A peripheral vein-based thrombectomy system

Abstract

This invention discloses a thrombectomy and thrombectomy system based on peripheral veins, belonging to the field of medical device technology. The system includes a double-sealed aspiration sheath and a thrombectomy and thrombectomy device. The device includes a thrombectomy structure, an inner guidewire tube, a tip, and an outer tube. The thrombectomy structure is made of woven wire mesh, heat-treated for shaping, and its free state configuration is an assembly of multiple disc-shaped or ellipsoidal units. The inner guidewire tube moves axially relative to the outer tube, driving the thrombectomy structure to switch between a contracted and extended state. A handle mechanism drives the inner guidewire tube to perform axial simple harmonic reciprocating motion, causing the thrombectomy structure to repeatedly switch between extended and contracted states to cut the thrombus; after thrombectomy, the thrombectomy structure is withdrawn in the extended state, removing any remaining thrombus. This invention achieves integrated thrombectomy and thrombectomy operations, with a compact structure, simple operation, and high efficiency in clearing chronic deep vein thrombosis and thrombi associated with dialysis access.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a thrombus fragmentation and thrombectomy system based on peripheral veins. Background Technology

[0002] Chronic peripheral deep vein thrombosis (CDVT) and dialysis access-related thrombosis are common clinical conditions. Treatment primarily includes medication and interventional surgery. Medication has a slow onset of action and a long treatment course, and is ineffective for established, old, or organized thrombi, while also carrying a risk of bleeding. Interventional surgery, due to its minimally invasive nature and rapid recovery, has become the preferred treatment option in clinical practice.

[0003] Existing interventional thrombectomy devices are mainly divided into two categories: one is a simple aspiration catheter, which uses negative pressure to suction out the thrombus. However, for old thrombi that have adhered to the vessel wall, simple aspiration is difficult to completely remove them and can easily cause damage to the vessel wall. The other is a mechanical thrombectomy device, which usually uses a self-expanding nickel-titanium alloy stent or basket structure to capture the thrombus and then retract it into the sheath for removal. However, most existing mechanical thrombectomy devices use laser-cut tubing or integrally woven into a cylindrical basket structure, whose free state is a continuous cylindrical or conical mesh stent. These structures have the following shortcomings when applied to chronic deep vein thrombosis: First, for mixed thrombi that have become organized and fibrotic, the single self-expansion capture method is insufficient to effectively break up the thrombus, resulting in incomplete thrombectomy. Second, some devices use separate thrombectomy components (such as rotary cutting heads, ultrasonic thrombectomy rods, etc.) from the thrombectomy components, increasing the complexity of the system and the difficulty of operation. Third, after the thrombectomy structure of existing devices is deployed in the blood vessel, it often relies solely on radial support force to push the thrombus to one side or wrap it up and then retract, lacking an effective cutting and fragmentation mechanism for the thrombus. For chronic thrombi with high load and long segments, a single operation is unlikely to achieve satisfactory results.

[0004] Furthermore, existing interventional thrombectomy devices, whether simple aspiration catheters or mechanical thrombectomy devices, typically have an outer sheath diameter significantly smaller than the inner diameter of peripheral veins. During the retraction of the thrombectomy device or thrombus-capturing basket into the sheath, due to the 'bottleneck' effect at the sheath inlet, the device can only capture and drag loose thrombi in its central area. Many thrombi located on the periphery of the device, tightly adhered to the vessel wall, or of large size, cannot be effectively compressed and enter the narrow catheter lumen, and are instead scraped, detached, and left on the vessel wall. More seriously, this mechanical traction and scraping can easily cause large thrombi to detach and migrate, drifting distally with the bloodstream, triggering a fatal risk of pulmonary embolism or distal limb embolism.

[0005] Therefore, it is necessary to develop a peripheral venous thrombus removal system that can simultaneously achieve efficient thrombus fragmentation and thrombus removal, has a compact structure, and is easy to operate. Summary of the Invention

[0006] The purpose of this invention is to provide a thrombectomy and thrombectomy system based on peripheral vein vessels, in order to solve the technical problems of low efficiency in clearing chronic deep vein thrombosis and thrombus-related dialysis access in existing mechanical thrombectomy devices, and the complexity and inconvenience of operation caused by the separation of thrombectomy and thrombectomy functions.

