CN113040986A

CN113040986A - Support, bolt taking device and bolt taking system

Info

Publication number: CN113040986A
Application number: CN201911379912.3A
Authority: CN
Inventors: 周炯; 于海瑞
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Microport Neurotech Shanghai Co Ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2021-06-29
Anticipated expiration: 2039-12-27
Also published as: CN113040986B

Abstract

The invention provides a support, a bolt taking device and a bolt taking system, wherein the bolt taking system comprises a conveying device and a bolt taking device, the bolt taking device comprises a support, a hollow connecting rod and a traction body, and the support comprises a plurality of capturing structures which are sequentially connected end to end; each capture structure comprises a scaffold and a capture layer; the scaffold comprises a proximal part and a distal part which are arranged from near to far, and the capture layer surrounds the scaffold and covers the surface of the distal part; the hollow connecting rod is connected with the head and the tail of the two adjacent capturing structures; the traction body can movably penetrate through each hollow connecting rod and is connected with the far end of the thrombus taking device; the traction body is configured to be pulled to generate an axial force on the bolt-removing device so as to cause the support frame of each capture structure to be outwards spread. The thrombus capture device has the advantages of reducing the volume of the thrombus capture device, improving the flexibility and adherence of the thrombus capture device, and improving the success rate of thrombus capture.

Description

Support, bolt taking device and bolt taking system

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to a support, a thrombus removal device and a thrombus removal system.

Background

Stroke has the characteristics of high morbidity, high mortality, high recurrence rate and the like, and seriously harms the health and the life quality of human beings. The cerebral apoplexy comprises ischemic stroke and hemorrhagic stroke, wherein the ischemic stroke accounts for 70-80 percent and is a main disease causing death and disability for the middle-aged and the elderly.

In patients with ischemic stroke, brain cells are easy to die in a short time due to cerebral ischemia, and then the patients are disabled or die, so that the treatment of ischemic stroke is also a great difficulty in the field of cerebral stroke treatment. The existing methods for treating ischemic stroke can be divided into drug treatment and physical treatment. Drug therapy generally employs recombinant tissue plasminogen activator (rt-PA) for either intravenous or arterial thrombolysis, and although systemic thrombolysis therapy offers some clinical benefit, only a few patients benefit from vascular thrombolysis therapy due to time window and embolus size limitations. The main physical therapy at present can be divided into suction suppository and stent suppository, or the combination of the two. Among them, the stent embolus has attracted much attention because of its wider adaptation diseases, higher patency rate, good recovery rate and less complications. However, the current embolectomy devices have the following problems: most thrombus taking stents capture thrombus by using meshes, but the mesh stents are easily limited by the shapes and sizes of the meshes, cannot effectively pull emboli in different forms, have poor adherence in tortuous blood vessels such as intracranial vessels and cannot effectively clamp the thrombus, so that the thrombus is easy to fall off in the thrombus taking and recovering process; some thrombus removal devices capture thrombus through a capture layer or membrane, but cannot be used in thinner vessels due to the large volume of the stent; and fragile small thrombi are difficult to capture and easy to escape from the meshes.

Therefore, there is a need to develop a stent, a thrombus extraction device and a thrombus extraction system, which are convenient to use in a thin or tortuous blood vessel, can adhere to the wall well, and can capture small thrombus, thereby improving the success rate of thrombus capture and reducing the risk of thrombus falling off in the thrombus extraction and recovery process.

Disclosure of Invention

The invention aims to provide a stent, a thrombus taking device and a thrombus taking system, which solve the problem that the existing thrombus taking device cannot extend into a thinner blood vessel due to larger volume.

Another object of the present invention is to provide a stent, a thrombus removal device and a thrombus removal system, so as to solve the problem of poor flexibility and adherence after the existing thrombus removal device is expanded.

Still another object of the present invention is to provide a stent, an embolectomy device and an embolectomy system, so as to solve the problem that the existing embolectomy device is difficult to capture escaping small thrombi.

To achieve the above object, according to one aspect of the present invention, there is provided a stent including a plurality of capturing structures connected end to end in series; each of the capture structures comprises a scaffold and a capture layer; the scaffold comprises a proximal portion and a distal portion arranged from the proximal to the distal, the capture layer surrounding the scaffold and covering a surface of the distal portion.

Optionally, each of the supports comprises a plurality of links that are foldable and extend from the proximal end to the distal end, the plurality of links being arranged about an axis of the corresponding capture structure.

Optionally, the projections of the plurality of connecting rods are distributed radially from the center in the direction perpendicular to the axis of the capturing structure.

Optionally, the projection of each link in a direction perpendicular to the axis of the capturing structure is linear or arcuate.

Optionally, each of the connecting rods is formed by hinging at least two rod pieces, or each of the connecting rods is provided with at least one notch to generate elastic deformation.

Optionally, each of said scaffolds has a free state and a fully deployed state;

when the support frame is in the free state, the extending direction of each connecting rod forms an included angle of 10-40 degrees with the axis of the capturing structure; when the support frame is in the fully unfolded state, the extending direction of each connecting rod and the axis of the capturing structure form an included angle of 40-70 degrees.

