CN114652394A

CN114652394A - Intravascular thrombus taking-out device

Info

Publication number: CN114652394A
Application number: CN202210355469.1A
Authority: CN
Inventors: 杨加静; 褚江; 黄海
Original assignee: Suzhou Hengrui Hongyuan Medical Technology Co ltd
Current assignee: Suzhou Hengrui Hongyuan Medical Technology Co ltd
Priority date: 2022-04-06
Filing date: 2022-04-06
Publication date: 2022-06-24

Abstract

The invention relates to a device for taking out thrombus in a blood vessel, which comprises a stent main body which can be self-expanded and is in a net tubular structure, wherein the stent main body comprises a near end and a far end; the bracket main body comprises a plurality of repeating units which are sequentially arranged along the axial direction; the repeating units comprise a plurality of closed grid units which are sequentially arranged along the circumferential direction of the network tubular structure; the closed grid unit comprises a first mesh and a plurality of second meshes which are arranged adjacent to the first mesh. According to the invention, the first mesh and the plurality of second meshes are adjacently arranged, and the area of the first mesh is larger than that of the second meshes, so that the first mesh with a larger size can be beneficial to cutting thrombus, and cut thrombus fragments can enter the stent main body in a net pipe-shaped structure through the first mesh; the second mesh of less size can prevent effectively that the thrombus piece from escaping from the support main part is inside, and first mesh and a plurality of second mesh are mutually supported, the capture thrombus piece that can be better.

Description

Intravascular thrombus taking-out device

Technical Field

The invention relates to a medical instrument for interventional therapy in the field of medical instruments, in particular to a device for taking out thrombus in a blood vessel.

Background

Acute ischemic stroke refers to the condition and sign of focal neurological deficit caused by the necrosis of localized brain tissue due to the blood supply disturbance of brain tissue caused by the stenosis or occlusion of the blood supply artery of brain. In all stroke patients, acute ischemic stroke accounts for about 70% to 80%. At present, the treatment modes of acute ischemic stroke mainly comprise two main types, namely drug thrombolysis and mechanical thrombus removal. The artery and vein drug thrombolysis is a conventional method for treating acute ischemic stroke, but the method has higher requirements on a treatment time window, the vein thrombolysis is carried out within 3 hours of the attack, and the artery thrombolysis time window is only 6 hours; secondly, the vascular recanalization time of the drug thrombolysis is long, and the thrombolysis treatment is only suitable for small-volume thrombus and has low vascular recanalization rate of acute ischemic stroke caused by serious large vessel occlusion. Mechanical embolectomy has become the first treatment of stroke in the anterior circulation and large vessel occlusion. The mechanical thrombus taking process is that the stent main body passes through intracranial blood vessels through a blood vessel way, the porous network structure of the stent main body is utilized to capture thrombus and mechanically remove the thrombus from the body, and the blood flow of the intracranial blood vessels is recovered.

Support main part among the prior art because its adherence with the blood vessel, the radial holding power of support main part causes irreversible damage to the vascular wall too big easily, can lead to other complications such as vascular rupture when serious, support main part among the prior art is unfavorable for catching thrombus fragment and drags the thrombus, and at the in-process of catching thrombus and dragging the thrombus, tiny thrombus fragment can drop from support main part, the thrombus fragment that drops flows to the blood vessel distal end under the blood flow impact effect in order to form new embolism, thereby cause the apoplexy risk.

Disclosure of Invention

In view of the above, it is desirable to provide an intravascular thrombus removal device that facilitates removal and capture of thrombus fragments and avoids escape of thrombus fragments.

An intravascular thrombus extraction device comprises a stent main body which is of a net-tube-shaped structure along the axial direction, wherein the stent main body has a self-expansion state and a compressed state after being stressed;

the stent main body comprises a proximal end part, an intermediate part and a distal end part which are arranged along the axial direction, the intermediate part comprises a plurality of repeating units, and the repeating units are sequentially arranged along the axial direction;

the repeating units comprise a plurality of closed grid units which are sequentially arranged along the circumferential direction of the net tubular structure; each closed grid unit comprises a first mesh and a plurality of second meshes which are arranged adjacent to the first mesh, and the area of the first mesh is larger than that of the second meshes.

