Thrombectomy stent and thrombectomy device

Abstract

The invention relates to the technical field of medical instruments, in particular to a thrombectomy stent and a thrombectomy device.The thrombectomy stent comprises a plurality of wave rods, a near-end connecting part, a near-end deformable part, a far-end deformable part and a far-end connecting part are sequentially defined by the wave rods, and the near-end deformable part and the far-end deformable part are each in a half-net-cage shape defined by the multiple wave rods; the near-end deformable part and the far-end deformable part are connected to form a complete net cage, the net cage is a shape memory type object which can be stored in a pipeline in a pressing and holding deformation mode and can automatically expand to form a net after being released out of the pipeline, and the near-end connecting part is formed by converging wave rods at the end of the near-end deformable part into a pipe shape. And the far-end connecting part is gathered into a tube shape by the wave rods at the end part of the far-end deformable part. The thrombus on the blood vessel wall is scraped by adopting the self-expanding stent, and the scraped thrombus is contained in the stent or is further crushed by tightening the stent, so that the adherent thrombus which is difficult to suck is effectively removed.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a thrombus removal bracket and a thrombus removal device. Background Art

[0002] Venous thromboembolism includes two forms: pulmonary thromboembolism and deep vein thrombosis.

[0003] Pulmonary thromboembolism refers to a disease caused by a blood clot originating from the venous system or the right heart blocking the pulmonary artery or its branches. It is characterized by pulmonary circulation (including right heart) and respiratory dysfunction as the main clinical manifestations and pathophysiological features. It is the most common type of pulmonary embolism.

[0004] Deep vein thrombosis refers to abnormal coagulation of blood in the deep vein cavity, which blocks the vein cavity, causes venous reflux obstruction, and causes varying degrees of deep vein insufficiency. It is most common in lower limb and inferior vena cava thrombosis, especially iliac-femoral vein thrombosis. If patients do not receive timely and effective treatment, it will lead to lower limb congestion and pigmentation. In severe cases, it can cause femoral cyanosis, limb ischemia and necrosis, and patients will lose part or all of their labor power. In addition, more than 50% of patients will be left with deep venous insufficiency in the lower limbs, which will affect the quality of life for a long time, and even cause pulmonary embolism and death. It has become a common disease that poses a great threat to human health.

[0005] Treatments for venous thromboembolism currently include anticoagulant medication, catheter-based thrombolysis, and surgical thrombectomy. For some organized thrombi, general treatments and thrombectomy may not be able to remove the thrombi, and stent-like devices are required to scrape or break them up. Thrombi are generally divided into acute, subacute, and chronic types, with different textures and morphologies. They can generally be removed with suction devices, but for some organized thrombi, which are harder and attached to the blood vessel wall, the effect of suction removal is limited. Summary of the invention

[0006] In view of this, the present invention provides a thrombus removal stent to solve the problem that the existing technology has poor effect in aspirating and removing the organized thrombus attached to the blood vessel wall in thrombus aspiration surgery.

[0007] The present invention provides a thrombus removal bracket, comprising a plurality of wave rods, wherein the wave rods are sequentially formed into a proximal connecting portion, a proximal deformable portion, a distal deformable portion and a distal connecting portion along a straight direction, the proximal deformable portion and the distal deformable portion are both formed into a half cage shape by a plurality of the wave rods, the proximal deformable portion and the distal deformable portion are connected to form a complete cage, the proximal connecting portion is formed into a tubular shape by the wave rods at the end of the proximal deformable portion, and the distal connecting portion is formed into a tubular shape by the wave rods at the end of the distal deformable portion.

[0008] Optionally, the proximal deformable portion and the distal deformable portion are both hemispherical, and the proximal deformable portion and the distal deformable portion are connected together to form a complete sphere.

[0009] Optionally, the wave rod of the proximal connecting portion extends and is connected to the distal deformable portion to form a proximal grid, and the proximal grid is distributed in the circumferential direction of the proximal deformable portion, occupying part of the proximal deformable portion and part of the distal deformable portion; The proximal grids include a plurality of proximal grids 1, a plurality of proximal grids 2 and a plurality of proximal grids 3; The proximal grid 1 and the proximal grid 2 are spaced apart in the circumferential direction of the proximal deformable portion, a notch is provided between the proximal grid 1 and the proximal grid 2, and the proximal grid 3 is partially located in the notch; When the wave rods of the distal deformable portion extend toward the distal end, they are radially gathered to form a plurality of distal grids, and the distal grids and the proximal grids are spaced apart and distributed along the circumference of the distal deformable portion.

