CN112890913B

CN112890913B - Thrombus taking device and thrombus taking device

Info

Publication number: CN112890913B
Application number: CN201911222564.9A
Authority: CN
Inventors: 李思漪
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2022-05-20
Anticipated expiration: 2039-12-03
Also published as: CN112890913A

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a thrombus extractor and a thrombus extraction device with the same. The thrombus remover comprises a support main body, a limiting piece and a push-pull piece, wherein the support main body comprises at least one section of net structure, the limiting piece is connected with the near end of the support main body and used for limiting the near end of the support main body, the support main body is connected with the push-pull piece, the support main body has a contraction state and an expansion state under the action of the push-pull piece, and the far end of the support main body can move towards the limiting piece under the action of the push-pull piece so as to shorten the distance between the near end and the far end of the support main body. According to the thrombus extractor disclosed by the invention, the radial force of the stent main body can be effectively improved, and the purpose of capturing hard thrombus is achieved, so that the occluded blood vessel is recanalized, and the recanalization rate of the blood vessel is improved.

Description

Thrombus taking device and thrombus taking device

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to a thrombus extractor and a thrombus extraction device with the same.

Background

Acute Ischemic Stroke (AIS), commonly known as cerebral infarction, is a nerve tissue injury caused by ischemic necrosis of local brain tissue due to sudden obstruction of blood flow in the brain. Acute ischemic stroke is the most common type of stroke and is the main lethal and disabling disease for the middle-aged and elderly people. Especially acute cerebral apoplexy caused by large vessel occlusion, the disease condition is extremely dangerous, and the mortality rate and disability rate are high. Once stroke occurs, great physical and psychological harm is caused to the patient, and heavy burden is also caused to the family and the society of the patient.

The recanalization of blood vessels is the key to the treatment of acute ischemic stroke. The current conventional methods for treating acute ischemic stroke include two main categories: interventional thrombolysis and mechanical thrombus removal. The interventional thrombolysis is that the catheter injects the thrombolysis agent near the focus of the blood vessel where the pathological changes are located, so that high thrombolysis agent concentration is formed in the focus of the blood vessel instantly, the thrombolysis speed is accelerated, and the chance of recanalization of the blood vessel is increased. Thrombolytic therapy is only suitable for small-volume thrombus, the effect on large-volume thrombus is not ideal, and in acute middle cerebral artery and cerebral infarction, if the thrombus length exceeds 8mm, venous thrombolysis can hardly lead the blocked blood vessel back, and even if the blood vessel can be led back, the probability of secondary blockage is also high. In order to solve the problems, for patients who exceed a thrombolysis time window and have thrombolysis treatment contraindications, a mechanical device can be used for removing thrombus, so that the method can quickly recanalize the occluded blood vessel, improve the recanalization rate of the blood vessel, reduce the dose of thrombolytic drugs, reduce the incidence rate of symptomatic cerebral hemorrhage, prolong the treatment time window and shorten the recanalization time, thereby striving for more time for reversible ischemic brain tissues and obviously improving the prognosis of the patients.

Among them, the commercially available embolectomy products are MERCI^TM、PENUMBRA^TM、TREVO^TM、SOLITAIRE^TM. The products neglect the performance and the variety of thrombus in the application process,the thrombus comprises hard thrombus and soft thrombus, the hard thrombus is sticky, the elasticity is strong, the soft thrombus is difficult to compress, and the soft thrombus is fragile. The existing thrombus taking instrument is embedded into thrombus by means of radial force of the existing thrombus taking instrument, so that the aim of capturing thrombus is fulfilled. However, this method is effective for soft thrombus (red thrombus), but for hard thrombus (white thrombus), the radial force of the existing thrombus extractor is insufficient, so that hard thrombus is difficult to compress, and the hard thrombus is difficult to capture and extract, and most of thrombus embolism of cerebral apoplexy is caused by hard thrombus.

Disclosure of Invention

The invention aims to at least solve the problem that the existing thrombus extraction equipment cannot capture thrombus due to insufficient radial force of the existing thrombus extraction equipment in the thrombus extraction process.