The first mesh and the second mesh are arranged adjacently, and the area of the first mesh is larger than that of the second mesh, so that thrombus can be cut off by the first mesh with larger size, and cut thrombus fragments can enter the stent main body with a net pipe-shaped structure through the first mesh; the second mesh of less size can prevent effectively that the thrombus piece from escaping from the support main part is inside, and first mesh and a plurality of second mesh are mutually supported, the capture thrombus piece that can be better.

In one embodiment, the proximal portion, the number of repeating units, and the distal portion are helically distributed along the axial direction.

In one embodiment, two adjacent repeating units are connected by rotating alpha angle along the axial direction.

In one embodiment, the proximal portion, the distal portion, and the plurality of repeating units have a plurality of developing units distributed thereon; the developing units on the proximal end part and the distal end part are arranged at intervals; the developing units on two adjacent repeating units are spirally distributed along the axial direction.

In one embodiment, the developing units on the distal end portion form a plurality of sets of developing structures arranged at intervals in the circumferential direction of the mesh tubular structure, two adjacent developing units in the same set are arranged in parallel in the axial direction with an interval in the circumferential direction of the mesh tubular structure.

In one embodiment, each of the repeating units includes two of the developing units, and the two developing units in the same repeating unit are symmetrically arranged with respect to the axial direction.

In one embodiment, the proximal portion is gathered at an end distal to the distal portion and forms a proximal tubular structure, and the endovascular thrombus removal device further comprises:

a first visualization spring comprising a proximal end connection portion and a distal end connection portion, the proximal end connection portion being connected to the proximal end tubular structure;

a connecting chuck is formed at one end of the pushing rod close to the proximal end part; the push rod is close to one end of the proximal end portion is penetrated and arranged in the proximal end connecting portion and the proximal end tubular structure, the distal end connecting portion is arranged between the connecting clamping head and the proximal end tubular structure, and the connecting clamping head is abutted to the distal end connecting portion.

In one embodiment, the distal portion is gathered at an end distal from the proximal portion and forms a distal tubular structure, and the endovascular thrombus removal device further comprises a second visualization spring connected to the distal tubular structure.

In one embodiment, the area of the first mesh is 1.5-2.5 times the area of the second mesh; the distal portion includes a plurality of closed mesh, a plurality of closed mesh is according to predetermined arrangement mode so that the distal portion is kept away from the one end of proximal portion is the closed structure, the area of closed mesh is less than or equal to the area of second mesh.

In one embodiment, the stent main body is made of a nickel-titanium alloy tubular material, and the pipe diameter of the nickel-titanium alloy tubular material is less than or equal to 0.4 mm.

In the scheme, the first mesh and the plurality of second meshes are adjacently arranged, and the area of the first mesh is larger than that of the second mesh, so that thrombus can be cut off by the first mesh with larger size, and cut thrombus fragments can enter the stent main body with a net pipe-shaped structure through the first mesh; the second mesh of less size can prevent effectively that the thrombus piece from escaping from the support main part is inside, and first mesh and a plurality of second mesh are mutually supported, the capture thrombus piece that can be better.

Drawings

FIG. 1 is a schematic structural view of an intravascular thrombus removal device according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a main body of a bracket according to an embodiment of the present invention;

FIG. 3 is a schematic plan view of the stent body shown in an expanded view according to one embodiment of the present invention;

fig. 4 is a schematic view of a connection structure of the bracket main body, the push rod and the first developing spring according to an embodiment of the invention.

Description of the reference numerals

10. An intravascular thrombus removal device; 100. a stent body; 110. a proximal end portion; 120. a repeating unit; 121. a closed grid cell; 1211. a first mesh; 1212. a second mesh; 130. a distal portion; 131. closing the meshes; 200. a developing unit; 300. a first developing spring; 310. a proximal end connection; 320. a distal end connection portion; 400. a second developing spring; 500. a push rod; 600. connecting a chuck; 700. a proximal tubular structure; 800. a distal tubular structure.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanying figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it will be understood that the term "axial" should be understood as the direction in which the device of the present invention is advanced, i.e. the longitudinal axis of the device of the present invention, and also coinciding with the longitudinal axis of the blood vessel along which the device of the present invention is advanced. The term "circumferential" should be understood as meaning the circumferential direction of the device of the invention, i.e. the direction around the axis of the device of the invention, which is perpendicular to the longitudinal direction of the device of the invention and also coincides with the circumferential direction of the blood vessel along which the device of the invention is advanced. The term "radial" should be understood as meaning that the direction of the inventive device along a radius, i.e. a straight line perpendicular to the longitudinal axis of the inventive device, also coincides with the radial direction of the blood vessel along which the inventive device is moved forward.