[0010] Optionally, the number of wave rods in the proximal connecting part is 2-4; the number of proximal grids 1 is 2-4; the number of proximal grids 2 is 2-4; and the number of grids in the distal deformable part is 6-20.

[0011] Optionally, the wave rod extending from the proximal connecting portion to the proximal deformable portion is forked to form two first support rods, the first support rod is forked to form two second support rods, the proximal grid 1 is surrounded by support rods formed by the same fork of the wave rod, and the proximal grid 2 is surrounded by support rods formed by different forks of the wave rods.

[0012] Optionally, the mesh density of the distal deformable portion is greater than the mesh density of the proximal deformable portion.

[0013] Optionally, the mesh size of the distal deformable portion is smaller than the mesh size of the proximal deformable portion.

[0014] Optionally, adjacent wave rods form nodes at the intersection, and the nodes where the proximal grid 1, the proximal grid 2 and the distal grid intersect have a grid wedge angle toward the proximal side for scraping thrombus, and the adjacent wave rods are acutely angled to form the grid wedge angle, and the grid wedge angle is located at the distal deformable portion.

[0015] Optionally, the length of all grids along the axial direction of the proximal connecting portion is greater than the width along the circumferential direction.

[0016] Another object of the present invention is to provide a thrombus removal device, comprising the thrombus removal bracket as described above, and further comprising: An outer sheath tube assembly comprises an outer sheath tube and an outer sheath tube seat, wherein the proximal end of the outer sheath tube is connected to the outer sheath tube seat, and the outer sheath tube seat is provided with an outer sheath tube hemostasis valve and an outer sheath tube emptying valve; The inner tube assembly comprises a TIP head, a distal inner tube, an inner tube and an inner tube seat; one end of the distal inner tube is connected to the TIP head, and the other end passes through the inner tube; the inner tube passes through the outer sheath, the proximal end of the inner tube is connected to the inner tube seat, one end of the thrombectomy bracket is connected to the TIP head, and the other end is connected to the inner tube, and includes a section of the distal inner tube.

[0017] Optionally, a step is provided on the TIP head to be plugged into the outer sheath tube and connected with the outer wall through transition.

[0018] Optionally, the thrombus removal device further comprises a second thrombus removal stent, which is an automatically expandable stent and can be compressed, deformed and housed in the outer sheath; the second thrombus removal stent is connected end to end to the stent, the second thrombus removal stent is located between the stent and the TIP head, the grid density of the second thrombus removal stent is greater than the grid density of the stent, and the second thrombus removal stent is used to block and assist in intercepting fine thrombi.

[0019] The technical solution of the present invention has the following advantages: 1. A self-expanding stent is used to scrape the thrombus on the blood vessel wall. The scraped thrombus is contained in the stent or further broken up by tightening the stent, thus achieving effective removal of the wall-adherent thrombus that is difficult to aspirate.

[0020] 2. The shape of the stent is spherical, so that the stent contacts the blood vessel wall in a tangential form. During the movement, the rounded contour of the sphere can reduce the friction between the stent and the blood vessel wall and reduce the risk of tissue damage.

[0021] 3. The main grid units included in the distal deformable part and the proximal deformable part of the stent are staggered at the maximum diameter dimension of the stent, so that the maximum diameter of the stent is in the hollow part of the grid, and the grid wedge angle of the proximal deformable part occupies the distal deformable part. When the maximum diameter of the stent fits the blood vessel wall, the target thrombus can be framed along the grid unit at the maximum diameter first, and then scraped through the grid wedge angle on the distal hemisphere during the withdrawal process, and enter the stent through the grid of the proximal deformable part.

[0022] 4. The grid unit density of the distal deformable part is greater than that of the proximal deformable part. The grid size of the proximal deformable part is large, which is more conducive to the introduction of thrombus. The grid size of the distal deformable part is small, which is suitable for accommodating or further breaking up thrombus.

[0023] 5. The proximal wave rod extends from the proximal connection part in a single piece and extends in an arc shape to naturally form a grid. This design can make the stent easier to be pressed and gripped along the wave rod into the outer sheath.

