Thrombectomy system

Abstract

The application provides a thrombus removing support and system, and relates to the technical field of medical devices.The thrombus removing support comprises a support and a basket supported on a distal end section of an elongated operating rod, the support and the basket both have an expanded state relative to an initial state, the support comprises a frame body, the frame body has a shape expanded into a cage structure, and the frame body is used for cutting or scraping a thrombus; the basket comprises a rib and an aperture, and the basket is used for intercepting or capturing a free thrombus; a radial supporting force of the support is greater than a radial supporting force of the basket, or a radial supporting capacity of the support is greater than a radial supporting capacity of the basket; the thrombus removing support in the scheme combines the functions of cutting and capturing, and can process different types and states of thrombus in one operation.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a thrombectomy stent and thrombus removal system. Background Technology

[0002] Peripheral artery disease (PAD) refers to arterial diseases located outside the heart or brain. PAD primarily involves the formation of atherosclerotic plaques in peripheral vessels such as the common iliac artery, femoral artery, radial artery, and brachial artery, resulting in stenosis greater than 50%. Acute mesenteric ischemia (AMI), often referred to as "intestinal stroke," has an insidious onset, rapid progression, and symptoms that frequently do not match physical examination, making it highly susceptible to misdiagnosis and missed diagnosis. Its mortality rate ranges from 20% to 50%.

[0003] Peripheral venous diseases are classified into two categories: chronic venous insufficiency and venous thromboembolism. Chronic venous insufficiency mainly includes venous valve insufficiency, varicose veins, and sequelae of venous thrombosis. Venous thromboembolism mainly includes deep vein thrombosis (DVT) and pulmonary embolism (PE), with PE primarily caused by DVT. Simple thrombolysis and anticoagulation combined with surgery are the main treatments for acute lower extremity deep vein thrombosis. However, due to the poor efficacy and high recurrence rate of simple thrombolysis and anticoagulation, surgery has largely replaced it. Comprehensive thrombectomy techniques such as catheter-directed thrombolysis (CDT), surgical thrombectomy, and percutaneous mechanical thrombectomy (PMT) have been developed. The AngioJet catheter is the most commonly used thrombectomy catheter in China.

[0004] In the prior art, Medtronic's CN201380069871 and CN201310471114 describe a self-expanding device with multiple compartments at the proximal and distal ends, the distal end of which is an opening, which is now a common treatment structure for neurointerventional stents; CN202110845847 describes a thrombectomy device with adjustable diameter and length, including a controller, a delivery guidewire, and several cage stent units. The controller has a gripping part and an adjustment button placed in the gripping part. The ball cage units can be uniformly controlled, so that one thrombectomy device can meet the needs of blood vessels of various diameters; CN202310700501 describes a double-layer thrombectomy stent, including an outer stent, a push tube connected to the proximal end of the outer stent, and an inner braided microfilter connected to the inner side of the distal end of the outer stent. This structure can effectively prevent thrombus escape; CN202020677733 describes a thrombectomy component and thrombus removal device for iliac vein thrombosis thrombus removal. The thrombectomy assembly includes: a radially elastically expandable thrombus isolation filter and a thrombus capture basket, which are coaxially arranged; the thrombus isolation filter and the thrombus capture basket are fixedly connected, and this structure can effectively remove thrombi. CN202010216583 describes a filter assembly and a thrombus aspiration assembly for pulmonary embolism thrombus removal. The filter assembly includes: a radially elastically expandable thrombus fragmentation filter, a first isolation filter, and a second isolation filter, which are coaxially arranged; the thrombus fragmentation filter is disposed between the first isolation filter and the second isolation filter. The thrombus aspiration assembly includes: a thrombus aspiration tube, a thrombus output tube, a thrombus aspirator, and a connecting seat with a hollow channel, which can effectively remove large thrombus structures.

[0005] Generally speaking, the existing technologies on the market each have their own advantages and disadvantages. For example, Angio Jet uses the Bernoulli method to fragment and remove thrombi, Indigo uses negative pressure to aspirate thrombi, and FlowTriever uses stents to remove thrombi. Each thrombectomy method has its own advantages and disadvantages, and in clinical practice, operators may also use a combination of methods to remove thrombi.

[0006] The purpose of this invention is to improve thrombectomy efficiency while reducing damage to the vascular intima, providing surgeons with new options. Summary of the Invention

[0007] The purpose of this invention is to provide a solution to the problems existing in the prior art, thereby improving the efficiency and effectiveness of thrombectomy.

[0008] To achieve the above objectives, the present invention provides the following solutions.

[0009] A thrombectomy stent includes a stent and a basket supported on the distal end of an elongated control lever. Both the stent and the basket are in an expanded state relative to their initial state. The stent includes a frame that expands into a cage-like structure and is used to cut or scrape thrombi. The basket includes ribs and pores and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket.

[0010] A thrombectomy stent includes a stent and a basket supported on the distal end of an elongated control lever. Both the stent and the basket are in an expanded state relative to their initial state. The stent includes a frame and a hub. The frame has an expanded cage-like structure and includes spokes and thrombectomizing ribs. One end of each spoke is fixed to the hub, and the other end of each spoke is fixed to the thrombectomizing rib. The hub includes a proximal hub near the proximal end of the frame and a distal hub near the distal end of the frame. The number of spokes in the proximal hub is less than or equal to the number of spokes in the distal hub. The frame is used to cut or scrape attached thrombi on the vessel wall. The basket includes ribs and pores and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket.

[0011] A thrombectomy stent includes a stent and a basket supported on the distal end of an elongated control lever. Both the stent and the basket are in an expanded state relative to their initial state. The stent includes a frame and a hub. The frame has an expanded cage-like structure and includes spokes and thrombectomizing ribs. One end of each spoke is fixed to the hub, and the other end of each spoke is fixed to the thrombectomizing rib. The hub includes a proximal hub near the proximal end of the frame and a distal hub near the distal end of the frame. The basket includes ribs and pores, and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. The frame includes a first stent pore near the proximal end of the frame and a second stent pore near the distal end of the frame. The geometry of the first stent pore is larger than the geometry of the second stent pore. The basket is deployed at the distal end of the stent and maintains a longitudinal gap with the distal hub of the stent.

[0012] Furthermore, when radially compressed to 50% of the expanded state, the following conditions are met: the radial support force of the bracket is 0.005 to 5 N / mm, and the radial support force of the basket is 0.0005 to 2 N / mm.

[0013] Furthermore, when radially compressed to 50% of the expanded state, the following conditions must be met: 0.01 N / mm ≤ radial support force of the bracket ≤ 0.2 N / mm, 0.001 N / mm ≤ radial support force of the basket ≤ 0.08 N / mm.

[0014] Furthermore, compared to stents, the flexible and easily deformable basket ribs can increase friction and wrapping force by deforming when they come into contact with viscous thrombi.

[0015] Furthermore, the net basket also includes a proximal net basket hub deployed at the proximal end of the net basket, and net basket spokes; one end of the net basket spokes is fixedly connected to the proximal net basket hub, and the other end of the net basket spokes is fixedly connected to the reinforcing ribs; at least three or more net basket spokes are circumferentially spaced from the proximal net basket hub.