For ease of description and understanding, the terms "distal" and "proximal" should be understood as looking from the direction of the handheld end of an attending physician or medical interventionalist. The distal end is the side distal from the hand-held end of the attending physician or medical interventionalist, while the proximal end denotes the side towards the hand-held end of the attending physician or medical interventionalist. If the phrase "axial" is used in this document, it is understood to mean the direction in which the device of the invention is advanced, i.e. the longitudinal axis of the device also coincides with the longitudinal axis of the vessel along which the device is advanced.

Referring to fig. 1, an embodiment of the present invention provides an intravascular thrombus removal device 10, which comprises a stent main body 100 having a mesh tube-like structure along an axial direction, wherein the stent main body 100 has a self-expanding state and a compressed state after being stressed, and in the compressed state, the stent main body 100 can be conveniently delivered in a blood vessel so as to deliver the stent main body 100 to a thrombus position. Under the self-expanding state, the thrombus at the thrombus position can be cut and captured, and finally the captured thrombus is withdrawn, so that the blockage of the blood vessel is realized, and the blood flow of the artery of the blood vessel is recovered.

It is to be understood that: the degree of compression or self-expansion of the stent body 100 is mainly influenced by the thickness of the blood vessel at the position, and the thinner the blood vessel is, the greater the degree of compression is, and the smaller the self-expansion degree of the stent body 100 is; the propping degree of the stent main body 100 is also influenced by the texture of the thrombus at the position, and the softer and looser the texture of the thrombus, the larger the propping degree of the stent main body 100 is; the harder and denser the texture of the thrombus, the less the stent body 100 struts; generally, the stent main body 100 stays for 3 to 5min after being released, so that the stent main body 100 is spread as much as possible, and more stent main bodies are embedded into thrombus tissue and fully combined with the stent main body 100.

Referring to fig. 1, 2 and 3, the stent body 100 includes a proximal end portion 110, an intermediate portion and a distal end portion 130 arranged in the axial direction. Wherein, the middle part includes a plurality of repeating units 120, and a plurality of repeating units 120 are arranged along the axial in proper order. The repeating unit 120 includes a plurality of closed grid units 121 sequentially arranged along the circumferential direction of the mesh tubular structure. Each closed grid cell 121 includes a first mesh 1211 and a plurality of second mesh 1212 disposed adjacent to the first mesh 1211, the first mesh 1211 having an area larger than that of the second mesh 1212. In this embodiment, the first mesh 1211 and the first mesh 1211 in the same repeating unit 120 are disposed circumferentially adjacent to each other along the mesh tubular structure.

The area of the first mesh 1211 is 1.5 to 2.5 times the area of the second mesh 1212. In this embodiment, the middle portion includes three repeating units 120, and the repeating unit 120 includes two closed grid units 121 sequentially arranged along the circumferential direction of the mesh tubular structure. In other embodiments, the number of the repeating units 120 and the number of the closed grid units 121 may be single or multiple, and is not limited herein and may be adjusted according to specific needs.

When thrombus is cleaned, the first mesh 1211 and the plurality of second mesh 1212 are adjacently arranged, the area of the first mesh 1211 is larger than that of the second mesh 1212, the first mesh 1211 with the larger size can be beneficial to cutting thrombus, and cut thrombus fragments can enter the stent main body 100 with a net pipe-shaped structure through the first mesh 1211; the second mesh openings 1212 with a smaller size can effectively prevent thrombus fragments from escaping from the stent body 100, and the first mesh openings 1211 and the plurality of second mesh openings 1212 cooperate with each other to better capture the thrombus fragments.