[0007] Specifically, the technical problems to be solved by this invention include: how to achieve the dual functions of mechanical thrombectomy and mechanical thrombectomy through a single thrombectomy structure; how to improve the cutting and fragmentation efficiency of mixed and organized thrombi; how to simplify the system structure and reduce the difficulty of operation while ensuring the thrombectomy effect; and how to solve the technical problem that existing thrombectomy devices, due to the outer sheath diameter being much smaller than the inner diameter of the blood vessel, cause thrombi to be easily scraped off and retained on the vessel wall during the thrombectomy process, increasing the risk of distal embolism; and how to solve the leakage problem caused by the failure of dynamic seals in ordinary single-stage sealed sheaths during the thrombectomy process.

[0008] This invention is achieved using the following technical solution: a thrombectomy system based on peripheral vein vessels for the removal of chronic peripheral deep vein thrombosis and thrombi associated with dialysis access, comprising: a double-sealed aspiration sheath; and a thrombectomy device, the thrombectomy device including a thrombectomy structure, an inner guidewire tube, a tip, and an outer tube; the thrombectomy structure is made of woven wire mesh and heat-treated to shape, its configuration in an unconstrained free state being an assembly of multiple disc-shaped or ellipsoidal units; the inner guidewire tube is inserted inside the outer tube, the distal end of the inner guidewire tube is fixedly connected to the head end of the thrombectomy structure and the tip, and the tail end of the thrombectomy structure is fixedly connected to the head end of the outer tube; the inner guidewire tube is positioned relative to... The outer tube moves axially, driving the head end of the thrombectomy structure to axially displace relative to its tail end, causing the thrombectomy structure to switch between a radially contracted state and a radially expanded state. The maximum radial dimension of the thrombectomy structure in its expanded state is configured to be larger than the inner diameter of the blood vessel to fit against the vessel wall. A handle mechanism is connected to the proximal end of the guidewire inner tube, which is configured to drive the guidewire inner tube to perform axial simple harmonic reciprocating motion, causing the thrombectomy structure to repeatedly switch between the expanded and contracted states, so as to cut and fragment the thrombus in the blood vessel through the reciprocating deformation of its braided wire. After fragmentation, the thrombectomy structure is placed in the expanded state and withdrawn from the double-sealed aspiration sheath to collect residual thrombus residue.

[0009] Furthermore, the unit set of the bolt removal structure is composed of 4, 5 or 6 disc-shaped units or ellipsoidal units arranged sequentially along the axial direction.

[0010] Furthermore, the bolt-removing structure is woven into a tubular mesh by a braiding machine using 24 or 48 nickel-titanium wires at a fixed pitch, and then heat-treated to set the shape.

[0011] Furthermore, the bolt-retrieving structure is a combination of two sections of woven mesh with different pitches, wherein the small-pitch dense mesh section is located at the far end as the bolt-retrieving unit, and the large-pitch sparse mesh section is located at the near end.

[0012] Furthermore, the small-pitch dense mesh and the large-pitch sparse mesh are separated by intertwining two adjacent wires and knotting them for 3-4 sections, or by fixing two adjacent wires with heat-shrink polymer tubes or by tightening them with stainless steel spring sheets to form a separation node.

[0013] Furthermore, the dual-stage sealed suction sheath includes an outer sheath, a three-way connector, a viewing window, a screw-on sealing valve, a sealing silicone ring, and a viewing window locking valve; the viewing window locking valve is configured to selectively connect or block the passage between the viewing window and the outer sheath; the screw-on sealing valve is configured to close or open the sealing valve by squeezing or releasing the sealing silicone ring.

[0014] Furthermore, the head end of the dual-stage sealed suction sheath is connected to a trumpet-shaped dense mesh, which is woven from nickel-titanium mesh and then heat-treated to shape it, and is used to receive the thrombus carried by the thrombus fragmentation and thrombectomy device.

[0015] Furthermore, the surface of the trumpet-shaped dense mesh is covered with a polymer film.

[0016] Furthermore, the head end of the dual-stage sealed suction sheath is connected to a flared structure directly molded from a polymer material, wherein the polymer material is one of TPU, PE, PI, or Pebax.

[0017] Furthermore, the system is configured such that: after the thrombectomy device is inserted into the distal end of the target thrombus location in the blood vessel in a contracted state, in response to handle operation, the inner cannula of the guidewire is axially displaced relative to the outer cannula, causing the thrombectomy structure to unfold to an unfolded state with a radial dimension larger than the inner diameter of the blood vessel; in response to continuous reciprocating operation of the handle, the inner cannula of the guidewire performs axial reciprocating motion, causing the thrombectomy structure to repeatedly switch between the unfolded and contracted states, so as to cut and fragment the thrombus through the reciprocating deformation of the braided wire; and after thrombectomy is completed, the thrombectomy structure is placed in the unfolded state, and the thrombectomy device together with the thrombectomy structure is withdrawn from the double-sealed aspiration sheath to remove residual thrombus residue.