Optionally, each of the capturing structures further comprises a linear body connected to the supporting frame, and the linear body is used for limiting the maximum diameter of the supporting frame when the supporting frame is expanded outwards.

Optionally, each support frame comprises a plurality of circumferentially arranged connecting rods, and each connecting rod is provided with at least one deformable node; each capturing structure comprises a plurality of linear bodies which are sequentially connected with the nodes of the connecting rods of the supporting frame;

the support frame has a free state, a fully deployed state and a deployed limited state; the total length of all the linear bodies is less than the maximum perimeter of the support frame in the fully unfolded state.

Optionally, the trapping layer comprises a woven mesh, a semi-permeable membrane or a membrane with pores.

In order to achieve the above object, according to one aspect of the present invention, there is also provided a thrombus removal device, including any one of the brackets, the thrombus removal device further including a hollow connecting rod and a traction body, wherein the hollow connecting rod connects the head and the tail of two adjacent capture structures; the traction body can movably penetrate through each hollow connecting rod and is connected with the far end of the thrombus taking device; the traction body is configured to move in tension towards a proximal end of the embolectomy device relative to the hollow connecting rod to generate an axial force on the embolectomy device to outwardly expand the scaffolding of each of the capture structures.

Optionally, each of the capturing structures further comprises a developing structure made of a developing material, the developing structure being disposed on an outer surface of the supporting frame.

Optionally, the developing structure is disposed at a position on the supporting frame having a maximum diameter.

Optionally, the thrombus removal device further comprises a proximal developing structure and a distal developing structure, wherein the proximal developing structure and the distal developing structure are made of developing materials, the proximal developing structure is arranged at the proximal end of the thrombus removal device, and the distal developing structure is arranged at the distal end of the thrombus removal device.

In order to achieve the above object, according to one aspect of the present invention, there is also provided a thrombus removal system, comprising a conveying device and any one of the thrombus removal devices;

the delivery device comprises a hollow push rod, and the far end of the hollow push rod is detachably connected with the near end of the thrombus removal device; one end of the traction body penetrates through each hollow connecting rod and is connected with the far end of the thrombus removal device, and the other end of the traction body penetrates through the hollow push rod and extends out of the near end of the conveying device.

Furthermore, according to the technical scheme provided by the invention, the bracket, the thrombus taking device and the thrombus taking system have the following beneficial effects:

firstly, the stent is provided with a plurality of capturing structures which are sequentially connected end to end, so that the volume of the stent and the thrombus taking device is reduced, and the stent and the thrombus taking device can be used in a thinner blood vessel, thereby improving the adaptability of the stent and the thrombus taking device and improving the effect of disease treatment;

secondly, the thrombus taking device also comprises a traction body, and the traction body controls each capturing structure to be expanded outwards, so that each capturing structure can better conform to the change of the diameter of a blood vessel, thereby better conforming to a tortuous blood vessel or a bent blood vessel and realizing good adherence, thereby improving the success rate of thrombus capturing and improving the thrombus taking effect;

thirdly, the capture layers are arranged at the distal end parts of the support frames of the capture structures, so that the risk of thrombus escape in the thrombus removal operation, especially in the intracranial thrombus removal operation, is reduced, the success rate of thrombus capture is further improved, and the thrombus removal effect is improved;

fourthly, the support frame is constructed through the connecting rods, and the support is further constructed, so that the structures of the support frame and the support are simplified, and the volumes of the support frame and the corresponding support are reduced; in addition, in the axial direction perpendicular to the capturing structure, the projection of each connecting rod is arc-shaped, so that the risk of scratching the blood vessel wall can be reduced, and the safety of the thrombus removal operation is improved;

fifthly, the linear bodies are arranged on the support frames, so that the maximum diameter of the support frames during opening can be restricted, the problem of overturning of the support frames during opening is avoided, and the reliability of the support and the plug taking device is improved; in addition, still set up the development structure on the surface of each support frame, be convenient for observe this development structure in order to confirm the state of strutting of support frame, improved the accuracy of bolt operation.

Drawings

The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention. Wherein:

FIG. 1 is a schematic structural view of a thrombectomy system according to a preferred embodiment of the present invention;

FIG. 2 is a schematic structural view of a preferred embodiment of the present invention in which the capturing layer is a woven mesh;

FIG. 3 is a schematic structural view of a capture layer of a preferred embodiment of the present invention as a cover film;

FIG. 4 is a schematic view of the thrombus capture in a tortuous vessel using the thrombectomy device of the preferred embodiment of the present invention;

FIG. 5 is a schematic view of the preferred embodiment of the thrombectomy device of the present invention in an operative condition for capturing thrombi in a tortuous vessel;

FIG. 6 is a schematic structural view of a single capture structure in a free state in a preferred embodiment of the invention, wherein a capture layer is disposed on the outer surface of the distal portion of the capture structure;

