Embolic retrieval stent

Abstract

The present invention discloses a thrombus removal stent, comprising a hollow tubular stent body and a thrombus capture component circumferentially arranged on the outer wall of the stent body, the stent body having a radially contracted state and a radially expanded state, when the stent body is in the contracted state, the thrombus capture component is tightly attached to the outer wall of the stent body, and when the stent body is in the expanded state, the thrombus capture component protrudes from the outer wall of the stent body, the thrombus capture component comprises a first capture rod, a second capture rod and an elastic component, the elastic component is connected between the first capture rod and the second capture rod, and is configured to be able to generate deformation so that the thrombus capture space formed by the first capture rod, the second capture rod and the elastic component and the stent body is variable, thereby ensuring that the thrombus capture component can always maintain a good capture ability for the thrombus, avoiding the thrombus from falling off or not being captured.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a thrombus removal stent. Background Art

[0002] A stent retriever is a medical device used to treat vascular occlusive diseases such as acute ischemic stroke. Its main purpose is to deliver the stent retriever to the location of the thrombus through minimally invasive surgery, then expand the stent to embed and capture the thrombus, and then withdraw the stent retriever to remove the thrombus from the body, thereby restoring vascular patency and normal blood flow.

[0003] Traditional thrombus retriever stents are usually composed of only a hollow tubular stent body. This design is often difficult to effectively capture large or irregularly shaped thrombi. In order to improve the capture effect, modern thrombus retriever stents have added thrombus capture components that are circumferentially arranged on the outer wall of the stent body. These thrombus capture components are tightly attached to the outer wall of the stent body when the stent body is in a contracted state, which is convenient for delivery to the target position through a catheter. When the stent body is in an expanded 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. However, since the thrombus capture space is immutable, after the thrombus retriever stent is embedded in the thrombus and the thrombus capture component captures the thrombus, during the process of withdrawing the thrombus retriever stent, some thrombi are still not easy to enter the thrombus retriever stent through the thrombus capture space, resulting in incomplete thrombus capture and increasing the risk of surgical failure. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a thrombus removal stent in view of the above-mentioned defects in the prior art, aiming to ensure that the thrombus capturing component can always maintain a good thrombus capturing ability to avoid the thrombus falling off or not being captured.

[0005] According to the present invention, there is provided a thrombus removal stent, comprising a hollow tubular stent body and a thrombus capture member circumferentially arranged on the outer wall of the stent body, the stent body having a radially contracted state and a radially expanded state, when the stent body is in the contracted state, the thrombus capture member is tightly attached to the outer wall of the stent body, and when the stent body is in the expanded state, the thrombus capture member protrudes from the outer wall of the stent body, the thrombus capture member comprises a first capture rod, a second capture rod and an elastic component, the elastic component is connected between the first capture rod and the second capture rod, and is configured to be able to generate deformation so that the thrombus capture space formed by the first capture rod, the second capture rod, the elastic component and the stent body is variable.

[0006] Furthermore, the proximal end of the first catch rod and the proximal end of the second catch rod are respectively connected to different parts of the bracket body, and the distal end of the first catch rod and the distal end of the second catch rod are connected via an elastic component.

[0007] Further, the first capture rod and the second capture rod extend axially in parallel and have the same length.

[0008] Further, the elastic member has a wave-like structure that can deform in the axial direction.

[0009] Further, the elastic member is integrally formed into a U-shaped profile, and the two open ends of the elastic member are respectively connected to the distal ends of the first capture rod and the second capture rod.

[0010] Further, the wave spacing of the wave-like structure is uniformly arranged.

[0011] Further, the wave spacing of the wave-like structure is non-uniformly arranged, and the wave spacing in the region close to the first capture rod and the second capture rod is greater than the wave spacing in the region far from the first capture rod and the second capture rod.

[0012] Further, a plurality of capture hooks are provided on the elastic member.

