Embolus removal stent

Abstract

The present invention discloses a thrombectomy stent, which comprises a hollow tubular stent body and a thrombus capture structure arranged circumferentially on the outer wall of the stent body. The stent body has a radially contracted state and a radially expanded state. Each set of thrombus capture structures includes a pair of interconnected inner capture members and outer capture members. When the stent body is in the contracted state, both the inner capture members and the outer capture members are closely attached to the outer wall of the stent body. When the stent body is in the expanded state, the outer capture members expand outward and protrude from the outer wall of the stent body, and the inner capture members expand inward and enter the internal space of the stent body. This design combining the inside and the outside significantly improves the overall capture effect, and the relative positions of the inner and outer capture members are more stable due to their interconnection, avoiding the problem of thrombus slippage caused by relative position changes, and further improving the success rate and safety of the operation.

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 stent to the thrombus location through minimally invasive surgery, then expand the stent to embed and capture the thrombus, and subsequently retract the stent to remove the thrombus outside the body, thereby restoring the patency of the blood vessel and normal blood flow.

[0003] In order to improve the thrombus capture effect, existing thrombectomy stents have added thrombus capture structures circumferentially arranged on the outer wall of the stent body. When the stent body is in the expanded state, these thrombus capture structures protrude outward from the outer wall of the stent body to better contact and capture the thrombus located outside the stent body; or, these thrombus capture structures extend inward into the interior of the stent body to better contact and capture the thrombus inside the stent body. That is to say, the existing designs usually adopt a single outward or inward thrombus capture structure to capture the thrombus. However, although this single-direction design can improve the thrombus capture effect, it is difficult to comprehensively cover the thrombus area only by the outward or inward thrombus capture structure, which may result in some thrombi not being captured. Especially when facing a larger or irregularly shaped thrombus, the thrombus may escape due to structural instability, 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 thrombectomy stent aiming at the above-mentioned defects in the prior art, aiming to improve the capture ability of the thrombus capture structure, and further improve the success rate and safety of the surgery.

[0005] According to the present invention, there is provided a thrombectomy stent, including a hollow tubular stent body and thrombus capture structures circumferentially arranged on the outer wall of the stent body. The stent body has a radially contracted state and a radially expanded state. Each group of thrombus capture structures includes a pair of internally connected and mutually restricted inner capture members and outer capture members. When the stent body is in the contracted state, both the inner capture members and the outer capture members are closely attached to the outer wall of the stent body. When the stent body is in the expanded state, the outer capture members expand outward and protrude from the outer wall of the stent body, and the inner capture members expand inward into the internal space of the stent body.

[0006] Furthermore, the projection of the outer capture member on the stent body is located within the corresponding inner capture member, so that when the stent body is in the contracted state, the outer capture member is received within the corresponding inner capture member.

[0007] Further, a plurality of meshes are provided on the surface of the stent body. A pair of inner capture members and outer capture members are both connected to a mesh on the stent body, and the projection of the inner capture member on the stent body is located in the corresponding mesh.

[0008] Further, a pair of inner capture members and outer capture members are commonly connected to an acting member and connected to the outer wall of the stent body through the acting member. The acting member is used to transfer the acting force received by one of the inner capture members or the outer capture members to the other member to maintain the relative positional relationship between the inner capture member and the outer capture member.

[0009] Further, both the inner capture member and the outer capture member are formed into a U-shaped profile, and two open ends of the inner capture member and two open ends of the outer capture member are both connected to the acting member.

[0010] Further, the closed end of the outer capture member can be deformed so that the thrombus capture space formed by the outer capture member is variable.

[0011] Further, the closed end of the outer capture member is in a wavy structure capable of deforming in the axial direction.

[0012] Further, the acting member includes two acting rods. The proximal ends of the two acting rods are both connected to the stent body, and the distal ends of the two acting rods are both connected to an open end of the inner capture member and an open end of the outer capture member at the same time.

[0013] Further, the two acting rods are arranged in parallel to be connected to different parts of the stent body.

[0014] Further, the two acting rods intersect to form a V-shaped profile to be connected to the same part of the stent body.