The first mesh 1211 generates weak radial supporting force when capturing thrombus, and can reduce excessive stimulation to the vessel wall; meanwhile, the second mesh 1212 generates a large radial supporting force when capturing thrombus, so that thrombus can be rapidly embedded, the stability of capturing thrombus is increased, and thrombus fragments can be effectively prevented from escaping from the inside of the stent main body 100. It is to be understood that: the radial support force is a force generated by the stent body 100 on the vessel wall in the self-expanded state, and the larger-sized first mesh 1211 is subjected to a larger pressure and is more easily deformed when the same force is applied, because the coverage rate per unit area is smaller, and therefore, the radial support force generated by the larger-sized first mesh 1211 when capturing the thrombus is weaker. When the second mesh 1212 with a smaller size receives the same force, the pressure is smaller because the coverage rate per unit area is larger, and therefore, the radial supporting force generated when the second mesh 1212 catches the thrombus is larger.

Referring to fig. 1, 2 and 3, the proximal portions converge at an end distal to the distal portions, and the distal portions converge at an end distal to the proximal portions. That is to say, the proximal end and the distal end of the stent main body 100 are both in the closed state, so that the thrombus fragments can be effectively prevented from escaping from the proximal end and the distal end of the stent main body, and the thrombus fragments can be captured more conveniently.

The proximal portion 110 includes a plurality of closed cells 131, and the plurality of closed cells 131 are arranged in a predetermined manner to form a closed structure at the proximal end. A plurality of closed cells 131 are interconnected and meet at proximal ends such that the ends of the proximal portions distal to the distal portions are in a closed configuration. The distal portion 130 includes a plurality of closed cells 131, and the plurality of closed cells 131 are arranged in a predetermined manner such that an end of the distal portion distal from the proximal portion is in a closed configuration. That is, the distal portions 130 are closed meshes 131 connected to each other, and meet at the distal-most ends to make the distal-most ends in a closed configuration,

the area of closed mesh 131 is less than or equal to the area of second mesh 1212, and when stent main body 100 withdraws, the distal end portion 130 that forms by less closed mesh 131 interconnect can block the thrombus piece that has fallen into in stent main body 100, and at the in-process of withdrawing, the thrombus is difficult for droing, more is favorable to dragging the thrombus, and can prevent escaping of thrombus piece. ,

the inventor finds that the stent body which is currently on the market at home can only reach the blood vessel with the diameter of more than 1.5mm, and for the thinner distal blood vessel, the thrombus can not be removed from the blood vessel embolism part with smaller blood vessel diameter (the blood vessel diameter is less than 1.5 mm). In order to solve the above problems, the applicant has made the following arrangement:

referring to fig. 1, the stent main body 100 is made of a nickel-titanium alloy tubular material, and the tube diameter of the nickel-titanium alloy tubular material is less than or equal to 0.4 mm. Specifically, the stent body 100 is integrally formed using a machining process of laser engraving or laser cutting. It is to be understood that: nickel titanium alloys have superelasticity and shape memory properties, and can be heat-set to retain their shape. Therefore, the stent body 100 made of nitinol has sufficient radial support force, super-elasticity and shape memory, and good adherence. It is more to be understood that: the stent body 100 can be kept in a compressed state under the action of the external circumferential restraining force, and when the external circumferential restraining force is removed, the stent body 100 made of the nickel-titanium alloy can be restored to the original shape.

For example, the tube diameter of a nitinol tubular material is 0.4mm, it being understood that: when the tube diameter of the nitinol tubular material is 0.4mm, the minimum compressed diameter of the stent body 100 in the compressed state is also the tube diameter of the nitinol tubular material, i.e. 0.4 mm. The invention can be transported in a blood vessel with smaller diameter, can be transported through a blood vessel with 0.43mm at minimum, and can reach a more tortuous and tiny distal blood vessel in the cranium.

Referring to fig. 2 and 3, proximal portion 110, plurality of repeating units 120, and distal portion 130 are arranged in a spiral pattern along an axial direction. Specifically, the plurality of closed meshes 131 of the distal end portion 130, the plurality of repeating units 120, and the plurality of closed meshes 131 of the proximal end portion 110 are sequentially spirally distributed in the axial direction.

