Thrombectomy stent

Abstract

The utility model discloses a thrombectomy stent which comprises a cutting net rack and a woven net basket, the cutting net rack is of a net-shaped cylindrical structure, the woven net basket is of a net-shaped sheet structure, and the cutting net rack can be elastically compressed or released in the radial direction and drives the woven net basket to be switched between the compressed state and the released state. The cutting net frame comprises a traction end, a diagonal plane is arranged on the side, away from the traction end, of the cutting net frame, the periphery of the woven net basket is connected to the diagonal plane of the cutting net frame in a sealed mode, and a thrombus containing cavity is formed between the woven net basket and the cutting net frame. Operation is easy and convenient, thrombus is not prone to escape, and operation risks are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a thrombectomy stent. Background Art

[0002] Stent thrombectomy is one of the effective treatment methods in current clinical surgeries, has a good curative effect on acute large vessel occlusion, and can effectively improve the vascular recanalization rate of patients.

[0003] A Chinese patent with the publication number of CN106388902A discloses a thrombectomy device for intravascular thrombectomy and its application, including: a stent main body with a reticular structure that expands and adheres to the inner wall of the blood vessel, and a film covering arranged on the outer surface of the stent main body to separate the inner wall of the blood vessel from the stent main body. The stent main body includes a proximal part, a central stent part and a distal part. The stent main body includes more than three mesh strips. One end of the mesh strips is connected to form an inlet at the proximal part. One side of the inlet is fixedly connected to a push-pull rod. The film covering is provided with a notch and coincides with the inlet. The stent part is of a reticular structure. When the stent is in a released state, it expands into a hollow tubular structure; there are many small holes at the distal end of the film covering to facilitate blood flow; the proximal part is a triangular or elliptical reticular opening structure, and the end is connected to the push-pull rod. The microcatheter is used to transport the thrombectomy device for intravascular thrombectomy.

[0004] However, the above-mentioned thrombectomy device has the following disadvantages:

[0005] 1. It is very difficult for this thrombectomy device to capture and transfer the adherent thrombus after cutting the thrombus. During the process of aspirating and dragging the thrombus, the fragmented thrombus will escape. Especially when thrombectomy is performed in a relatively thick blood vessel, if the stent is too large, the thrombus will be broken and escape. If the stent is too small, the captured thrombus and other occlusions may also rupture and fall off during the transfer process of the thrombectomy device and flow along the blood flow direction to the distal end, and accumulate in other parts, blocking other branch blood vessels.

[0006] 2. The operation of this thrombectomy device is cumbersome during the release and recovery processes. Especially during release, the distal part of the stent main body needs to be controlled and expanded separately using a guide wire, which is likely to cause the braided structure at the distal part to fail to open, resulting in difficult recovery and increasing the risk of the surgery. Content of the Utility Model

[0007] The purpose of the utility model is to provide a thrombectomy stent, which has the effects of simple and convenient operation, difficult thrombus escape, and reduced surgical risk.

[0008] The above technical object of the present utility model is achieved by the following technical solutions: A thrombectomy stent, comprising a cutting wire mesh and a braided mesh basket. The cutting wire mesh has a net-shaped cylindrical structure, and the braided mesh basket has a net-shaped sheet structure. The cutting wire mesh can be elastically compressed or released radially, and drives the braided mesh basket to switch between a compressed state and a released state.

[0009] The cutting wire mesh includes a traction end. An inclined surface is provided on a side of the cutting wire mesh away from the traction end. The periphery of the braided mesh basket is hermetically connected to the inclined surface of the cutting wire mesh, and a thrombus receiving cavity is formed between the braided mesh basket and the cutting wire mesh.

[0010] By adopting the above technical solutions, during operation, first pass the end of the microcatheter through the thrombus, then place the radially compressed cutting wire mesh and braided mesh basket into the microcatheter. After that, by pushing the traction end of the cutting wire mesh, push the cutting wire mesh and the braided mesh basket through the microcatheter to release through the thrombus. When releasing, the cutting wire mesh relies on its own elastic restoring force to expand outwards, so that one end of the inclined surface expands outwards. The expanded inclined surface drives the braided mesh basket to expand outwards synchronously. After the release is completed, pull the traction end to drive the cutting wire mesh and the braided mesh basket to be retrieved. During the retrieval process, the cutting wire mesh cuts the thrombus on the blood vessel side wall, and the chopped thrombus pieces fall into the thrombus receiving cavity formed by the cutting wire mesh and the braided mesh basket for collection. Different from the traditional thrombectomy device, in which the middle of the braided mesh basket needs to be controlled and released separately by a guide wire, the braided mesh basket of the present utility model is completely released by relying on the expanding force of the inclined surface of the cutting wire mesh, without the need for a guide wire to control the release, and the operation is more convenient. In addition, the braided mesh basket of the traditional thrombectomy device has a bowl-shaped structure. When retrieving, the bowl-shaped braided mesh basket is prone to friction with the blood vessel side wall, causing dragging and deformation and being stretched, resulting in the enlargement of the weaving pores of the braided mesh basket, which is likely to cause the escape of broken fine thrombus and blockage of other blood vessel branches. However, the braided mesh basket with a net-shaped sheet structure adaptively arranged at one end of the inclined surface of the cutting wire mesh of the present utility model is not prone to deformation during the retrieval process, and the retrieval is more convenient, reducing the surgical risk, and having the effects of simple and convenient operation, not easy for thrombus to escape, and reducing the surgical risk.