[0015] Compared with the prior art, in the present invention, each group of thrombus capture structures is set as a pair of inner capture members and outer capture members that are connected to each other and restrict each other. When the stent body is in the expanded state, the outer capture member expands outward and protrudes from the outer wall of the stent body, and can more effectively contact and capture external thrombi. The inner capture member expands inward into the inner space of the stent body to capture thrombus fragments entering the stent. This internal and external combination design significantly improves the overall capture effect. Especially when facing larger or irregularly shaped thrombi, it can more comprehensively cover the thrombus area and ensure more thorough thrombus removal. At the same time, the inner capture member and the outer capture member are connected to each other to ensure that the relative position between the two is more stable, enabling the two to work together and avoiding the problem of thrombus slippage caused by the change of the relative position, further improving the success rate and safety of the operation. Description of the Drawings

[0016] A more complete understanding of the present invention and an easier appreciation of its attendant advantages and features will be more readily achieved by reference to the accompanying drawings and by referring to the detailed description below.

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

[0018] Figure 2 is Figure 1 an enlarged view of part A in

[0019] Figure 3 is a schematic diagram of the internal capture structure and the external capture structure in the first embodiment of the present invention.

[0020] Figure 4 is a schematic diagram of the external capture structure in the second embodiment of the present invention.

[0021] In the drawings: 10 is the stent main body; 20 is the thrombus capture structure, 21 is the internal capture member, 22 is the external capture member; 30 is the acting member, 31 is the acting rod.

[0022] It should be noted that the drawings are used to illustrate the present invention, rather than to limit 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 Embodiments

[0023] 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 drawings.

[0024] As used in the present invention, "proximal" and "distal" should be understood as, when observed from the direction of the attending physician, "proximal" refers to the end closer to the attending physician, that is, corresponding to the "left end" as indicated in the reference drawings, and "distal" refers to the end farther from the attending physician, that is, corresponding to the "right end" as indicated in the reference drawings. Similarly, "proximal segment" refers to a segment or a specific area closer to the attending physician, and "distal segment" refers to a segment or a specific area farther from the attending physician.

[0025] Embodiment 1: As shown in Figures 1 to 3As shown in the figure, the thrombectomy stent of this embodiment includes a stent body 10 and multiple groups of thrombus capture structures 20 disposed 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 nickel-titanium tube and heat treatment for shaping. The surface is provided with a number of meshes, and has a radially contracted state and a radially expanded state, and these two states respectively correspond to the non-thrombectomy state and the thrombectomy state. The multiple thrombus capture structures 20 are circumferentially arranged on the outer wall of the stent body 10 and are arranged in a staggered manner approximately to maximize the capture efficiency. They are specifically used to capture thrombus outside the stent body 10. These thrombus capture structures 20 and the stent body 10 are integrally formed, which means that the entire thrombectomy stent is manufactured by cutting a single metal tube and undergoing a heat setting process.

[0026] Specifically for each thrombus capture structure 20, it is respectively connected to a corresponding mesh on the stent body 10. Each group of thrombus capture structures 20 includes a pair of internally connected and mutually constrained inner capture members 21 and outer capture members 22. When the stent body 10 is in the contracted state, both the inner capture members 21 and the outer capture members 22 can be received in the corresponding meshes, and then closely adhere to the outer wall of the stent body 10, hardly increasing the overall diameter. Such a design helps the thrombectomy stent to smoothly pass through the catheter to reach the lesion site. When the stent body 10 is in the expanded state, the outer capture members 22 expand outward and protrude from the corresponding meshes, thus extending beyond the outer wall of the stent body 10, and can more effectively contact and capture external thrombus. The inner capture members 21 expand inward and enter the corresponding meshes, thus extending into the internal space of the stent body 10, and can capture thrombus fragments entering the stent interior. This internal and external combined design significantly improves the overall capture effect. Especially when facing larger or irregularly shaped thrombus, it can more comprehensively cover the thrombus area and ensure more thorough thrombus removal.

