Thrombectomy device
The thrombus removal device with a shape memory alloy stent assembly and push-pull core wires addresses incomplete thrombus removal by enabling rotational cutting and axial displacement, improving the efficiency and safety of thrombus extraction.
Patent Information
- Application Number
- CN202420307869.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-02-20
AI Technical Summary
Existing thrombectomy stents face challenges in complete thrombus removal due to risk of thrombus plaque detachment and difficulty in withdrawing larger and harder thrombi, leading to secondary strokes and multiple surgical injuries.
A thrombus removal device comprising a microcatheter, shape memory alloy stent assembly, and delivery guide wire, with a stent assembly having multiple push-pull core wires, allowing for rotational cutting, axial displacement, and squeezing actions to capture and remove thrombi effectively.
Enhances the success rate and efficiency of single thrombus removal by preventing thrombus fragments from falling back into blood vessels, reducing the risk of secondary strokes and surgical complications.
Smart Images
Figure CN222130212U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a vascular intervention medical device, in particular to a thrombus removal device. Background Art
[0002] Cerebral stroke, also known as "stroke" or "cerebral vascular accident" (CVA), is an acute cerebrovascular disease. It is a type of disease that causes brain tissue damage due to sudden rupture of brain blood vessels or blood vessel blockage that prevents blood from flowing into the brain. It includes ischemic stroke and hemorrhagic stroke. The incidence of ischemic stroke is higher than that of hemorrhagic stroke, accounting for 60% to 70% of the incidence of stroke. Ischemic stroke is mainly caused by cerebrovascular thrombosis and is the most common fatal and disabling disease of the central nervous system. It is characterized by high incidence, high disability rate, high mortality rate and high recurrence rate.
[0003] Recanalization of blood vessels is the key to treating ischemic stroke. Currently, there are two main treatment methods for intracranial thrombosis: drug thrombolysis and mechanical thrombectomy. At present, mechanical thrombectomy is often performed using a thrombectomy stent. However, in order to facilitate the capture of thrombi and ensure good wall adhesion and flexibility, the existing thrombectomy stents are usually equipped with larger meshes. However, during the withdrawal of the stent, there is often a risk of thrombus plaque detachment, and it is difficult to withdraw larger and harder thrombi into the suction catheter, causing the thrombi to fall back into the blood vessels, thereby causing secondary stroke, causing danger to the patient and multiple surgical injuries. Summary of the invention
[0004] In order to solve the above technical problems, the utility model proposes a thrombus removal device to solve the problems of incomplete thrombus removal, the need for multiple thrombus removals, and the easy escape of thrombus fragments and their remaining in the blood vessels.
[0005] In order to achieve one of the above-mentioned purposes of the utility model, an embodiment of the utility model provides a thrombus removal device, including a microcatheter, a shape memory alloy stent assembly and a delivery guide wire, wherein the delivery guide wire is connected to the proximal end of the stent assembly, and the stent assembly has a folded state folded and stored in the microcatheter, and an expanded state detached from the microcatheter, wherein the stent assembly includes:
[0006] First bracket;
[0007] A second bracket, located inside the first bracket;
[0008] A first push-pull core wire is inserted into the delivery guide wire, and its distal end is connected to the proximal end of the second stent;
[0009] The second push-pull core wire connects the distal end of the first stent and the distal end of the second stent.
[0010] As a further improvement of an embodiment of the utility model, the stent assembly also includes a third push-pull core wire, which is inserted into the delivery guide wire and the second stent, and the distal end of the third push-pull core wire is connected to the distal end of the first stent.
[0011] As a further improvement of an implementation manner of the utility model, the first push-pull core wire and the third push-pull core wire are both rigid parts.
[0012] As a further improvement of an embodiment of the utility model, the second push-pull core wire is a flexible member.
[0013] As a further improvement of an embodiment of the utility model, when the bracket assembly is in the expanded state, the first bracket is in a mesh tube shape, and the first bracket includes a first tube segment located at its distal end, and the tube diameter of the first tube segment gradually decreases from the proximal end to the distal end.
[0014] As a further improvement of an embodiment of the utility model, the first bracket also includes a second tube segment, the distal end of the second tube segment is connected to the proximal end of the first tube segment, and the mesh of the first tube segment is smaller than the mesh of the second tube segment.
