A thrombectomy system

Abstract

The application provides a thrombus extraction system, and belongs to the technical field of interventional medical instruments. The system comprises a thrombus extraction stent, a delivery sheath, a pulling wire and a plurality of contraction units. The thrombus extraction stent has a self-expanding mesh cage structure and can be radially expanded from a compressed state to an expanded state. The delivery sheath is used for delivering and recovering the thrombus extraction stent. The distal end of the pulling wire is arranged in the interior of the thrombus extraction stent in an axial direction, and the proximal end extends to the proximal end of the delivery sheath. The plurality of contraction units are arranged in the axial direction at the distal end of the pulling wire. One end of each contraction unit is connected to the thrombus extraction stent, and the other end is connected to the pulling wire. When the pulling wire is pulled towards the proximal end after the thrombus extraction is completed, the contraction units move towards the proximal end to pull the side wall of the thrombus extraction stent, so that the thrombus extraction stent is radially contracted. The system is mainly used for solving the technical problem that the existing self-expanding thrombus extraction stent cannot simultaneously consider the stability of thrombus capture and the protection of blood vessels.

Description

Technical Field

[0001] This invention belongs to the field of interventional medical device technology, specifically relating to a thrombectomy system. Background Technology

[0002] Acute ischemic stroke and acute peripheral vascular embolism are characterized by high rates of disability and mortality. Timely and effective restoration of blood flow is crucial for improving patient prognosis. Currently, mechanical thrombectomy, especially surgery using stent-based interventional thrombectomy devices, has become the mainstream treatment for these diseases.

[0003] Existing thrombectomy stents are typically self-expanding mesh cage structures. The surgical procedure is as follows: First, the compressed thrombectomy stent is delivered to the thrombus inside the target blood vessel through a delivery sheath; then the delivery sheath is withdrawn to release the thrombectomy stent. The stent automatically expands by its own radial expansion force. During the expansion process, its own mesh structure embeds the thrombus, causing the thrombus to be squeezed into the thrombectomy stent.

[0004] However, there is a pressing technical problem in the clinical application of the aforementioned thrombectomy stents that needs to be solved, specifically: First, to ensure that the stent can effectively embed and securely fix thrombi of different textures (especially calcified or fibrotic ones) after deployment, and to prevent thrombus detachment and escape during withdrawal, existing thrombectomy stents are designed with high radial support strength. While this strong radial support ensures the effectiveness of thrombectomy, during the withdrawal and retrieval phase, when the operator pulls the delivery wire axially to retrieve the stent, axial friction and scraping effects are generated between the expanded stent mesh and the vascular intima. Due to the large radial support force of the stent, its mesh continuously exerts significant pressure on the vessel wall. During axial movement, this high-pressure sliding friction can easily lead to mechanical damage to the vascular intima, causing complications such as vasospasm, intimal tearing, or even perforation and bleeding. Meanwhile, the continuous mechanical stimulation of blood vessels during stent withdrawal can trigger local inflammatory reactions, exacerbate endothelial damage, delay postoperative vascular repair, and increase the probability of postoperative thrombosis recurrence and vascular stenosis. In addition, intraoperative vasospasm caused by severe vascular stimulation can further narrow the lumen of the blood vessel, increase the resistance to stent withdrawal, not only increasing the difficulty of the operation and prolonging the operation time, but also potentially causing stent entrapment, thrombus fragmentation and escape, significantly increasing the surgical risk and affecting the patient's postoperative prognosis.

[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0006] The purpose of this invention is to provide a thrombectomy system that can maintain sufficient radial expansion force during the thrombectomy operation to ensure efficient capture of thrombi, while effectively reducing or regulating the radial pressure and axial stimulation of the thrombectomy stent on the vessel wall during the retrieval phase. This ensures a high success rate of thrombectomy while effectively reducing vascular injury complications and improving the overall safety and effectiveness of the procedure.

[0007] To achieve the above objectives, the thrombectomy system of the present invention provides the following technical solution: A thrombectomy system, comprising: A thrombectomy bracket, wherein the thrombectomy bracket has a self-expanding mesh cage structure, capable of radially expanding from a compressed state to an expanded state; A delivery sheath for delivering and retrieving the thrombectomy stent; A pull wire, the distal end of which passes through the inside of the thrombectomy bracket along the axial direction, and the proximal end which extends to the proximal end of the delivery sheath; Multiple shrink units are arranged axially at intervals at the distal end of the pull wire, with one end of each shrink unit connected to a tack bracket and the other end connected to the pull wire; When the retrieval wire is pulled proximally after thrombectomy, the contraction unit moves proximally to pull the sidewall of the thrombectomy stent, causing the thrombectomy stent to contract radially.