[0011] A further setting of the present utility model is: The inclined surface includes a proximal end close to the traction end and a distal end away from the traction end. The braided mesh basket is hermetically arranged between the distal end and the proximal end of the inclined surface.

[0012] By adopting the above technical solutions, the braided mesh basket is arranged parallel to the plane where the inclined surface of the cutting wire mesh is located. When releasing, the distal end and the proximal end of the inclined surface expand away from each other radially, and the automatic release of the braided mesh basket can be realized.

[0013] A further setting of the present utility model is that the periphery of the woven wire basket is fixedly connected to the inclined plane end of the cutting wire frame through hanging the wire mesh.

[0014] A further setting of the present utility model is that the periphery of the woven wire basket is fixedly connected to the inclined plane end of the cutting wire frame through laser welding.

[0015] By adopting the above technical solution, the fixing method of laser welding can ensure that a relatively high connection firmness and sealing property can be maintained between the peripheral direction of the woven wire basket and the inclined plane of the cutting wire frame.

[0016] A further setting of the present utility model is that a push-pull rod is fixedly connected to the traction end of the cutting wire frame.

[0017] By adopting the above technical solution, the push-pull rod can be used to push the cutting wire frame to pass through the microcatheter for release or pull the cutting wire frame to cut the thrombus attached to the blood vessel.

[0018] A further setting of the present utility model is that the traction end of the cutting wire frame is adapted to the shape of the inclined plane, so that the longitudinal section of the cutting wire frame is a parallelogram.

[0019] By adopting the above technical solution, the cutting wire frame arranged in a parallelogram shape has higher concentricity when compressed, and the overall outer diameter after compression can basically remain the same at each position, thereby improving the smoothness of the guiding and sliding of the cutting wire frame in the microcatheter.

[0020] A further setting of the present utility model is that the cutting wire frame is composed of several wire strips, and cutting structures for cutting thrombus are arranged on the wire strips.

[0021] By adopting the above technical solution, when the cutting wire frame is retrieved from the blood vessel, the cutting structure of the wire strip can be used to cut the thrombus attached to the inner wall of the blood vessel.

[0022] A further setting of the present utility model is that the cutting structure includes several cutting edges arranged along the length direction on the periphery of the wire strip.

[0023] A further setting of the present utility model is that the wire strip is chamfered at a flat angle along the length direction of the cutting edge.

[0024] By adopting the above technical solution, the setting of the flat angle increases the number of cutting edges on the outer surface of the wire strip, thereby improving the thrombus cutting ability of the cutting wire frame of the present utility model.

[0025] A further setting of the present utility model is that several of the wire strips cooperate on the cutting wire frame to form a plurality of through holes distributed in a matrix and allowing blood flow to pass through.

[0026] By adopting the above technical solution, blood flow can pass through the through-hole and out of the thrombus receiving cavity, so that when the present utility model is in operation, the present utility model will not block blood vessels.

[0027] In summary, the present utility model has the following beneficial effects:

[0028] A bevel surface is arranged on one side of the cutting wire frame away from the traction end, and a woven wire basket in a net-shaped sheet structure is fixedly connected to one side of the bevel surface of the cutting wire frame. The bevel surface includes a proximal end close to the traction end and a distal end away from the traction end. Different from the traditional thrombus extractor in which the middle of the woven wire basket needs to be controlled and released separately through a guide wire, the woven wire basket of the present utility model is completely released by the expanding force of the unfolding of the bevel surface of the cutting wire frame and does not require a guide wire for control and release, making the operation more convenient; in addition, the woven wire basket of the traditional thrombus extractor is in a bowl-shaped structure, and when recovering, the bowl-shaped woven wire basket is prone to friction with the blood vessel side wall, causing dragging and deformation and being stretched, resulting in the enlargement of the weaving pores of the woven wire basket, which is likely to cause the escape of broken small thrombi and block other blood vessel branches. However, the woven wire basket in a net-shaped sheet structure adaptively arranged at one end of the bevel surface of the cutting wire frame of the present utility model is not prone to deformation during the recovery process, is more convenient to recover, reduces the surgical risk, and has the effects of simple and convenient operation, difficult thrombus escape, and reduced surgical risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural diagram of the present utility model.