[0016] Furthermore, in the expanded state, the basket has a basket-shaped cage-like spatial shape extending from the proximal basket hub toward the distal end of the thrombectomy stent; the outer contour of the basket-shaped cage-like spatial shape has a waveform formed in the longitudinal direction; with the extension line of the proximal basket hub as the baseline, the waveform includes a peak far from the baseline and a trough close to the baseline; compared with the unloaded thrombus state, the trough can be further moved closer to the baseline by the thrombus effect.

[0017] Furthermore, the net basket also includes a distal net basket hub deployed at the distal end of the net basket; the aperture geometry near the proximal net basket hub is larger than the aperture geometry near the distal net basket hub.

[0018] Furthermore, the basket also includes a distal basket hub deployed at the distal end of the basket; in the expanded state, the basket has a basket-shaped cage-like spatial form extending away from the proximal basket hub toward the distal end of the retrieval bracket; the basket is provided with a filter membrane, on which several filter holes are distributed.

[0019] Furthermore, the proximal hub is coaxially fixed to the control lever, and the distal hub can slide controllably in the longitudinal direction; or, the distal hub is coaxially fixed to the control lever, and the proximal hub can slide controllably in the longitudinal direction.

[0020] Furthermore, in the expanded state, the support can form cage-like structures of different diameters.

[0021] Furthermore, a spoke is fixedly connected to two or more cleaving bars to form a bifurcation unit; the bifurcation unit has a converging part where the converging spokes and cleaving bars converge; taking the line connecting the proximal hub and the distal hub as the baseline, the distance from the outer contour of the support to the baseline in the self-expansion state is defined as the self-expansion radius of the support; the distance from some converging parts to the baseline is greater than 0.5 times the self-expansion radius of the support.

[0022] Furthermore, the distance from some convergence points to the baseline is less than or equal to 0.5 times the self-expansion radius of the stent.

[0023] A thrombus removal system includes any of the aforementioned thrombectomy stents, and further includes an aspiration catheter capable of connecting to a negative pressure source and a cannula capable of maintaining the thrombectomy stent in its initial state; the cannula is fitted over the thrombectomy stent and extends from the distal end of the thrombectomy stent to the proximal end of a control lever; the cannula can deliver the thrombectomy stent through the lumen of the aspiration catheter; and the sliding of the distal end of the cannula towards the proximal end of the thrombectomy stent allows the thrombectomy stent to be released into an expanded state.

[0024] Furthermore, it also includes a control handle connected near the proximal end of the control lever, which controls the expansion or longitudinal displacement of the retrieval bracket via a pull wire or rod.

[0025] Furthermore, the control handle includes a handle housing, a slider, and a screw; the handle housing supports the screw, the slider slides in conjunction with the screw, and the handle housing restricts the circumferential rotation of the slider.

[0026] Furthermore, it also includes a mesh sheath for use with the aspiration catheter; and / or, a occlusion balloon is deployed near the distal end of the aspiration catheter.

[0027] Furthermore, the control lever is a hollow tube; several through holes are deployed on the tube wall near the distal end of the control lever, which are used to apply thrombolytic drugs into the blood vessel lumen.

[0028] The beneficial effects of this invention are:

[0029] The thrombectomy stent in this protocol combines cutting and catching functions, enabling the treatment of different types and states of thrombi in a single operation. By setting the radial support capacity of the stent to be greater than that of the basket, the stent can provide stronger support within the blood vessel, ensuring its effective deployment and close adherence to the vessel wall, thereby facilitating better cutting and scraping operations. The basket, on the other hand, mainly relies on weaker support to maintain its shape, making it easier to catch free thrombi. This achieves a highly efficient synergistic thrombectomy effect and also makes this protocol applicable to various vascular environments, especially cases with complex thrombotic conditions.

[0030] This solution employs a phased design that prioritizes the deployment of the net basket, allowing the net basket to begin capturing free-state thrombi before the stent is deployed. This improves the overall efficiency and safety of the device and effectively prevents the spread of thrombus fragments.

[0031] This approach utilizes a bifurcation unit to distribute stress and optimize the secondary shearing effect generated during the thrombectomy stent retrieval process, thereby reducing the risk of secondary shearing of the thrombus. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, 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 these drawings without creative effort.

[0033] Figure 1 A physical image of the thrombectomy bracket 1 provided in the embodiments of the present invention;

[0034] Figure 2This is a physical image showing a simulated thrombectomy after using the thrombectomy bracket 2 provided in this embodiment of the invention.

[0035] Figure 3 for Figure 2 Longitudinal distribution of thrombi in the net basket after interception or capture of free-state thrombi;

[0036] Figure 4 The image shows a simulated thrombectomy using the thrombectomy stent 2 provided in this embodiment of the invention.

[0037] Figure 5 for Figure 4 A diagram showing the concentrated distribution of thrombi distal to the stent after cutting or scraping away viscous thrombi in the stent.

[0038] Figure 6 A three-dimensional structural schematic diagram of a thrombectomy bracket 3 with waveform grid units is provided for use in embodiments of the present invention;

[0039] Figure 7 for Figure 6 A schematic diagram of the structure of a medium-waveform grid cell;

[0040] Figure 8 This is a three-dimensional structural diagram of the thrombectomy bracket 4 provided in an embodiment of the present invention;

[0041] Figure 9 A three-dimensional structural schematic diagram of a thrombectomy stent 5 with a waveform outer contour is provided for use in embodiments of the present invention;

[0042] Figure 10 A three-dimensional structural schematic diagram of an integrated thrombectomy bracket 6 is provided for use in embodiments of the present invention;

[0043] Figure 11 A schematic diagram of a basket structure with near-end bundling is provided for use in embodiments of the present invention;

[0044] Figure 12 A schematic diagram of a basket structure with a filter membrane is provided for use in embodiments of the present invention;

[0045] Figure 13 A schematic diagram of a basket structure with an umbrella-shaped dense net is provided for use in embodiments of the present invention;

[0046] Figure 14 To illustrate the node distribution of the wave troughs in the waveform basket structure using embodiments of the present invention;

[0047] Figure 15 To provide a schematic diagram of the trough state of the waveform basket before and after loading thrombus using embodiments of the present invention;

[0048] Figure 16To illustrate the support structure with an expanded cage-like shape provided in the embodiments of the present invention Figure 1 ;

[0049] Figure 17 To illustrate the support structure with an expanded cage-like shape provided in the embodiments of the present invention Figure 2 ;

[0050] Figure 18 for Figure 16 A schematic diagram of the support structure projected from the proximal hub to the distal hub;

[0051] Figure 19 This is a schematic diagram showing the distance from the converging portion of the support to the baseline in some embodiments of the present invention;

[0052] Figure 20 A schematic diagram of a thrombus removal system provided by the present invention;

[0053] Figure 21 This is a schematic diagram of the internal structure of the control handle in a thrombus removal system;

[0054] Figure 22 This is a schematic diagram of the cross-sectional structure of the control handle in a thrombus removal system;

[0055] Figure 23 This is a schematic diagram showing the connection between the pull wire and the hub in a thrombus removal system.