[0008] As a further optimized technical solution, each of the shrinking units includes multiple drive wires arranged circumferentially along the traction wire, with one end of each drive wire connected to the tack bracket and the other end connected to the traction wire.

[0009] As a further optimized technical solution, when the thrombectomy bracket is in the expanded working state, each of the contraction units is arranged perpendicular to the axial direction of the thrombectomy bracket.

[0010] As a further optimized technical solution, each of the contraction units further includes: Each sliding ring is slidably sleeved on the pulling wire, and one end of the drive wire of each shrink unit is fixedly connected to the sliding ring, and the other end is fixedly connected to the thrombectomy bracket. A stop block is fixedly arranged on the pull wire at the distal end of the sliding ring, and at least a portion of the size of the stop block perpendicular to the extension direction of the pull wire is larger than the inner hole size of the sliding ring. When the traction wire is pulled proximally, the stop block pushes the sliding ring to move proximally, thereby driving the retrieval stent to retract radially.

[0011] As a further optimized technical solution, any two adjacent shrinkage units have the same axial spacing.

[0012] As a further optimized technical solution, each of the shrinking units has 2-6 drive wires, which are evenly arranged along the circumference of the drawing wire.

[0013] As a further optimized technical solution, the pull wire is located at the axial position of the thrombectomy bracket.

[0014] As a further optimized technical solution, the distal end of the thrombectomy stent has an escape-prevention section for collecting thrombi.

[0015] As a further optimized technical solution, the mesh size of the anti-escape section is smaller than that of the main body of the thrombectomy stent, and is used to block the distal port of the stent to prevent thrombus from escaping from the distal end of the thrombectomy stent.

[0016] As a further optimized technical solution, the escape prevention section is a conical structure integrally woven with the thrombectomy bracket, or a flexible filter bag independently connected to the distal end of the thrombectomy bracket.

[0017] Beneficial effects: First, by incorporating a contraction unit within the thrombectomy stent, this invention enables actively controllable radial contraction of the stent. This proactive reduction of the stent's outer diameter before retrieval significantly decreases the contact pressure and friction area between the stent's outer wall mesh and the vessel wall, thereby reducing mechanical damage to the vascular intima and effectively preventing complications such as vasospasm, intimal tearing, and perforation bleeding. Simultaneously, the significantly reduced stimulation of the vessel wall during stent retrieval significantly alleviates local inflammatory responses, promoting rapid postoperative endothelial repair and lowering the probability of postoperative thrombosis recurrence and restenosis.

[0018] Secondly, the overall outer diameter of the thrombectomy stent in this invention is reduced after active contraction, which greatly reduces the frictional resistance when it is retrieved to the delivery sheath, making the retrieval operation smoother and less strenuous. This effectively avoids the risk of stent jamming, reduces the difficulty of retrieval, reduces the operation time of the surgery, and effectively reduces the probability of intraoperative complications.

[0019] In addition, the present invention causes the stent to expand axially while contracting radially, which deforms the stent mesh and reduces the effective area of ​​the mesh. This allows the stent body to clamp and enclose the thrombus inside, preventing the thrombus from coming out of the stent mesh.

[0020] Furthermore, the distal end of the thrombectomy stent is equipped with an escape prevention section, which can intercept tiny embolic fragments that may escape from the main stent to the distal end. This can prevent thrombi that are crushed during radial contraction from escaping, greatly improving the integrity of thrombectomy and the first-time recanalization rate, and reducing the incidence of distal vascular embolism caused by embolic escape.

[0021] Furthermore, in this invention, when the thrombectomy stent is in the expanded working state, the drive wires of each contraction unit are arranged radially, that is, perpendicular to the axial direction, so that the thrombus will not interfere with the entry of the thrombus into the stent during the thrombectomy process, and will not affect the embedding and bonding of the thrombus with the stent mesh, thus ensuring the effectiveness of thrombectomy. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the radial expansion state of the thrombectomy support in Embodiment 1 of the thrombectomy system of the present invention; Figure 2 This is a radial cross-sectional schematic diagram of the thrombectomy bracket in Embodiment 1 of the thrombectomy system of the present invention; Figure 3 This is a schematic diagram of the radially contracted state of the thrombectomy support in Embodiment 1 of the thrombectomy system of the present invention; Figure 4 This is a schematic diagram of the radial expansion state of the thrombectomy support in Embodiment 2 of the thrombectomy system of the present invention; Figure 5 This is a schematic diagram of the radial contraction state of the thrombectomy support in Embodiment 2 of the thrombectomy system of the present invention.