[0013] Further, the elastic member has a wave-like structure, and each capture hook is connected to the concave portion of the wave structure of the elastic member and bends towards the bracket body.

[0014] Further, the capture hook includes a hook body and a hook tip. The hook body is in the same plane as the elastic member, and the hook tip bends inward from the end of the hook body.

[0015] Compared with the prior art, the elastic member of the present invention enables the thrombus capture space to be adjusted according to the actual size and shape of the thrombus, thereby ensuring that more thrombi are effectively captured. Even during the process of withdrawing the thrombectomy stent, the elastic member can dynamically expand according to the pressure and shape of the thrombus, increasing the thrombus capture space, enabling the thrombus to smoothly enter the thrombectomy stent and be captured. In this way, it is ensured that the thrombus capture member can always maintain a good thrombus capture ability, avoiding the occurrence of thrombus detachment or non-capture. 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 more easily understand its accompanying advantages and features.

[0017] Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

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

[0019] Figure 3 is a schematic diagram of the structure of the capture hook in Embodiment 2 of the present invention.

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

[0021] It should be noted that the accompanying 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. Also, in the drawings, the same or similar elements are labeled with the same or similar reference numerals. Detailed implementation manners

[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 the accompanying drawings.

[0023] As used in the present invention, "proximal" and "distal" should be understood as follows: when observed from the direction of the attending physician, "proximal" refers to the end close to the attending physician, that is, the "left end" corresponding to the reference accompanying drawings, and "distal" refers to the end far from the attending physician, that is, the "right end" corresponding to the reference accompanying 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] Embodiment 1: As Figure 1 shown, the thrombus removal stent of this embodiment includes a stent body 10 and a plurality of thrombus capture members 20 arranged around the outer wall of the stent body 10. The stent body 10 is a hollow tubular structure, which is formed by laser engraving a metal tube such as a nitinol 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 arranged circumferentially on the outer wall of the stent body 10 and are arranged in a substantially staggered manner to maximize the capture efficiency, and are specifically used to capture thrombus outside the stent body 10. These thrombus capture members 20 and the stent 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] Specific to 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 removal 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. Each thrombus capture member 20 includes a first capture rod 21, a second capture rod 22, and an elastic member 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 elastic member 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 elastic member 23 together with the stent body 10 enclose a thrombus capture space 30. Moreover, the elastic member 23 has the ability to deform, which enables the thrombus capture space 30 to change. Therefore, in practical applications, the elastic member 23 can be adjusted accordingly according to the actual size and shape of the thrombus, so as to ensure that more thrombi can be effectively captured. Even during the process of withdrawing the thrombus removal stent, the elastic member 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.

[0026] Specifically, during the process of the stent body 10 changing from a contracted state to a dilated state within the blood vessel, along with the thrombus capture member 20 gradually protruding from the outer wall of the stent body 10, an effective thrombus capture space 30 is gradually formed. Since the elastic member 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 elastic member 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 clamped in the thrombus capture space 30 can smoothly embed into the interior of the stent body 10.

[0027] In this embodiment, the proximal ends of the first capture rod 21 and the second capture rod 22 are respectively connected to different parts of the bracket body 10, while the distal ends of the first capture rod 21 and the second capture rod 22 are connected by an elastic member 23. In addition, the first capture rod 21 and the second capture rod 22 extend axially in parallel and have the same length. The elastic member 23 is presented as 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. The elastic member 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 elastic member 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 section of the arc-shaped rod protrudes outward relative to its proximal section. 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 elastic member 23 protrudes outward in a direction perpendicular to the U-shaped plane relative to its two open ends. This unique design enables the thrombus capture member 20 to better contact the thrombus and effectively capture the thrombus.

[0028] It can be understood that the wave spacing of the wavy structure can also be set non-uniformly. For example, the wave spacing in the area close to the first capture rod 21 and the second capture rod 22 can be set to be greater than the wave spacing in the area far from the first capture rod 21 and the second capture rod 22. Through such a design, a certain inhibition can be imposed on the deformation of the elastic member 23 to prevent the situation of thrombus capture failure caused by excessive deformation amplitude.