[0056] Figure 24 A schematic diagram of a thrombus removal system that can adjust the diameter of the thrombectomy stent or reciprocate its movement, provided by the present invention;

[0057] Figure 25 A schematic diagram of a thrombus removal system capable of administering thrombolytic drugs is provided by the present invention;

[0058] Figure 26 A schematic diagram of a thrombus removal system with an occlusion balloon is provided for the purpose of utilizing this invention;

[0059] Figure 27 A schematic diagram of a thrombus removal system with a mesh sheath is provided for the purpose of utilizing the present invention;

[0060] In the diagram: 1-Thrombectomy bracket; 2-Thrombectomy bracket; 3-Thrombectomy bracket; 4-Thrombectomy bracket; 5-Thrombectomy bracket; 6-Thrombectomy bracket; 101-Bracket; 102-Bracket; 103-Bracket; 201-Basket; 202-Basket; 203-Basket; 204-Basket; 205-Basket; 300-Operating lever; 310-Through hole; 330-Flexible distal end of operating lever; 400-Sleeve; 500-Suction guide tube; 110-Frame; 111-Hub; 1111-Proximal hub; 1112-Distal hub; 112-Spoke; 1121-Proximal spoke of bracket; 1122 - Distal spoke of the support; 113 - Cutting bolt rib; 114 - Diverging unit; 1141 - Converging part; 11411 - First converging part; 11412 - Second converging part; 1151 - First support aperture; 1152 - Second support aperture; 210 - Basket body; 211 - Basket hub; 2111 - Proximal basket hub; 2112 - Distal basket hub; 212 - Basket spoke; 2121 - Proximal basket spoke; 2122 - Distal basket spoke; 213 - Rib; 214 - Aperture; 240 - Waveform; 241 - Crest; 242 - Trough; 2401 - First peak; 2402 - First trough; 2403 - Second peak; 2404 - Second trough; 2405 - Third peak; 2406 - Second trough; 2501 - Proximal basket hub pores; 2502 - Distal basket hub pores; 260 - Umbrella-shaped dense mesh; 600 - Baseline; 270 - Filter membrane; 2701 - Filter pores; 340 - Operating handle; 341 - Handle housing; 342 - Slider; 343 - Screw; 344 - Suction port; 345 - Injection port; 346 - Pulling wire; 347 - Rotation limiting rail; 700 - Mesh sheath; 510 - Occlusion balloon; 8 00 - Imaging marker; 900 - Thrombus; 910 - Viscous thrombus; 2011 - Distal end of cluster; 2021 - Distal end of non-cluster; 2022 - Cluster; 2023 - Outward flare; 810 - First waveform component; 820 - Second waveform component; 830 - Third waveform component; 840 - Waveform grid unit; 25 - Node unit; 251 - First node; 252 - Second node; 253 - Third node; 920 - Unloaded thrombus state; 930 - Loaded thrombus state; R1 - Stent self-expansion radius; R2 / R3 - Distance from convergence 1141 to baseline. Detailed Implementation

[0061] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] In this invention, the terms "cage-like" and "cage-like structure" refer to a three-dimensional frame structure composed of multiple rods or wires, resembling a cage structure in appearance (also referring to a spatial frame composed of a series of interconnected rods or wires, forming a closed or semi-closed geometric shape), possessing good stability and the ability to withstand radial or axial pressure. The cage-like structure exhibits spatial stability (i.e., providing excellent spatial stiffness and resistance to deformation through multi-directional support and cross-connections) and scalability (i.e., its size and shape can be adjusted as needed to adapt to different application scenarios).

[0063] In this invention, the term "geometric dimension" refers to a specific measurement of the size and shape of an object in space. Geometric dimensions include length, width, height, radius, angle, etc.

[0064] The value or range of the term "radial support force" in this invention is measured in accordance with ASTM F3067-14, published by the American Society for Testing and Materials (ASTM). ASTM F3067-14 provides guidance for developing in vitro test methods for measuring the radial strength or collapse pressure of balloon-expandable vascular stents and the chronic outward force of self-expanding vessels. The standard applies to balloon-expandable and self-expandable stents with tubular geometry and covers stents and stent grafts.

[0065] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0066] Example 1

[0067] like Figures 1 to 13 As shown, a thrombectomy support (1, 2, 3, 4, 5, 6) includes a bracket (101, 102, 103, 104) and a basket (201, 202, 203, 204, 205, 206, 207, 208, 209) supported on the distal end of an elongated operating lever 300. Both the bracket and the basket are in an expanded state relative to their initial state. Figures 1 to 13 The support or basket shown is in an expanded state. The support includes a frame 110, which has an expanded cage-like structure (e.g., Figures 16-18As shown, the stent frame 110 is used to cut or scrape thrombi (or thrombi attached to the vessel wall); the basket includes ribs 213 and openings 214, and is used to intercept or capture free thrombi; the radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. Basket ribs 213: form the basic framework of the basket, creating a capture space. Basket openings 214: distributed between the ribs 213, allowing blood to pass through but intercepting free thrombi. The stent frame 110 is designed to cut or scrape thrombi attached to the vessel wall, helping to loosen and remove these difficult-to-capture thrombi. The main function of the basket is to intercept or capture free thrombi that detach from the vessel wall, preventing them from further flowing to other sites and causing complications. The radial support force of the stent is greater than that of the basket, meaning the stent provides stronger support within the blood vessel, ensuring effective deployment and close contact with the vessel wall, thus facilitating cutting and scraping operations. The basket, on the other hand, relies primarily on weaker support to maintain its shape, making it easier to capture free thrombi. This invention's thrombectomy stent is highly efficient (combining cutting and capture functions, enabling the handling of different types and states of thrombi in a single operation), safe (its phased design reduces the risk of damage to the vessel wall and effectively prevents the spread of thrombus fragments), and adaptable (suitable for various vascular environments, especially cases with complex thrombotic conditions). Radial support force / radial support performance refers to the mechanical support force that the stent / basket can provide in the radial direction (i.e., perpendicular to its axis). It reflects the stent / basket's ability to maintain its opening / expansion when compressed by the vessel wall or thrombus after expansion. The mesh structure, thickness, and shape of the stent / basket all affect its support effect. In this application, the radial support force values ​​of the stent and basket are tested separately using ASTM F3067-14 (ASTM F3067-14 (2021) Standard Guide for Radial Loading of Balloon-Expandable and Self-Expanding Vascular Stents). The larger the radial support force value, the more rigid (not easily compressed) the stent / basket becomes after expansion. The thrombectomy stent in this application is generally rigider (relatively less prone to compression and deformation) than the basket, while the basket is softer (relatively easier to compress and deform) than the stent.

[0068] Cage-like support structures can also be designed as follows: a spiral-woven cage structure, where the ribs are woven in a spiral pattern to form a basket-like structure, creating a spring-like structure; a diamond-woven cage structure, where the ribs are woven in a diamond mesh pattern to form evenly distributed pores, with each intersection fixed by welding or other methods to ensure structural stability; a conical expanding cage structure, where the support is cone-shaped overall, gradually widening at the front to form a progressively expanding capture area; a multi-layered stacked cage structure, where the support is woven from multiple layers of fine filaments, with a certain spacing between each layer to form a multi-layered structure; and an adjustable shrinkable cage structure, where the support design... There are several types of stents: Adjustable contraction mechanisms that allow the stent to adjust its shape as needed during deployment and retrieval; these mechanisms are typically implemented through external control devices, such as push rods within the catheter or electromagnetic control systems; self-expanding cage structures where the stent uses self-expanding materials that automatically expand to a predetermined shape after entering the blood vessel; umbrella-shaped deployment cage structures where the stent is designed in an umbrella shape, unfolding rapidly to cover a large vascular cross-section; and multi-segment tandem cage structures, which consist of multiple small baskets or balloon-like structures strung together to form a string of "beads." Similarly, baskets can also be designed as the aforementioned cage structures.