[0023] In the diagram: 100, thrombus retrieval bracket; 200, delivery sheath; 300, pull wire; 400, retraction unit; 410, sliding ring; 420, stop block; 430, drive wire; 500, anti-escape section. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, the term "proximal end" uniformly refers to the end closer to the operator, while "distal end" refers to the end farther from the operator.

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0027] The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions of the product; they are only intended to illustrate the content of the invention.

[0028] To address the technical problem that existing self-expanding thrombectomy stents cannot simultaneously achieve stability in thrombus capture and vascular protection, according to specific embodiments of the present invention, such as... Figure 1-5 As shown, this invention provides a thrombectomy system, which includes a thrombectomy stent 100, a delivery sheath 200, a traction wire 300, and multiple contraction units 400. The thrombectomy stent 100 has a self-expanding mesh structure, capable of radially expanding from a compressed state to an expanded working state. The delivery sheath 200 is used for delivering and retrieving the thrombectomy stent 100. The distal end of the traction wire 300 passes axially inside the thrombectomy stent 100, and the proximal end extends to the proximal end of the delivery sheath 200. Multiple contraction units 400 are axially spaced at the distal end of the traction wire 300, with one end of each contraction unit 400 connected to the thrombectomy stent 100 and the other end connected to the traction wire 300. After thrombectomy, when the traction wire 300 is pulled proximally, the contraction units 400 move proximally to pull the sidewall of the thrombectomy stent 100, causing the thrombectomy stent 100 to contract radially and deform axially. This reduces the radial dimension and also reduces the mesh size of the thrombectomy stent 100, effectively preventing the thrombus within the stent from escaping. This invention enables active and controllable shrinkage of the radial dimension of the thrombectomy stent during the retrieval phase, significantly reducing frictional damage between the stent and the vessel wall, lowering retrieval resistance, and effectively preventing emboli escape through mesh tightening, thereby improving the safety and effectiveness of the thrombectomy procedure.

[0029] Example 1

[0030] like Figure 1 , Figure 2 As shown, the thrombectomy system includes a thrombectomy bracket 100, a delivery sheath 200, a pull wire 300, and multiple retraction units 400.

[0031] The thrombectomy stent 100 is a self-expanding mesh cage structure, manufactured from a nickel-titanium alloy tube using a laser-cutting process, exhibiting super-elastic properties. When not constrained by external forces, the thrombectomy stent 100 can automatically expand radially to a predetermined working diameter. The mesh of the thrombectomy stent 100 is diamond-shaped, designed to embed and grasp the thrombus upon expansion. In the delivery state, the thrombectomy stent 100 is compressed to a smaller diameter and housed within the delivery sheath 200.

[0032] The delivery sheath 200 is a flexible polymer material catheter with an inner diameter slightly larger than the outer diameter of the compressed thrombectomy stent 100. It is used to deliver the thrombectomy stent 100 along the vascular pathway to the target thrombus site and to retrieve the thrombectomy stent 100 from the body after thrombectomy. The proximal end of the delivery sheath 200 is typically equipped with a hemostatic valve and an operating handle (not shown in the figure) for controlling the pushing and retraction of the delivery sheath 200.

[0033] The traction wire 300 is a slender metal wire, preferably a nickel-titanium alloy wire or a stainless steel wire with superelastic properties. The traction wire 300 passes through the interior of the thrombectomy bracket 100 along its axis, with its distal end extending to the vicinity of the distal end of the thrombectomy bracket 100 but not protruding from the distal port of the thrombectomy bracket 100. Its proximal end extends along the inner lumen of the delivery sheath 200 to the external operating end, which is connected to the operating handle (not shown in the figure) for the operator to manipulate the axial displacement of the traction wire 300 proximally or distally from outside the body.