[0024] 6. The inner tube adopts a structure with reinforced ribs. For such devices that are long and require self-expanding stents with large supporting force, the inner tube with reinforced ribs and the inner tube design with appropriate size and hardness also make the catheter have good bending performance, adapt to different blood vessel curvature radii, and can push and release the stent more stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 is a schematic structural diagram of the thrombus removal device in Example 1; Figure 2 is a three-dimensional diagram of the bracket in Example 1; Figure 3 is a front view of the bracket in Example 1; Figure 4 is a schematic structural diagram of the thrombus removal device in Example 2; Figure 5 Schematic diagram of the structure of the thrombus removal device in Example 3.

[0027] In the figure: thrombectomy bracket 1, proximal deformable portion 1a, distal deformable portion 1b, proximal connecting portion 1c, distal connecting portion 1d, wave rod 11, first support rod 111, second support rod 112, node 12, proximal grid one 13, proximal grid two 14, proximal grid three 15, distal grid 16, grid wedge angle 17, inner tube 2, distal inner tube 3, TIP head 4, inner tube seat 5, outer sheath tube 6, outer sheath tube seat 7, outer sheath tube hemostatic valve 8, outer sheath tube emptying valve 9, inner tube hemostatic valve 10, inner tube emptying valve 18, distal inner tube fixing seat 19, second thrombectomy bracket 20, and developing member 21. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the description of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Unless otherwise clearly specified and limited, the terms "disposed", "installed", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] The directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front”, “back”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0031] The terms "first", "second", "third", etc. are merely used to distinguish elements of similar nature, and do not indicate or imply relative importance or a particular order.

[0032] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of the elements listed and may also include additional elements not expressly listed.

[0033] Please refer to Figure 1 The present invention provides a thrombus removal device, comprising a thrombus removal bracket 1, an inner tube assembly and an outer sheath assembly, the outer sheath assembly comprising an outer sheath 6 and an outer sheath seat 7, and the inner tube assembly comprising a TIP head 4, a distal inner tube 3, an inner tube 2 and an inner tube seat 5.

[0034] The inner tube 2 is passed through the outer sheath tube 6, and the proximal end of the inner tube 2 (close to the operator end) is connected to the inner tube seat 5; the proximal end of the outer sheath tube 6 is connected to the outer sheath tube seat 7, and the outer sheath tube seat 7 is provided with an outer sheath tube hemostatic valve 8, and the outer sheath tube hemostatic valve 8 is a variable diameter hemostatic valve, which can be completely sealed at the minimum and can pass instruments with a diameter of 9F at the maximum; the side of the outer sheath tube hemostatic valve 8 is connected to the outer sheath tube emptying valve 9 for emptying the instrument; the inner tube assembly is longer than the outer sheath tube assembly, and the inner tube 2 can move back and forth in the outer sheath tube 6. When the seats of the two components are against each other, that is, when the inner tube seat 5 and the outer sheath tube seat 7 are against each other, the inner tube 2 can extend out of the outer sheath tube by 10-15cm.

[0035] The inner and outer surfaces of the inner tube 2 are made of smooth polymer materials. The inner wall of the inner tube 2 is sandwiched with a metal braided reinforcement layer, and the side is provided with reinforcement ribs, which can be flat ribs or round ribs. The inner tube 2 of this structure is more stable to control. The distal inner tube 3 is free in the inner tube 2 and can move forward and backward with the change of the shape of the thrombus removal stent 1. The inner tube seat 5 at the end of the inner tube 2 can be a Luer seat for emptying.

[0036] The outer sheath tube 6 is a polymer composite tube, the inner layer is made of a polymer material with a smooth surface and low friction, such as PTFE, PI, etc. The middle layer is a metal reinforcement layer, the material is stainless steel, and it is woven. The shape of the woven wire can be flat wire or round wire, and the density range is 30ppi-60ppi. The outer layer is a polymer material with excellent tensile and compressive properties, such as PEBAX. And from the proximal end to the distal end (away from the operator end) of the outer sheath tube 6, the hardness changes: the outer sheath tube 6 is the distal head, the softer part, and the harder part from the distal end to the proximal end. The length of the distal head is 5-10mm and the hardness is greater than 55D. The length of the softer part is 20-40cm and the hardness is 35D-55D. The hardness of the harder part is 63D-72D; more preferably, the transition hardness of the transition part between the softer part and the harder part is 10-15mm, and the hardness of the transition part gradually becomes harder from the distal end to the proximal end. A developing ring is provided at a position of 1-2 mm from the distal end of the outer sheath 6. The developing ring material is a metal material with good developing performance such as platinum-iridium alloy. The developing member is provided on the wave rod at the boundary between the distal hemispherical part and the proximal hemispherical part, and / or on the wave rod of the distal connecting part. The developing member 21 can be an enhanced developing structure or an additional developing member.