The invention provides a thrombus remover, which comprises:

a stent body comprising at least one section of a mesh structure;

the limiting piece is connected with the near end of the bracket main body and is used for limiting the near end of the bracket main body;

the push-pull piece is connected with the support main body, the support main body is in the effect of push-pull piece has contraction state and expansion state, wherein, the distal end of support main body can push-pull piece's effect down towards the locating part motion, in order to shorten the distance between the near-end of support main body and the distal end.

According to the thrombus extractor disclosed by the invention, the near end of the stent main body is limited by the limiting part, the push-pull part is connected with the stent main body, when thrombus in a blood vessel needs to be extracted, the thrombus extractor in a contracted state is transferred to a focus part, and because the near end of the stent main body is limited by the limiting part, when the far end of the stent main body moves towards the limiting part under the action of the push-pull part, namely moves towards the near end of the stent main body, the whole length of the stent main body is shortened, so that a reticular structure is expanded outwards along the radial direction after being axially extruded and is in an unfolded state, and the thrombus is extruded and captured. When hard thrombus is encountered, the pushing and pulling piece can be further retracted, so that the whole length of the stent main body is further reduced, the net-shaped structure is continuously expanded outwards along the radial direction, the radial force of the stent main body is improved, the hard thrombus is dehydrated and reduced under the action of the radial force of the stent main body, the hard thrombus more easily enters the stent main body and is finally discharged out of the body together with the thrombus remover, the occluded blood vessel is rethreaded, the blood vessel rethreading rate is improved, the treatment time window is prolonged, the rethreading time is shortened, more time is won for reversible ischemic brain tissue, and the prognosis of a patient is obviously improved.

In addition, the embolectomy device according to the invention can also have the following additional technical characteristics:

in some embodiments of the invention, the stent body structure comprises a first mesh structure, a second mesh structure and a third mesh structure arranged in sequence along the distal end of the stent body towards the proximal end of the stent body.

In some embodiments of the invention, the second mesh structure has a length greater than a length of the third mesh structure when the stent body is in a compressed state, the length of the third mesh structure being greater than the length of the first mesh structure.

In some embodiments of the present invention, the first mesh structure, the second mesh structure and the third mesh structure are respectively composed of a plurality of mesh holes, and the number of mesh holes of the second mesh structure is smaller than the number of mesh holes of the third mesh structure.

In some embodiments of the present invention, the first mesh structure, the second mesh structure and the third mesh structure are each composed of a plurality of mesh holes, the average area of the mesh holes of the second mesh structure is larger than the average area of the mesh holes of the first mesh structure, and the average area of the mesh holes of the third mesh structure is larger than or equal to the average area of the mesh holes of the second mesh structure.

In some embodiments of the invention, the number of the push-pull member is one, and the push-pull member is connected with the distal end of the first net structure or the push-pull member is connected with the distal end of the second net structure; or,

the number of the push-pull pieces is three, and the three push-pull pieces are respectively connected with the far end of the first reticular structure, the far end of the second reticular structure and the far end of the third reticular structure.

In some embodiments of the invention, the embolectomy device further comprises a first bridge and a second bridge, the first mesh structure is connected to the second mesh structure by the first bridge, the second mesh structure is connected to the third mesh structure by the second bridge, and the first bridge and the second bridge are capable of moving in an axial direction relative to the push-pull member.

In some embodiments of the present invention, the stent main body is composed of two mesh structures, wherein the proximal end of one mesh structure is connected with the distal end of the other mesh structure to form a joint, and the push-pull member is connected with the distal end of the stent main body or the push-pull member is connected with the joint.

In some embodiments of the invention, the at least one length of mesh structure has a distal opening angle and a proximal opening angle that are both greater than 30 °.

In another aspect, the present invention further provides an embolectomy device, which has a catheter and an embolectomy device, wherein the embolectomy device has a compressed state arranged in the catheter and an expanded state arranged outside the catheter, and the embolectomy device is the embolectomy device according to any one of the above aspects.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like parts are designated by like reference numerals throughout the drawings. Wherein:

FIG. 1 is a schematic structural view of an embolectomy device in an expanded state according to an embodiment of the present invention;

FIG. 2 is a schematic view of the bolt remover of FIG. 1 in a compressed state;

FIG. 3 is a schematic view of the embolic device of FIG. 1 in a deployed, extreme state;

