Embolus retrieval stent

Abstract

The present invention discloses a thrombectomy stent, which comprises a stent body and a plurality of thrombus capture members. The surface of the stent body is provided with a number of meshes. Each thrombus capture member is connected to a mesh on the stent body and is received in the corresponding mesh when the stent body is in a contracted state, and protrudes outward from the corresponding mesh when the stent body is in a deployed state. The thrombus capture member is formed into a U-shaped profile, and its two open ends are respectively connected to different parts of the mesh of the stent body. The closed end protrudes outward in a direction perpendicular to the U-shaped plane relative to the two open ends, and is provided with a plurality of capture hooks inwardly. Any one of the capture hooks is not coplanar with the closed end of the thrombus capture member, and its hook tip faces the stent body and its projection on the stent body is located in the corresponding mesh. The present invention combines the capture hooks and the thrombus capture members, which can effectively "catch" the difficult-to-capture thrombus, not only improving the overall capture efficiency, but also ensuring a more thorough thrombus removal.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a thrombectomy stent. Background Art

[0002] A thrombectomy stent is a medical device used to treat vascular obstructive diseases such as acute ischemic stroke. Its main purpose is to deliver the thrombectomy stent to the thrombus location through minimally invasive surgery, then expand the stent to embed and capture the thrombus, and subsequently retract the thrombectomy stent to remove the thrombus outside the body, thereby restoring the patency of the blood vessel and normal blood flow. In order to improve the capture effect of the thrombectomy stent on the thrombus, the prior art often adds thrombus capture components to the outer wall of the stent body of the thrombectomy stent. These thrombus capture components are closely attached to the outer wall of the stent body when the stent body is in a contracted state, facilitating transportation to the target location through a catheter. When the stent body is in a dilated state, the thrombus capture components protrude outward from the outer wall of the stent body and form a thrombus capture space to better contact and capture the thrombus.

[0003] However, despite the addition of thrombus capture components, due to the different physical properties of thrombi such as hardness and viscosity, the existing thrombus capture components may still have problems with poor capture effects. Especially for those relatively loose or smooth-surfaced thrombi, the existing thrombus capture components lack sufficient grasping force and fixing points, making it difficult to effectively capture these types of thrombi. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a thrombectomy stent aiming at the above-mentioned defects in the prior art, aiming to improve the capture ability of the thrombus capture components and avoid the situation of thrombus shedding or not being captured.

[0005] According to the present invention, there is provided a thrombectomy stent, comprising a stent body and a plurality of thrombus capture components. The surface of the stent body is provided with a number of meshes. Each thrombus capture component is connected to a mesh on the stent body and is received in the corresponding mesh when the stent body is in a contracted state, and protrudes outward from the corresponding mesh when the stent body is in a dilated state. The thrombus capture component forms a U-shaped profile, and its two open ends are respectively connected to different parts of the mesh of the stent body. The closed end protrudes outward in a direction perpendicular to the U-shaped plane relative to the two open ends, and a plurality of capture hooks are arranged inward. Any one of the capture hooks is not coplanar with the closed end of the thrombus capture component, and its hook tip faces the stent body and its projection on the stent body is located in the corresponding mesh.

[0006] Furthermore, the thrombus capture component, the capture hook and the stent body are formed by cutting a metal tube and then heat setting.

[0007] Further, the thrombus capture member and the stent body are formed by heat setting after cutting a metal tube, and the capture hooks are fixed on the thrombus capture member by welding or bonding.

[0008] Further, the thrombus capture member includes a first capture rod, a second capture rod, and a third capture rod. The proximal ends of the first capture rod and the second capture rod are respectively connected to different parts of the stent body grid. The distal ends of the first capture rod and the second capture rod are connected by the third capture rod, and a plurality of capture hooks are arranged on the third capture rod.

[0009] Further, a plurality of capture hooks are radially and spacedly connected to the third capture rod.

[0010] Further, a through capture groove is provided on the hook body of the capture hook.

[0011] Further, both the first capture rod and the second capture rod are arc-shaped rods, and the distal segment of the arc-shaped rod protrudes outward relative to its proximal segment and is smoothly transitionally connected to the third capture rod.