[0015] As a further improvement of an embodiment of the utility model, a constriction is formed at the proximal end of the second tube segment.
[0016] As a further improvement of an embodiment of the utility model, when the bracket assembly is in the expanded state, the second bracket is in a mesh tube shape, and the mesh of the second bracket is larger than the mesh of the first tube segment and smaller than the mesh of the second tube segment.
[0017] As a further improvement of an embodiment of the utility model, the second bracket includes a plurality of bracket units arranged in series from the proximal end to the distal end; when the bracket assembly is in the expanded state, each of the bracket units is in the shape of a net tube.
[0018] As a further improvement of an embodiment of the utility model, the proximal end and the distal end of each of the bracket units are respectively formed with a constriction.
[0019] Compared with the prior art, the utility model has the following beneficial effects:
[0020] The thrombus removal device of the utility model, during the thrombus removal process, when the stent assembly is in the deployed state, the first push-pull core wire is operated to rotate around its axial direction, so that the second stent can be rotated around its axial direction relative to the first stent, thereby performing rotational cutting on the thrombus block, so that the thrombus block is peeled off from the blood vessel wall; the first push-pull core wire is operated to move toward the distal end, so that the second stent can be moved toward the distal end relative to the first stent, and the second stent can be squeezed, deformed and compressed under the action of the first stent, thereby achieving further squeezing and cutting of the thrombus block; the first push-pull core wire is operated to move toward the proximal end, so that the second stent can be moved toward the proximal end relative to the first stent, and the second stent can be stretched under the action of the first stent and the second push-pull core wire, thereby achieving further cutting of the target thrombus;
[0021] The utility model can cut the target thrombus according to the shape of the stent assembly itself, and further operate the first push-pull core wire to make the second stent rotate, axially displace, and squeeze relative to the first stent to perform more precise cutting and capturing of the target thrombus, and drag the thrombus into the entire stent assembly, so as to prevent a large and hard thrombus from being difficult to withdraw into the suction catheter, or difficult to pass through the narrow part of the blood vessel and unable to be withdrawn into the suction catheter, thereby falling back into the blood vessel, and then causing a secondary stroke, bringing danger to the patient and harm from the secondary operation, thereby improving the success rate and efficiency of a single thrombus removal, and also clearing the suction catheter by the movement of the second stent relative to the first stent, avoiding the situation that the suction catheter is blocked and the operation cannot be performed due to the thrombus being too large or hard. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings provided herein are used to further illustrate the understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0023] Figure 1 The utility model is a schematic diagram of the thrombus removal process. Figure 1 ;
[0024] Figure 2 The utility model is a schematic diagram of the thrombus removal process. Figure 2 ;
[0025] Figure 3 This is a schematic structural diagram of a bracket assembly according to one embodiment of the utility model;
[0026] Figure 4 for Figure 3 Schematic diagram of the explosion. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical solution and advantages of this application clearer, the technical solution of this application will be clearly and completely described in combination with the specific embodiments of this application and the corresponding drawings. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0028] In various drawings of the present invention, for the convenience of illustration, some dimensions of structures or parts are enlarged relative to other structures or parts, and therefore, are only used to illustrate the basic structure of the subject matter of the present invention.
[0029] It should be understood that, unless otherwise expressly specified and limited, in the description of the present invention, the terms "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.
[0030] In the present invention, the terms "distal end" and "proximal end" should be understood as viewed from the direction of the instrument operator, the proximal end is the end facing the instrument operator, and the distal end is the end away from the instrument operator. The direction indicated by the arrow in the figure is from the proximal end to the distal end.
[0031] See also Figures 1 to 4 The utility model proposes a thrombus removal device 100, comprising a microcatheter 1, a shape memory alloy stent assembly 2 and a delivery guide wire, wherein the stent assembly 2 is cut, carved or woven from a shape memory alloy tube material having superelasticity. The delivery guide wire is connected to the proximal end of the stent assembly 2, and the microcatheter 1 can compress, fold and store the stent assembly 2 inside, and the stent assembly 2 has a folded state in which it is folded and stored in the microcatheter 1, and an unfolded state in which it is separated from the microcatheter 1.