FIG. 4 is a schematic view of the embolectomy device of FIG. 1 in a compressed state during the embolectomy process;

FIG. 5 is a schematic view of the thrombus removal device in FIG. 1 in an expanded state during a thrombus removal process;

FIG. 6 is a schematic view of the embolectomy device of FIG. 1 in a further expanded state during the embolectomy procedure;

FIG. 7 is a schematic view of an alternate embodiment of the present invention showing the embolectomy device in a deployed configuration;

FIG. 8 is a schematic view of an alternate embodiment of the present invention showing the thrombectomy device in a deployed state;

FIG. 9 is a schematic view of an alternate embodiment of the present invention showing the embolectomy device deployed;

FIG. 10 is a schematic view of an alternate embodiment of the present invention showing the deployment of an embolectomy device.

The reference numerals in the drawings denote the following:

100: a thrombus taking device;

10: support main part, 11: first net structure, 12: second network structure, 13: a third network structure;

20: a limiting member;

30: a push-pull member;

41: first lap joint, 42: a second lap joint portion;

50: a tip;

200: a conduit;

300: a blood vessel;

400: thrombosis.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

For ease of description, the following description uses the terms "proximal" and "distal", where "proximal" refers to the end proximal to the operator and "distal" refers to the end distal from the operator, the phrase "axial direction", and within the context of the present invention should be understood to mean the direction in which the present embolectomy device is advanced and ejected, the direction perpendicular to the "axial direction" being defined as the "radial direction", and the phrase "length direction" being understood to mean the direction in which the physical dimension of the embolectomy device is the longest, and the direction perpendicular to the "length direction" being defined as the "radial direction".

Implementation mode one

Fig. 1 is a schematic structural view of an embolectomy device 100 in a deployed state according to an embodiment of the present invention. Fig. 2 is a schematic view of the embolectomy device 100 of fig. 1 in a compressed state. Fig. 3 is a schematic view of the embolectomy device 100 of fig. 1 in a deployed to limit state. As shown in fig. 1, 2, and 3, the embolectomy device 100 of the present embodiment includes a holder main body 10 and a stopper 20. The stent main body 20 comprises at least one section of net structure, the limiting member 20 is connected with the proximal end of the stent main body 10, and the proximal end of the limiting member 20 extends out of the body, so that an operator can limit the proximal end of the stent main body 10 in the body in the outside of the body. Wherein, the stent main body 10 is connected with the push-pull member 30, at least one section of the mesh structure has a contracted state and an expanded state under the action of the push-pull member 30, the distal end of the stent main body 10 can move towards the limiting member 20 under the action of the push-pull member 30 to shorten the distance between the proximal end and the distal end of the stent main body 10, or the distal end of the stent main body 10 can move towards the direction far away from the limiting member 20 under the action of the push-pull member 30 to increase the distance between the proximal end and the distal end of the stent main body 10.

According to the thrombectomy device 10 of the present invention, the proximal end of the stent body 10 is limited by the limiting member 20, the push-pull member 30 is connected to the stent body 10, and when the thrombus 400 in the blood vessel 300 needs to be removed, the thrombectomy device 100 in the contracted state is first transferred to the lesion site, and the state of the thrombectomy device 100 is shown in fig. 4. Since the proximal end of the stent body 10 is limited by the limiting member 20, when the distal end of the stent body 10 moves toward the limiting member 20 under the action of the push-pull member 30, i.e., moves toward the proximal end of the stent body 10, the entire length of the stent body 10 is shortened, so that the mesh structure is expanded outward in the radial direction after being axially compressed, and is in a deployed state, and the state of the embolectomy device 100 is as shown in fig. 5, so as to compress and capture the thrombus 400. When hard thrombus (one of thrombus) 400 is encountered, after the stent main body 10 is expanded, the hard thrombus 400 is limited between the stent main body 10 and the inner wall of the blood vessel 300, the push-pull piece 30 can be further pulled back, the whole length of the stent main body 10 is further reduced, so that the reticular structure is continuously expanded outwards along the radial direction, at the moment, the state of the thrombus taking device 100 is shown in figure 6, the direction shown by an arrow in figure 6 is the further withdrawing direction of the push-pull piece 30, so that the radial force of the stent main body 10 is improved, the hard thrombus 400 is dehydrated and reduced under the action of the radial force of the stent main body 10, the hard thrombus more easily enters the stent main body 10, the purpose of capturing the hard thrombus 400 is achieved, the hard thrombus is together discharged out of the body with the thrombus taking device 100, the occluded blood vessel 300 is recanalized, the recanalization rate of the blood vessel 300 is improved, the treatment time window is prolonged, the recanalization time is shortened, and more time is won for reversible ischemic brain tissue, the prognosis of the patient is significantly improved.