FIG. 7 is a schematic structural diagram of a single trapping structure in a free state with the trapping layer omitted in a preferred embodiment of the present invention;

FIG. 8 is a schematic view of a preferred embodiment of the present invention showing a notch formed in the connecting rod;

FIGS. 9a to 9c are schematic views of a preferred embodiment of the present invention with links radiating from the center in a direction perpendicular to the axis;

FIG. 9d is a schematic view of two adjacent links forming a parallelogram in the preferred embodiment of the present invention;

FIG. 9e is a schematic view of a hexagonal configuration of two adjacent links in accordance with a preferred embodiment of the present invention;

FIGS. 10a to 10c are schematic views of a plurality of links according to a preferred embodiment of the present invention, respectively, in which projections of the links in a direction perpendicular to the axis are arc-shaped;

FIG. 11 is a schematic view of the preferred embodiment of the present invention showing the extending direction of the connecting rod forming a first angle with the axis of the embolectomy device when the embolectomy device is in a free state;

FIG. 12 is a schematic view of the preferred embodiment of the present invention showing the direction of extension of the linkage at a second angle to the axis of the embolectomy device when the embolectomy device is in a deployed state.

In the figure:

a bolt taking system-100;

a thrombus removal device-110; capture structure-11; a support frame-12; a connecting rod-121; rod members-1211, 1212, 1213; a trapping layer-13; a mesh grid-131; coating film-132; a tractor body-14; a linear body-15; a hollow connecting rod-16; a distal connector-17; proximal connector-18; proximal visualization structure-19; distal visualization structure-20;

-a conveying device-120; a hollow push rod-1201; a delivery sheath-1202;

proximal end-a of the thrombectomy device; distal end-b of the thrombectomy device; emboli-S1, S2, S3; a node-c; a notch-d; a first included angle- α; the second included angle-beta.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

Furthermore, each of the embodiments described below has one or more technical features, and thus, the use of the technical features of any one embodiment does not necessarily mean that all of the technical features of any one embodiment are implemented at the same time or that only some or all of the technical features of different embodiments are implemented separately. In other words, those skilled in the art can selectively implement some or all of the features of any embodiment or combinations of some or all of the features of multiple embodiments according to the disclosure of the present invention and according to design specifications or implementation requirements, thereby increasing the flexibility in implementing the invention.

To further clarify the objects, advantages and features of the present invention, various embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the meaning of "a plurality" generally includes two or more unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. The terms "longitudinal", "axial" and "axial" generally refer to a direction parallel to the axis of the embolectomy device, and "transverse", "radial" and "transverse" generally refer to a direction perpendicular to the axis of the embolectomy device. The term "proximal" refers to the end proximal to the operator's site, and "distal" refers to the end distal to the operator's site. The same or similar reference numbers in the drawings identify the same or similar elements.

It is also to be understood that the present invention repeats reference numerals and/or letters in the various embodiments. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. It will also be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or one or more intervening elements may be present.

A core idea of the invention is to provide a scaffold comprising a plurality of capture structures connected end to end in series. Each of the capture structures includes a scaffold and a capture layer. The scaffold comprises a proximal portion and a distal portion arranged from the proximal to the distal, the capture layer surrounding the scaffold and covering a surface of the distal portion.

Another core idea of the invention is to provide a thrombus removal device, which comprises a bracket, a hollow connecting rod and a traction body. The hollow connecting rod is connected with the head and the tail of two adjacent capture structures to form a hollow channel. During the practical application, the traction body movably wears to locate each in the cavity connecting rod to with the distal end of thrombectomy device is connected, and then through to near-end pulling traction body, makes the traction body move in order to produce the axial effort to thrombectomy device for the near-end of thrombectomy device of cavity connecting rod, under the effect of axial force, each the support frame of catching the structure outwards struts. By doing so, each capture structure can conform to the shape of the blood vessel, achieve the effect of tightly fitting with the blood vessel wall, improve the flexibility and adherence of the thrombus removal device, and realize the effects even in curved and tortuous blood vessels. In addition, the compressed diameter of the embolectomy device formed by the plurality of capturing structures in the delivery sheath is small, so that the embolectomy device can conveniently enter tiny blood vessels, particularly intracranial blood vessels. Therefore, the thrombus removal device is particularly suitable for small blood vessels, particularly intracranial blood vessels. Meanwhile, the design of the capturing layer greatly reduces the risk of thrombus escape in an intracranial thrombus removal operation, and greatly improves the success rate of thrombus capturing.

The bracket, the thrombus removal device and the thrombus removal system comprising the thrombus removal device provided by the invention are further described in detail in the following with reference to the attached drawings and the detailed description.