[0029] Embodiment 2: Different from Embodiment 1, in combination with Figure 2 and Figure 3As shown, in this embodiment, a plurality of capture hooks 40 are added to the elastic member 23. These capture hooks 40 are radially arranged and connected to the elastic member 23 at intervals. Specifically, each capture hook 40 is connected to the concave portion of the wave structure of the elastic member 23 and bends towards the stent main body 10. In addition, any one of the capture hooks 40 is not coplanar with the thrombus capture member 20 or even the closed end of the elastic member 23. Its hook tip faces the stent main body 10, and its projection on the stent main body 10 is located within the corresponding grid. The capture hook 40 mainly consists of a hook body 41 and a hook tip 42. Among them, the hook body 41 is in the same plane as the elastic member 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 or even the closed end of the elastic member 23. This design cleverly fills the possible gap between the closed end and the stent main body 10, thereby further enhancing the thrombus capture ability. Especially when facing those relatively loose or smooth-surfaced thrombi, the capture hook 40 can effectively "catch" these difficult-to-capture thrombi by virtue of its angle and tip design. This embodiment introduces the capture hook 40 on the basis of the first embodiment, which significantly improves the capture ability for specific types of thrombi.

[0030] 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, effectively preventing it from slipping off.

[0031] Other structures of this embodiment are the same as those of the first embodiment and will not be elaborated here.

[0032] 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 technical content disclosed above, 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 the protection of the technical solution of the present invention.

Claims

1. A thrombectomy stent, comprising a stent body in the form of a hollow tube and a thrombus capture member disposed circumferentially on the outer wall of the stent body. The stent body has a radially contracted state and a radially expanded state. When the stent body is in the contracted state, the thrombus capture member is closely attached to the outer wall of the stent body. When the stent body is in the expanded state, the thrombus capture member protrudes from the outer wall of the stent body, characterized in that The thrombus capturing component includes a first capturing rod, a second capturing rod and an elastic component, wherein the elastic component is connected between the first capturing rod and the second capturing rod and is configured to be deformable so that a thrombus capturing space formed by the first capturing rod, the second capturing rod, the elastic component and the stent body is variable.

2. The thrombectomy stent according to claim 1, characterized in that, The proximal end of the first catch rod and the proximal end of the second catch rod are respectively connected to different parts of the bracket body, and the distal end of the first catch rod and the distal end of the second catch rod are connected through an elastic component.

3. The thrombectomy stent according to claim 2, wherein The first catch rod and the second catch rod extend axially parallel and have the same length.

4. The thrombectomy stent according to claim 2, wherein, The elastic component is in a wave-like structure capable of being deformed in the axial direction.

5. The thrombectomy stent according to claim 4, wherein The elastic component is formed as a U-shaped profile as a whole, and two open ends of the elastic component are respectively connected to the distal ends of the first catch rod and the second catch rod.

6. The thrombectomy stent according to claim 4, wherein The wave spacing of the wavy structure is evenly arranged.

7. The thrombectomy stent according to claim 4, wherein The wave spacing of the wavy structure is non-uniformly arranged, and the wave spacing of the area close to the first grabbing rod and the second grabbing rod is greater than the wave spacing of the area far from the first grabbing rod and the second grabbing rod.

8. The thrombectomy stent according to claim 1, wherein, The elastic component is provided with a plurality of catching hooks.

9. The thrombectomy stent according to claim 8, characterized in that, The elastic component is in a wavy structure, and each catching hook is connected to a concave portion of the wavy structure of the elastic component and is bent toward the bracket body.

10. The thrombectomy stent according to claim 8, wherein, The catching hook comprises a hook body and a hook tip, wherein the hook body and the elastic component are located in the same plane, and the hook tip is bent inward from the end of the hook body.

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