[0037] The TIP head 4 is connected to the thrombus removal bracket 1 and the distal inner tube 3. The distal inner tube 3 is a polymer single-lumen tube, and the material is a polymer tube with stable performance, preferably a metal braided composite polymer tube, with a hardness of 55D-73D. One end of the distal inner tube 3 is connected to the TIP head 4, and the other end is inserted into the inner tube 2; there is a step on the TIP head 4, and the TIP head 4 is plugged and matched with the outer sheath tube 6 through the step; when the TIP head 4 is plugged with the outer sheath tube 6, the outer walls of the two are connected in transition. The thrombus removal device is used in conjunction with a guide wire, which enters from the TIP head 4, enters the inner tube 2 through the distal inner tube 3, and finally passes through the inner tube seat 5.

[0038] The thrombectomy stent 1 includes a section of the distal inner tube 3, and one end of the thrombectomy stent 1 is connected to the TIP head 4, and the other end is connected to the inner tube 2. When the TIP head 4 is plugged into the outer sheath 6, the thrombectomy stent 1 is compressed and hidden in the outer sheath 6; the thrombectomy stent 1 is a self-expanding stent, and when the thrombectomy stent 1 is removed from the outer sheath 6, it can automatically expand into a mesh object. The material used for the thrombectomy stent 1 is a memory alloy, preferably a nickel-titanium alloy; the thrombectomy stent 1 is formed into a spherical shape through a special process, and can be deformed by compression and gripping in vitro, and automatically expand and unfold into a predetermined shape after being released in vivo.

[0039] Please refer to Figure 2The thrombus removal stent 1 is spherical as a whole and is composed of cut wave rods 11. The wave rods 11 are connected to form nodes 12. Different wave rods 11 and nodes 12 form grids of different sizes. The axial length of all grids is greater than the circumferential length, and the thrombus removal stent 1 can be compressed in the radial direction. The thrombus removal stent 1 includes four areas distributed in sequence along the axial direction: a proximal connecting portion 1c, a proximal deformable portion 1a, a distal deformable portion 1b, and a distal connecting portion 1d. The proximal deformable portion 1a and the distal deformable portion 1b form a complete cage-shaped sphere, and its maximum diameter ( Figure 2 The dimension where the middle dotted line is located is the boundary, and the boundary surface is a plane perpendicular to the central axis of the distal inner tube 3. The maximum diameter of the thrombus removal stent 1 is 16-28mm, and the radial diameter can be compressed to 2mm. The shape of the thrombus removal stent 1 is designed to be spherical, so that the thrombus removal stent 1 contacts the blood vessel wall in a tangential form. During the movement, the rounded contour of the sphere can reduce the friction between the thrombus removal stent 1 and the blood vessel wall, reducing the risk of tissue damage.

[0040] Please refer to Figure 2 and Figure 1 The proximal connection part 1c is composed of 2-4 wave rods 11, which are connected to the inner tube 2. The proximal connection part 1c is provided with a developing member 21 for indicating the proximal end of the thrombectomy stent 1. The developing member 21 surrounds the proximal connection part 1c and is circumferentially distributed on the plurality of wave rods 11. The wave rods 11 of the proximal connection part 1c extend and are connected to the distal deformable part 1b to form a proximal grid, which occupies the proximal deformable part 1a and part of the distal deformable part 1b. This type of grid is circumferentially distributed along the proximal deformable part 1a.

[0041] Please refer to Figure 3 The proximal grid includes a proximal grid one 13, a proximal grid two 14 and a proximal grid three 15; the proximal grid one 13 is distributed circumferentially on the proximal deformable portion 1a, occupying part of the proximal deformable portion 1a and part of the distal deformable portion 1b; the proximal grid two 14 is distributed circumferentially on the proximal deformable portion 1a, occupying part of the proximal deformable portion 1a and part of the distal deformable portion 1b; the proximal grid three 15 is distributed circumferentially on the proximal deformable portion 1a, occupying part of the proximal deformable portion 1a and part of the distal deformable portion 1b.