More specifically, the two adjacent repeating units 120 are connected by rotating the angle α in the axial direction, that is, the second one of the two adjacent repeating units 120 is rotated by the angle α in the circumferential direction relative to the first one. The angle α ranges from 0 to 90. The preferred angular range of α is 45 °. For example, the repeating unit 120 includes a first repeating unit, a second repeating unit, and a third repeating unit, the second repeating unit is rotated by an angle α with respect to the first repeating unit, and the third repeating unit is rotated by an angle α with respect to the second repeating unit.

The first mesh 1211 may be spirally arranged in the axial direction by connecting the adjacent two repeating units 120 by rotating the angle α in the axial direction so that the first mesh 1211 of the adjacent two repeating units 120 is not on the same connecting line in the axial direction. When cleaning thrombus, the stent body 100 can be rotated by itself, and by arranging the first mesh 1211 spirally in the axial direction so that the first mesh 1211 having a larger size is arranged in both the axial direction and the circumferential direction, it is possible to more advantageously rotate the thrombus by rotation.

In this embodiment, the first mesh 1211 of two adjacent repeating units 120 are adjacently disposed. The connection between two adjacent first mesh holes 1211 rotates in the axial direction by an angle α, which is in the range of 0 to 90 °. The preferred angular range of α is 45 °.

The inventor finds that the radiopacity effect of the stent main body is poor, and the problems of inaccurate positioning of the stent main body, overlong thrombus removal time, thrombus falling and the like can also be caused. In order to solve the above problems, the applicant has made the following arrangement:

referring to fig. 1 and 3, a plurality of developing units 200 are distributed on proximal end portion 110, distal end portion 130, and a plurality of repeating units 120. The connection manner of the developing unit 200, the proximal end portion 110, the distal end portion 130 and the plurality of repeating units 120 may be nesting, crimping, metal collar, laser welding, adhesive bonding, etc. of mechanical structures, and may be one of the connection manners, or a combination of multiple connection manners, which is not limited herein and may be adjusted according to specific needs.

Specifically, the developing units 200 on two adjacent repeating units 120 are spirally distributed along the axial direction, so that the developing units 200 on two adjacent repeating units 120 are not on the same straight line. Each repeating unit 120 includes two developing units 200, and the two developing units 200 in the same repeating unit 120 are arranged symmetrically with respect to the axial direction. By spirally distributing the developing units 200 on two adjacent repeating units 120 in the axial direction and symmetrically arranging the two developing units 200 of each repeating unit 120 in the axial direction, the spatial resolution and the visibility of the developing units 200 can be increased, thereby improving the spatial resolution and the visibility of the holder main body 100. More specifically, the developing units 200 of adjacent two of the repeating units 120 are arranged at an angle α ranging from 0 ° to 90 °. The preferred angular range of α is 45 °.

The plurality of developing units 200 on the proximal end portion 110 and the distal end portion 130 are disposed at intervals. More specifically, the developing units 200 on the distal end portion 130 form a plurality of sets of developing structures arranged at intervals in the circumferential direction of the mesh tubular structure, and two adjacent developing units 200 in the same set are arranged in parallel in the axial direction with intervals in the circumferential direction of the mesh tubular structure. In the present embodiment, the number of sets of the developing structures is two, each set of the developing structures includes two developing units 200, and two developing units 200 are provided on the proximal end portion 110. In other possible embodiments, two adjacent developing units 200 have a spacing in both the axial direction and the circumferential direction of the mesh-like structure. The number of the developing units 200 and the number of the developing structures may be plural, and are not limited herein and may be adjusted according to specific needs.

The developing unit 200 is made of a metal material opaque to X-rays, and may be any one of gold, platinum, tungsten, tantalum, or platinum-iridium alloy. The position of the developing unit 200 can be checked by a treating doctor or a medical interventionalist through DSA (digital subtraction angiography), which can help the treating doctor or the medical interventionalist to better observe the state of the stent body 100, and further judge the capture condition of the thrombus by the stent body 100.