[0018] The thrombectomy system based on peripheral veins described in this invention has the following beneficial effects: The thrombus fragmentation and thrombus removal are integrated, simplifying the system structure: The thrombus removal structure of the present invention realizes the functions of fragmentation and thrombus removal on the same braided mesh, eliminating the need for separate fragmentation and thrombus removal components. The system structure is compact, the manufacturing cost is low, and the operation process is simple.

[0019] Mechanical thrombectomy is highly efficient and versatile: the axial harmonic reciprocating motion of the guidewire inner tube drives the thrombectomy structure to repeatedly switch between the expanded and contracted states. The braided wire repeatedly cuts the thrombus like scissors, effectively pulverizing mixed thrombi that have become organized and fibrotic, solving the problem that traditional self-expanding thrombectomy devices are unable to break up old thrombi.

[0020] Mechanical thrombectomy is thorough and reduces the risk of residual thrombus: After the thrombus is fragmented, the thrombectomy structure is pulled out of the sheath in an unfolded state. The woven mesh can catch any thrombus fragments that are not completely fragmented or larger residual thrombi and remove them from the blood vessel, significantly reducing the rate of residual thrombus.

[0021] It offers good operational controllability and high safety: the deployment and contraction of the thrombectomy structure are actively controlled by the axial translation of the guidewire inner cannula, rather than relying on self-expansion release. Doctors can precisely adjust the deployment degree of the thrombectomy structure according to the vessel diameter and thrombus length to avoid excessive damage to the vessel wall.

[0022] Thorough thrombectomy significantly reduces the risk of distal embolism: This invention employs a fragmentation-then-removal strategy, first breaking up large thrombi in situ within the blood vessel, then using an unfolded woven mesh structure to collect and extract the entire fragment. During the retraction process, all cut, loose, and incompletely fragmented thrombus remnants are collected and removed, avoiding the problems of thrombus scraping, retention, and displacement caused by the small diameter of the sheath in traditional devices, thus greatly reducing the risk of distal embolism. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the existing technology structure; Figure 2 This is a schematic diagram of the deployed state of the bolt removal structure in this application; Figure 3 This is a schematic diagram of the shrinkage state of the thrombus removal structure in this application; Figure 4 This is a schematic diagram of the thrombus insertion state of the thrombectomy structure in this application; Figure 5 This is a schematic diagram of the thrombus removal structure after thrombus breakage in this application; Figure 6 A schematic diagram illustrating how the thrombus is moved to the inlet of the sheath for thrombectomy. Figure 7 A schematic diagram illustrating the movement of the thrombus portion into the sheath for thrombectomy. Figure 8 A schematic diagram illustrating how the thrombus is completely moved into the sheath for thrombectomy. Figure 9 This is a schematic diagram of a bolt-removing structure with a variable pitch using a winding and knotting method; Figure 10 A schematic diagram of a bolt-removing structure with a variable pitch that uses additional material for securing; Figure 11 This is a schematic diagram of the overall structure of the double-stage sealed suction sheath. Figure 12 This is a schematic diagram of the trumpet-shaped dense mesh structure at the head end of the sheath. Figure 13 A schematic diagram of a funnel-shaped dense mesh structure with a membrane structure; In the diagram, 1-double-sealed aspiration sheath, 2-thrombus fragmentation and thrombectomy device, 3-thrombectomy structure, 4-guidewire inner tube, 5-tip tip, 6-outer tube, 7-blood vessel, 8-thrombus. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] Example 1: like Figure 1 As shown, this embodiment provides a peripheral venous thrombectomy system for the removal of chronic peripheral deep vein thrombosis and thrombi associated with dialysis access. The system mainly consists of a double-sealed aspiration sheath 1 and a thrombectomy device 2.