Referring first to FIG. 1, the construction of the embolectomy system of the preferred embodiment of the present invention is shown. As shown in FIG. 1, an embodiment of the present invention provides a embolectomy system 100, which comprises a embolectomy device 110 and a delivery device 120. The embolectomy device 110 comprises a scaffold including a plurality of capture structures 11 connected end-to-end in series. In the present invention, the number of the capturing structures 11 is determined according to the distribution of the thrombus in the blood vessel, and if the distribution range of the thrombus in the blood vessel is wide, more capturing structures can be arranged to increase the thrombus extraction length, and conversely, fewer capturing structures can be arranged to decrease the thrombus extraction length. Further, the holder of the embolectomy device 110 of the present embodiment can include 2, 3, or more capture structures 11. Furthermore, the present invention does not limit the distance between two adjacent capturing structures 11, and theoretically, the closer the capturing structures 11 are arranged, the better the thrombus can be captured, the thrombus can be prevented from escaping, and the thrombus taking device can be conveniently transported and operated. Therefore, the spacing distance of the respective capturing structures 11 should be as small as possible without causing interference.

Wherein each of said capturing structures 11 comprises a supporting frame 12 and a capturing layer 13. The support frame 12 has a circle of meshes arranged circumferentially, and the support frame 12 can be folded and unfolded. In addition, the capturing layer 13 surrounds the supporting frame 12 and covers a part of the outer surface of the supporting frame 12. In particular, the scaffold 12 includes proximal and distal portions disposed from proximal to distal, but the present invention is not limited to the relative sizes of the distal and proximal portions, and preferably the distal and proximal portions are the same size. Here, the distal portion is further from the delivery device 120 relative to the proximal portion. And the capture layer 13 covers the outer surface of the distal part, so that small emboli escaping from the front end are intercepted at the distal end, and the small emboli are prevented from flowing to other branch blood vessels to form secondary embolism. In other embodiments, the capture layer 13 covers the inner surface of the distal section, or both the inner and outer surfaces of the distal section.

In certain embodiments, the capture layer 13 has holes that allow blood flow to pass through. In practice, as shown in fig. 2, the trapping layer 13 may be a woven mesh 131, for example woven from metal wires. Alternatively, as shown in fig. 3, the trapping layer 13 may be a film 132, and the film 132 may be perforated to form the holes. The material of the braided mesh 131 may be selected from one or more of a combination of a metal material and a polymer material, and the metal material is preferably nickel-titanium alloy. The material of the covering film 132 may be selected from high molecular polymers including, but not limited to, PTFE (polytetrafluoroethylene). In other embodiments, the trapping layer may be a semi-permeable membrane that only allows liquid to pass through but not solids, in which case the membrane 132 may be a non-porous membrane. In other embodiments, the trapping layer 13 may be a polymer film leached in a polymer solution.

The embolectomy device 110 further comprises a hollow connecting rod 16 and a traction body 14, wherein the hollow connecting rod 16 is connected with the head and the tail of two adjacent capture structures 11 and forms a hollow channel. In use, the pulling body 14 is movably disposed through each hollow connecting rod 16 and connected to the distal end b of the embolectomy device 110, and more specifically, one end of the pulling body 14 is connected to the distal end of the most distal one of the capturing structures 11. For example, the stent of the embolectomy device 110 includes 5 capturing structures 11 connected end to end in sequence, and the first, second, third, fourth, and fifth capturing structures are arranged in sequence from the far side to the near side, such that one end of the traction body 14 is connected to the far side of the first capturing structure. It should be understood that the tractor 14 is only under tension and may be made of a softer material to provide sufficient flexibility, but the present invention is not limited to any particular material or configuration of the tractor 14. For example, the tractor 14 may be a wire, hose, or the like. Preferably, the material of the pulling body 14 is a shape memory alloy material, and more preferably, the material of the pulling body 14 is a nickel titanium alloy. In this embodiment, the pulling body 14 is a nickel titanium pulling wire, and has good flexibility. In addition, the connection manner of the traction body 14 and the distal end of the stent of the embolectomy device 110 is not limited, and the connection manner can be realized by knotting, welding, bonding and the like.

The delivery device 120 comprises a hollow pusher rod 1201 and a delivery sheath 1202. In practical use, the hollow push rod 1201 movably penetrates through the delivery sheath 1202 (also called a microcatheter), and the distal end of the hollow push rod 1201 is detachably connected to the proximal end a of the embolectomy device 110, so as to push and pull the embolectomy device 110 conveniently, and realize the operations of delivery, release, recovery, and the like of the embolectomy device 110. And after one end of the traction body 14 passes through each hollow connecting rod 16 and is connected with the distal end b of the embolectomy device 110, the other end also passes through the hollow push rod 1201 and extends to the outside of the proximal end of the delivery device 120, so that a doctor or an external instrument can conveniently control the diameter of each capture structure 11 by controlling the other end of the traction body 14.