[0032] See also Figure 3 to Figure 4 , wherein the stent assembly 2 comprises a first stent 21, a second stent 22, a first push-pull core wire 23 and a second push-pull core wire 24. The second stent 22 is located inside the first stent 21; the first push-pull core wire 23 is inserted into the delivery guide wire, and its distal end is connected to the proximal end of the second stent 22; the second push-pull core wire 24 connects the distal end of the first stent 21 with the distal end of the second stent 22.
[0033] Combination Figure 1 to Figure 2 In clinical operation, the blood vessel 200 puncture intervention technique is used to insert the microcatheter 1 into the blood vessel 200 and make the distal end of the microcatheter 1 exceed the target thrombus 300 by a certain distance. Figure 1 As shown, by utilizing the guiding function of the microcatheter 1, the delivery guide wire is operated to deliver the shape memory alloy stent assembly 2 into the microcatheter 1 and push it to its distal end. When the distal end of the stent assembly 2 reaches the distal end of the microcatheter 1, that is, Figure 2 When in the position shown, the stent assembly 2 is kept stationary relative to the human body and the microcatheter 1 is withdrawn toward the proximal end. As the microcatheter 1 is withdrawn, the stent assembly 2 will self-expand and unfold around its axial direction at the position of the target thrombus 300, that is, the stent assembly 2 changes from the folded state to the unfolded state, the stent assembly 2 cuts into the target thrombus 300 to hang on the thrombus as a whole, and then the delivery guide wire and the stent assembly 2 are withdrawn, thereby achieving thrombus removal. During this process, when the stent assembly 2 is in the deployed state, the first push-pull core wire 23 is operated to rotate around its axis, so that the second stent 22 can rotate around its axis relative to the first stent 21, thereby performing rotational cutting on the thrombus block and causing the thrombus block to be peeled off from the wall of the blood vessel 200; the first push-pull core wire 23 is operated to move distally, so that the second stent 22 can move distally relative to the first stent 21, and the second stent 22 can be squeezed, deformed and compressed under the action of the first stent 21, thereby achieving further squeezing and cutting of the thrombus block; the first push-pull core wire 23 is operated to move proximally, so that the second stent 22 can move proximally relative to the first stent 21, and the second stent 22 can be stretched under the action of the first stent 21 and the second push-pull core wire 24, thereby achieving further cutting of the target thrombus 300; in this way, the stent assembly can be 2, on the basis of cutting the target thrombus 300 according to its own shape, the first push-pull core wire 23 is further operated to make the second stent 22 rotate, axially displace, squeeze, etc. relative to the first stent 21 to perform more refined cutting and capture of the target thrombus 300, and the thrombus is dragged into the entire stent assembly 2, so as to prevent the thrombus with a large volume and a hard texture from being difficult to withdraw into the suction catheter, or from being difficult to pass through the narrow part of the blood vessel 200 and unable to withdraw into the suction catheter, thereby falling back into the blood vessel 200, thereby causing a secondary stroke, bringing danger to the patient and harm to the secondary operation, thereby improving the success rate and efficiency of a single thrombus removal, and the suction catheter can be unblocked by the movement of the second stent 22 relative to the first stent 21, thereby avoiding the situation that the suction catheter is blocked and the operation cannot be performed due to the thrombus being too large or hard.
[0034] See also Figure 4Furthermore, the stent assembly 2 further includes a third push-pull core wire 25, which is inserted into the delivery guide wire and the second stent 22, and the distal end of the third push-pull core wire 25 is connected to the distal end of the first stent 21. When the stent assembly 2 is in the deployed state, the third push-pull core wire 25 is operated to rotate around its axial direction, so that the first stent 21 can be rotated relative to the second stent 22 around its axial direction, thereby performing rotational cutting on the thrombus, so as to prevent the thrombus with a hard texture from being difficult to peel off from the blood vessel 200 and causing difficulty in removal; the third push-pull core wire 25 is operated to move along its axial distal end or proximal end, so that the first stent 21 can be moved distally or proximally relative to the second stent 22, because the second stent 22 is pulled by the first push-pull core wire 23, and the distal ends of the first stent 21 and the second stent 22 are connected by the second push-pull core wire 24, so that the first stent 21 can be squeezed or stretched to achieve sufficient squeezing and cutting of the thrombus, thereby ensuring smooth aspiration of the thrombus and reducing the risk of thrombus leakage.