[0034] Multiple shrinkage units 400 are arranged at intervals along the axial direction of the drawing wire 300 inside the thrombectomy bracket 100. In this embodiment, the number of shrinkage units 400 is 3-8, preferably 4-6, and they are evenly distributed along the axial direction, that is, the axial spacing between any two adjacent shrinkage units 400 is the same, to ensure that the deformation of each part of the thrombectomy bracket 100 is consistent along the axial direction when it shrinks radially, and to avoid local stress concentration or torsional deformation. The axial spacing between adjacent shrinkage units 400 can be reasonably arranged according to the total length of the thrombectomy bracket 100.

[0035] In this embodiment, each shrinkage unit 400 specifically includes a sliding ring 410, a stop block 420, and multiple drive wires 430.

[0036] The sliding ring 410 is a metal ring, preferably made of platinum-iridium alloy, which has sufficient mechanical properties and is also recognizable. The inner diameter of the sliding ring 410 is slightly larger than the outer diameter of the drawing wire 300, so that the sliding ring 410 can slide freely along the axial direction of the drawing wire 300.

[0037] The stop block 420 is fixedly disposed on the drawing wire 300, located at the distal end of the corresponding sliding ring 410, i.e., the stop block 420 is in the distal direction of the sliding ring 410. All stop blocks 420 are arranged axially corresponding to the sliding rings 410, and at least a portion of the dimension of the stop block 420 perpendicular to the extending direction of the drawing wire 300 is larger than the inner diameter of the sliding ring 410. In this embodiment, the stop block 420 is a spherical body directly welded to the drawing wire 300, and the outer diameter of the stop block 420 is larger than the inner diameter of the sliding ring 410 to ensure that the stop block 420 can reliably push against the sliding ring 410 without passing through the inner diameter of the sliding ring 410. In other embodiments, it can also be an ellipsoidal body, as long as the dimension along the major axis of the ellipsoid is larger than the inner diameter of the sliding ring 410.

[0038] Multiple drive wires 430 are non-elastic flexible threads, preferably medical polyester sutures or fine metal wires. One end of each drive wire 430 is fixedly connected to the outer wall of the sliding ring 410 by welding, bonding, or knotting, while the other end extends radially outward and is fixedly connected to the inner wall of the thrombectomy stent 100, for example, at the mesh node of the thrombectomy stent 100. Each contraction unit 400 has 2-6 drive wires 430, preferably 4, which are evenly distributed along the circumference of the traction wire 300, i.e., the included angle between adjacent drive wires 430 is equal, and the included angle is 90° when there are 4. This circumferentially uniform arrangement ensures that the circumferential traction force of each drive wire 430 on the inner wall of the thrombectomy stent 100 is uniform, so that the stent has a regular shape and does not produce eccentric deformation when it contracts radially.

[0039] Furthermore, the distal end of the thrombectomy bracket 100 is provided with an escape prevention section 500.

[0040] The escape prevention section 500 is located at the distal end of the thrombectomy stent 100, and is closed at the distal end. Its mesh aperture is smaller than that of the main body of the thrombectomy stent 100. The escape prevention section 500 is used to block the distal end of the thrombectomy stent 100 to prevent thrombi, especially tiny embolic fragments, from escaping from the distal end of the thrombectomy stent 100 to downstream blood vessels.

[0041] In this embodiment, the escape prevention section 500 is a conical mesh structure integrally woven with the main body of the thrombectomy bracket 100, meaning that the escape prevention section 500 gradually tapers into a cone shape from the distal end of the main body of the thrombectomy bracket 100. Its mesh density is 2-3 times that of the main body of the thrombectomy bracket 100.

[0042] During the radial contraction and axial shortening of the thrombectomy stent 100, the escape prevention section 500 contracts simultaneously. Its conical structure more tightly wraps around the distal part of the thrombus after contraction, effectively preventing thrombus fragments from escaping from the distal end.

[0043] In other embodiments, the escape prevention section 500 may also be a flexible filter bag independently connected to the distal end of the retrieval bracket 100.

[0044] The working process of this invention is as follows: First, the thrombectomy stent 100, compressed within the delivery sheath 200, is delivered via a vascular pathway to the target thrombus site. The operator then withdraws the delivery sheath 200 proximally externally, releasing the thrombectomy stent 100. The thrombectomy stent 100 automatically expands radially to its working state due to its elasticity; its mesh embeds and compresses the thrombus, anchoring it within the mesh and internal space of the stent. At this point, as... Figure 1 and Figure 2 As shown, the drive wire 430 of each contraction unit 400 is in a taut state and extends radially along the thrombectomy stent 100, that is, perpendicular to the axial direction. This will not interfere with the entry of the thrombus into the stent, nor will it affect the embedding and bonding of the thrombus with the stent mesh, thus ensuring the effectiveness of thrombectomy.