[0042] The number of wave rods in the proximal connecting portion 1c is 2-4. Each wave rod 11 of the proximal connecting portion 1c is bifurcated to form two first support rods 111 and then extends into the proximal deformable portion 1a. Each first support rod 111 is bifurcated into two second support rods 112 in the proximal deformable portion 1a. The proximal grid 1 13 is surrounded by support rods formed by bifurcation of the same wave rod 11, and the proximal grid 2 14 is surrounded by support rods formed by bifurcation of different wave rods. The proximal grid 2 14 and the proximal grid 1 13 are distributed at intervals in the circumferential direction of the proximal deformable portion 1a. A notch is provided between the proximal grid 1 13 and the proximal grid 2 14, and the proximal grid 3 15 is partially located in the notch. The number of the proximal grid 1 13 and the proximal grid 2 14 is 2-4.

[0043] The distal grid and the proximal grid three are distributed at intervals along the circumference of the distal deformable part. When the wave rod of the distal deformable part extends to the distal end, it is radially gathered to form a distal grid 16. There are multiple distal grids 16 regularly distributed circumferentially on the distal deformable part 1b. The number of grids of the distal deformable part 1b is 6-20, that is, the number of the distal grid 16 and the proximal grid three 15 is 6-20 in total; the grid size of the proximal grid three 15 gradually decreases towards the distal direction as it is radially gathered. Please refer to Figure 3 , the intersection of adjacent wave bars 11 forms a node, the node where the proximal grid 13, the proximal grid 2 14 and the distal grid 16 intersect has a grid wedge angle 17 for scraping thrombus toward the proximal side, and the adjacent wave bars 11 are acutely angled to form the grid wedge angle 17. At the maximum diameter of the spherical thrombectomy stent 1, the grid wedge angles 17 of the proximal grid 1 13 and the proximal grid 2 14 are distributed circumferentially. When the thrombectomy stent 1 is fully deployed, the maximum diameter position is the hollow part of the proximal grid 1 13 and the proximal grid 2 14, and the grid wedge angles 17 are all located at the distal deformable part 1b. The main grid units included in the distal deformable portion 1b and the proximal deformable portion 1a of the thrombectomy stent 1 are staggered at the maximum diameter dimension of the thrombectomy stent 1, so that the maximum diameter of the thrombectomy stent 1 is in the hollow part of the grid, and the grid wedge angle 17 of the proximal deformable portion 1a occupies the distal deformable portion 1b. When the maximum diameter of the thrombectomy stent 1 is in contact with the blood vessel wall, the target thrombus can be first framed along the grid unit at the maximum diameter, and then scraped through the grid wedge angle 17 on the distal deformable portion 1b during the withdrawal process, and enter the thrombectomy stent 1 through the grid of the proximal deformable portion 1a.

[0044] The mesh density of the distal deformable portion 1b is greater than that of the proximal deformable portion 1a. The proximal deformable portion 1a has a large mesh size, which is more conducive to the introduction of thrombi, and the distal deformable portion 1b has a small mesh size, which is suitable for receiving or further breaking up thrombi. The mesh size of the distal deformable portion 1b is smaller than the proximal mesh of the proximal deformable portion 1a, which is conducive to holding the thrombi cut by the thrombectomy stent 1.

[0045] Please refer to Figure 3 and Figure 1 The distal connection portion 1d is a thin and long grid, which is gathered to the diameter of the TIP head 4 and is connected and fixed to the distal inner tube 3 and the TIP head 4. Optionally, the distal end of the thrombus removal stent 1 is provided with a developing member 21, and the setting mode of the developing member 21 is the same as that on the proximal connection portion 1c. More preferably, the developing member 21 is provided at the boundary dimension of the thrombus removal stent 1 to strengthen the indication of the maximum diameter of the thrombus removal stent 1.

[0046] Please refer to Figure 1 and Figure 3 The thrombus removal device proposed by the present invention is used as follows: 1) The inner tube assembly and the outer sheath tube assembly are assembled to form a complete device.

[0047] 2) Since the distal inner tube 3 is in a free state, the thrombectomy stent 1 can be radially compressed and gripped, that is, the thrombectomy stent 1 is stretched, and the TIP head 4 moves distally with the distal inner tube 3. The outer sheath assembly is assembled outside the inner tube assembly, and moves toward the inner tube assembly through the outer sheath 6. The thrombectomy stent 1 starts from the proximal connection part 1c, and each grid is compressed and gripped in sequence until the head end of the outer sheath 6 contacts the upper step of the TIP head 4.

[0048] 3) The thrombectomy stent 1 is pressed and gripped into the outer sheath 6 outside the body, and the outer sheath hemostatic valve 8 is locked to be relatively fixed. After entering the body and reaching the target blood vessel, the thrombectomy stent 1 passes through the area where the thrombus is located, and then the outer sheath 6 is withdrawn and released until the thrombectomy stent 1 is completely exposed, and then the thrombectomy stent 1 is withdrawn and the thrombus is scraped along the blood vessel.

