases.

[0087] That is to say, the first rod 121 and the second rod 122 are both curved within the range of the first extension section 1201 and the range of the second extension section 1202, which can improve the anti-deformation ability of the first rod 121 and the second rod 122. And when implanted into the human blood vessel, the bending directions of the first rod 121 and the second rod 122 are both convex towards the blood vessel. The first rod 121 and the second rod 122 can withstand greater radial pressure brought by the blood vessel wall, facilitating the maintenance of the shape stability.

[0088] It can be understood that in other feasible structures, the first extension section 1201 and the second extension section 1202 can also be both straight-line segments extending. In the direction from the distal end to the proximal end, the increasing speed of the distance from the first extension section 1201 to the central axis L remains unchanged, and the decreasing speed of the distance from the second extension section 1202 to the central axis L also remains unchanged. That is, the first rod 121 and the second rod 122 are both straight-section structures within the range of the first extension section 1201 and the range of the second extension section 1202. In addition, when the first extension section 1201 extends in a curved shape, the second extension section 1202 can extend in a straight shape. When the first extension section 1201 extends in a straight shape, the second extension section 1202 can also extend in a curved shape.

[0089] The structural form of the sinus cavity frame 12 in this embodiment is simple and easy to manufacture. And the number of structural members of the sinus cavity frame 12 is small, and the metal coverage rate is small, avoiding excessive stimulation of the human blood vessel and causing intimal hyperplasia. By using the sinus area 102 formed inside the sinus cavity frame 12, a vortex can be formed in the sinus area 102 when blood refluxes, which is beneficial to the pressure balance of the valve 2.

[0090] Based on the structure of the above venous valve stent 1, refer to Figure 4 , the valve 2 is located inside the stent body 11 of the venous valve stent 1, is arranged aligned with the sinus cavity frame 12, and at least covers a part of the sinus area 102. The valve 2 has a fixed edge 201 that is generally V-shaped, and the fixed edge 201 is fixed to the stent body 11 or the thin film 3 by means such as suturing or bonding.

[0091] The V-shaped vertex of the fixed edge 201 is located on the side where the sinus cavity frame 12 is located, is close to the sinus cavity frame 12, and is closer to the distal end relative to the sinus cavity frame 12. For example, the V-shaped vertex of the fixed edge 201 can be fixed on a wave crest 1115 of the distal support body 111, and this wave crest 1115 is located between the two columns 112 connected to the sinus cavity frame 12.

[0092] In the direction from the distal end to the proximal end, the fixed edge 201 starts from the V-shaped vertex and extends obliquely towards the proximal end along the inner wall of the stent body 11 towards the opposite side of the sinus cavity frame 12. Thus, if viewed in the Figure 2 front view shown ( Figure 2The middle valve 2 is blocked and not shown. The valve 2 covers a part of the sinus region 102. The length of the valve 2 in the axial direction along the stent body 11 can, for example, exceed the sinus cavity frame 12.

[0093] The side of the valve 2 facing away from the sinus region 102 is not fixed to the stent body 11, thus forming a free edge 202. The two ends of the free edge 202 are connected to the V-shaped opening of the fixed edge 201. By changing the position of the free edge 202, the valve 2 can close or open the channel 101 inside the stent body 11.

[0094] When the blood flows from the proximal end to the distal end in the channel 101, the blood passes through the sinus region 102, pushing the valve 2 against the inner wall of the stent body 11 on the side opposite to the sinus cavity frame 12, causing the free edge 202 of the valve 2 to fit against the thin film 3 on the stent body 11, and the blood cannot flow further distally through the valve 2, and the channel 101 is closed. When the blood flows from the distal end to the proximal end, the blood will push the valve 2 towards the side where the sinus region 102 is located. At this time, the free edge 202 of the valve 2 is separated from the thin film 3, and the channel 101 is opened. It should be noted that when the valve 2 is pushed against the inner wall of the stent body 11 on the side opposite to the sinus cavity frame 12, there may be a small gap between the free edge 202 and the thin film 3. At this time, the free edge 202 does not fit against the thin film 3, thereby reducing the risk of adhesion between the free edge 202 and the stent body 11 or the thin film 3. The small gap between the free edge 202 and the thin film 3 does not affect the valve 2 from blocking most of the backflow blood flow.