[0012] Further, the third capture rod has an elastic structure that can be deformed in the axial direction, so that the thrombus capture space formed by the first capture rod, the second capture rod, and the third capture rod surrounding the stent body is variable.

[0013] Further, the third capture rod has a wave-like structure, and each capture hook is connected to the concave part of the wave-like structure of the third capture rod.

[0014] Further, the third capture rod has a plurality of helical bending structures arranged along the axis, and each capture hook is connected to the helical bending part of the third capture rod.

[0015] Compared with the prior art, in the present invention, the thrombus capture member is set to a U-shaped profile, and its closed end protrudes outward in a direction perpendicular to the U-shaped plane relative to the two open ends, and a plurality of capture hooks are arranged inward. This design enables the thrombus capture member to better contact and capture thrombus. At the same time, the capture hooks fill the possible gap between the closed end and the stent body, further enhancing the thrombus capture ability. Especially for those relatively loose or smooth-surfaced thrombi, the capture hooks can effectively "catch" these difficult-to-capture thrombi through their angle and tip design. Therefore, the present invention not only improves the overall capture efficiency but also ensures more thorough thrombus removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] With reference to the accompanying drawings and by referring to the following detailed description, it will be easier to have a more complete understanding of the present invention and easier to understand its accompanying advantages and features.

[0017] Figure 1It is a schematic diagram of the overall structure of the embodiment of the present invention without the capture hook.

[0018] Figure 2 It is a schematic diagram of the thrombus capture member and the capture hook in the embodiment of the present invention.

[0019] Figure 3 It is a schematic diagram of the capture hook in the embodiment of the present invention.

[0020] In the drawings: 10 is the stent main body; 20 is the thrombus capture member, 21 is the first capture rod, 22 is the second capture rod, 23 is the third capture rod; 30 is the thrombus capture space; 40 is the capture hook, 41 is the hook body, 42 is the hook tip 42.

[0021] It should be noted that the drawings are used to illustrate the present invention, rather than limiting the present invention. Note that the drawings showing the structure may not be drawn to scale. And, in the drawings, the same or similar elements are labeled with the same or similar reference numerals. Detailed Description of the Invention

[0022] In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be described in detail below in conjunction with specific embodiments and drawings.

[0023] As used in the present invention, "proximal" and "distal" should be understood as being observed from the direction of the attending physician. "Proximal" refers to the end close to the attending physician, that is, corresponding to the "left end" in the reference drawings, and "distal" refers to the end far from the attending physician, that is, corresponding to the "right end" in the reference drawings. Similarly, "proximal segment" refers to a segment or a specific area close to the attending physician, and "distal segment" refers to a segment or a specific area far from the attending physician.

[0024] As Figures 1 to 3 shown, the thrombus removal stent of this embodiment includes a stent main body 10 and a plurality of thrombus capture members 20 arranged around the outer wall of the stent main body 10. The stent main body 10 is a hollow tubular structure, which is formed by laser engraving a metal tube such as a nickel-titanium tube and heat treatment for shaping. The surface is provided with a plurality of meshes and has a radially contracted state and a radially expanded state, and these two states respectively correspond to the non-thrombus removal state and the thrombus removal state. The plurality of thrombus capture members 20 are circumferentially arranged on the outer wall of the stent main body 10 and are arranged in a substantially staggered manner to maximize the capture efficiency. They are specifically used to capture thrombus outside the stent main body 10. These thrombus capture members 20 and the stent main body 10 are integrally formed, which means that the entire thrombus removal stent is manufactured by cutting a single metal tube and passing through a heat setting process.

[0025] Specifically for each thrombus capture member 20, it is respectively connected to a corresponding mesh on the stent body 10. When the stent body 10 is in a contracted state, the thrombus capture member 20 can be received within the corresponding mesh, and thus closely adheres to the outer wall of the stent body 10, hardly increasing the overall diameter. Such a design helps the thrombus extraction stent to smoothly pass through the catheter to reach the lesion site. When the stent body 10 is in a dilated state, the thrombus capture member 20 will protrude outward from the corresponding mesh, thus protruding from the outer wall of the stent body 10 and forming a thrombus capture space 30.