[0035] Preferably, the first push-pull core wire 23 and the third push-pull core wire 25 are both rigid parts, so as to better realize the rotation, compression and stretching of the first bracket 21 and the second bracket 22 .
[0036] The second push-pull core wire 24 is preferably a flexible member, so that when the first push-pull core wire 23 is operated to move distally, the second bracket 22 can move to the distal end of the first bracket 21 and be compressed and deformed under the support of the distal end of the first bracket 21, so as to achieve better squeezing and cutting of the thrombus block.
[0037] Furthermore, when the stent assembly 2 is in the expanded state, the first stent 21 is in the shape of a mesh tube, so that the target thrombus 300 can be cut under the action of the shape structure of the first stent 21 itself; the first stent 21 includes a first tube segment 211 located at its distal end, and the tube diameter of the first tube segment 211 gradually decreases from the proximal end to the distal end. On the one hand, the thrombus block can be withdrawn into the microcatheter 1 to prevent the thrombus block from escaping to the distal end of the blood vessel 200. On the other hand, when the first push-pull core wire 23 is operated to push the second stent 22 to move distally, the distal end of the second stent 22 can be pressed against the distal end of the first stent 21, thereby realizing compression deformation of the second stent 22.
[0038] Preferably, the distal end of the first tube segment 211 is constricted, so that the first tube segment 211 is in the shape of a net bag, thereby being able to collect small, scattered thrombi, thereby better preventing the thrombi from escaping to the distal end of the blood vessel 200 and falling back into the blood vessel 200 to form secondary embolism.
[0039] See also Figure 3 to Figure 4Furthermore, the first bracket 21 also includes a second tube segment 212, the distal end of the second tube segment 212 is connected to the proximal end of the first tube segment 211, and the mesh of the first tube segment 211 is smaller than the mesh of the second tube segment 212. In this way, the first tube segment 211 mainly cuts the thrombus, while the second tube segment 212 is conducive to withdrawing the thrombus into the microcatheter 1 and preventing the thrombus from escaping.
[0040] Preferably, the proximal end of the second tube section 212 forms a constriction, thereby limiting the movement space of the second bracket 22 within the first bracket 21, preventing the second push-pull core wire 24 from breaking due to improper force when the first push-pull core wire 23 is pulled toward the proximal end.
[0041] Furthermore, when the stent assembly 2 is in the expanded state, the second stent 22 is in the shape of a mesh tube, and the mesh of the second stent 22 is larger than the mesh of the first tube segment 211, and smaller than the mesh of the second tube segment 212. In this way, through the cooperation of the first stent 21 and the second stent 22, not only can the thrombus be cut in multiple directions and angles, but also thrombus blocks of various sizes can be captured, and it can be suitable for thrombus of different properties. In particular, the mesh of the second stent 22 located in the first stent 21 is smaller, and its cutting of the central area of the thrombus block is more precise, forming a smaller thrombus block, which can be captured with the help of the first tube segment 211 with smaller mesh to prevent escape; and the large mesh of the first stent 21 gives it a stronger radial cutting force.
[0042] In one embodiment, the second support 22 may be a single mesh tube, so that the support assembly 2 has a simple structure and is easy to process.
[0043] See also Figure 3 to Figure 4 In a preferred embodiment, the second stent 22 includes a plurality of stent units 221 arranged in series from the proximal end to the distal end; in the unfolded state, each stent unit 221 is in the shape of a net tube. In this way, in the tortuous and complex blood vessel 200 environment, the second stent 22 not only has better passability, but also can be expanded better; when the first stent 21 cannot be completely opened in the tortuous and complex blood vessel 200, or the first stent 21 forms a "fish mouth"-shaped bend at the curved section of the blood vessel 200 with a large bending angle, by operating the first push-pull core wire 23, the second push-pull core wire 24 and the third push-pull core wire 25, the second stent 22 can be moved relative to the first stent 21 along the axial direction of the first push-pull core wire 23, so that the second stent 22 is compressed and deformed to expand, and then the first stent 21 is supported from the inside to the outside to expand, so as to ensure the cutting and thrombus removal ability of the stent assembly 2 in the complex blood vessel 200 environment, and improve the thrombus removal effect of the stent assembly 2 in the complex blood vessel 200 environment.