[0095] The valve 2 can include a valve body 21 and valve leaflets 22. The valve body 21 forms the above-mentioned fixed edge 201 and is fixedly connected to the venous valve stent 1. The valve leaflets 22 are connected between the valve bodies 21. The area of the valve leaflets 22 is larger than the area enclosed by the fixed edge 201. The part of the valve leaflets 22 not combined with the valve body 21 forms the free edge 202. The valve leaflets 22 can be deformed, and a sinus cavity is formed between the valve leaflets 22 and the valve body 21. By deforming the valve leaflets 22, the position of the free edge 202 of the valve leaflets 22 can be changed, realizing the switching between the closed and open states.

[0096] Due to the presence of the valve 2, a one-way passage for blood when passing through the venous valve stent 1 can be constructed, and the valve 2 is used as a one-way valve.

[0097] Both the valve 2 and the thin film 3 are made of xenobiotic biomaterials or medical polymer materials, such as polyester, polytetrafluoroethylene, polyurethane, medical silicone, polyester, biological valves, pericardium, or other implantable medical materials.

[0098] Refer to Figure 7When the venous valve prosthesis 100 of this embodiment is implanted into the human blood vessel 500, the venous valve stent 1 fits against the inner wall of the blood vessel 500. Under the action of the backflow blood flow flowing from the proximal end to the distal end, the valve 2 moves towards the side opposite to the sinus cavity frame 12 under the impact of the blood flow, thereby closing the channel 101 in the stent body 11, effectively avoiding the backflow of distal blood. At this time, the eddy current formed in the sinus region 102 causes the backflow blood flow to flow back towards the proximal end, avoiding the retention and accumulation of blood at the root of the valve 2, thereby avoiding the formation of local thrombus.

[0099] Reference Figure 8 As shown in the figure, during the flow of the forward blood flow in the blood vessel 500, an eddy current is formed in the area of the sinus region 102 covered by the valve 2, which is beneficial to the pressure balance of the valve 2. At this time, the valve leaf 22 of the valve 2 is in a suspended state under the combined action of the eddy current and the forward blood flow, without adhering to the stent body 11, the thin film 3 or the inner wall of the blood vessel 500. Furthermore, the risk of adhesion can be reduced to ensure that the valve 2 continuously has the function of one-way closing, and the formed eddy current can also avoid the risk of blood stasis at the root of the valve 2 and the formation of thrombus.

[0100] Based on the above description, it can be known that in the venous valve prosthesis 100 of this embodiment, since the sinus region 102 is formed on the venous valve stent 1, the existence of this sinus region 102 enables the reflux blood to form an eddy current in the sinus region 102. When the blood is flowing forward, the pressure balance generated by the eddy current in the sinus region 102 can cause the valve 2 to open the channel 101 while the valve leaf 22 of the valve 2 is suspended in the channel 101 without adhering to the venous valve stent 1 or the thin film 3, reducing the risk of the valve leaf 22 adhering and failing. And when there is blood reflux, the blood flow impacting the suspended valve leaf 22 can more easily cause the valve 2 to close the channel 101 compared to impacting the adhered venous valve stent 1 or the thin film 3.