[0026] The thrombus capture member 20 is formed into a U-shaped profile, and its two open ends are respectively connected to different parts of the mesh of the stent body 10. The closed end protrudes outward in a direction perpendicular to the U-shaped plane relative to the two open ends, and a plurality of capture hooks 40 are arranged inwardly. This unique design enables the thrombus capture member 20 to better contact the thrombus and effectively capture the thrombus, and can effectively "catch" these difficult-to-capture thrombi by using the capture hooks 40. Any one of the capture hooks 40 is not coplanar with the closed end of the thrombus capture member 20, and its hook tip faces the stent body 10, and its projection on the stent body 10 is located within the corresponding mesh. In this way, the capture hooks 40 fill the possible gap between the closed end of the thrombus capture member 20 and the stent body 10, thereby further enhancing the thrombus capture ability. Especially when facing those relatively loose or smooth-surfaced thrombi, the capture hooks 40, relying on their angle and tip design, can effectively "catch" these difficult-to-capture thrombi, and thus the capture ability for specific types of thrombi has been significantly improved. All the capture hooks 40 and the thrombus capture member 20 and even the stent body 10 are integrally formed. Of course, all the capture hooks 40 can also be separately provided from the thrombus capture member 20, and these capture hooks 40 are fixed on the thrombus capture member 20 by means such as welding or bonding.

[0027] Each thrombus capture member 20 includes a first capture rod 21, a second capture rod 22, and a third capture rod 23. Among them, the first capture rod 21 and the second capture rod 22 are respectively connected to the outer wall of the stent body 10, and the third capture rod 23 is connected between the first capture rod 21 and the second capture rod 22. In this way, the first capture rod 21, the second capture rod 22, and the third capture rod 23 together with the stent body 10 enclose a thrombus capture space 30. Moreover, the third capture rod 23 is an elastic structure and has the ability to deform, generally presenting a wavy structure that can deform in the axial direction, and its wave spacing is uniformly set. Such a design enhances its adaptability to thrombi of different shapes, and thus the size of the thrombus capture space 30 can be changed. Therefore, in practical applications, the third capture rod 23 can be adjusted according to the actual size and shape of the thrombus to ensure that more thrombi can be effectively captured. Even during the process of withdrawing the thrombus removal stent, the third capture rod 23 can also be dynamically expanded according to the pressure and shape of the thrombus, further increasing the thrombus capture space, so that the thrombus can smoothly enter the interior of the thrombus removal stent and be captured, thereby ensuring that the thrombus capture member 20 can always maintain a good thrombus capture ability and effectively avoiding the situation of thrombus shedding or not being captured.

[0028] Specifically, during the process of the stent body 10 changing from the contracted state to the expanded state in the blood vessel, along with the gradual protrusion of the thrombus capture member 20 from the outer wall of the stent body 10, an effective thrombus capture space 30 is gradually formed. Since the third capture rod 23 can deform, the thrombus capture space 30 will correspondingly adjust its size to ensure that the thrombus can smoothly embed into the interior of the stent body 10. After the thrombus is embedded, during the process of withdrawing the thrombus removal stent from the human body, the third capture rod 23 is affected by the withdrawal force and will also be dynamically expanded according to the pressure and shape of the thrombus, so that the thrombus sandwiched in the thrombus capture space 30 can smoothly embed into the interior of the stent body 10.