The embolectomy device 100 is an integral self-expandable stent structure with a closed proximal end and a closed distal end, which is formed by laser cutting a metal tube (such as a NiTi alloy tube) with shape memory effect and superelasticity, molding the tube by a mold, and heat-treating the shaped tube.

When the thrombus 400 needs to be taken out, the push-pull piece 30 and the thrombus taking device 100 are connected together in a non-limited mode, and the connection mode can be welding, gluing, riveting, crimping and the like. The attached push-pull member 30 and embolectomy device 100 are pressed into the catheter. The embolectomy device 100 is compressed within the catheter 200, and the embolectomy device 100 can be translated between the retracted position and the deployed position by pushing or pulling the push-pull member 30. In the retracted position, the embolectomy device 100 is retracted within the catheter 200, in a compressed state. In the deployed position, the thrombectomy device 100 is pushed out of the catheter 200, and the thrombectomy device 100 in the deployed state expands itself to form a deployed state, and the thrombectomy device 400 in the deployed state can directly remove a soft thrombus (a type of thrombus). When the hard thrombus 400 is encountered, the whole length of the stent main body 10 is further reduced by further withdrawing the push-pull member 30, so that the reticular structure is continuously expanded outwards along the radial direction, the radial force of the stent main body 10 is increased, the hard thrombus 400 is dehydrated and reduced under the action of the radial force of the stent main body 10, and the hard thrombus 400 is discharged out of the body together with the thrombus remover 100.

The distal end of the catheter 200 has a visualization marker, which is a metallic material or a rare earth material with a large atomic mass ratio, such as gold, platinum, thallium, tantalum, etc. In operation, the imaging marker points can display the position reached by the catheter 200 under the equipment such as CT angiography (CTA) and MRA (magnetic resonance angiography), so that the relationship between the thrombus device and the thrombus 400 can be accurately controlled.

The thrombus taking device reaches the thrombus position from the outside of the body through a blood vessel by a minimally invasive operation, passes through the thrombus 400 from the proximal end of the thrombus 400, and determines the relative position between the catheter 200 and the thrombus 400 under the observation of a CT and/or MRA, DSA or other contrast equipment. After the push-pull member 30 and the stopper member 20 are fixed, the catheter 200 is retracted, and the visualization mark is observed under the imaging device, so that the path along which the catheter 200 is retracted in the body can be known. The compressed stent body 100 is restored to a natural state, i.e., a deployed state, after being released from the catheter 200. Under the limiting action of the limiting part 20, the mesh structure of the stent main body 100 begins to expand, the mesh structure penetrates into the thrombus 400 through the radial force of the expansion of the mesh structure, the mesh structure is fully contacted with the thrombus 400, the push-pull part 30 is withdrawn, the stent main body 100 drives the thrombus 400 to move towards the near end of an operator under the dragging of the push-pull part 30, finally, the thrombus extractor 100 and the thrombus 400 are withdrawn into the catheter 200 together, the catheter 200 and the thrombus extractor 100 and the thrombus in the catheter 200 are withdrawn towards the near end to the outside of the patient, and therefore the whole thrombus extraction process of the thrombus extraction device is completed.

When the stent body 100 cannot penetrate into the hard thrombus 400 by the radial force of the self-expansion of the mesh structure, the entire length of the stent body 10 is further reduced by withdrawing the push-pull member 30, so that the mesh structure continues to expand outward in the radial direction. On the one hand, the expanded net structure can further extrude the hard thrombus 400, so that the size of the dehydrated hard thrombus 400 is reduced, on the other hand, the diameter of the net opening is increased after the net structure is fully expanded, so that the hard thrombus 400 can enter the frame of the thrombus extractor 100, the purpose of capturing the hard thrombus 400 is achieved, and the hard thrombus is discharged out of the body along with the thrombus extractor 100. The push-pull member 30 may be made of a metal with good elasticity, including stainless steel, nitinol, cobalt-chromium alloy, etc.