[0069] For the specific structural design of the stent or basket, the applicant's published Chinese patent application entitled "A Vascular Thrombectomy Stent" can also be used; the application number of this Chinese patent application is CN202410965918.3, the application date is 20240718, the publication number is CN118766546A, and the publication date is 20241015. All the technical solutions and technical features of the vascular thrombectomy stent described in the specification of the Chinese patent application can be used as specific embodiments of this application (i.e., specific examples and references to the specific structural design of the stent or basket) to further explain the inventive concept. Although the specification of this application does not fully describe the technical solutions of the vascular thrombectomy stent in CN118766546A, it does not prevent / affect the further supplementary explanation of the stent or basket structure example of this application in CN118766546A. If necessary, CN118766546A can be included as part of the specification of this application. The original text of CN118766546A describes: "A thrombectomy frame includes a thrombectomy frame having a distal end and a proximal end, the thrombectomy frame being a mesh-like or cage-like structure with ribs; a narrowed portion formed by the lateral narrowing of the thrombectomy frame is provided between the distal end and the proximal end of the thrombectomy frame; the narrowed portion divides the thrombectomy frame into a first mesh portion and a second mesh portion for stripping or capturing thrombi, the second mesh portion being able to further strip or capture residual thrombi relative to the first mesh portion; the ribs forming the thrombectomy frame having a plurality of pairs of connected ribs forming a plurality of first node units; the ribs forming the narrowed portion having a plurality of pairs of connected ribs forming a plurality of second node units; the plurality of second node units forming a three-dimensional array capable of laterally intercepting free thrombi."

[0070] like Figure 10 As shown, this embodiment of the invention provides an integrated thrombectomy stent 6, including a stent 104 and a basket 206 supported on the distal end of an elongated operating lever 300. The stent 104 and basket 206 are integrated, meaning they are interconnected. The ribs at the distal end of the stent 104 serve as supports for the proximal end of the basket 206. In other words, different radial support forces / radial support capacities can be deployed in the longitudinal (axial) direction of the elongated cage-like stent, allowing for the distribution of different rigidity components along the longitudinal direction, thereby achieving functional zoning. Furthermore, the distal end of the thrombectomy stent 6 is provided with an umbrella-shaped dense mesh 260 to increase the interception of small thrombi.

[0071] like Figure 11As shown, this embodiment of the invention provides a basket 207 with a proximal cluster; in other words, the hub of the retrieval bracket of the present invention can be a cluster 2022 formed by directly gathering several spokes (cluster distal end 2011), rather than being limited to a ring. Further, the distal end of the basket 207 can be a non-cluster distal end 2021, which gradually moves away from the central axis to form an outwardly flared opening 2023.

[0072] like Figure 12 and Figure 13 As shown, the basket structure can also have a filter membrane 270 with filter holes 2701 attached to its basket body 210, or an umbrella-shaped dense mesh 260 attached.

[0073] The deployment process of the thrombectomy stent: The stent and basket are initially in a compressed state (e.g., compressed and stored in the cannula 400) and delivered to the target location via the slender manipulator 300; after reaching the lesion site, (with the cannula 400 withdrawn) the stent first unfolds into a cage-like structure and begins to cut or scrape the attached thrombus on the vessel wall; subsequently, the basket unfolds to intercept or capture the free thrombus that has been loosened by the stent.

[0074] Thrombectomy stent retrieval process: After thrombus removal, the stent and basket are recompressed and withdrawn into the body, carrying the captured thrombus with them.

[0075] Compared to stents, the support force of the basket has been weakened. The basket is designed with weaker radial support, a characteristic that plays a crucial role in the overall function of the thrombectomy stent: 1) Maintaining shape and flexibility; the weaker radial support means it does not exert excessive pressure on the vessel wall within the blood vessel, which helps reduce the risk of damage, especially in cases where the vessel is fragile or already damaged. The basket's contact within the vessel is gentle, reducing irritation and damage to the vascular endothelial cells, which is crucial for preventing postoperative complications such as inflammation or restenosis; the weaker support allows the basket to adapt more flexibly to the complex geometry of the blood vessel. When encountering bends, bifurcations, or other irregular structures, the basket can naturally conform without excessive deformation or twisting; the weaker support allows the basket to adapt more flexibly to the complex geometry of the blood vessel, ensuring stable deployment in different vascular environments. (ii) Capturing free thrombi; the pores on the basket can adaptively expand and close in the thrombus capture environment, ensuring efficient thrombus capture without significantly obstructing blood flow; the basket's design ensures that all loosened free thrombi can be captured, and its weak support prevents thrombi from detaching again or escaping to distal vessels, improving the safety and success rate of the procedure; (iii) Facilitating operation and retrieval; the weak support makes the basket more smooth and controllable during expansion and contraction; during the procedure, the surgeon can more easily and accurately position the basket to the target area and smoothly retrieve it within the aspiration catheter 500 / cannulas 400 after thrombectomy; during retrieval, the basket's weak support allows for better compression, thereby reducing resistance during retrieval and lowering the difficulty and risk of the operation.

[0076] Example 2

[0077] like Figures 1-9 and Figure 16 As shown, a retrieval bracket includes a bracket (101, 102, 103) and a basket supported on the distal end of an elongated control lever 300. Both the bracket and the basket are in an expanded state relative to their initial state. The bracket includes a frame 110 and a hub 111. The frame 110 has an expanded cage-like structure. The frame 110 includes spokes 112 and retrieval ribs 113. One end of the spokes 112 is fixed to the hub 111, and the other end of the spokes 112 is fixed to the retrieval ribs 113. The ligature 113 is fixed in place; the hub 111 includes a proximal hub 1111 near the proximal end of the frame 110 and a distal hub 1112 near the distal end of the frame 110; the number of spokes of the proximal hub 1111 is less than or equal to the number of spokes of the distal hub 1112, such that the first stent aperture 1151 of the frame 110 is greater than or equal to the second stent aperture 1152, so that the frame 110 can scrape thrombi attached to the vessel wall and hold clumps of thrombus clots 910 (e.g., Figure 5The viscous thrombus 910 is intercepted by the distal spokes 1122 of the stent in the frame 110; the frame 110 is used to cut or scrape the attached thrombus on the vessel wall (such as...). Figure 2 , Figure 5 As shown, the thrombectomy bar 113 scrapes away the thrombus 900 attached to the vessel wall; the basket includes bars 213 and pores 214, and is used to intercept or capture free-floating thrombi (such as...). Figures 2-4 As shown, the thrombectomy strip 113 scrapes away the thrombus 900 / viscous thrombus 910 adhering to the vessel wall; some thrombus 900 / viscous thrombus 910 escaping from the distal spokes 1122 of the stent are captured by the basket and further entangled and anchored; the radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. For example... Figures 16-18 As shown, the frame 110 unfolds into a cage-like structure with multiple spokes 112 and thrombectomizing ribs 113. Spokes 112 are fixed at one end to the hub and at the other end to the thrombectomizing ribs 113, serving to provide support and transmit force. Thrombectomizing ribs 113 are connected to the spokes and used to cut or scrape thrombi attached to the vessel wall. The hub 111 is located at the center of the frame, serving as the fixing point for the spokes and ensuring the stability of the entire structure. The hub is mounted on the operating lever 300 and can be either fixedly connected or slidably connected (e.g.,...). Figure 23 and Figure 24 As shown, the hubs (one or all) slide back and forth on the lever 300 by traction of the pull wire 346 to which they are fixed. In this embodiment, the stent is designed as an adaptively expanding biconical cage structure; the spokes of the proximal hub 1111 / distal hub 1112 expand to form a cone (umbrella-shaped). Compared to the basket, the stent has a stronger radial support force, allowing the thrombectomy strips 113 to embed inside the thrombus, thereby cutting or scraping the attached thrombus on the vessel wall. This high support force ensures that the stent can effectively handle hard thrombus masses; after the stent enters the blood vessel, it first opens up the narrowed or occluded vessel segment with its high radial support force (0.005~5N / mm), restoring the blood flow channel; this initial support provides the necessary space and environment for the deployment of the basket.