[0027] In addition, the inner capture members 21 and the outer capture members 22 are connected to each other to ensure that the relative position between the two is more stable, enabling the two to work together and avoiding the problem of thrombus slippage caused by changes in the relative position. Specifically, when the outer capture members 22 are subjected to the force of the thrombus during the capture of external thrombus, their movement is restricted by the restraint of the inner capture members 21. Similarly, when the inner capture members 21 are subjected to the force during the capture of internal thrombus fragments, their movement is also restricted by the restraint of the outer capture members 22. This mutually restrictive relationship effectively avoids the situation where a single member is displaced or deformed due to excessive force, thereby ensuring that the inner and outer capture members can always maintain a cooperative working state and further improving the stability and reliability of thrombus capture.

[0028] In the same set of thrombus capture structures 20, both the inner capture member 21 and the outer capture member 22 are connected to a mesh on the stent body 10. The size of the outer capture member 22 is smaller than that of the inner capture member 21, and the projection of the outer capture member 22 on the stent body 10 is located within the corresponding inner capture member 21, while the projection of the inner capture member 21 on the stent body 10 is located within the corresponding mesh. In this way, when the stent body 10 is in a contracted state, both the inner capture member 21 and the outer capture member 22 can be completely received within the corresponding meshes, and the outer capture member 22 is received within the corresponding inner capture member 21, further reducing the overall external dimension and ensuring that the thrombus extraction stent causes as little irritation and damage to blood vessels as possible during transportation.

[0029] The inner capture member 21 and the outer capture member 22 in the same set are commonly connected to an acting member 30 and are connected to the outer wall of the stent body 10 through the acting member 30. The design of the acting member 30 not only serves as a connection but also can transfer the force received by one of the inner capture member 21 or the outer capture member 22 to the other member to maintain the relative positional relationship between the inner capture member 21 and the outer capture member 22, thereby ensuring that they can maintain the best cooperative working state when capturing thrombus. Specifically, both the inner capture member 21 and the outer capture member 22 are formed into a U-shaped profile. The two open ends of the inner capture member 21 and the two open ends of the outer capture member 22 are both connected to the acting member 30. The acting member 30 includes two parallel acting rods 31. The proximal ends of the two acting rods 31 are respectively connected to different parts of the mesh of the stent body 10, and the distal ends are simultaneously connected to an open end of the inner capture member 21 and an open end of the outer capture member 22. This design ensures that the force can be efficiently transferred between the inner capture member 21 and the outer capture member 22, enhancing the stability and anti-deformation ability of the overall structure.

[0030] It can be understood that the layout of the two acting rods 31 in the acting member 30 can also be adjusted according to actual needs. For example, the two acting rods 31 can be arranged non-parallelly but intersect to form a V-shaped profile and are connected to the same part of the mesh of the stent body 10. This V-shaped arrangement can optimize the force transfer path to a certain extent, and at the same time further simplify the connection point design on the stent body 10, reduce the damage to the integrity of the mesh structure, and thus improve the mechanical performance and service life of the overall stent.

[0031] Embodiment 2: Different from Embodiment 1, in combination with Figure 4As shown, in this embodiment, the closed end of the outer capture member 22 has the ability to deform, and can generate deformation so that the size of the thrombus capture space 30 formed by the outer capture member 22 is adjustable. Its closed end adopts an elastic structure design, presenting a wavy structure that can deform in the axial direction, and the wave spacing is uniformly set. This design enhances the adaptability to the external thrombus morphology, so that in practical applications, the outer capture member 22 can be adjusted accordingly according to the actual size and shape of the thrombus, ensuring that more thrombi can be effectively captured. This characteristic is particularly helpful during the withdrawal process of the thrombectomy stent. According to the pressure and shape of the thrombus, the thrombus capture space can be dynamically expanded, so as to ensure that the thrombus can smoothly enter the interior of the thrombectomy stent and be captured, and effectively avoid the situation of thrombus shedding or not being captured.