The stopper 20 in this embodiment has a structure having an inner cavity, and the push-pull member 30 can pass through the inner cavity of the stopper 20 and be connected to the distal end of the stent main body 100. In other embodiments of the present invention, if the limiting member 20 has no inner cavity structure, the push-pull member 30 may extend along the outer surface of the limiting member 20 and be connected to the distal end of the stent main body 10, and the push-pull member 30 can move relative to the limiting member 20, so as to ensure that the limiting member 20 can limit the stent main body 10 when the push-pull member 30 pushes or pulls the stent main body 100.

As shown in fig. 1, at least one section of the mesh structure in this embodiment includes a first mesh structure 11, a second mesh structure 12 and a third mesh structure 13 sequentially arranged along the distal end of the stent body 10 toward the proximal end of the stent body 10.

Wherein, the first net-like structure 11, the second net-like structure 12 and the third net-like structure 13 respectively have different functions in the thrombus removal process, and the distal end of the first net-like structure 11 is farther than the distal end of the thrombus 400, and the function thereof is to prevent the thrombus 400 from escaping after being captured. The second mesh structure 12 functions to capture the thrombus 400. The third mesh structure 13 assists the second mesh structure 12 in capturing the thrombus 400. Through the mutual cooperation of the first net-shaped structure 11, the second net-shaped structure 12 and the third net-shaped structure 13, the flexibility of the thrombus taking device 100 can be improved, and the thrombus 400 can be prevented from being cracked, so that the thrombus 400 can be captured more accurately.

The first net structure 11, the second net structure 12 and the third net structure 13 are respectively composed of a plurality of net holes, and the number of the net holes of the second net structure 12 is less than that of the net holes of the third net structure 13. In particular, the method comprises the following steps of,

the second mesh structure 12 has a relatively sparse mesh structure with 2-4 meshes in one circumferential direction, so that the thrombus 400 can fall into the meshes of the second mesh structure 12. Meanwhile, in order to prevent the thrombus 400 from falling off from the embolectomy device 100, the first mesh structure 11 has dense meshes and a second mesh structure having 3 to 8 meshes in one circumferential direction. The third net structure 13 has 2 to 4 meshes in one circumferential direction, and assists the second net structure 12 to capture the thrombus 400.

In order to further increase the radial supporting force of the second net structure 12, thereby better pressing the hard thrombus 400 and capturing the hard thrombus 400, the second net structure 12 should have the maximum radial dimension when the stent body 10 is in the deployed state. As shown in FIG. 2, when the stent body 10 is in a compressed state, the length D2 of the second mesh structure 12 is greater than the length D3 of the third mesh structure 13, and the length D3 of the third mesh structure 13 is greater than the length D1 of the first mesh structure 11. As shown in fig. 3, when the retaining member 20 is fixed, the pushing and pulling member 30 is retracted in the proximal direction to make the distal end of the first net-like structure 11 approach to the second net-like structure 12, the distal end of the second net-like structure 12 approach to the third net-like structure 13, and the distal end of the third net-like structure 13 approach to the retaining member 20, so that the first net-like structure 11 has a maximum radial dimension D4, the second net-like structure 12 has a maximum radial dimension D5, the third net-like structure 13 has a maximum radial dimension D6, the radial dimension D5 of the second net-like structure 12 is greater than the radial dimension D6 of the third net-like structure 13, and the radial dimension D6 of the third net-like structure 13 is greater than the radial dimension D4 of the first net-like structure 11, thereby increasing the radial supporting force of the second net-like structure 12.

In this embodiment, the proximal end of the third net structure 13 is connected to the distal end of the limiting member 20. The connection method may be welding, bonding, riveting, etc., and is not limited herein. The first net-like structure 11, the second net-like structure 12 and the third net-like structure 13 each have a respective proximal end and a respective distal end, the proximal end of the more distal net-like structure of two adjacent net-like structures is connected with the distal end of the more proximal net-like structure to form an overlapping portion, the first net-like structure 11 is connected with the second net-like structure 12 through the first overlapping portion 41, the second net-like structure 12 is connected with the third net-like structure 13 through the second overlapping portion 42, the first overlapping portion 41 and the second overlapping portion 42 can move in the axial direction relative to the push-pull member 30, and the connection manner for forming the overlapping portion can be welding, bonding, riveting, and the like, and is not limited herein.