[0078] Example 3

[0079] like Figures 1-9As shown, a thrombectomy stent includes a stent and a basket (201, 202, 203, 204, 205, 206, 207, 208, 209) supported on the distal segment of an elongated control lever 300. Both the stent and the basket are in an expanded state relative to their initial state. The stent includes a frame 110 and a hub. The frame 110 has an expanded cage-like structure and includes spokes and thrombectomy ribs 113. One end of each spoke is fixed to the hub, and the other end is fixed to the thrombectomy ribs 113. The hub includes a proximal hub 1111 near the proximal end of the frame 110 and a distal hub 1112 near the distal end of the frame 110. The basket includes ribs and pores, and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. Figures 16-18 As shown, the frame 110 includes a first support aperture 1151 near the proximal end of the frame 110 and a second support aperture 1152 near the distal end of the frame 110; the geometric dimensions of the first support aperture 1151 are larger than the geometric dimensions of the second support aperture 1152 (the frame 110 includes a first support aperture 1151 near the proximal end of the frame 110, the geometric dimensions of which are larger than those of the second support aperture 1152; the second support aperture 1152 is deployed near the distal end of the frame 110); the basket is deployed at the distal end of the support and maintains a longitudinal gap with the distal end hub 1112 of the support (or the support and the basket are sequentially and intermittently arranged on the control lever 300). The stent and basket in the thrombectomy stent achieve highly efficient synergistic thrombectomy through their unique structural design, difference in radial support force, and functional complementarity. In particular, the basket's priority deployment design allows it to begin capturing free thrombi before the stent is deployed, thus improving the overall efficiency and safety of the device. The stent provides strong mechanical support and cutting ability, while the basket, with its flexibility and deformability, gently captures free thrombi. This synergistic mechanism not only improves thrombectomy efficiency but also minimizes damage to the vessel and the risk of secondary dislodgement. The stent has a large radial support force, thus achieving effective cutting of subacute and chronic thrombi.

[0080] like Figure 1 As shown, in some embodiments, the outer diameter dimensions of the support and the basket are at least partially the same or substantially the same. In some embodiments, the support and the basket are independently and spaced apart in series on the joystick 300.

[0081] When radially compressed to 50% of its expanded state, the following conditions are met: the stent's radial support force is 0.005–5 N / mm, and the basket's radial support force is 0.0005–2 N / mm. This design ensures functional complementarity between the stent and the basket. The stent provides sufficient support to cut or scrape attached thrombi, while the basket relies on weaker support to gently capture free thrombi. Working together, they improve the overall safety and effectiveness of the procedure. For patients with acute ischemic stroke, the stent can effectively cut or scrape thrombi in the major arteries of the brain, while the basket intercepts detached thrombus fragments distally, preventing them from entering smaller vessels and causing secondary infarction. In peripheral artery disease (PAD) or peripheral venous disease, the stent can handle larger and more refractory thrombi, while the basket captures loose thrombus fragments, ensuring therapeutic efficacy while reducing postoperative complications. By designing a multi-grid stent (or different grids), such as the thrombectomy stent structure design in Examples 1 to 3 that connects the stent and the basket in series, subacute and chronic thrombi that are difficult to remove in normal surgery can be removed. At the same time, the removed thrombi can be captured multiple times to prevent thrombus escape and reduce intimal damage. The multi-grid structure enhances the bending performance of the device and improves the overall passability.

[0082] Furthermore, when radially compressed to 50% of its expanded state, the following conditions must be met: 0.01 N / mm ≤ stent radial support force ≤ 0.2 N / mm, 0.001 N / mm ≤ basket radial support force ≤ 0.08 N / mm. The stent's radial support force is relatively high (0.01 N / mm to 0.2 N / mm), providing sufficient support to cut or scrape attached thrombi; this high support force allows the thrombectomy ribs 113 to embed within the thrombus, achieving effective cutting or scraping. The basket's radial support force is relatively low (0.001 N / mm to 0.08 N / mm), gently capturing free thrombi and avoiding excessive pressure on the vessel wall; the weaker support force allows the basket to deform more flexibly, adapting to different thrombus states.

[0083] like Figure 4As shown, compared to stents, the flexible and easily deformable ribs of the basket can increase friction and entanglement force by deforming when encountering viscous thrombi. The weaker radial support of the basket does indeed mean that its ribs are more easily deformed, a characteristic that has a positive impact on capturing and entangled viscous thrombi. The weaker radial support of the basket increases the probability of thrombus entanglement: 1) Rib deformation and thrombus entanglement: The weaker radial support makes the basket ribs more flexible, allowing them to adapt more flexibly to changes in blood flow; when encountering larger or irregularly shaped thrombi, the flexible ribs can better wrap and entangle the thrombus, increasing the contact area and thus improving the entanglement effect; the captured thrombus will gradually aggregate within the basket, forming a larger mass. Due to the flexibility of the basket, it can deform slightly to accommodate more thrombi without causing blockage or rupture. (ii) Facilitates the handling of viscous thrombi; viscous thrombi are usually composed of red blood cells, fibrin, and other components, and have high viscosity and elasticity, making them difficult to filter or cut simply. For this type of thrombus, traditional rigid structures may not be able to capture it effectively, and may even cause the thrombus to rupture or escape; the flexible and easily deformable mesh reinforcement strips can increase friction and wrapping force by slightly deforming when in contact with viscous thrombi. The pores between the mesh reinforcement strips can also be adaptively adjusted to a certain extent according to the size and shape of the thrombus, ensuring that even very viscous thrombi can be effectively captured and fixed.

[0084] The basket also includes a proximal basket hub 2111 deployed at the proximal end of the basket, and basket spokes 212; one end of the basket spokes 212 is fixedly connected to the proximal basket hub 2111, and the other end of the basket spokes is fixedly connected to the reinforcing ribs; the proximal basket hub 2111 is circumferentially spaced with at least 3 or more basket spokes.