[0030] Figure 2 is a schematic diagram of the recovery process of the present utility model in a blood vessel.

[0031] Figure 3 is a partial enlarged view of the cutting wire frame of the present utility model.

[0032] In the figure: 1. Cutting wire frame; 10. Through-hole; 11. Traction end; 12. Bevel surface; 121. Proximal end; 122. Distal end; 2. Woven wire basket; 3. Push rod; 4. Wire strip; 41. Cutting edge; 42. Flat angle; 5. Thrombus. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present utility model will be further described below with reference to the accompanying drawings.

[0034] A thrombus extraction stent, as Figure 1As shown in the figure, it includes a cutting grid frame 1 and a woven mesh basket 2. The cutting grid frame 1 is in a net-shaped cylindrical structure, and the woven mesh basket 2 is in a net-shaped sheet structure. The cutting grid frame 1 can be elastically compressed or released radially, and drives the woven mesh basket 2 to switch between a compressed state and a released state. The cutting grid frame 1 includes a traction end 11. On the side of the cutting grid frame 1 away from the traction end 11, there is an inclined plane 12. The periphery of the woven mesh basket 2 is hermetically connected to the inclined plane 12 of the cutting grid frame 1, and a thrombus 5 receiving cavity is formed between the woven mesh basket 2 and the cutting grid frame 1.

[0035] As Figure 1-2 shown in the figure, the inclined plane 12 includes a proximal end 121 on the side close to the traction end 11 and a distal end 122 on the side away from the traction end 11. The woven mesh basket 2 is hermetically arranged between the distal end 122 and the proximal end 121 of the inclined plane 12, so that the woven mesh basket 2 is arranged parallel to the plane where the inclined plane 12 of the cutting grid frame 1 is located. When released, the distal end 122 and the proximal end 121 of the inclined plane 12 expand away along the radial direction, and the automatic release of the woven mesh basket 2 can be realized. The periphery of the woven mesh basket 2 is fixedly connected to the end of the inclined plane 12 of the cutting grid frame 1 through hanging the mesh. The periphery of the woven mesh basket 2 is fixedly connected to the end of the inclined plane 12 of the cutting grid frame 1 by laser welding. The fixed way of laser welding can ensure that a high connection firmness and tightness can be maintained between the periphery of the woven mesh basket 2 and the inclined plane 12 of the cutting grid frame 1. A push-pull rod 3 is fixedly connected to the traction end 11 of the cutting grid frame 1. By using the push-pull rod 3, the cutting grid frame 1 can be pushed through the microcatheter for release or the cutting grid frame 1 can be pulled to cut the thrombus 5 attached to the blood vessel. The traction end 11 of the cutting grid frame 1 is arranged to adapt to the shape of the inclined plane 12, so that the longitudinal section of the cutting grid frame 1 is a parallelogram. The cutting grid frame 1 arranged in a parallelogram has a higher concentricity when compressed, and the overall outer diameter after compression can basically remain the same at each position, thereby improving the smoothness of the guiding and sliding of the cutting grid frame 1 in the microcatheter.

[0036] As Figure 3 shown in the figure, the cutting grid frame 1 is composed of several mesh strips 4. The mesh strips 4 are provided with cutting structures for cutting the thrombus 5. When the cutting grid frame 1 is retrieved from the blood vessel, the cutting structure of the mesh strips 4 can be used to cut the thrombus 5 attached to the inner wall of the blood vessel. The cutting structure includes several cutting edges 41 arranged along the length direction on the periphery of the mesh strip 4. The mesh strip 4 is chamfered with a flat angle 42 along the length direction of the cutting edge 41. The setting of the flat angle 42 increases the number of cutting edges 41 on the outer surface of the mesh strip 4, thereby improving the cutting ability of the cutting grid frame 1 of the present invention for the thrombus 5. Several mesh strips 4 cooperate to form a plurality of through holes 10 distributed in a matrix on the cutting grid frame 1 and allowing blood flow to pass through. The blood flow can pass through the through holes 10 and flow out from the thrombus 5 receiving cavity, so that during the operation of the present invention, the present invention will not block the blood vessel.