[0101] Furthermore, the stent body 11 of the venous valve stent 1 is a radially expandable and contractible structure, with a smaller size before being implanted into the blood vessel 500, resulting in less surgical trauma. The stent body 11 adopts a support body 111 with a closed-loop structure at both ends, having the advantages of high radial support force and strong anchoring force. After being implanted into the blood vessel 500, it can be reliably anchored on the inner wall of the blood vessel 500 and uniformly apply force to the inner wall of the blood vessel 500 in the circumferential direction, reducing the irritation to the inner wall of the blood vessel 500 and preventing the excessive hyperplasia of the inner wall of the blood vessel 500. The column 112 located in the middle of the stent body 11 increases the axial stiffness of the venous valve stent 1, so that the part of the stent body 11 carrying the valve 2 does not change in diameter due to factors such as muscle pump and pressure gradient changes. The entire structure of the venous valve stent 1 shows relatively large rigidity, and after implantation, the venous valve stent 1 always maintains a fixed shape, without affecting the valve body 21 of the valve 2 and further affecting the function of the valve leaf 22 due to the change of the transmural pressure of the blood vessel 500.

[0102] The sinus cavity frame 12 of the venous valve stent 1 forms a sinus region 102 on the side of the stent body 11, forming a structural advantage that conforms to fluid mechanics, so that blood does not form thrombus at the valve 2. In particular, the sinus cavity frame 12 is designed with a free end 1203 and has elasticity in the radial direction, which can avoid excessive stimulation of the sinus cavity frame 12 on the blood vessel 500. And after being implanted into the human body, since the free end 1203 is overhanging, the support body 111 that is closer to the proximal end than the sinus cavity frame 12 will not form a constraint on the free end 1203, and the sinus cavity frame 12 can more easily maintain a structural form that is convex outward from the stent body 11, thereby maintaining the stability of the sinus region 102.

[0103] At the same time, the sinus cavity frame 12 of this embodiment is formed by connecting the first strut 121 and the second strut 122 to the stent body 11. It has few structural components and a simple structure. During actual production, the stent body 11 and the sinus cavity frame 12 can be manufactured separately first, and then the two are connected into one body, which is convenient for production. In addition, the sinus cavity frame 12 is connected to the column 112. The simple-structured sinus cavity frame 12 cooperates with the spaced columns 112, so that the venous valve stent 1 also has a large operating space for connecting the valve 2, and the metal coverage rate is small, effectively reducing the stimulation to the intima of the blood vessel 500.

[0104] It can be understood that in other structures not shown, the sinus cavity frame 12 is not limited to the structural form composed of the first strut 121 and the second strut 122 in this embodiment. Based on the concept of the present invention, the sinus cavity frame 12 only needs to meet the following conditions: one end thereof is a fixed end fixedly connected to the stent body 11, and the opposite end is a free end 1203 overhanging outside the stent body 11, and the sinus cavity frame 12 is convex outward from the stent body 11 to form a sinus region 102 inside. Among them, in this embodiment, the proximal end portions of the first strut 121 and the second strut 122 constitute the fixed end. In fact, since one end of the sinus cavity frame 12 is fixed and the other end is a free end, the overall structural shape of the sinus cavity frame 12 is not restricted by the stent body 11 or specifically by the window 115 of the stent body 11. Therefore, the structural form of the sinus cavity frame 12 can be flexibly set according to the actual situation, which is convenient for the production of the sinus cavity frame 12 and its connection with the stent body 11.

[0105] The venous valve stent 1 of this embodiment can be manufactured by laser engraving of nitinol. In some embodiments, the total length L1 (excluding the length of the visualization rod 1112) of the venous valve stent 1 can be 15 mm to 30 mm, the diameter D1 of the support body 111 can be 5 mm - 30 mm, and the maximum diameter D2 at the location of the sinus cavity frame 12 protrudes 2.5 mm from the diameter D1 of the support body 111.

[0106] The thickness of the rod of the venous valve stent 1 can be designed to be 0.35 mm, the width of each rod in the support body 111 can be designed to be 0.35 mm, and the width of each rod in the upright post 112 and the sinus cavity frame 12 can be designed to be 0.6 mm, so that the venous valve stent 1 has better radial supporting force and axial stiffness.

[0107] The second embodiment, refer to Figures 9 to 12 the structure shown.