[0085] like Figure 14 and Figure 15As shown, in the expanded state, the basket has a basket-shaped cage-like spatial shape extending from the proximal basket hub 2111 toward the distal end of the thrombectomy stent; the outer contour of the basket-shaped cage-like spatial shape has a waveform 240 formed in the longitudinal direction; with the extension line of the proximal basket hub 2111 as the baseline 600, the waveform 240 includes peaks 241 (2401, 2403, 2405) away from the baseline 600, and troughs 242 (2402, 2404, 2406) close to the baseline 600; compared with the unloaded thrombus state 920, the troughs of the loaded thrombus state 930 can be further moved closer to the baseline due to the thrombus effect. Unlike the troughs (which are brought closer to the baseline due to thrombus action), the basket body 210 (or ribs) at the crests has the ability to resist the radial contraction deformation force / tendency caused by the thrombus; in other words, by adjusting the geometry of the ribs, the radial support force of the basket crests can be made greater than that of the basket troughs (trough ribs are softer than crest ribs). This design allows the basket-like cage-like spatial shape to adapt to the vascular morphology in an expanded state, increasing the capture area. The crests and troughs in the waveform's outer contour can flexibly deform according to the effect of the thrombus, further approaching the baseline 600, enhancing the capture effect. Figure 14 As shown, the trough 242 of the thrombus-laden state 930 exhibits deformation close to the baseline 600. The ribs at the lowest point of the trough 242 may abut or misalign with each other. The abutment of the ribs provides necessary support to the basket 210 at the crest 241. The misalignment of the ribs allows the basket 210 of adjacent crests 241 to adaptively contract and deform, while also increasing the cross-sectional interception density at the trough 242. Considering that a single performance characteristic often cannot meet the comprehensive performance requirements of thrombectomy, further optimization, such as... Figure 14 As shown, the node units 25 in the trough of the wave basket structure have a non-uniform distribution in the longitudinal direction; specifically, the node unit 25 includes a first node 251 and a second node 252, the first node 251 is evenly distributed at the bottom of the trough, and the second node 252 is evenly distributed on both sides of the bottom of the trough; this arrangement can increase the friction and entanglement force of the basket on the thrombus, and increase the overall performance of the basket.

[0086] The basket also includes a distal basket hub 2112 deployed at the distal end of the basket; the pore geometry near the proximal basket hub 2111 is larger than the pore geometry near the distal basket hub 2112, enabling the basket to capture free thrombi more effectively.

[0087] The basket also includes a distal basket hub 2112 deployed at the distal end of the basket; in the expanded state, the basket has a basket-shaped cage-like space extending away from the proximal basket hub 2111 toward the distal end of the retrieval bracket; the basket is provided with a filter membrane 270, on which a plurality of filter holes 2701 are distributed.

[0088] like Figure 23and Figure 24 As shown, the proximal hub 1111 is coaxially fixed to the control lever 300, and the distal hub 1112 can slide controllably longitudinally through the traction of the pull wire 346 fixed to it; or, the distal hub 1112 is coaxially fixed to the control lever 300, and the proximal hub 1111 can slide controllably longitudinally, or the hubs of the bracket can all slide on the control lever 300. In this embodiment, the bracket is designed as an adaptively expanding double-conical cage structure; the spokes of the proximal hub 1111 / distal hub 1112 expand to form a cone shape; one end hub of the bracket is fixed to the control lever 300, while the other end hub can slide longitudinally on the control lever 300; the slidable hub is provided with a pull wire or a push-pull rod, so that the bracket can achieve controllable expansion (e.g., Figure 23 As shown, the pull wire 346 pulls the distal hub 1112, causing it to slide closer to the proximal hub 1111 in the direction of the arrow, thereby forcing the frame 110 to expand further radially; by manipulating the longitudinal displacement of the pull wire or push-pull rod, the diameter of the support can be adjusted or it can be reciprocated (e.g., Figure 24 As shown, the relevant changes are achieved via a joystick 300 or a traction wire, adapting to different blood vessel diameters. In the expanded state, the stent can form a cage-like structure of different diameters. By adjusting the stent diameter or reciprocating movement, mechanical thrombectomy can be performed on subacute and chronic thrombi that are difficult to remove via interventional surgery.

[0089] During the retraction of the thrombectomy stent into the cannula 400, there is a risk of secondary shearing and fragmentation of the thrombus by the spokes. This phenomenon may lead to the formation and escape of small thrombi, thus affecting the safety and effectiveness of the thrombectomy procedure. Spoke contraction: When the operating handle controls the retraction of the thrombectomy stent into the cannula 400 via the pull wire or rod, the stent gradually contracts. At this time, the spokes and the thrombectomy ribs 113 will undergo relative displacement, generating friction or compression with the captured thrombus. Secondary shearing effect: 1) Mechanical stress: During contraction, the spokes and thrombectomy ribs 113 will apply additional mechanical stress to the thrombus, which may lead to further rupture or fragmentation of the thrombus; 2) Thrombus characteristics: Thrombi themselves are loose and fragile tissues, easily broken by external forces, especially thrombi that have already been partially cut or scraped, which are more prone to secondary shearing and fragmentation. Risks of small thrombus escape: 1) Difficult to capture: Due to their small size and light weight, small thrombi easily escape the capture range of the basket with the blood flow and enter distal vessels, increasing the risk of embolism; 2) Reduced safety: The presence of small thrombi not only increases the possibility of postoperative complications but may also require additional treatment measures, thus prolonging hospitalization and increasing the burden on patients. When considering how to reduce secondary shearing and fragmentation of thrombi during retrieval by adjusting the design of the thrombectomy stent, increasing the spoke length or increasing the initial gap between spokes are two potential design improvement directions. Increasing spoke length: 1) Extending the contact path: Increasing the spoke length allows the spokes to contact the thrombus more slowly during stent contraction, thereby reducing the sudden impact force on the thrombus; 2) Reducing local stress concentration: Longer spokes can disperse the mechanical stress applied to the thrombus over a larger area, reducing the possibility of local stress concentration and thus reducing the risk of secondary shearing; 3) Improving flexibility: Longer spokes may have better flexibility and deformability, better adapting to the shape of the thrombus and more gently enveloping the thrombus during contraction. However, increasing spoke length can also present some challenges: increased operational complexity; longer spokes may make stent handling more complex, especially when navigating narrow vessels, where they may encounter more resistance and obstruction. Increasing the initial gap between spokes has two advantages: 1) reduced direct contact: a larger initial gap means more space between spokes during stent contraction, reducing the likelihood of adjacent spokes compressing the thrombus; 2) reduced friction: a larger gap reduces friction during thrombus encapsulation, lowering the risk of secondary shear fragmentation. However, this method also has limitations: decreased structural stability: excessively large gaps between spokes may weaken the overall structural stability of the stent, especially under strong blood flow impacts, potentially leading to stent deformation or failure; weakened capture effect: while larger gaps help reduce shear forces, excessively large gaps may allow thrombi to escape between spokes, making effective capture impossible. Figure 19As shown, the optimized scheme can be: one spoke is fixedly connected to two or more thrombectomy strips 113 to form a bifurcation unit 114; the bifurcation unit 114 has a converging portion 1141 of the converging spokes and thrombectomy strips 113; with the line connecting the proximal hub 1111 and the distal hub 1112 as the baseline 600, the following is defined: in the self-expansion state, the distance from the outer contour of the stent to the baseline is the stent self-expansion radius R1; the distance R2 of some converging portions 1141 to the baseline is greater than 0.5 times the stent self-expansion radius; and, or, the distance R3 of some converging portions 1141 to the baseline is less than or equal to 0.5 times the stent self-expansion radius. The fixed connection of the spokes and thrombectomy strips 113 to form the bifurcation unit 114 can disperse stress: since the spokes are connected to multiple thrombectomy strips 113, the mechanical stress can be dispersed at multiple points, avoiding local stress concentration, thereby reducing the risk of secondary shearing of the thrombus. The design features of the converging section 1141 are as follows: 1) Reduced direct contact: A larger distance (>0.5 times the self-expansion radius) means less direct contact between the spokes and the thrombus-cutting ribs 113 and the thrombus during contraction, reducing compression and friction on the thrombus; 2) Optimized wrapping path: A smaller distance (≤0.5 times the self-expansion radius) allows the spokes and thrombus-cutting ribs 113 to wrap the thrombus more tightly, ensuring that the thrombus does not easily escape. Furthermore, the uneven distance distribution (the distance from the converging section 1141 to the baseline is unevenly distributed, with some parts greater than 0.5 times the stent's self-expansion radius and some parts less than or equal to 0.5 times) effectively optimizes the secondary shear effect generated during the thrombectomy stent retrieval process; this design not only enhances the stability of the stent structure but also reduces the risk of secondary shearing of the thrombus through reasonable stress dispersion and gradual contraction. Gradual contraction: The uneven convergence section 1141 design allows the stent to exhibit a gradual shape change during contraction, rather than a sudden and violent contraction. This gradual contraction helps to smoothly encapsulate and guide the thrombus into the cannula 400, reducing secondary damage to the thrombus. Improved capture efficiency: The convergence section 1141 design with varying distances can cover a larger area of ​​the thrombus, improving capture efficiency while maintaining gentle handling of the thrombus. Figure 6 and Figure 7As shown, the secondary shearing of the thrombus by the spokes can also be suppressed / reduced by adding a waveform grid unit 840 at the distal end of the stent / basket. The waveform grid unit 840 is typically formed by connecting a pair of waveform members (e.g., 810-820, 820-830) to form a closed gourd-shaped opening; the gourd-shaped opening includes a first opening 8401 and a second opening 8402 that are connected; as an example, the waveform grid unit 840 can preferably be formed by three-shaped waveform members (formed by connecting an outwardly convex arc 8404, an inwardly concave arc 8405 and an outwardly convex arc 8406 in sequence). As the thrombectomy stent is gradually retracted into the lumen of the cannula 400 or the aspiration catheter 500, the waveform components on both sides of the waveform grid unit 840 are gradually compressed and brought closer together until the inwardly concave arcs 8405 partially come into contact with each other to resist this compression, so as to maintain the second opening 8402 formed by the outwardly convex arcs 8404 and prevent the thrombus stuck at the intersection of the tendons 8403 from being sheared.