Wherein, the centers of the first overlapping part 41 and the second overlapping part 42 are provided with through holes, the distal end of the push-pull member 30 can pass through the center through holes of the first overlapping part 41 and the second overlapping part 42 to be connected with the distal end of the first mesh-shaped structure 11, and an end head 50 is formed, and the specific connection mode can be welding, bonding, riveting, etc., and the connection mode is not limited herein.

Referring again to fig. 1, in this embodiment, the total length of the embolectomy device 100 is the length from the distal end of the first mesh structure 11 to the proximal end of the third mesh structure 13, wherein L1 is the effective embolectomy interval of the embolectomy device 100 in this embodiment. The greater the effective thrombus removal interval of the thrombus removal device 100, the higher the thrombus removal efficiency of the thrombus removal device 100. When the thrombus removal operation is carried out, the thrombus 400 is ensured to be within the range of L1. The distal end of the first mesh structure 11 has an opening angle a in the deployed state, which is greater than 30 ° in order to sufficiently lift the effective interval length L1 of the embolectomy device 100. The proximal end of the third mesh structure 13 has an opening angle B in the deployed state, which is greater than 30 ° to sufficiently lift the effective interval length L1 of the embolectomy device 100.

Second embodiment

Fig. 7 is a schematic structural view of an embolectomy device 100 according to another embodiment of the present invention in a deployed state. As shown in fig. 7, most of the structure of the embolectomy device 100 of the present embodiment is the same as that of the first embodiment, except that the net-like structures of the stent body 10 are woven net structures. Each mesh-structured woven mesh is formed by interweaving 1-20 independent wires. The wire has good elasticity and can be made of nickel-titanium alloy, cobalt-chromium alloy, stainless steel and other materials.

In the present embodiment, the first net structure 11, the second net structure 12 and the third net structure 13 are respectively composed of a plurality of net holes, wherein the average area of the net holes of the second net structure 12 is larger than the average area of the net holes of the first net structure 11, and the average area of the net holes of the third net structure 13 is larger than or equal to the average area of the net holes of the second net structure 12. The average area of the mesh herein means the ratio of the area of all the mesh to the number of the mesh.

To achieve the regular mesh distribution, there are two embodiments. One embodiment is: the woven meshes of the first net structure 11, the second net structure 12 and the third net structure 13 are woven by using the same number of wires. In a natural state, the length of the first net structure 11 is smaller than that of the second net structure 12, and the length of the second net structure 12 is smaller than that of the third net structure 13, so that the average area of the meshes of the second net structure 12 is larger than that of the meshes of the first net structure 11, and the average area of the meshes of the third net structure 13 is larger than that of the meshes of the second net structure 12. Or the length of the first net structure 11 is smaller than that of the second net structure 12, and the length of the second net structure 12 is equal to that of the third net structure 13, so that the average area of the meshes of the second net structure 12 is larger than that of the meshes of the first net structure 11, and the average area of the meshes of the third net structure 13 is equal to that of the meshes of the second net structure 12.

In order to achieve the regular mesh distribution, another embodiment is as follows: the length of the first reticular structure 11 is equal to the length of the second reticular structure 12 and equal to the length of the third reticular structure 13. The number of independent wires of the first net-shaped structure 11 is greater than the number of independent wires of the second net-shaped structure 12, and the number of independent wires of the second net-shaped structure 12 is greater than the number of independent wires of the third net-shaped structure 13, so that the average area of meshes of the second net-shaped structure 12 is greater than the average area of meshes of the first net-shaped structure 11, and the average area of meshes of the third net-shaped structure 13 is greater than the average area of meshes of the second net-shaped structure 12. Alternatively, the number of individual wires of the first mesh structure 11 is greater than that of the second mesh structure 12, and the number of individual wires of the second mesh structure 12 is equal to that of the third mesh structure 13, so that the average area of the meshes of the second mesh structure 12 is greater than that of the meshes of the first mesh structure 11, and the average area of the meshes of the third mesh structure 13 is equal to that of the meshes of the second mesh structure 12.