[0045] Secondly, after thrombectomy, the operator pulls the traction wire 300 proximally from outside the body. The movement of the traction wire 300 proximally causes all the stop blocks 420 fixed to it to move proximally simultaneously. During the proximal movement, each stop block 420 pushes against its corresponding sliding ring 410, which slides proximally. During the proximal movement of the sliding ring 410, multiple drive wires 430 fixedly connected to it pull inwards on the inner wall of the thrombectomy stent 100. Since the drive wires 430 are evenly distributed circumferentially, each drive wire 430 simultaneously applies a near-axial pulling force to the inner wall of the thrombectomy stent 100, causing the entire thrombectomy stent 100 to radially contract, such as... Figure 3 As shown.

[0046] Simultaneously, during the radial contraction of the thrombectomy stent 100, its axial direction undergoes deformation and displacement. This is because the rhomboid angle of the mesh openings changes during radial contraction of the stent's cage structure. This deformation causes the stent mesh openings to tighten into a narrower rhomboid shape, effectively clamping and encapsulating the internal thrombus and preventing it from dislodging from the mesh.

[0047] Subsequently, the surgeon retracts the radially contracted thrombectomy stent 100 entirely into the delivery sheath 200. Because the thrombectomy stent 100 has actively reduced its outer diameter, the frictional resistance between it and the inner wall of the delivery sheath 200 is significantly reduced, making the retrieval operation smoother and less strenuous. Finally, the delivery sheath 200, along with the thrombectomy stent 100 inside, is removed from the body, completing the thrombectomy procedure.

[0048] Throughout the retrieval process, the outer diameter of the thrombectomy stent 100 has been significantly reduced compared to existing stents without actively reducing their radial dimensions. This significantly reduces the contact pressure and friction area between the stent 100's mesh and the vessel wall, thereby effectively avoiding mechanical damage to the vascular intima and preventing complications such as vasospasm and intimal tearing.

[0049] Example 2

[0050] like Figure 4 and Figure 5 As shown, this embodiment provides a contraction unit 400 with a structure different from that of Embodiment 1. In this embodiment, the contraction unit 400 only includes a drive wire 430. One end of the drive wire is fixedly connected to the traction wire 300, and the other end is fixedly connected to the thrombectomy stent 100. In this embodiment, the sliding ring 410 and the stop block 420 are omitted to further simplify the structure, reduce manufacturing costs, and reduce the number of internal components of the thrombectomy stent 100. This is beneficial for maintaining the flexibility of the thrombectomy stent 100 and its ability to pass through tortuous blood vessels. Specifically, one end of each drive wire 430 is directly fixed to the outer wall of the pull wire 300 by welding, bonding, laser welding, or knotting, while the other end extends radially outward and is fixedly connected to the inner wall of the thrombectomy bracket 100, for example, at the mesh node of the thrombectomy bracket 100. The number of drive wires 430 in each shrinkage unit 400 is 2-6, preferably 4, and they are evenly distributed along the circumference of the pull wire 300 to ensure uniform circumferential tension on the inner wall of the thrombectomy bracket 100, so that the bracket has a regular shape when it shrinks radially.

[0051] When the stent 100 is in its fully expanded working state, each drive wire 430 is taut and extends radially along the stent 100, i.e., perpendicular to the axial direction. The length of the drive wire 430 is equal to the radial distance from the axis to the inner wall of the stent at the location of the contraction unit 400. At this time, the drive wire 430 is only slightly taut and does not generate additional tension. Therefore, it does not restrict or resist the normal expansion of the stent 100, nor does it interfere with the entry of thrombus into the stent. It does not affect the embedding and bonding of thrombus with the stent mesh, thus ensuring the effectiveness of thrombectomy.

[0052] When the thrombectomy is completed and the traction wire 300 is pulled proximally, since one end of the drive wire 430 is fixed to the traction wire 300, the movement of the traction wire 300 proximally directly drives the fixed ends of all drive wires 430 to move proximally synchronously. The other end of the drive wire 430 pulls on the inner wall of the thrombectomy stent 100, causing the thrombectomy stent 100 to contract radially. During the radial contraction process, the axial length of the thrombectomy stent 100 shortens accordingly, and the mesh tightens, effectively preventing thrombus escape. Subsequently, the contracted thrombectomy stent 100 is returned to the delivery sheath 200 and withdrawn from the body.