[0029] A plurality of capture hooks 40 are provided on the third capture rod 23, and these capture hooks 40 are radially arranged and connected to the third capture rod 23 at intervals. Each capture hook 40 includes a hook body 41 and a hook tip 42. The hook body 41 is in the same plane as the third capture rod 23, and the hook tip 42 bends inward from the end of the hook body 41. In this way, the entire capture hook 40 is not coplanar with the thrombus capture member 20 and even the closed end of the third capture rod 23. Specifically, each capture hook 40 is connected to the concave portion of the wave structure of the third capture rod 23 and bends toward the stent body 10. The proximal ends of the first capture rod 21 and the second capture rod 22 are respectively connected to different parts of the grid of the stent body 10, and the distal ends of the first capture rod 21 and the second capture rod 22 are connected by the third capture rod 23. In addition, the first capture rod 21 and the second capture rod 22 extend axially in parallel and have the same length. The third capture rod 23 is integrally formed into a U-shaped profile, and its two open ends are respectively connected to the distal ends of the first capture rod 21 and the second capture rod 22, so that the first capture rod 21, the second capture rod 22, and the third capture rod 23 as a whole also form a U-shaped profile. Among them, both the first capture rod 21 and the second capture rod 22 are arc-shaped rods, and the distal segment of the arc-shaped rod protrudes outward relative to its proximal segment. In this way, the closed end of the U-shaped profile thrombus capture member 20 formed by the first capture rod 21, the second capture rod 22, and the third capture rod 23 protrudes outward in a direction perpendicular to the U-shaped plane relative to its two open ends.

[0030] In order to further improve the capture effect, a through capture groove can also be provided on the hook body 41 of the capture hook 40. The capture groove can not only increase the friction force, but also play a role in fixing the thrombus to a certain extent and effectively prevent it from slipping off. In addition, the third capture rod 23 can also be designed to have a plurality of helical bending structures arranged axially. Such a design can not only achieve the deformation function, but also effectively connect the capture hooks 40 and provide a mechanism similar to that of a helical spring. In this way, the entire device can be more flexible and efficient when dealing with complex and changeable thrombus conditions.

[0031] It can be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, many possible changes and modifications can be made to the technical solution of the present invention by using the above-disclosed technical content, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A thrombectomy stent, comprising a stent body and a plurality of thrombus capture members. A plurality of meshes are provided on the surface of the stent body. Each thrombus capture member is connected to one mesh on the stent body and is received in the corresponding mesh when the stent body is in a contracted state, and protrudes outward from the corresponding mesh when the stent body is in a deployed state. It is characterized in that, The thrombus capture member is formed into a U-shaped profile, with its two open ends respectively connected to different parts of the stent body mesh. The closed end protrudes outward in a direction perpendicular to the U-shaped plane relative to the two open ends, and is provided with a plurality of capture hooks inwardly. Any one of the capture hooks is not coplanar with the closed end of the thrombus capture member, and its hook tip faces the stent body and its projection on the stent body is located in the corresponding mesh; The thrombus capture member includes a first capture rod, a second capture rod, and a third capture rod. The distal ends of the first capture rod and the second capture rod are connected by the third capture rod. The third capture rod is an elastic structure capable of deforming in the axial direction, so that the thrombus capture space formed by the first capture rod, the second capture rod, and the third capture rod surrounding the stent body is variable, and a plurality of capture hooks are arranged on the third capture rod.

2. The thrombectomy stent according to claim 1, characterized in that, The thrombus capture member, the capture hooks, and the stent body are formed by heat setting after cutting a metal tube.

3. The thrombectomy stent according to claim 1, wherein, The thrombus capture member and the stent body are formed by heat setting after cutting a metal tube, and the capture hooks are fixed to the thrombus capture member by welding or bonding.

4. The thrombectomy stent according to claim 1, wherein The proximal ends of the first capture rod and the second capture rod are respectively connected to different parts of the stent body mesh.

5. The thrombectomy stent according to claim 4, characterized in that, A plurality of capture hooks are radially and spacedly connected to the third capture rod.

6. The thrombectomy stent according to claim 4, wherein A through capture groove is provided on the hook body of the capture hook.

7. The thrombectomy stent according to claim 4, wherein Both the first capture rod and the second capture rod are arc-shaped rods, and the distal section of the arc-shaped rod protrudes outward relative to its proximal section and is smoothly and transitionally connected to the third capture rod.

8. The thrombectomy stent according to claim 1, wherein The third capture rod has a wave-like structure, and each capture hook is connected to the concave portion of the wave-like structure of the third capture rod.

9. The thrombectomy stent according to claim 1, wherein The third capture rod has a plurality of helical bending structures arranged axially, and each capture hook is connected to the helical bending portion of the third capture rod.

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