The operation of the present embodiment of the embolectomy system 100 is illustrated in FIGS. 4 and 5. After the thrombus removal device 110 is ejected out of the delivery sheath 1202 by the hollow push rod 1201, if the pull body 14 is pulled towards the proximal end while the hollow push rod 1201 is kept still, the distal end of the thrombus removal device 110 is stressed by the pull body 14, and then the capture structures 11 are expanded (or called to be expanded) outwards along the direction indicated by the arrow and are respectively attached to the blood vessel wall, and the diameters of the expanded capture structures 11 can be the same or different, so that the thrombus removal device 110 can better conform to the shape of the blood vessel, and has good adherence even in a curved section of the blood vessel and a tortuous blood vessel in the cranium. In more detail, before the embolectomy device 110 is opened, the hollow pushing rod 1201 is kept stationary to restrain the proximal end of the embolectomy device 110, and then the pulling body 14 is pulled proximally to tighten the pulling body 14 with a certain tightening force, so as to generate an axial force on the most distal capturing structure 11, and the generated axial force is sequentially transmitted from the first capturing structure to the most proximal capturing structure until each capturing structure 11 is tightly adhered to the blood vessel wall. It should be understood that the traction body 14 of the present invention is connected to only the first capturing structure, the compression force between the traction body 14 and the hollow pushing rod 1201 is equally distributed to each capturing structure 11, and the thrombectomy device 110 has the same clinging force to the vessel wall no matter the thickness of the vessel or the change of a certain local diameter, so that the thrombectomy device has better flexibility and adherence. Therefore, after the thrombus taking device 110 is expanded outwards under the action of the traction body 14, the large thrombus S1 can be stripped off the blood vessel by the aid of the support frame 12, and in the stripping process, if small emboli S2 and S3 are generated, the small emboli can be intercepted by the capturing layer 13, so that the escaped small emboli can be successfully captured.

In this embodiment, each capture structure 11 has a plurality of structural states, including specifically a collapsed state, an expanded state, and a free state. When the thrombus removal device 110 is positioned inside the delivery sheath 1202, the capturing structure is in a contracted state due to the constraint of the delivery sheath 1201; after the thrombectomy device 110 is detached from the delivery sheath 1202, the capture structure 11 is free if the traction body 14 is not under tension. If the traction body 14 is further tightened, the capturing structure 11 can be expanded outward in the free state to be in the deployed state, and at this time, the capturing structure 11 can capture the thrombus normally. After the thrombus is captured, the traction body 14 is released (i.e., the traction body 14 is not subjected to any tension), so that the capture structure 11 can be restored to a free state, and at the moment, the hollow push rod 1201 is withdrawn, so that the whole thrombus removal device 110 can be retracted into the delivery sheath 1202 again; or after the thrombus is captured, the pulling force applied to the traction body is reduced, so that the capture structure is between the expanded state and the free state, the hollow push rod 1201 is retracted, and the pulling force applied to the traction body is slowly released in the process that the thrombus removal device 110 is retracted into the delivery sheath 1202. In the conveying sheath 1202, the embolectomy device 110 is pressed to be in a contraction state, and finally the whole embolectomy device 100 is removed from the human body, so that the whole embolectomy recovery operation can be completed.

Therefore, the thrombus extraction device 110 provided by the invention has better flexibility and adherence, high thrombus capture rate and good capture effect. In particular, the compressed diameter of the whole embolectomy device 110 is small, which facilitates the embolectomy device to penetrate into small blood vessels such as the intracranial space, thereby improving the adaptive range of the embolectomy device 110 and improving the therapeutic effect of diseases. And the trapping layer also reduces the risk of thrombus escape in the thrombus taking operation, so that fine and fragile thrombus which is easy to drop and separate can be easily trapped, and the thrombus trapping effect is better.

Fig. 6 shows the structural condition of the single catching structure 11 in the free state, and fig. 7 shows the structural condition of the supporting frame 12 of the single catching structure in the free state. As shown in fig. 6 and 7, in the free state, the traction body 14 is not pulled and the tightening of each capturing structure 11 is not generated, at this time, the capturing structure 11 is similar to a folded umbrella, wherein the supporting frame 12 serves as a supporting framework of the umbrella, and the capturing layer 13 forms an umbrella cover, the whole capturing structure has small volume, is convenient to convey and recover, and can firmly and effectively restrain the thrombus in the capturing structure after the thrombus is captured, so that the thrombus is prevented from falling off in the thrombus taking and recovering process.

With continued reference to fig. 6 and 7, the capturing structure 11 further includes a linear body 15 connected to the supporting frame 12, and the linear body 15 is used to limit the maximum diameter of the supporting frame 12 when the supporting frame is expanded outwards, so as to avoid the problem of overturning during the supporting frame expansion process, thereby improving the reliability of the bolt-removing operation. In this embodiment, as shown in fig. 7, the support frame 12 includes a plurality of links 121 that are foldable and extend from the proximal end to the distal end, and the plurality of links 121 are arranged around the axis of the capturing structure 11. Here, the extension from the proximal end to the distal end is not entirely parallel to the stent axis, or may be in a direction parallel to the axis in the free state, and may be not parallel to the axis in the deployed state, but may be bent or bent. Further, for any one of the cages 12, at least one deformable node c is provided on each link 121 to enable the link 121 to be folded.