[0108] The difference between the venous valve prosthesis 100a of this embodiment and the first embodiment is that: the venous valve stent 1a of the venous valve prosthesis 100a has a plurality of sinus regions 102a. In this embodiment, there are two sinus regions 102a. Correspondingly, the valve 2a is a double-valve structure. The thin film 3a covers the two sinus regions 102a.

[0109] There are two relatively arranged sinus cavity frames 12a in the venous valve stent 1a. The two sinus cavity frames 12a protrude outward relative to the stent body 11a respectively, so that the directions of the two sinus regions 102a are also opposite.

[0110] Two valves 2a are sewn between the two sinus cavity frames 12a. The free edges 202a of the two valves 2a meet in the middle of the venous valve stent 1a.

[0111] When blood refluxes, the two valves 2a arch up, and the free edges 202a of the two valves 2a fit together to close the channel 101a and prevent the reflux blood from passing through. Eddy currents are respectively formed in the two sinus regions 102a to promote the blood to return to the proximal end again and avoid blood accumulation.

[0112] When the forward-flowing blood passes through, the blood flow impacts the valve 2a, and the free edges 202a of the two valves 2a separate to open the channel 101a to allow the blood to flow to the proximal end normally.

[0113] In this embodiment, the structure of two sinus cavity frames 12a is adopted to effectively balance the opening state of the valve 2a, and eddy currents are formed on both sides of the venous valve stent 1a to avoid local thrombosis caused by blood accumulation.

[0114] Compared with the four upright posts 112 of the first embodiment, in this embodiment, an additional upright post 112a is provided in the interval between the two upright posts 112a that are not connected to the sinus cavity frame 12a. That is, the stent body 11a of this embodiment has a total of six upright posts 112a, increasing the radial supporting strength. Of course, when the radial supporting strength is sufficient, these two extra upright posts 112a can also be omitted.

[0115] This second embodiment is described by taking the double-valve as an example. Based on the concept of the present invention, the venous valve prosthesis can also have three or more sinus regions. Correspondingly, the sinus cavity frames are correspondingly arranged as three or more, and the valves are also correspondingly three-valve and multi-valve structures.

[0116] The third embodiment, refer to Figure 13 and Figure 14 the structures shown.

[0117] This embodiment is a further extension of the above-mentioned second embodiment. In the venous valve prosthesis 100b of this embodiment, the venous valve stent 1b is provided with four sinus cavity frames 12b, and the four sinus cavity frames 12b are evenly distributed along the circumferential direction of the venous valve stent 1b, and are respectively arranged between two adjacent columns 112a. Correspondingly, four sinus regions 102b are formed in the venous valve stent 1b. The number of valves 2b also corresponds to four, and they are arranged one by one relative to the sinus regions 102b.

[0118] The fourth embodiment, refer to Figure 15 and Figure 16 the structures shown.

[0119] The difference between the venous valve prosthesis 100c of this embodiment and the first embodiment lies in the different structure of the sinus cavity frame 12c of the venous valve stent 1c.

[0120] In this embodiment, the free end 1203c of the sinus cavity frame 12c does not bend towards the inside of the stent body 11c. Instead, the sinus cavity frame 12c is divided into a first extension section 1201c close to the distal end and a second extension section 1202c close to the proximal end along the axial direction of the stent body 11c. In the direction from the distal end to the proximal end, the distance from the first extension section 1201c to the central axis L of the stent body 11c gradually increases, and the distance from the second extension section 1202c to the central axis L remains unchanged.

[0121] In this embodiment, the free end 1203c of the sinus cavity frame 12c still does not extend beyond the outermost side 1204c of the remaining part of the sinus cavity frame 12c except the free end 1203c in the radial direction of the stent body 11c.