[0028] The thrombus fragmentation and thrombus retrieval device 2 includes a retrieval structure 3, an inner guidewire tube 4, a tip 5, and an outer tube 6. The retrieval structure 3 is woven from nickel-titanium or high-elasticity polymer wire into a mesh, heat-treated and shaped, its free state being a collection of disc-shaped or ellipsoidal units, with 4, 5, or 6 units. The inner guidewire tube 4 passes inside the outer tube 6, and its head end is heat-fused to the head end of the retrieval structure 3 and the tip 5 to form a single unit; the other end of the retrieval structure 3 is also heat-fused to the head end of the outer tube 6. The tail end of the inner guidewire tube 4 is connected to a handle assembly, which contains a locking switch and a sliding mechanism, allowing the inner guidewire tube 4 to move axially by operating the handle.

[0029] When the system is in the initial state, the retrieval structure 3 is in a retracted state (defined as state II) under the traction of the guidewire inner tube 4. At this time, each unit of the retrieval structure 3 is closely attached to the guidewire inner tube 4, and the outer diameter is smaller than the inner diameter of the sheath tube, which facilitates delivery to the target position through the sheath tube.

[0030] In use, the thrombectomy device 2, in state II configuration, is first inserted into the distal end of the target location of the thrombus 8 within the blood vessel 7 via the double-sealed aspiration sheath 1. Once in place, the locking switch on the handle is opened to release the locking of the guidewire inner tube 4. The handle is operated to displace the guidewire inner tube 4 proximally or distally relative to the outer tube 6, thereby moving the tip of the thrombectomy structure 3. The thrombectomy structure 3, freed from axial constraint, naturally unfolds, forming a disc-shaped or ellipsoidal shape (defined as state I). Its unfolded size is slightly larger than the inner diameter of the blood vessel 7 to ensure full contact with the vessel wall and coverage of the thrombus area.

[0031] The mechanical thrombectomy procedure is then performed: the handle is continuously reciprocated, causing the guidewire inner tube 4 to undergo axial simple harmonic motion. During this process, the guidewire inner tube 4 drives the tip of the thrombectomy structure 3 to continuously switch between state I and state II. When the guidewire inner tube 4 is pulled proximally, the thrombectomy structure 3 is stretched and contracted, with each unit moving closer to the other; when the guidewire inner tube 4 is pushed distally, the thrombectomy structure 3 returns to its extended state. This high-frequency morphological change causes the braided mesh wire to repeatedly cut the thrombus 8 within the blood vessel 7, gradually breaking large thrombi into tiny particles. Simultaneously, the double-sealed suction sheath 1 can be connected to an external negative pressure suction device to draw the chopped tiny thrombus particles out of the body with the blood flow or negative pressure, further clearing the thrombus.

[0032] After mechanical thrombectomy, the mechanical thrombectomy procedure is performed: Axial harmonic motion is stopped, and the guidewire inner tube 4 is adjusted so that the thrombectomy structure 3 returns to the contracted state II position. Then, the entire thrombectomy and thrombectomy device 2 is moved, allowing the thrombectomy structure 3 to move to the distal end of the thrombus 8 in state II. The handle is operated again to displace the guidewire inner tube 4, switching the thrombectomy structure 3 to the deployed state I. Maintaining state I, the entire thrombectomy and thrombectomy device 2, along with the thrombectomy structure 3, is slowly withdrawn from the sheath. When the thrombectomy structure 3 reaches the sheath opening, because the sheath's inner diameter is smaller than the deployed diameter of the thrombectomy structure 3, the handle needs to be gradually and slightly operated to allow the guidewire inner tube 4 to move slightly, gradually transitioning the thrombectomy structure 3 to the contracted state II, thus allowing it to pass smoothly through the sheath opening and be completely removed from the body. During this process, the mesh of the thrombectomy structure 3 can catch any incompletely fragmented thrombus fragments or larger residual thrombi, carrying them out of the blood vessel for complete removal.

[0033] Through the above structural design and operation process, this system realizes the dual functions of mechanical thrombus fragmentation and mechanical thrombectomy, which can efficiently treat chronic peripheral deep vein thrombosis and thrombi related to dialysis access, reduce operation time and reduce the risk of residual thrombi.

[0034] Example 2: Based on Example 1, this embodiment further optimizes the weaving process and structural design of the bolt removal structure 3.

[0035] The bolt-removing structure 3 is woven into a tubular mesh by a braiding machine using 24 or 48 nickel-titanium wires at a fixed pitch, and then heat-treated to form a mesh structure with good elastic recovery and radial support.