In one embodiment, the capturing structure 11 comprises only one linear body 15, and the linear body 15 sequentially passes through a plurality of nodes c on a plurality of connecting rods 121 forming the supporting frame 12, and the nodes c are arranged at the maximum diameter of the supporting frame 12, so as to restrict the spreading diameter of the supporting frame 12 where the passed nodes c are located. Preferably, the line connecting the plurality of nodes c traversed by the linear body 15 defines the maximum diameter of the support, that is to say, said linear body 15 traverses all the nodes c distributed on the maximum diameter of the support 12 in sequence. In this embodiment, a small hole may be provided at each node c to facilitate the threading of the linear body 15. The linear body 15 may be a wire, rope, band, or thread. The two ends of the linear body 15 may or may not be fixed together.

Further, the scaffold 12 has a fully deployed state and a deployment-constrained state. When the linear body 15 is not arranged, the support frame 12 can be completely unfolded under the tightening of the traction body 14 and is in a completely unfolded state; when the linear body 15 is arranged, the support frame 12 is unfolded until the linear body 15 is straightened and is in a unfolding limited state under the tightening of the traction body 14. Therefore, the overall length of one of the linear bodies 15 should be less than the maximum circumference of the support frame 12 in the fully deployed state. The support frame 12 also has a free state, that is, the traction body 14 is not tightened, and the support frame 12 is not unfolded, at this time, if the linear bodies 15 are provided, in the free state, the total length of one linear body 15 is greater than the perimeter of the support frame 12 defined by the connecting line of the nodes c through which the linear body 15 is inserted, so as to ensure that the support frame 12 has a certain extension amount, so that the support frame 12 is not bound by the linear body 15 when being unfolded. Thus, during the expansion process, when the whole linear body 15 is completely straightened, the maximum circumference of the stent 12 when being expanded can be defined, and at this time, the total length of the linear body 15 is equal to the circumference of the stent 12 defined by the connection line of the plurality of nodes c penetrated by the linear body.

In an alternative embodiment, the whole linear body 15 can be divided into multiple segments, each segment connecting the nodes c of two of the connecting rods 121, in this case, it is equivalent to disposing multiple linear bodies 15 on the support 12, and these linear bodies 15 are sequentially connected to multiple nodes c of multiple connecting rods 121 on the support frame 12. Similarly, when the support frame 12 is in a free state, the length of each linear body is greater than the length of a connecting line between two nodes c connected by the linear body; in this way, the maximum circumference of the support frame 12 is defined when all the linear bodies 15 are straightened during the process of expanding the support frame 12. In other alternative embodiments, one threadlike body 15 may pass through the same node c a plurality of times. It should be noted that the present invention does not specifically limit the specific positions where the linear bodies 15 are connected to the connecting rod 121, including but not limited to connecting the connecting rod 121 at the node c, and the present invention does not specifically limit the number of linear bodies connected to the node c, and the relative positions of the connected nodes c; the nodes c on all the adjacent connecting rods 121 can be connected in sequence, and the nodes c on part of the adjacent connecting rods 121 can be connected; node c on adjacent link 121 may be connected, and node c on non-adjacent link 121 may also be connected.

With continued reference to fig. 6 and 7, the support frame 12 includes a plurality of circumferentially arranged mesh openings, each mesh opening being defined by two adjacent links 121. Further, for any one support frame 12, the number of the connecting rods 121 may be three, four, five, six, eight or more, and the specific number of the connecting rods 121 is set according to actual needs, for example, when dense meshes need to be obtained, more connecting rods 121 may be configured, and when sparse meshes need to be obtained, fewer connecting rods 121 may be configured. Further, the shape and number of sides of the net hole are not limited, and the net hole may be formed of a straight line or a curved line as long as the net hole can be unfolded and folded in the radial direction, for example, the net hole may have four sides, six sides or eight sides, and preferably, the net hole has a symmetrical structure. In addition, the present disclosure is not limited to the manner in which the scaffold 12 is manufactured, and in some embodiments, the scaffold 12 may be formed by laser cutting a tube. The material of the support frame 12 is primarily a metallic elastic material including, but not limited to, stainless steel, nitinol, and the like.

As further shown in fig. 8, each link 121 may be a single-piece structure, and at least one gap d (i.e., node c) may be formed on the link 121 by cutting off a portion of the material, so that the link 121 may be partially elastically deformed to be foldable and unfoldable. The at least one notch d includes at least one notch d facing the inner side of the capturing structure 11, where "inner side" refers to the side near the axis of the capturing structure 11. In other embodiments, each connecting rod 121 may also be a split structure, in which case, each connecting rod 121 is formed by at least two rod members hinged together, and the hinged part forms a node c. Preferably, the hinge structure is replaced by cutting off the material to form the gap d, so that the volume of the embolectomy device 110 can be reduced, and the processing difficulty can be reduced. Referring to fig. 7, in the present embodiment, each link 121 is formed with a gap d (also, a node c) at a middle position thereof, and also with gaps d at both ends of the link 121, so that both ends and the middle position of each link 121 can be rotated.