[0122] The distance from the second extension section 1202c to the central axis L remains unchanged. When the venous valve prosthesis 100c is implanted into the human blood vessel, through the second extension section 1202c, local stress concentration on the blood vessel wall can be avoided, the pressure caused by the outward convexity of the sinus cavity frame 12c on the blood vessel wall can be relieved, and the blood vessel wall can be prevented from bearing excessive pressure due to local stress concentration.

[0123] The fifth embodiment, refer to Figure 17 and Figure 18 the structures shown.

[0124] The difference between the venous valve prosthesis 100d of this embodiment and the first embodiment lies in the different structure of the sinus cavity frame 12d of the venous valve stent 1d.

[0125] In this embodiment, the sinus cavity frame 12d further includes a cross bar 123d; the cross bar 123d extends along the circumferential direction of the stent body 11d, and both ends of the cross bar 123d are respectively connected to the proximal end portions of the first support rod 121d and the second support rod 122d.

[0126] The arrangement of the cross bar 123d can increase the support area of the film 3d and ensure the firmness of the part of the film 3d covering the sinus area under the impact of eddy currents. Moreover, the cross bar 123d can weaken the sharpness of the free end of the sinus cavity frame 12d, and the increase of its lateral area can avoid damaging the blood vessel wall during implantation.

[0127] The sixth embodiment is shown in Figures 19 to 21 the structure shown.

[0128] The difference between the venous valve prosthesis 100e in this embodiment and the first embodiment lies in that the connection position between the sinus cavity frame 12e and the stent body 11e in the venous valve stent 1e is different.

[0129] In this embodiment, the first support rod 121e and the second support rod 122e of the sinus cavity frame 12e are not connected to the end portions of the column 112e, but to the middle area of the column 112e.

[0130] Among them, there is a distance S1 between the free end 1203e of the sinus cavity frame 12e and the support body 111e near the proximal end, and there is a distance S2 between the proximal end portions of the first support rod 121e and the second support rod 122e and the support body 111e near the distal end. In this embodiment, S1 is equal to S2.

[0131] The seventh embodiment is shown in Figure 22 and Figure 23 the structure shown.

[0132] The difference between the venous valve prosthesis 100f in this embodiment and the first embodiment lies in that the structure of the stent body 11f of the venous valve stent 1f is different.

[0133] In this embodiment, the stent body 11f is an integral mesh stent, and its entire outer peripheral wall is in a mesh shape, and no longer has the column 112 as in the first embodiment. A window 115f is formed by opening a substantially rectangular notch on the side of the stent body 11f, and the window 115f is located in the middle area of the stent body 11f along the axial direction of the stent body 11f. The sinus cavity frame 12f is arranged at the window 115f.

[0134] The stent body 11f includes a plurality of annular corrugated rings 1111f, and the plurality of annular corrugated rings 1111f are sequentially arranged along the axis of the stent body 11f and axially connected to form a grid. The window 115f can be formed by cutting on the stent body 11f.

[0135] In this embodiment, the stent body 11f with an integrated mesh structure is adopted, which has good radial contraction and expansion performance. The fenestration 115f provided on the side of the stent body 11f can improve the overall flexibility of the venous valve stent 1f. The venous valve stent 1f can be bent at the fenestration 115f, enabling it to more easily pass through tortuous and complex vascular accesses, and having higher flexibility compared to the first embodiment.

[0136] Although the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A venous valve stent, characterized in that, Comprising: A stent body, which is a hollow cylindrical structure and can be radially telescoped; a window is provided on the side of the stent body; the window is located in the middle region of the stent body in the axial direction; the stent body includes two support bodies arranged at intervals and a plurality of columns connected between the two support bodies; the support bodies are in the shape of a circumferentially closed cylinder; the two support bodies are coaxially arranged and spaced apart axially; the plurality of columns are circumferentially spaced around the central axis of the support body; the window is formed in the interval between two adjacent columns. A sinus cavity frame, having a fixed end and a free end; the fixed end is connected to the window; the free end extends outside the stent body; a sinus region is formed inside the sinus cavity frame, and the sinus region communicates with the inside of the stent body through the window; in the direction from the distal end to the proximal end along the axis of the stent body, the sinus cavity frame starts at the distal end of the column, then extends proximally beyond the midpoint of the column, but has a gap with the support body at the proximal end, the sinus cavity frame gradually extends outwardly and then gradually extends inwardly relative to the stent body, and the free end bends towards the inside of the stent body; the length of the sinus cavity frame in the axial direction of the stent body is greater than half of the axial length of the window.