[0032] Specifically, when the stent body 10 is converted from the contracted state to the expanded state, along with the outer capture member 22 gradually protruding outward from the outer wall of the stent body 10, an effective thrombus capture space is gradually formed. Due to the elastic deformation ability of the closed end of the outer capture member 22, the size of the thrombus capture space can be adjusted accordingly to adapt to thrombi of different sizes and shapes, ensuring that they can smoothly embed into the interior of the stent body 10. Once the thrombus is successfully embedded, during the process of withdrawing the thrombectomy stent from the human body, the closed end of the outer capture member 22 will be affected by the withdrawal force and dynamically expand according to the pressure and shape of the thrombus, so that the thrombus clamped in the thrombus capture space can more smoothly embed into the interior of the stent body 10. Such a design not only improves the success rate of thrombus capture, but also reduces the risk of thrombus shedding, further enhancing the safety and effectiveness of the thrombectomy operation.

[0033] In addition, it is worth noting that although the closed end of the outer capture member 22 has a unique deformation ability, its basic structure and working principle are still consistent with the description in Embodiment 1. The inner capture member 21 and the outer capture member 22 are connected by the acting member 30 to ensure the relative position stability between the two and maintain the cooperative working state. At the same time, the U-shaped contour design of the inner capture member 21 and the outer capture member 22 and the acting mechanism of the acting rod 31 also remain unchanged. These jointly ensure that even when the outer capture member 22 deforms, the stability of the overall structure is not affected, and the thrombus capture task can still be efficiently completed.

[0034] Thus, in this embodiment, by introducing the closed end of the outer capture member 22 with elastic deformation ability, the adaptability to thrombi of different morphologies is significantly enhanced, the thrombus capture space can be flexibly adjusted according to the actual situation, and the efficiency and reliability of thrombus capture are greatly improved. This design provides a more flexible and efficient solution for thrombus removal in complex lesion environments, further enriching and perfecting the functional characteristics of the thrombectomy stent.

[0035] The other structures of this embodiment are the same as those of the first embodiment and will not be elaborated here.

[0036] 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 protection of the technical solution of the present invention.

Claims

1. A thrombectomy stent, comprising a stent body in a hollow tubular shape and a thrombus capture structure disposed circumferentially on the outer wall of the stent body. The stent body has a radially contracted state and a radially expanded state, and is characterized in that, Each group of thrombus capture structures includes a pair of mutually connected and constrained inner capture members and outer capture members. When the stent body is in a contracted state, both the inner capture member and the outer capture member are closely attached to the outer wall of the stent body, and the projection of the outer capture member on the stent body is located within the corresponding inner capture member, so that the outer capture member is received within the corresponding inner capture member. When the stent body is in an expanded state, the outer capture member expands outward and protrudes from the outer wall of the stent body, and the inner capture member expands inward and enters the internal space of the stent body.

2. The thrombectomy stent according to claim 1, wherein The surface of the stent body is provided with a plurality of meshes. The same pair of inner capture members and outer capture members are both connected to one mesh on the stent body, and the projection of the inner capture member on the stent body is located within the corresponding mesh.

3. The thrombectomy stent according to claim 1, characterized in that, The same pair of inner capture members and outer capture members are commonly connected to an acting member and are connected to the outer wall of the stent body through the acting member. The acting member is used to transfer the acting force received by one of the inner capture member or the outer capture member to the other member to maintain the relative positional relationship between the inner capture member and the outer capture member.

4. The thrombectomy stent according to claim 3, wherein, Both the inner capture member and the outer capture member are formed into a U-shaped profile, and the two open ends of the inner capture member and the two open ends of the outer capture member are both connected to the acting member.

5. The thrombus extraction stent according to claim 4, wherein, The closed end of the outer capture member can be deformed so that the thrombus capture space formed by the outer capture member is variable.

6. The thrombectomy stent according to claim 5, characterized in that, The closed end of the outer capture member is in a wavy structure that can be deformed in the axial direction.

7. The thrombectomy stent according to claim 4, wherein The acting member includes two acting rods. The proximal ends of the two acting rods are both connected to the stent body, and the distal ends of the two acting rods are both connected to an open end of the inner capture member and an open end of the outer capture member at the same time.

8. The thrombectomy stent according to claim 7, wherein, The two acting rods are arranged in parallel to be connected to different parts of the stent body.

9. The thrombectomy stent according to claim 7, wherein The two acting rods intersect and are formed into a V-shaped profile to be connected to the same part of the stent body.

Images