Referring back to fig. 7, in the single capturing structure 11, a hollow connecting rod 16 is connected to both ends of the supporting frame 12, more specifically, both ends of each link 121 of the supporting frame 12 are connected to the hollow connecting rod 16, and the connection manner of each link 121 to the hollow connecting rod 16 is not limited. Optionally, the connecting rod 121 is hinged to the hollow connecting rod 16, or the connecting rod 121 may be welded or bonded to the hollow connecting rod 16. If the connecting rod 121 is welded or bonded to the hollow connecting rod 16, a notch d may be formed at a position of the connecting rod 121 adjacent to the hollow connecting rod 16 to form a deformation region. It should be noted that, when the number of the capturing structures 11 is three or more, two adjacent supporting frames 12 are connected by one hollow connecting rod 16, but the structures of the hollow connecting rods 16 may be the same or different, for example, the lengths may be the same or different.

Further, one connector, a distal connector 17 and a proximal connector 18, may be provided at the proximal end a and the distal end b of the embolectomy device 110, respectively. The proximal connector 18 is connected to the most proximal one of the catch structures 11 and is also adapted to be detachably connected to the distal end of the hollow push rod 1201. The distal attachment element 17 is attached to the distal most one of the capturing structures 11 and is also adapted to be attached to the tractor 14. Optionally, the proximal connector 18 and the distal connector 17 are both hollow connecting rods 16, so as to simplify the component configuration and reduce the manufacturing cost. In other cases, the proximal and

distal connectors

18, 17 may be used without the hollow connecting rods 16, i.e., only the two ends of each capturing structure 11 in the middle portion are provided with hollow connectors 16.

Referring to fig. 1, the embolectomy device 110 further comprises a proximal visualization structure 19 and a distal visualization structure 20, wherein the proximal visualization structure 19 is made of a visualization material, the proximal visualization structure 19 is disposed at the proximal end a of the embolectomy device 110, and the distal visualization structure 20 is disposed at the distal end of the embolectomy device 110. Based on the developability of the proximal visualization structure 19, the proximal position of the embolectomy device 110 can be determined; and determining the distal position of the embolectomy device 110 according to the developability of the distal developing structure 20; thereby the operation of bolt taking is more accurate and convenient. In this embodiment, the proximal visualization structure 19 is disposed on the proximal connector 18, and is preferably a visualization ring. The distal visualization structure 20 is disposed on the distal attachment member 17, and is also preferably structured as a visualization ring. Any developing ring can be wound on the corresponding connecting piece, and the developing ring and the connecting piece can be integrally formed or separately formed. For the split molding, the developing ring and the connecting member are assembled together after being molded separately. For integral molding, a part of the segment of the attachment may be formed into the developing ring at the time of preparing the attachment.

As mentioned above, the support frame 12 has a plurality of circumferentially arranged mesh openings, wherein the edge of any one mesh opening may be linear or curved, and a mesh opening may include a linear edge and/or a curved edge. In other words, each link 121 may have a linear configuration or a curved configuration (e.g., an arc configuration).

For example, as shown in fig. 9a to 9c, the supporting frame 12 includes a plurality of straight-line-shaped connecting rods 121, and the plurality of connecting rods 121 of the supporting frame 12 are distributed radially at the center, as viewed along the direction of the axis of the capturing structure 11, i.e. on a projection plane perpendicular to the axis of the capturing structure 11, for example, four connecting rods 121 are distributed in a cross shape, or six connecting rods 121 are distributed in a snowflake shape, or eight connecting rods 121 are distributed in a rice shape. Further, the projection of each link 121 may be linear on a projection plane perpendicular to the axis of the capturing structure 11. Further, as shown in fig. 9d, each link 121 is hinged by two

straight rod members

1211 and 1212, so that two adjacent links 121 form a quadrilateral structure, preferably a diamond structure. Further, as shown in fig. 9e, each connecting rod 121 may also be composed of three

straight rod members

1211, 1212 and 1213 hinged end to end in sequence, so that two adjacent connecting rods 121 form a hexagonal structure, and the hexagonal configuration is not required, and may be an equilateral hexagon, an equiangular hexagon or a regular hexagon. Besides, two adjacent connecting rods 121 may also form other polygonal structures, such as symmetrical octagons, dodecagons, etc.

As shown in fig. 10a to 10c, when viewed along the direction of the axis of the capturing structure 11, i.e. on the projection plane perpendicular to the axis of the capturing structure 11, the projections of the plurality of links 121 of the supporting frame 12 are radially distributed in the center, and the projection of each link 121 is arc-shaped. In contrast, the link 121 projected in an arc shape can reduce the risk of scratching the blood vessel wall, and has better safety.

It is further preferable that a developing structure (not labeled, see fig. 9e) made of a developing material is further disposed on the outer surface of the support frame 12 for indicating the state of the support frame 12 being spread. In this embodiment, the developing structure is specifically a developing section, and a developing section may be disposed on a portion of the connecting rod 121, so that a doctor can conveniently determine the opening state of the support frame 12 according to the position of the developing section. Preferably, the development section is disposed on the support frame 12 at a location having a maximum diameter, or alternatively, the development section is disposed on the support frame 12 adjacent to the maximum diameter. In this embodiment, all of the developing materials may be one or a combination of more of tungsten, barium, and bismuth.