[0053] The advantages of this embodiment compared to embodiment 1 are: the elimination of two components, the sliding ring 410 and the stop block 420, results in a simpler structure, fewer assembly steps, and lower manufacturing costs; at the same time, the reduced number of moving parts inside the bolt retrieval bracket 100 further improves the reliability of the entire system and reduces the risk caused by component failure.

[0054] Other structures in this embodiment, including the thrombectomy bracket 100, the delivery sheath 200, the traction wire 300 proximal operating structure, and the workflow, are the same as in Embodiment 1, and will not be described again here.

[0055] In summary, the thrombectomy system and method provided by this invention, through the design of the contraction unit, realizes active and controllable radial contraction and axial shortening of the thrombectomy stent during the retrieval stage, effectively solving the core technical problem of damage to the blood vessel wall during the retrieval of existing thrombectomy stents. At the same time, through the synergistic effect of the mesh tightening during contraction and the distal anti-escape segment, it effectively prevents embolus escape.

[0056] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the protection scope of the present invention.

Claims

1. A thrombectomy system, characterized in that, include: A thrombectomy bracket (100) has a self-expanding mesh cage structure that can radially expand from a compressed state to an expanded state; A delivery sheath (200) is used to deliver and retrieve the thrombectomy stent (100). A pull wire (300) has its distal end axially inserted inside the thrombectomy bracket (100) and its proximal end extending to the proximal end of the delivery sheath (200). Multiple shrink units (400) are arranged axially at intervals at the distal end of the pull wire (300), with one end of each shrink unit (400) connected to the thimble support (100) and the other end connected to the pull wire (300). When the retrieval wire (300) is pulled proximally after thrombectomy is completed, the contraction unit (400) moves proximally to pull the sidewall of the thrombectomy bracket (100), causing the thrombectomy bracket (100) to contract radially.

2. The thrombectomy system according to claim 1, characterized in that, Each of the contraction units (400) includes multiple drive wires (430) arranged circumferentially along the traction wire (300), with one end of each drive wire (430) connected to the thimble support (100) and the other end connected to the traction wire (300).

3. The thrombectomy system according to claim 2, characterized in that, When the thrombectomy bracket (100) is in the expanded working state, each of the contraction units (400) is arranged perpendicular to the axial direction of the thrombectomy bracket (100).

4. The thrombectomy system according to claim 2, characterized in that, Each of the contraction units (400) further includes: Sliding ring (410), each of the sliding rings (410) is slidably sleeved on the pulling wire (300), and one end of the driving wire (430) of each of the contraction units (400) is fixedly connected to the sliding ring (410), and the other end is fixedly connected to the thrombectomy bracket (100); A stop block (420) is fixedly arranged on the pull wire (300) at the distal end of the sliding ring (410). At least a portion of the size of the stop block (420) perpendicular to the extension direction of the pull wire (300) is larger than the inner hole size of the sliding ring (410). When the pull wire (300) is pulled proximally, the stop block (420) pushes the sliding ring (410) to move proximally to drive the thrombectomy bracket (100) to retract radially.

5. The thrombectomy system according to claim 1, characterized in that, Any two adjacent shrinking units (400) have the same axial spacing.

6. The thrombectomy system according to claim 2 or 4, characterized in that, Each of the shrinking units (400) has 2-6 drive wires (430) and they are evenly arranged around the circumference of the drawing wires (300).

7. The thrombectomy system according to any one of claims 1-5, characterized in that, The pull wire (300) is located on the axis of the thrombectomy bracket (100).

8. The thrombectomy system according to any one of claims 1-5, characterized in that, The distal end of the thrombectomy stent (100) has an escape prevention section (500) for collecting thrombi.

9. The thrombectomy system according to claim 8, characterized in that, The mesh size of the anti-escape section (500) is smaller than that of the main body of the thrombectomy stent (100), and is used to block the distal port of the stent to prevent thrombus from escaping from the distal end of the thrombectomy stent (100).

10. The thrombectomy system according to claim 8, characterized in that, The escape prevention section (500) is a conical structure integrally woven with the bolt removal bracket (100), or a flexible filter bag independently connected to the far end of the bolt removal bracket (100).

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