[0036] Preferably, the thrombectomy structure 3 can be a combination of two sections of woven mesh with different pitches. After shaping, the denser mesh section with a smaller pitch is located at the distal end of the thrombectomy structure, serving as the thrombectomy unit; the looser mesh section with a larger pitch is located at the proximal end of the thrombectomy structure. During the opening and retraction process of this variable pitch structure, the larger pitch acts like a large net, facilitating the entry of the thrombus into the denser mesh, while the smaller pitch at the distal end, with its denser tissue, ensures that the trapped thrombus does not leak out.

[0037] To achieve the above-mentioned variable pitch structure, the following two methods can be used: Method 1: During the weaving process, first weave a dense mesh with a small pitch parameter, then twist two adjacent wires together and tie 3 to 4 knots to form a separating node; then reset the weaving parameters and continue weaving the sparse mesh section with a large pitch.

[0038] Method 2: During the weaving process, first weave a dense mesh with a small pitch parameter, then fix two adjacent wires with heat shrinking polymer tubes or tie them tightly with stainless steel springs to form a tight node; then reset the weaving parameters and continue weaving the sparse mesh section with a large pitch.

[0039] Example 3: Based on Embodiment 1, this embodiment further describes in detail the specific structure and operation method of the double-stage sealed suction sheath 1.

[0040] The dual-stage sealed suction sheath 1 consists of an outer sheath, a three-way connector, a sight glass, a rotary sealing valve, a sealing silicone ring, and a sight glass locking valve. The sight glass locking valve controls the opening and closing of the sight glass; the rotary sealing valve closes or opens by squeezing or releasing the internal sealing silicone ring.

[0041] When an outer sheath is connected to a high-pressure blood vessel, there is a risk of blood leakage from the sheath if a direct access route for interventional devices exists. This double-sealed sheath allows for safe interventional procedures, as detailed below: First, close the window tube locking valve and open the screw sealing valve to allow the tip of the interventional instrument to enter the window tube. The second step is to loosen the screw on the sealing valve appropriately so that there is appropriate damping between the sealing silicone ring and the instrument. The instrument can continue to advance under certain resistance, while preventing blood from spilling out. The third step is to open the locking valve of the viewing window tube so that the instrument can be fully inserted into the blood vessel.

[0042] Through the above three-stage operation, the double-sealed aspiration sheath maintains good sealing throughout the entire instrument intervention process, effectively preventing high-pressure blood from leaking out of the sheath, ensuring the safety of the operation, and reducing the risk of operation contamination and thrombus dispersal.

[0043] Example 4: Based on Embodiment 1, this embodiment further optimizes the head end structure of the dual-stage sealed suction sheath 1.

[0044] To facilitate the use of the thrombus breaking and removal device 2, the head end of the double-sealed suction sheath 1 can be connected to a trumpet-shaped mesh. This trumpet-shaped mesh is woven from nickel-titanium mesh and then heat-treated to set its shape. Its opening expands outward in a trumpet shape, forming a large-diameter receiving port.

[0045] When the thrombectomy device 2 completes the thrombectomy and retracts to the sheath opening in the deployed state, the funnel-shaped mesh can catch a large number of thrombus fragments carried by the thrombectomy structure 3 like a funnel, guiding them smoothly into the lumen of the sheath, and preventing the thrombus from accumulating, blocking or being scraped off at the sheath entrance and remaining on the blood vessel wall.

[0046] Preferably, the funnel-shaped head structure can be composed of a dense mesh device covered with a polymer membrane. The membrane design can further reduce the mesh size while maintaining the funnel shape, preventing tiny thrombus particles from leaking out of the mesh and improving the integrity of thrombus capture.

[0047] Preferably, the flared end structure can also be directly molded from a polymer material, such as TPU, PE, PI, Pebax, or other medical polymer materials, through injection molding or thermoforming processes. This flared end structure made of pure polymer material has the characteristics of a smooth surface and a low coefficient of friction, which facilitates the smooth passage of the thrombectomy structure and reduces manufacturing costs.