[0090] Example 4

[0091] like Figures 20-23 As shown, a thrombus removal system includes a thrombectomy stent (1, 2, 3, 4, 5, 6), an aspiration catheter 500 that can be connected to a negative pressure source, and a cannula 400 that can maintain the thrombectomy stent in its initial state. The cannula 400 is sleeved on the thrombectomy stent and extends from the distal end of the thrombectomy stent to the proximal end of the control rod 300. The cannula 400 can travel through the lumen of the aspiration catheter 500 to deliver the thrombectomy stent. Sliding the distal end of the cannula 400 towards the proximal end of the thrombectomy stent allows the thrombectomy stent to be released into an expanded state.

[0092] The thrombus removal system also includes a control handle 340 connected to the proximal end of the control lever 300, which controls the expansion or longitudinal displacement of the thrombectomy stent via a pull wire 346 or a rod.

[0093] The control handle includes a handle housing 341, a slider 342, and a screw 343. The handle housing 341 supports the screw 343, and the slider 342 slides in conjunction with the screw 343. The handle housing restricts the circumferential rotation of the slider 342 via a rotation limiting rail 347. By turning the knob screw 343, the slider 342's traction hub 111 / 211 moves towards the proximal end of the control lever 300, thereby achieving controllable radial expansion of the support or basket (adjusting the diameter or reciprocating movement).

[0094] like Figure 26 and Figure 27As shown, the thrombus removal system also includes a mesh sheath 700 used in conjunction with the aspiration catheter 500; and / or, a occlusion balloon 510 is deployed distal to the aspiration catheter 500. During thrombectomy, the balloon is inflated, creating negative pressure at the tip, which facilitates aspiration and effectively prevents the outflow of thrombolytic drugs during thrombolysis, improving thrombolysis efficiency and safety. During stent withdrawal, the thrombus attached to the stent can be retrieved within the mesh sheath (usually made of woven wire mesh), preventing thrombus escape during stent withdrawal.

[0095] like Figure 25 As shown, the control lever 300 is a hollow tube; several through holes 310 are deployed on the tube wall near the distal end of the control lever 300. The through holes 310 are used to apply thrombolytic drugs into the blood vessel lumen. The through holes 310 can be arranged in the same direction or opposite directions. Thrombolytic drugs or liquids such as saline are injected through the lumen of the control lever 300 to further achieve thrombolysis or thrombus fragmentation.

[0096] The stent or basket may be coated with a material that has a lubricating effect, such as PVP or PTFE, or with a thrombolytic or antithrombotic drug, such as plasminogen activator (t-PA), urokinase, warfarin, or heparin.

[0097] The hub of the support or basket can be a bundle of multiple ribs (spokes) or a metal ring.

[0098] Thrombus removal procedure:

[0099] Initial Entry and Deployment Phase:

[0100] 1) Cannula 400 protection: The thrombectomy stent is wrapped by the cannula 400 and maintained in its initial state, making it easy to deliver to the lesion site.

[0101] (ii) Prioritize basket deployment: Upon reaching the target position, the retractable cannula 400 first releases the basket, allowing it to deploy first, adapt to the vascular morphology, and prepare to capture free thrombi.

[0102] (iii) Stent deployment: After the basket is deployed, the cannula is retracted 400 to release the stent, which expands and opens up the narrowed or occluded vascular segment, while the basket captures more thrombi.

[0103] Thrombus capture phase:

[0104] 1) Net basket capture: The net basket relies on its flexibility and deformability to gently capture free-state thrombi and prevent them from escaping;

[0105] (ii) Stent cutting or scraping: After the stent is deployed, the thrombus strip 113 is embedded in the attached thrombus and then cut or scraped.

[0106] Recycling phase:

[0107] 1) Tightly wrapped by the net basket: The net basket tightly wraps the captured blood clot to ensure that it does not fall off again;

[0108] (ii) Negative pressure aspiration: The aspiration catheter 500 is connected to a negative pressure source and the distal aspiration port is kept in a negative pressure state to transfer the thrombus / clot captured in the thrombectomy stent to the patient's body through negative pressure aspiration.

[0109] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A thrombectomy support, comprising a bracket and a basket supported on the distal end of an elongated control lever, both the bracket and the basket having an expanded state relative to their initial state, characterized in that, The stent includes a frame, which expands into a cage-like structure for cutting or scraping thrombi. The basket includes ribs and pores for intercepting or capturing free-floating thrombi. The radial support force of the stent is greater than that of the basket, or the radial support capacity of the stent is greater than that of the basket. Compared to the stent, the flexible and easily deformable ribs of the basket can increase friction and entanglement force by deforming upon contact with viscous thrombi. The basket also includes a proximal basket hub deployed near the proximal end, and basket spokes. One end of each basket spoke is fixed to the proximal basket hub, and the other end is fixed to the ribs. At least three basket spokes are circumferentially spaced around the proximal basket hub. In the expanded state, the basket has a basket-shaped cage-like spatial form extending from the proximal basket hub towards the distal end of the thrombectomy stent. The outer contour of the basket-shaped cage-like spatial form has a wave-like shape formed longitudinally. With the extension of the near-end basket hub as the baseline, the waveform includes peaks far from the baseline and troughs close to the baseline. The radial support force of the crest is greater than that of the trough; compared to the unloaded thrombus state, the trough can be further moved closer to the baseline by the action of the thrombus.