[0044] Preferably, the proximal end and the distal end of each bracket unit 221 each form a constriction, that is, each bracket unit 221 is oval or ovate, which is beneficial to the connection between adjacent bracket units 221.
[0045] The first bracket 21 and the second bracket 22 are both made of a shape memory alloy tube with superelasticity. Specifically, the first bracket 21 can be made by laser cutting of a shape memory alloy tube with superelasticity; the second bracket 22 can be made by laser cutting or weaving of a shape memory alloy tube with superelasticity, or each bracket unit 221 of the second bracket 22 is made by laser cutting or weaving of a shape memory alloy tube with superelasticity, and then the bracket units 221 are connected to each other to form.
[0046] Preferably, a developing device may be provided at the connection of adjacent stent units 221, and the developing device is fixed by physical extrusion, gluing, brazing, laser welding, etc., so as to facilitate clinicians to check the grasping of thrombus by the stent assembly 2 through the developing device. The developing device may specifically be a developing spring, a developing ring 222, a developing film, etc.
[0047] Preferably, when each bracket unit 221 is formed separately, adjacent bracket units 221 can be connected by a developing ring 222, that is, the proximal end and the distal end of each bracket unit 221 can be gathered in the developing ring 222, and the third push-pull core wire 25 passes through each bracket unit 221 and each developing ring 222. This is not only convenient for operation, but also the third push-pull core wire 25 can serve as a track for the second bracket 22 to move along its axial direction relative to the first bracket 21.
[0048] Among them, the number of stent units 221 can be set according to the applied blood vessel 200 and the axial length of the second stent 22, and can also be set in combination with the axial length of each stent unit 221, such as setting 2, 3, 4, 5, etc.
[0049] Preferably, the first bracket 21 and the second bracket 22 are made of nickel-titanium alloy, stainless steel, cobalt-chromium alloy, platinum-tungsten alloy, nickel-titanium-platinum composite material, and more preferably made of platinum-tungsten alloy, nickel-titanium-platinum composite material and other materials with developing properties, so that they can have a developing effect and facilitate the observation of the position and deployment state of the thrombectomy device 100 during surgery.
[0050] See also Figure 3 to Figure 4 Furthermore, the thrombus removal device 100 further includes a protective head 3 disposed at the distal end of the stent assembly 2. The protective head 3 is preferably a flexible member to prevent the protective head 3 from directly pressing against the wall of the blood vessel 200 during misoperation and causing damage to the blood vessel 200, thereby causing secondary damage to the patient.
[0051] Preferably, the material of the protective head end 3 can be a material with development properties such as platinum-tungsten alloy, nickel-titanium-platinum composite material, etc., so that clinicians can monitor the protective head end 3 through blood vessel 200 imaging equipment, such as DSA (digital subtraction angiography), and then understand the end position of the stent assembly 2 in the blood vessel 200.
[0052] Preferably, the distal end of the second push-pull core wire 24 is connected to the protection head end 3 , and the distal end of the third push-pull core wire 25 is connected to the protection head end 3 , which is beneficial to the stable connection of the first bracket 21 and the second bracket 22 .