[0049] 4) During the process of pulling back the thrombus removal stent 1, the thrombus enters the thrombus removal stent 1 through the proximal grid 1 13 and the proximal grid 2 14. The distal deformable portion 1b has dense grids and can accommodate the scraped thrombus.

[0050] 5) In conjunction with the suction catheter during the suction operation, the thrombus removal stent 1 can be directly placed into the suction catheter after scraping the thrombus.

[0051] 6) The release position of the thrombus retriever stent 1 is at the distal end of the thrombus lesion. By pulling the thrombus retriever stent 1 and the device backward, the grid wedge angle 17 located at the maximum diameter of the thrombus retriever stent 1 scrapes off the wall thrombus and enters the thrombus retriever stent 1 through the proximal grid 13 and the proximal grid 2 14. Then, as the thrombus retriever stent 1 is withdrawn and gripped in the outer sheath 6, the thrombus that has entered the thrombus retriever stent 1 is received and removed by the distal deformable portion 1b, or is broken by the grid of the thrombus retriever stent 1.

[0052] Example 1 Please refer to Figure 1In this embodiment, the thrombus removal device is composed of a thrombus removal stent 1, an outer sheath assembly and an inner tube assembly, wherein the outer sheath assembly includes an outer sheath 6, an outer sheath hemostatic valve 8 and an outer sheath drain valve 9, and the inner tube assembly includes a TIP head 4, a distal inner tube 3, an inner tube 2 and an inner tube seat 5. The outer sheath hemostatic valve 8 connected to the proximal end of the outer sheath 6 is an adjustable hemostatic valve, and a two-way valve is connected to the outer sheath hemostatic valve 8 as an outer sheath drain valve 9 for draining. The inner tube seat 5 is a Luer connector. The inner tube 2 is 10-25 cm longer than the outer sheath 6 so that the thrombus removal stent 1 can be fully released.

[0053] Please refer to Figure 3 The thrombectomy stent 1 is in the shape of a sphere, with four wave rods 11 gathered at the proximal end to form a proximal connecting portion 1c, and four proximal grids 13 covering the entire proximal deformable portion 1a and part of the distal deformable portion 1b are distributed on the proximal deformable portion 1a. Four proximal grids 2 14 are distributed circumferentially on the proximal deformable portion 1a, and their grid wedge angles 17 are of the same dimension as the grid wedge angles 17 of the proximal grids 13. Proximal grids 3 15 are evenly distributed circumferentially on the distal deformable portion 1b, and the number is 8.

[0054] The mesh units of the distal deformable portion 1b gradually converge to the distal connection portion 1d. The proximal connection portion 1c has a developing member 21, and the material of the developing member 21 can be selected from nickel-titanium alloy, platinum-iridium alloy, etc. The distal connection portion 1d is a mesh in a gradually contracted state, and the mesh units gradually become smaller and gather together, and are divided into separate straight wave rods 11, and then connected to the TIP head 4.

[0055] When using the thrombus removal device of this embodiment, the inner tube 2 is withdrawn outside the body, and the thrombus removal stent 1 is pressed and gripped into the outer sheath 6, so that the head end of the outer sheath 6 and the TIP head 4 on the inner tube assembly are smoothly transitioned; during the pressing and gripping process, the entire device is emptied through the outer sheath evacuation valve 9 and the inner tube seat 5. A guide wire passage has been pre-established, and a suction catheter used in surgery is placed. The guide wire passes through the TIP head 4, enters the distal inner tube 3, and then passes through the inner tube 2. The thrombus removal device locked by the outer sheath hemostasis valve 8 enters the suction catheter along the guide wire, reaches the target blood vessel, passes through the lesion position, and according to the development of the thrombus removal stent 1 on the intraoperative DSA image, through the development of the thrombus removal stent 1 itself and the development part 21 of the proximal connecting part 1c, it is confirmed that the thrombus removal stent 1 is at the distal end of the target thrombus. The inner tube assembly and the outer sheath assembly are unfastened from each other, the outer sheath 6 is withdrawn, and the thrombus retriever stent 1 is released until it is completely exposed. The nickel-titanium memory alloy thrombus retriever stent 1 is expanded to a predetermined shape at body temperature, and the maximum diameter fits the blood vessel wall. The outer sheath 6 and the inner tube 2 are locked again, and the thrombus retriever device is withdrawn. The thrombus is scraped off along the grid wedge angle 17 of the proximal grid 13 and the proximal grid 2 14 and enters the thrombus retriever stent 1 from the proximal grid 13 or the proximal grid 2 14. The thrombus retriever stent 1 enters the suction catheter with the scraped thrombus. When the thrombus is too large to enter the catheter directly, the grid unit of the proximal deformable portion 1a will squeeze and break the thrombus received in the thrombus retriever stent 1 from the grid unit during the retraction of the thrombus retriever stent 1, and then it is removed by secondary scraping or catheter suction.