[0048] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Modifications and variations made by those skilled in the art without departing from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A peripheral vein vessel based thrombectomy system for chronic peripheral deep vein thrombosis and dialysis access related thrombus removal, characterized in that, include: A double-sealed suction sheath (1); and a thrombus fragmentation and thrombus removal device (2), the thrombus fragmentation and thrombus removal device (2) comprising a thrombus removal structure (3), a guidewire inner tube (4), a tip (5), and an outer tube (6); the thrombus removal structure (3) is woven from wire into a mesh and then heat-treated to shape, and its configuration in an unconstrained free state is a collection of multiple units in a disc or ellipsoidal shape; the guidewire inner tube (4) passes through the interior of the outer tube (6), the distal end of the guidewire inner tube (4) is fixedly connected to the head end of the thrombus removal structure (3) and the tip (5), and the tail end of the thrombus removal structure (3) is fixedly connected to the head end of the outer tube (6); the thrombus removal structure (3) is driven by the axial translation of the guidewire inner tube (4) relative to the outer tube (6). The head end generates an axial displacement relative to its tail end, causing the thrombectomy structure (3) to switch between a radially contracted state and a radially expanded state; the maximum radial dimension of the thrombectomy structure (3) in its expanded state is configured to be greater than the inner diameter of the blood vessel (7) so as to adhere to the blood vessel wall; the proximal end of the guidewire inner tube (4) is connected to a handle mechanism, which is configured to drive the guidewire inner tube (4) to perform axial simple harmonic reciprocating motion, so that the thrombectomy structure (3) repeatedly changes between the expanded state and the contracted state, so as to cut and fragment the thrombus (8) in the blood vessel (7) through the reciprocating deformation of its braided wire; after the fragmentation is completed, the thrombectomy structure (3) is placed in the expanded state and withdrawn from the double-sealed suction sheath (1) to remove residual thrombus residue.

2. The peripheral vein based thrombectomy system of claim 1, wherein, The unit set of the bolt removal structure (3) is composed of 4, 5 or 6 disk-shaped units or ellipsoidal units arranged sequentially along the axial direction.

3. The peripheral vein based thrombectomy system of claim 2, wherein, The bolt-taking structure (3) is woven into a tubular mesh by a braiding machine using 24 or 48 nickel-titanium wires at a fixed pitch, and then heat-treated to shape it.

4. The thrombectomy system based on peripheral veins according to claim 3, characterized in that, The bolt-retrieving structure (3) is a combination structure of two sections of braided mesh with different pitches, wherein the small pitch dense mesh section is located at the far end as the bolt-retrieving unit, and the large pitch sparse mesh section is located at the near end.

5. A thrombectomy system based on peripheral veins according to claim 4, characterized in that, The small-pitch dense mesh and the large-pitch sparse mesh are separated by intertwining two adjacent wires and knotting them for 3-4 sections, or by fixing two adjacent wires with heat-shrink polymer tubes or by binding them with stainless steel spring sheets to form a separation node.

6. The thrombectomy system based on peripheral veins according to claim 1, characterized in that, The dual-stage sealed suction sheath (1) includes an outer sheath, a three-way connector, a viewing window, a screw-on sealing valve, a sealing silicone ring, and a viewing window locking valve; the viewing window locking valve is configured to selectively connect or block the passage between the viewing window and the outer sheath; the screw-on sealing valve is configured to close or open the sealing valve by squeezing or releasing the sealing silicone ring.

7. A thrombectomy system based on peripheral veins according to claim 6, characterized in that, The head end of the double-sealed suction sheath (1) is connected to a trumpet-shaped dense mesh, which is woven from nickel-titanium mesh and then heat-treated to shape it, and is used to receive the thrombus carried by the thrombus fragmentation and thrombectomy device.

8. A thrombectomy system based on peripheral veins according to claim 7, characterized in that, The surface of the trumpet-shaped dense mesh is covered with a polymer film.

9. A thrombectomy system based on peripheral veins according to claim 6, characterized in that, The head end of the double-sealed suction sheath (1) is connected to a flared structure made of polymer material directly molded from it. The polymer material is one of TPU, PE, PI or Pebax.

10. A thrombectomy system based on peripheral veins according to any one of claims 1 to 9, characterized in that, The system is configured to: after the thrombectomy device is inserted into the distal end of the target thrombus location in the blood vessel in a contracted state, in response to handle operation, cause the inner cannula of the guidewire to undergo axial displacement relative to the outer cannula, so that the thrombectomy structure is unfolded to an unfolded state with a radial dimension larger than the inner diameter of the blood vessel; in response to continuous reciprocating operation of the handle, cause the inner cannula of the guidewire to perform axial reciprocating motion, causing the thrombectomy structure to repeatedly switch between the unfolded state and the contracted state, so as to cut and fragment the thrombus through the reciprocating deformation of the braided wire; and after the thrombectomy is completed, place the thrombectomy structure in the unfolded state, and withdraw the thrombectomy device together with the thrombectomy structure from the double-sealed aspiration sheath to remove residual thrombus residue.

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