Referring to fig. 1, 2 and 3, the intravascular thrombus extraction device 10 further comprises a first visualization spring 300 and a second visualization spring 400, wherein the proximal end portions are gathered at the end far away from the distal end portion and form a proximal tubular structure 700, and the first visualization spring 300 is connected to the proximal tubular structure 700. The distal portion is gathered at an end distal to the proximal portion and forms a distal tubular structure. The second visualization spring 400 is connected to the distal tubular structure 800. The connection manner of the first visualization spring 300 and the proximal tubular structure 700 and the connection manner of the second visualization spring 400 and the distal tubular structure 800 may be nesting, crimping, metal collar, laser welding, adhesive bonding, etc. of mechanical structures, one of the connection manners, or a combination of multiple connection manners, which is not limited herein and can be adjusted according to specific needs.

The first and second developing

springs

300 and 400 are made of a metal material opaque to X-rays, and may be any one of a gold wire, a platinum wire, or a platinum-tungsten alloy wire. The position of the first and second developing

springs

300 and 400, which are opaque to X-rays, can be viewed through DSA (digital subtraction angiography) by the treating physician or medical interventionalist, which can help the treating physician or medical interventionalist to better observe the position of the proximal and distal ends of the stent body 100.

The inventor finds that most of the support bodies on the market are connected with the pushing rod and the developing spring in a simple welding mode, and due to the technical defects of welding, welding points are easy to fall off or break, so that the support bodies are damaged and fall off in blood vessels of human bodies, and serious clinical accidents are caused. In order to solve the above problems, the applicant has made the following arrangement:

referring to fig. 1, 3 and 4, the endovascular thrombus extraction device 10 further comprises a push rod 500, and a connection cartridge 600 is formed at one end of the push rod 500 near the proximal end portion. The first visualization spring 300 comprises a proximal connection portion 310 and a distal connection portion 320, the proximal connection portion 310 being connected to the proximal tubular structure 700. One end of the push rod 500 near the proximal end portion is inserted through the proximal end connecting portion 310 and the proximal end tubular structure 700, the distal end connecting portion 320 is disposed between the connection chuck 600 and the proximal end tubular structure 700, and the connection chuck 600 can abut against the distal end connecting portion 320.

Specifically, the inner diameter of the proximal tubular structure 700 is larger than the diameter of the connection cartridge 600, the inner diameter of the proximal connection portion 310 is larger than the diameter of the connection cartridge 600, and the connection cartridge 600 and the push rod 500 can pass through the proximal connection portion 310 and the proximal tubular structure 700 when assembled. The inner diameter of the distal end connecting part 320 is smaller than the diameter of the connecting clamp 600 and larger than the inner diameter of the proximal end tubular structure 700, and the distal end connecting part 320 is arranged between the connecting clamp 600 and the proximal end tubular structure 700, so that the connecting clamp 600 can be effectively prevented from falling off from the proximal end part of the stent main body 100, and the problem that the stent main body 100 is damaged and falls off in a blood vessel of a human body is effectively solved.

The connection mode of the proximal tubular structure 700, the first developing spring 300 and the pushing rod 500 can adopt the nesting mode, and then the connection modes are connected by welding, bonding by adhesives and the like, so that the connection mode is a combination of various connection modes, and the connection mode is not limited here and can be adjusted according to specific needs. For example, the proximal connection portion 310 is welded to the proximal tubular structure 700, and the connection cartridge 600 is welded to the proximal tubular structure 700 via the distal connection portion 320.

The intravascular thrombus removal device 10 of the present invention is used in cooperation with a microcatheter, and when used, the position of a thrombus in a blood vessel is first determined by DSA (digital subtraction angiography), and then the microcatheter is transported to the position of the thrombus and passed through the thrombus.

The stent body 100 is pushed to the thrombus position by the pushing and pulling action of the push rod 500, and the second contrast spring 400 is checked by DSA (digital subtraction angiography) to determine the position of the distal end of the stent body 100. After the distal-most end of the stent body 100 is adjusted to the proper position, the microcatheter is withdrawn. As the micro-catheter is withdrawn, the stent body 100 will self-expand and deploy at the thrombus site, the repeating units 120 of the middle portion of the stent body 100 are embedded in the thrombus, and at the same time, the plurality of closed meshes 131 of the distal end portion 130 of the stent body 100 will self-expand and deploy.