Third embodiment

Fig. 8 is a schematic structural view of an embolectomy device 100 according to another embodiment of the present invention in a deployed state. As shown in fig. 8, most of the structure of the embolectomy device 100 of the present embodiment is the same as that of the first embodiment, and only the number of push-pull members 30 is different. The number of the push-pull members 30 in this embodiment is three, and the three push-pull members 30 are respectively connected to the distal end of the first net structure 11, the distal end of the second net structure 12, and the distal end of the third net structure 13. In order to facilitate connection, the three push-pull pieces 30 can be respectively connected with the end heads 50, the first bridging parts 41 and the second bridging parts 42, so that the states of all the net-shaped structures can be controlled independently, and the three push-pull pieces 30 can be matched with each other for pushing and pulling, so that the first net-shaped structure 11, the second net-shaped structure 12 and the third net-shaped structure 13 can have various forms simultaneously, the supporting force and the flexibility of the stent main body 10 are further improved, and the capturing requirements of various types of thrombus are met.

Of course, the arrangement of the push-pull member 30 in the present embodiment can be applied to the second embodiment.

Embodiment IV

Fig. 9 is a structural diagram of an embolectomy device 100 according to another embodiment of the present invention in a deployed state, and as shown in fig. 9, most of the structure of the embolectomy device 100 according to this embodiment is the same as that of the first embodiment, except that the connection position of the push-pull member 30 and the stent main body 10 is different.

As shown in fig. 9, the number of the push-pull members 30 in this embodiment is one, and the push-pull members 30 are connected to the distal end of the second net structure 12. The push-pull member 30 can control the second net structure 12 and the third net structure 13 of the stent body 10. When the embolectomy device 100 is released from the catheter 200, the first mesh structure 11 is always in the expanded state regardless of pulling or pushing the push-pull member 30, thereby effectively preventing the thrombus 400 from falling off the distal end of the embolectomy device 100.

Of course, the connection mode of the push-pull tool 30 and the stent body 10 in the present embodiment can also be applied to the second embodiment.

Fifth embodiment

Fig. 10 is a structural view of an embolectomy device 100 according to another embodiment of the present invention, which is in a deployed state, and as shown in fig. 10, the embolectomy device 100 according to this embodiment is provided with only one mesh structure, preferably, the structure of the second mesh structure 12 can be selected. The second mesh structure 12 has a large mesh size, and can easily capture the hard thrombus 400. In this embodiment, the distal end of the push-pull member 30 is connected to the distal end of the second mesh structure 12 by a tip 50, thereby controlling the movement of the second mesh structure 12. The proximal end of the second net structure 12 is connected to the stopper 20 through the first bridging portion 41, so as to close the proximal end of the second net structure 12 and to stop the second net structure 12. Alternatively, the first bridging portion 41 is not provided, and the proximal end of the second net structure 12 is directly connected to the limiting member 20. The specific operation is the same as the first embodiment.

In other embodiments of the present invention, two or more than three net structures may be further provided on the stent main body 10, and the specific arrangement form thereof may be any of the specific structures in the first to fourth embodiments. Set up a network structure's support main part and compare with the support main part that sets up a plurality of network structure, be in the natural expansion state at the support main part under the prerequisite that has the same axial length, in the support main part is in comparatively crooked vascular environment, set up a network structure's support main part and appear "banana" effect easily, it is crooked that the support main part expands the back is the arc promptly, the support main part can not be fully with the vascular wall laminating to lead to reducing the compressive force to the thrombus, be unfavorable for getting the bolt. And set up the support main part inflation back of a plurality of structures, can adapt to crooked vascular environment better, be difficult for appearing "banana" effect, the compliance is better than a network structure's support main part simultaneously, passes through crooked vascular environment more easily.

In other embodiments, two mesh structures are disposed on the stent body 10, wherein the proximal end of one mesh structure is connected to the distal end of the other mesh structure to form a joint, and the push-pull member is connected to the distal end of the stent body, or the push-pull member is connected to the joint. The push-pull member is attached to the connection in a manner similar to that of fig. 9, i.e., the embolic support of fig. 9 has the third mesh structure 13 removed.