2. The venous valve stent according to claim 1, wherein, In the radial direction of the stent body, the free end does not extend beyond the outermost side of the remaining part of the sinus cavity frame except the free end.

3. The venous valve stent according to claim 2, wherein, In the direction from the fixed end to the free end along the axis of the stent body, the sinus cavity frame includes a first extension section and a second extension section, and the distance from the first extension section to the central axis of the stent body gradually increases; the junction of the first extension section and the second extension section is the outermost side of the sinus cavity frame, and the end of the second extension section is the free end.

4. The venous valve stent according to claim 3, characterized in that, In the direction from the outermost side to the free end, the distance from the second extension section to the central axis of the stent body gradually decreases.

5. The venous valve stent according to claim 4, wherein, In the direction from the outermost side to the free end, the decreasing speed of the distance from the second extension section to the central axis of the stent body gradually increases.

6. The venous valve stent according to claim 4, wherein The second extension section extends linearly.

7. The venous valve stent according to claim 3, characterized in that, In the direction from the fixed end to the outermost side, the increasing speed of the distance from the first extension section to the central axis of the stent body gradually decreases.

8. The venous valve stent according to claim 3, characterized in that The first extension section extends linearly.

9. The venous valve stent according to claim 1, wherein, The sinus cavity frame includes a first strut and a second strut; the first ends of the first strut and the second strut are separated and serve as the fixed end to be respectively connected to the window; the second ends of the first strut and the second strut are joined to form the free end.

10. The venous valve stent according to claim 9, wherein, The second ends of the first strut and the second strut are directly connected.

11. The venous valve stent according to claim 9, wherein The sinus cavity frame further includes a cross bar; the cross bar extends circumferentially along the stent body, and the two ends of the cross bar are respectively connected to the second ends of the first strut and the second strut.

12. The venous valve stent according to claim 9, wherein, In the direction from the first end to the second end, the first strut and the second strut gradually approach each other.

13. The venous valve stent according to claim 12, wherein, The included angle between the first strut and the second strut is 30° - 90°.

14. The venous valve stent according to claim 12, wherein, The first support rod and the second support rod are symmetrical.

15. The venous valve stent according to claim 1, characterized in that, The support body includes a plurality of axially connected wave circles; each wave circle has staggered wave crests and wave troughs along the circumferential direction, and the wave crests and wave troughs of two adjacent wave circles are connected to form a grid; the column is connected to the opposite wave crests and wave troughs of the two support bodies.

16. The venous valve stent according to claim 1, characterized in that, The column is in a straight line shape and extends along the axial direction of the bracket body.

17. The venous valve stent according to claim 1, characterized in that, The support body is an integrated structure, the entire peripheral wall of which is in a mesh shape, and the window is provided on the peripheral wall.

18. The venous valve stent according to any one of claims 1-14, characterized in that, The number of the windows is multiple and distributed along the circumference of the stent body; the sinus cavity stent is provided with multiple windows, which are connected to the windows one by one.

19. An intravenous valve prosthesis, characterized in that, It comprises a valve and a venous valve stent as described in any one of claims 1 to 18; the valve is fixed in the stent body and covers at least a portion of the sinus area; the valve has a free edge, and the free edge is located on the side of the valve away from the sinus area.

20. The venous valve prosthesis according to claim 19, characterized in that, The venous valve prosthesis further comprises a film, which covers the entire peripheral wall of the venous valve stent.

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