[0037] The basic working principle of the present utility model is as follows: During operation, first pass the end of the microcatheter through the thrombus, then place the radially compressed cutting wire frame and braided wire basket into the microcatheter. After that, by pushing the traction end of the cutting wire frame, push the cutting wire frame and the braided wire basket through the microcatheter to pass through the thrombus for release. When releasing, the cutting wire frame relies on its own elastic restoring force to expand outwards, so that one end of the inclined plane expands outwards. The expanded inclined plane drives the braided wire basket to expand outwards synchronously. After the release is completed, pull the traction end to drive the cutting wire frame and the braided wire basket to be retrieved. During the retrieval process, the cutting wire frame cuts the thrombus on the side wall of the blood vessel, and the chopped thrombus pieces fall into the thrombus receiving cavity formed by the cutting wire frame and the braided wire basket for collection. Different from the traditional thrombus extractor, in which the middle of the braided wire basket needs to be controlled and released separately through a guide wire, the braided wire basket of the present utility model is completely released by relying on the expanding force of the inclined plane of the cutting wire frame, without the need for a guide wire to control the release, and the operation is more convenient; in addition, the braided wire basket of the traditional thrombus extractor is a bowl-shaped structure, and when retrieved, the bowl-shaped braided wire basket is prone to friction with the side wall of the blood vessel, causing dragging and deformation and being stretched, resulting in an increase in the weaving pores of the braided wire basket, making it easy for the broken small thrombus to escape and cause blockage of other blood vessel branches. However, the braided wire basket with a mesh sheet-shaped structure adaptively arranged at one end of the inclined plane of the cutting wire frame of the present utility model is not prone to deformation during the retrieval process, and the retrieval is more convenient, reducing the surgical risk. It has the effects of simple and convenient operation, not easy for thrombus to escape, and reducing surgical risk.

[0038] The above is only the preferred embodiment of the present utility model. Therefore, all equivalent changes or modifications made according to the structure, features and principles described in the scope of the patent application of the present utility model are included in the scope of the patent application of the present utility model.

Claims

1. A thrombus removal stent, characterized in that: The invention comprises a cutting grid (1) and a woven net basket (2), wherein the cutting grid (1) is a net-shaped cylindrical structure, and the woven net basket (2) is a net-shaped sheet structure, and the cutting grid (1) can be elastically compressed or released in the radial direction, and drives the woven net basket (2) to switch between a compressed state and a released state; The cutting grid (1) comprises a traction end (11), and a beveled surface (12) is provided on a side of the cutting grid (1) away from the traction end (11). The woven mesh basket (2) is sealedly connected to the beveled surface (12) of the cutting grid (1) on all sides, and a thrombus receiving cavity is formed between the woven mesh basket (2) and the cutting grid (1).

2. The thrombus removal stent according to claim 1, characterized in that: The chamfered surface (12) comprises a proximal end (121) close to the traction end (11) and a distal end (122) away from the traction end (11), and the woven basket (2) is sealed between the distal end (122) and the proximal end (121) of the chamfered surface (12).

3. The thrombus removal stent according to claim 1, characterized in that: The woven mesh basket (2) is fixedly connected to the ends of the beveled surfaces (12) of the cutting mesh frame (1) via hanging meshes on all sides.

4. The thrombus removal stent according to claim 1, characterized in that: The woven mesh basket (2) is fixedly connected to the ends of the beveled surfaces (12) of the cutting mesh frame (1) by laser welding on all sides.

5. The thrombus removal stent according to claim 1, characterized in that: The traction end (11) of the cutting grid (1) is fixedly connected to a push-pull rod (3).

6. The thrombus removal stent according to claim 1, characterized in that: The traction end (11) of the cutting grid (1) is adapted to the shape of the chamfered surface (12), so that the longitudinal cross-section of the cutting grid (1) is a parallelogram.

7. The thrombus removal stent according to claim 1, characterized in that: The cutting grid (1) is composed of a plurality of grid strips (4), and the grid strips (4) are provided with a cutting structure for cutting a thrombus.

8. The thrombus removal stent according to claim 7, characterized in that: The cutting structure comprises a plurality of cutting edges (41) arranged around the mesh strip (4) and along the length direction.

9. The thrombus removal stent according to claim 8, characterized in that: The mesh strip (4) has a right angle (42) along the length direction of the cutting edge (41).

10. The thrombus removal stent according to claim 7, characterized in that: A plurality of mesh strips (4) cooperate with each other on the cutting grid (1) to form a plurality of through holes (10) distributed in a matrix and allowing blood to flow through.

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