2. A thrombectomy support, comprising a bracket and a basket supported on the distal end of an elongated control lever, both the bracket and the basket having an expanded state relative to their initial state, characterized in that, The stent comprises a frame and a hub. The frame has an expanded, cage-like structure and includes spokes and thrombectomy ribs. One end of each spoke is fixed to the hub, and the other end is fixed to the thrombectomy ribs. The hub includes a proximal hub near the proximal end of the frame and a distal hub near the distal end of the frame. The number of spokes in the proximal hub is less than or equal to the number of spokes in the distal hub. The frame is used to cut or scrape attached thrombi on the vessel wall. The basket includes ribs and pores, and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. Support capacity; compared to a stent, the flexible and easily deformable basket ribs can increase friction and entanglement force by deforming when in contact with viscous thrombi; the basket also includes a proximal basket hub deployed at the proximal end of the basket, and basket spokes; one end of the basket spokes is fixed to the proximal basket hub, and the other end of the basket spokes is fixed to the ribs; at least 3 basket spokes are circumferentially spaced on the proximal basket hub; in the expanded state, the basket has a basket-shaped cage-like space extending away from the proximal basket hub toward the distal end of the thrombectomy stent; the outer contour of the basket-shaped cage-like space has a wave-like shape formed in the longitudinal direction; With the extension of the near-end basket hub as the baseline, the waveform includes peaks far from the baseline and troughs close to the baseline. The radial support force of the peak is greater than that of the trough; compared to the unloaded thrombus state, the trough can be further moved closer to the baseline by the action of the thrombus.

3. A thrombectomy support, comprising a bracket and a basket supported on the distal end of an elongated control lever, both the bracket and the basket having an expanded state relative to their initial state, characterized in that, The stent comprises a frame and a hub. The frame has an expanded, cage-like structure and includes spokes and thrombectomy ribs. One end of each spoke is fixed to the hub, and the other end is fixed to the thrombectomy ribs. The hub includes a proximal hub near the proximal end of the frame and a distal hub near the distal end of the frame. The basket includes ribs and openings, and is used to intercept or capture free thrombi. The radial support force of the stent is greater than the radial support force of the basket, or the radial support capacity of the stent is greater than the radial support capacity of the basket. The frame includes a first stent opening near the proximal end of the frame and a second stent opening near the distal end of the frame. The geometry of the first stent opening is larger than that of the second stent opening. The basket is deployed at the distal end of the stent and maintains a longitudinal gap with the distal hub of the stent. Compared to the stent, the flexible and easily deformable ribs of the basket can increase friction and entanglement force by deforming when in contact with viscous thrombi. The basket also includes a proximal basket hub deployed at the proximal end of the basket, and basket spokes. One end of the basket spokes is fixed to the proximal basket hub, and the other end of the basket spokes is fixed to the ribs. At least three basket spokes are circumferentially spaced around the proximal basket hub. In the expanded state, the basket has a basket-shaped cage-like spatial form that extends away from the proximal basket hub toward the distal end of the thrombectomy stent. The outer contour of the basket-shaped cage-like spatial form has a wave-like shape formed in the longitudinal direction. With the extension of the near-end basket hub as the baseline, the waveform includes peaks far from the baseline and troughs close to the baseline. The radial support force of the peak is greater than that of the trough; compared to the unloaded thrombus state, the trough can be further moved closer to the baseline by the action of the thrombus.

4. The thrombectomy stent according to any one of claims 1 to 3, characterized in that, When radially compressed to 50% of its expanded state, the following conditions are met: the radial support force of the bracket is 0.005~5 N / mm, and the radial support force of the basket is 0.0005~2 N / mm.

5. The thrombectomy bracket according to claim 4, characterized in that, When radially compressed to 50% of its expanded state, the following conditions must be met: 0.01 N / mm ≤ radial support force of the bracket ≤ 0.2 N / mm, 0.001 N / mm ≤ radial support force of the basket ≤ 0.08 N / mm.

6. The thrombectomy bracket according to claim 1, characterized in that, The basket also includes a distal basket hub deployed at the far end of the basket; the aperture geometry near the proximal basket hub is larger than the aperture geometry near the distal basket hub.

7. The thrombectomy bracket according to claim 1, characterized in that, The basket also includes a distal basket hub deployed at the far end of the basket; in the expanded state, the basket has a basket-shaped cage-like space extending away from the proximal basket hub toward the distal end of the retrieval bracket; the basket is provided with a filter membrane, on which several filter holes are distributed.

8. The thrombectomy stent according to any one of claims 2 to 3, characterized in that, The proximal hub is coaxially fixed to the control lever, and the distal hub can slide controllably along the longitudinal direction; or, the distal hub is coaxially fixed to the control lever, and the proximal hub can slide controllably along the longitudinal direction.

9. The thrombectomy bracket according to claim 8, characterized in that, In the expanded state, the support can form cage-like structures of different diameters.

10. The thrombectomy stent according to any one of claims 2 to 3, characterized in that, A spoke is fixedly connected to two or more cleaving bars to form a bifurcation unit; the bifurcation unit has a converging part where the converging spokes and cleaving bars converge; taking the line connecting the proximal hub and the distal hub as the baseline, the distance from the outer contour of the support to the baseline in the self-expansion state is defined as the self-expansion radius of the support; the distance from the partial converging part to the baseline is greater than 0.5 times the self-expansion radius of the support.

11. The thrombectomy bracket according to claim 10, characterized in that, The distance from the partial convergence point to the baseline is less than or equal to 0.5 times the self-expansion radius of the stent.

12. A thrombus removal system, characterized in that, The stent includes any one of claims 1 to 11, and further includes an aspiration catheter capable of connecting to a negative pressure source and a cannula capable of maintaining the stent in its initial state; the cannula is sleeved over the stent and extends from the distal end of the stent to the proximal end of the control lever; the cannula is capable of delivering the stent through the lumen of the aspiration catheter; the sliding of the distal end of the cannula towards the proximal end of the stent allows the stent to be released into an expanded state.

13. The thrombus removal system according to claim 12, characterized in that, It also includes a control handle connected near the end of the control lever, which controls the expansion or longitudinal displacement of the retrieval bracket via a pull wire or rod.

14. The thrombus removal system according to claim 13, characterized in that, The control handle includes a handle housing, a slider, and a screw; the handle housing supports the screw, the slider slides in conjunction with the screw, and the handle housing restricts the circumferential rotation of the slider.

15. The thrombus removal system according to claim 12, characterized in that, It also includes a mesh sheath for use with the aspiration catheter; and / or, a occlusion balloon is deployed near the distal end of the aspiration catheter.

16. The thrombus removal system according to claim 12, characterized in that, The control lever is a hollow tube; several through holes are deployed on the tube wall near the distal end of the control lever, which are used to apply thrombolytic drugs into the blood vessel lumen.

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