Wherein, the first mesh 1211 and the plurality of second mesh 1212 of the repeating unit 120 are adjacently arranged, and the area of the first mesh 1211 is larger than that of the second mesh 1212, so that the first mesh 1211 with larger size is beneficial to cutting thrombus and can make the cut thrombus fragment enter the stent main body 100 with a net tubular structure through the first mesh 1211; the second mesh openings 1212 with a smaller size can effectively prevent thrombus fragments from escaping from the stent body 100, and the first mesh openings 1211 and the plurality of second mesh openings 1212 cooperate with each other to better capture the thrombus fragments.

When the microcatheter is withdrawn to the distal exit of the microcatheter and aligned with the first visualization spring 300, the stent body 100 is fully released from the microcatheter. Waiting for 3-5 min to make the stent main body 100 fully embedded with the thrombus. Then synchronously withdrawing the microcatheter, the stent main body 100 and the push rod 500 until the stent main body 100 and the thrombus are pulled out of the body, and finishing the operation of thrombus extraction.

Wherein, distal portion 130 is by less closed mesh 131 interconnect, and intersects so that the distalmost is the closed configuration at the distalmost, and when stent main body 100 withdraws, the distal portion 130 that forms by less closed mesh 131 interconnect can block the thrombus piece that has fallen into in stent main body 100, and at the withdrawal in-process, the thrombus is difficult for droing, more is favorable to dragging the thrombus, and can prevent escaping of thrombus piece.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An intravascular thrombus taking-out device is characterized by comprising a stent main body which is of a net pipe-shaped structure along the axial direction, wherein the stent main body has a self-expansion state and a compressed state after being stressed;

2. The endovascular thrombus extraction device of claim 1, wherein the proximal portion, the plurality of repeat units, and the distal portion are helically distributed along the axial direction.

3. The endovascular thrombus extraction device of claim 1, wherein two adjacent repeat units are connected by an angle of a rotation in the axial direction.

4. The endovascular thrombus extraction device according to claim 1, wherein a plurality of visualization units are distributed on the proximal portion, the distal portion, and a plurality of the repeating units; the developing units on the proximal end part and the distal end part are arranged at intervals; the developing units on two adjacent repeating units are spirally distributed along the axial direction.

5. The endovascular thrombus extraction device according to claim 4, wherein the visualization units on the distal end portion form a plurality of sets of visualization structures arranged at intervals in a circumferential direction of the mesh tubular structure, and two adjacent visualization units in the same set are arranged in parallel in the axial direction with an interval in the circumferential direction of the mesh tubular structure.

6. The endovascular thrombus extraction device according to claim 4, wherein each of the repeating units comprises two of the visualization units, and the two visualization units in the same repeating unit are symmetrically arranged about the axial direction.

7. The intravascular thrombus extraction device of claim 1, wherein the proximal portions converge at an end distal to the distal portion and form a proximal tubular structure, further comprising:

a connecting chuck is formed at one end of the pushing rod close to the proximal end part; the push rod is close to one end of the proximal end portion is penetrated and arranged in the proximal end connecting portion and the proximal end tubular structure, the distal end connecting portion is arranged between the connecting clamping head and the proximal end tubular structure, and the connecting clamping head is connected with the proximal end tubular structure in an abutting mode through the distal end connecting portion.

8. The intravascular thrombus extraction device of claim 1, wherein the distal portion is gathered at an end distal from the proximal portion and forms a distal tubular structure, further comprising a second visualization spring coupled to the distal tubular structure.

9. The endovascular thrombus extraction device of claim 1, wherein the area of the first mesh is 1.5-2.5 times the area of the second mesh; the distal portion includes a plurality of closed mesh, a plurality of closed mesh is according to predetermined arrangement mode so that the distal portion is kept away from the one end of proximal portion is the closed structure, the area of closed mesh is less than or equal to the area of second mesh.

10. The endovascular thrombus extraction device of claim 1, wherein the stent body is made of a tubular nickel-titanium alloy material, and the diameter of the tubular nickel-titanium alloy material is less than or equal to 0.4 mm.