[0056] Example 2 Please refer to Figure 4 In this embodiment, on the basis of the first embodiment, the distal inner tube 3 is extended until it extends out of the inner tube seat 5, and a distal inner tube fixing seat 19 is added. The inner tube seat 5 is provided with an inner tube hemostatic valve 10, and the inner tube hemostatic valve 10 is connected to the inner tube emptying valve 18 on the side. When the inner tube hemostatic valve 10 is in an open state, the distal inner tube 3 is in a free state and can move with the deformation of the thrombus removal stent 1; when the inner tube hemostatic valve 10 is in a locked state, the distal inner tube 3 is fixed, and the shape of the thrombus removal stent 1 is fixed. The thrombus removal stent 1 is pressed and gripped into the outer sheath 6 outside the body, at which time the outer sheath hemostatic valve 8 is locked, the inner tube hemostatic valve 10 is opened, and enters the diseased blood vessel along the guide wire and passes through the thrombus.

[0057] When there are many mural thrombi in the blood vessels, or the thrombi are hard and the thrombus removal stent 1 cannot be fully deployed, the mesh of the maximum diameter dimension of the thrombus removal stent 1 is not fully deployed, the wedge angle is not deployed, and the thrombus scraping effect is limited. At this time, the distal inner tube fixing seat 19 is pulled back by the operator, and the thrombus removal stent 1 is manually pulled until the spherical diameter becomes larger, and the inner tube hemostatic valve 10 is locked to fix the distal inner tube 3, that is, the shape of the thrombus removal stent 1 is maintained. The shape of the thrombus removal stent 1 can be adjusted according to the thrombus state at the lesion and the scraping effect.

[0058] Example 3 Please refer to Figure 5 In this embodiment, multiple stent structures can be added on the basis of embodiment 1, preferably 1-2. This thrombectomy device comprises a TIP head 4, a thrombectomy stent 1 and a second thrombectomy stent 20, a distal inner tube 3, an inner tube 2, an inner tube seat 5, an outer sheath 6, an outer sheath hemostatic valve 8, and an outer sheath exhaust valve 9. The thrombectomy stent 1 and the second thrombectomy stent 20 are connected end to end and are both sleeved on the outer side of the distal inner tube 3. The proximal ends of the thrombectomy stent 1 and the second thrombectomy stent 20 both have a developing member 21. The proximal end of the thrombectomy stent 1 is connected to the inner tube 2. The second thrombectomy stent 20 is a self-expanding braided structure (or a cut self-expanding stent). The thrombectomy stent 1 is a cut self-expanding stent. The braided mesh density of the second thrombectomy stent 20 is greater than the cut mesh density of the thrombectomy stent 1. Before the operation, the thrombus removal stent 1 and the second thrombus removal stent 20 are pressed and grasped together into the outer sheath 6. After entering the lesion position of the target blood vessel, the thrombus removal stent 1 exceeds the thrombus position. The outer sheath 6 is withdrawn to release the thrombus removal stent 1 and the second thrombus removal stent 20. The thrombus removal stent 1 is used for scraping the thrombus. After the second thrombus removal stent 20 is deployed, it acts on the distal end of the thrombus removal stent 1. Due to the tightly woven mesh of the second thrombus removal stent 20, the scraped small thrombus is prevented from floating further while ensuring the smooth flow of blood. The thrombus retriever stent 1 mainly removes the mural thrombus through the wedge angle at the maximum diameter. The scraped thrombus enters the thrombus retriever stent 1 or is free in the blood vessel. The second thrombus retriever stent 20 blocks and collects the thrombus that has not entered the thrombus retriever stent 1 and brings them into the outer sheath 6 together. Or, when the second thrombus retriever stent 20 is unfolded and blocked, suction is performed with a suction catheter to remove the thrombus between the thrombus retriever stent 1 and the second thrombus retriever stent 20, and then the second thrombus retriever stent 20 assists in removing the thrombus at the lesion.