In another aspect of the present invention, a thrombus removal device is further provided, the thrombus removal device comprises a catheter 200 and a thrombus removal device 100, the thrombus removal device 100 has a compressed state arranged in the catheter 200 and an expanded state arranged outside the catheter 200, wherein the thrombus removal device 100 is the thrombus removal device 100 of any one of the above embodiments.

According to the thrombectomy device of the present invention, the stopper 20 is provided in the thrombectomy device, the proximal end of the stent body 10 is stopped by the stopper 20, the push-pull member 30 is connected to the stent body 10, and when the thrombectomy device 100 in the contracted state is first transferred to the lesion site when the thrombectomy device 400 in the blood vessel 300 needs to be removed, the state of the thrombectomy device 100 is as shown in fig. 4. Since the proximal end of the stent body 10 is limited by the limiting member 20, when the distal end of the stent body 10 moves toward the limiting member 20 under the action of the push-pull member 30, i.e., moves toward the proximal end of the stent body 10, the entire length of the stent body 10 is shortened, so that the mesh structure is expanded outward in the radial direction after being compressed, and is in a deployed state, in which the state of the embolectomy device 100 is as shown in fig. 5, so as to compress and capture the thrombus 400. When a hard thrombus (one of the thrombi) 400 is encountered, the pushing and pulling part 30 can be further retracted, so that the whole length of the stent main body 10 is further reduced, the reticular structure is further expanded outwards along the radial direction, at the moment, the state of the thrombus taking device 100 is shown in figure 6, the direction shown by the arrow in figure 6 is the further retraction direction of the pushing and pulling part 30, so that the radial force of the stent main body 10 is improved, the hard thrombus 400 is dehydrated and reduced under the action of the radial force of the stent main body 10, the hard thrombus more easily enters the stent main body and is discharged out of the body along with the thrombus taking device 100, the occluded blood vessel 300 is re-passed, the re-passing rate of the blood vessel 300 is improved, the treatment time window is prolonged, the re-passing time is shortened, so that more time is taken for reversible ischemic brain tissues, and the prognosis of a patient is obviously improved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A embolectomy device, comprising:

the stent comprises a stent main body and a first and a second mesh structures, wherein the stent main body comprises a first mesh structure, a second mesh structure and a third mesh structure which are sequentially arranged from the far end of the stent main body to the near end of the stent main body;

the push-pull piece is connected with the bracket main body, the bracket main body has a contraction state and an expansion state under the action of the push-pull piece, and the far end of the bracket main body can move towards the limiting piece under the action of the push-pull piece so as to shorten the distance between the near end and the far end of the bracket main body;

the first mesh structure, the second mesh structure and the third mesh structure are respectively composed of a plurality of meshes, the average area of the meshes of the second mesh structure is larger than that of the meshes of the first mesh structure, and the average area of the meshes of the third mesh structure is larger than or equal to that of the meshes of the second mesh structure.

2. The embolectomy device of claim 1, wherein the length of the second mesh structure is greater than the length of the third mesh structure when the stent body is in a compressed state, and the length of the third mesh structure is greater than the length of the first mesh structure.

3. The embolectomy device of claim 1, wherein the first, second, and third mesh structures are each comprised of a plurality of mesh openings, and the number of mesh openings of the second mesh structure is less than the number of mesh openings of the first mesh structure.

4. The embolectomy device of claim 1, wherein the number of the push-pull member is one, and the push-pull member is connected with the distal end of the first reticular structure or the push-pull member is connected with the distal end of the second reticular structure; or,

5. The embolectomy device of claim 1, further comprising a first bridge and a second bridge, the first web being connected to the second web by the first bridge, the second web being connected to the third web by the second bridge, the first bridge and the second bridge being axially movable relative to the push-pull member.

6. The embolectomy device of claim 1, wherein the stent body has a distal flare angle and a proximal flare angle that are each greater than 30 °.

7. An embolectomy device, comprising a catheter and an embolectomy device, wherein the embolectomy device comprises a compressed state arranged in the catheter and an expanded state arranged outside the catheter, and wherein the embolectomy device is according to any one of claims 1 to 6.