[0053] To summarize, the thrombus removal device 100 proposed in the utility model, in clinical operation, adopts the blood vessel 200 puncture intervention technology, sends the microcatheter 1 into the blood vessel 200 and makes the distal end of the microcatheter 1 exceed the target thrombus 300 by a certain distance, utilizes the guiding effect of the microcatheter 1, operates the delivery guide wire to send the shape memory alloy stent assembly 2 into the microcatheter 1 and push it to its distal end, when the distal end of the stent assembly 2 reaches the farthest end of the microcatheter 1, keeps the stent assembly 2 motionless relative to the human body and withdraws the microcatheter 1 proximally, with the withdrawal of the microcatheter 1, the stent assembly 2 will expand and unfold around its axial direction at the position of the target thrombus 300, that is, the stent assembly 2 changes from the folded state to the unfolded state, the stent assembly 2 cuts into the target thrombus 300 to hang the thrombus as a whole, and then withdraws the delivery guide wire and the stent assembly 2, thereby achieving thrombus removal. During this process, when the stent assembly 2 is in the deployed state, the first push-pull core wire 23 is operated to rotate around its axis, so that the second stent 22 can rotate around its axis relative to the first stent 21, thereby performing rotational cutting on the thrombus block and causing the thrombus block to be peeled off from the wall of the blood vessel 200; the first push-pull core wire 23 is operated to move distally, so that the second stent 22 can move distally relative to the first stent 21, and the second stent 22 can be squeezed, deformed and compressed under the action of the first stent 21, thereby achieving further squeezing and cutting of the thrombus block; the first push-pull core wire 23 is operated to move proximally, so that the second stent 22 can move proximally relative to the first stent 21, and the second stent 22 can be stretched under the action of the first stent 21 and the second push-pull core wire 24, thereby achieving further cutting of the target thrombus 300; in this way, the stent assembly can be 2, on the basis of cutting the target thrombus 300 according to its own shape, the first push-pull core wire 23 is further operated to make the second stent 22 rotate, axially displace, squeeze, etc. relative to the first stent 21 to perform more refined cutting and capture of the target thrombus 300, and the thrombus is dragged into the entire stent assembly 2, so as to prevent the thrombus with a large volume and a hard texture from being difficult to withdraw into the suction catheter, or from being difficult to pass through the narrow part of the blood vessel 200 and unable to withdraw into the suction catheter, thereby falling back into the blood vessel 200, thereby causing a secondary stroke, bringing danger to the patient and harm to the secondary operation, thereby improving the success rate and efficiency of a single thrombus removal, and the suction catheter can be unblocked by the movement of the second stent 22 relative to the first stent 21, thereby avoiding the situation that the suction catheter is blocked and the operation cannot be performed due to the thrombus being too large or hard.
[0054] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.
Claims
1. A thrombus removal device, comprising a microcatheter, a shape memory alloy stent assembly and a delivery guide wire, wherein the delivery guide wire is connected to the proximal end of the stent assembly, and the stent assembly has a folded state in which it is folded and stored in the microcatheter, and an expanded state in which it is detached from the microcatheter, It is characterized in that The bracket assembly comprises: First bracket; A second bracket, located inside the first bracket; A first push-pull core wire is inserted into the delivery guide wire, and its distal end is connected to the proximal end of the second stent; The second push-pull core wire connects the distal end of the first stent and the distal end of the second stent.
2. The thrombus removal device according to claim 1, It is characterized in that The stent assembly further includes a third push-pull core wire, which is inserted into the delivery guide wire and the second stent, and the distal end of the third push-pull core wire is connected to the distal end of the first stent.
3. The thrombus removal device according to claim 2, It is characterized in that The first push-pull core wire and the third push-pull core wire are both rigid parts.
4. The thrombus removal device according to claim 1, It is characterized in that The second push-pull core wire is a flexible member.
5. The thrombus removal device according to claim 1, It is characterized in that When the stent assembly is in the expanded state, the first stent is in a mesh tube shape, and the first stent includes a first tube section located at its distal end, and the diameter of the first tube section gradually decreases from the proximal end to the distal end.
6. The thrombus removal device according to claim 5, It is characterized in that The first stent also includes a second tube segment, the distal end of the second tube segment is connected to the proximal end of the first tube segment, and the mesh of the first tube segment is smaller than the mesh of the second tube segment.
7. The thrombus removal device according to claim 6, It is characterized in that The proximal end of the second tube section forms a constriction.
8. The thrombus removal device according to claim 6, It is characterized in that When the support assembly is in the expanded state, the second support is in a mesh tube shape, and the mesh holes of the second support are larger than the mesh holes of the first tube segment and smaller than the mesh holes of the second tube segment.
9. The thrombus removal device according to claim 1, It is characterized in that The second stent includes a plurality of stent units which are arranged in series from the proximal end to the distal end at intervals; when the stent assembly is in the expanded state, each of the stent units is in the shape of a net tube.
10. The thrombus removal device according to claim 9, It is characterized in that The proximal end and the distal end of each stent unit are respectively formed with constrictions.