[0059] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A thrombus removal stent, characterized in that: The invention comprises a plurality of wave rods, wherein the wave rods are sequentially formed into a proximal connecting part, a proximal deformable part, a distal deformable part and a distal connecting part along a straight direction; the proximal deformable part and the distal deformable part are both formed into a half cage shape by a plurality of the wave rods; the proximal deformable part and the distal deformable part are connected to form a complete cage; the proximal connecting part is formed into a tubular shape by the wave rods at the end of the proximal deformable part, and the distal connecting part is formed into a tubular shape by the wave rods at the end of the distal deformable part.

2. The thrombus removal stent according to claim 1, characterized in that: The proximal deformable portion and the distal deformable portion are both hemispherical, and the proximal deformable portion and the distal deformable portion are connected together to form a complete sphere.

3. The thrombus removal stent according to claim 2, characterized in that: The wave rod of the proximal connecting part extends and is connected to the distal deformable part to form a proximal grid, and the proximal grid is distributed in the circumferential direction of the proximal deformable part, occupying part of the proximal deformable part and part of the distal deformable part; The proximal grids include a plurality of proximal grids 1, a plurality of proximal grids 2 and a plurality of proximal grids 3; The proximal grid 1 and the proximal grid 2 are spaced apart in the circumferential direction of the proximal deformable portion, a notch is provided between the proximal grid 1 and the proximal grid 2, and the proximal grid 3 is partially located in the notch; When the wave rods of the distal deformable portion extend toward the distal end, they are radially gathered to form a plurality of distal grids, and the distal grids and the proximal grids are spaced apart and distributed along the circumference of the distal deformable portion.

4. The thrombus removal stent according to claim 3, characterized in that: The number of wave rods in the proximal connecting part is 2-4; the number of proximal grids 1 is 2-4; the number of proximal grids 2 is 2-4; and the number of grids in the distal deformable part is 6-10.

5. The thrombus removal stent according to claim 3, characterized in that: The wave rod extending from the proximal connecting portion to the proximal deformable portion is forked to form two first support rods, the first support rod is forked to form two second support rods, the proximal grid 1 is surrounded by support rods formed by the same fork of the wave rod, and the proximal grid 2 is surrounded by support rods formed by different forks of the wave rods.

6. The thrombus removal stent according to claim 3, characterized in that: The mesh density of the distal deformable portion is greater than the mesh density of the proximal deformable portion.

7. The thrombus removal stent according to claim 3, characterized in that: The mesh size of the distal deformable portion is smaller than the mesh size of the proximal deformable portion.

8. The thrombus removal stent according to claim 3, characterized in that: A node is formed at the intersection of adjacent wave rods, and a node where the proximal grid 1, the proximal grid 2 and the distal grid intersect has a grid wedge angle toward the proximal side. The adjacent wave rods are formed in an acute angle to form the grid wedge angle, and the grid wedge angle is located at the distal deformable portion.

9. The thrombus removal stent according to claim 3, characterized in that: The length of all grids along the axial direction of the proximal connecting portion is greater than the width along the circumferential direction.

10. A thrombus removal device, characterized in that: The thrombus removal stent according to any one of claims 1 to 9 further comprises: An outer sheath tube assembly comprises an outer sheath tube and an outer sheath tube seat, wherein the proximal end of the outer sheath tube is connected to the outer sheath tube seat, and the outer sheath tube seat is provided with an outer sheath tube hemostasis valve and an outer sheath tube emptying valve; The inner tube assembly comprises a TIP head, a distal inner tube, an inner tube and an inner tube seat; one end of the distal inner tube is connected to the TIP head, and the other end passes through the inner tube; the inner tube passes through the outer sheath, the proximal end of the inner tube is connected to the inner tube seat, one end of the thrombectomy bracket is connected to the TIP head, and the other end is connected to the inner tube, and includes a section of the distal inner tube.

11. The thrombus removal device according to claim 10, characterized in that: The TIP head is provided with a step which is plugged into the outer sheath tube and connected with the outer wall through transition.

12. The thrombus removal device according to claim 11, characterized in that: The thrombus removal device also includes a second thrombus removal stent, which is an automatically expandable stent and can be compressed, deformed and accommodated in the outer sheath; the second thrombus removal stent is connected to the stent end to end, the second thrombus removal stent is located between the stent and the TIP head, the grid density of the second thrombus removal stent is greater than the grid density of the stent, and the second thrombus removal stent is used to block and assist in intercepting fine thrombi.

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