Further, each of said links 121 is angled with respect to the axis of the capturing structure 11. Specifically, as shown in fig. 11, when the supporting frame 12 is in a free state, the extending direction of the connecting rod 121 and the axis of the capturing structure 11 form a first included angle α, and the first included angle α may be selected between 10 ° and 40 °. In addition, as shown in fig. 12, in the fully unfolded state, the extending direction of the connecting rod 121 and the axis of the capturing structure 11 have a second included angle β, and the second included angle β may be selected between 40 ° and 70 °.

Finally, it should be appreciated that the foregoing discloses features of preferred embodiments of the invention so that those skilled in the art may better understand the invention. Those skilled in the art will appreciate that the present invention is susceptible to considerable modification based on the disclosure herein, to achieve the same objects and/or achieve the same advantages as the disclosed embodiments of the present invention. Those skilled in the art should also realize that such similar constructions do not depart from the scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the scope of the present disclosure.

In addition, aiming at the technical scheme provided by the embodiment of the invention, the bracket, the thrombus removal device and the thrombus removal system have the following advantages.

The stent comprises a plurality of capturing structures which are connected end to end in sequence, and the arrangement can reduce the diameters of the stent and the thrombus taking device, so that the stent and the thrombus taking device can be used in a thinner blood vessel, thereby improving the adaptability of the stent and the thrombus taking device and improving the effect of disease treatment.

The thrombus taking device can control the diameter of each capturing structure through the traction body, and each capturing structure can better conform to the change of the diameter of a blood vessel, so that the thrombus taking device can better conform to a tortuous blood vessel or a bent blood vessel and realize good adherence, thereby improving the success rate of thrombus capturing and improving the thrombus taking effect. Meanwhile, the stent reduces the risk of thrombus escape in thrombus extraction operation, particularly intracranial thrombus extraction operation, through a plurality of capturing layers, further improves the success rate of thrombus capturing, and improves the thrombus extraction effect.

Not only the support frame is constructed by the connecting rod, and the support frame is further constructed, so that the structures of the support frame and the corresponding support frame are simplified, and the volumes of the support frame and the support frame are reduced. Particularly, in the axial direction perpendicular to the capturing structure, the projection of each connecting rod is arc-shaped, so that the risk of scratching the blood vessel wall is reduced, and the safety of the thrombus removal operation is improved. Particularly, the linear bodies are arranged on the support frames, the maximum diameter of the support frames during opening can be restrained, the problem that the support frames are overturned during opening is avoided, and the reliability of the support and the plug taking device is improved.

It will also be appreciated that the thrombectomy device of the present invention is particularly useful for performing thrombectomy procedures in small vessels, particularly intracranial vessels.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the present invention.

Claims

1. A stent is characterized by comprising a plurality of capture structures which are connected end to end in sequence; each of the capture structures comprises a scaffold and a capture layer; the scaffold comprises a proximal portion and a distal portion arranged from the proximal to the distal, the capture layer surrounding the scaffold and covering a surface of the distal portion.

2. The stent of claim 1, wherein each of the support struts comprises a plurality of links that are foldable and extend from a proximal end to a distal end, the plurality of links being arranged about an axis of the corresponding capture structure.

3. The stent of claim 2, wherein a projection of the plurality of links is radially distributed from a center in a direction perpendicular to an axis of the capturing structure.

4. A support according to claim 3, wherein the projection of each link in a direction perpendicular to the axis of the capture structure is linear or arcuate.

5. A support according to claim 2, wherein each link is formed by at least two bars hinged together, or wherein each link has at least one notch to allow elastic deformation.

6. The stent of claim 2, wherein each of the struts has a free state and a fully deployed state;

7. The stent of claim 1, wherein each of the capturing structures further comprises a wire-like body connected to the scaffold for limiting a maximum diameter of the scaffold when expanded outwardly.

8. The carrier in accordance with claim 7, wherein each of said support brackets comprises a plurality of circumferentially arranged links, each link having at least one deformable node disposed thereon; each capturing structure comprises a plurality of linear bodies which are sequentially connected with the nodes of the connecting rods of the supporting frame;

9. The stent of claim 1, wherein the capture layer comprises a woven mesh, a semi-permeable membrane, or a membrane with holes.

10. A thrombectomy device, comprising the stent of any one of claims 1-9, further comprising a hollow connecting rod and a traction body; the hollow connecting rod is connected with the head and the tail of the two adjacent capturing structures; the traction body can movably penetrate through each hollow connecting rod and is connected with the far end of the thrombus taking device; the traction body is configured to move in tension towards a proximal end of the embolectomy device relative to the hollow connecting rod to generate an axial force on the embolectomy device to outwardly expand the scaffolding of each of the capture structures.

11. The embolectomy device of claim 10, wherein each of the capturing structures further comprises a visualization structure made of a visualization material, the visualization structure being disposed on an outer surface of the support frame.

12. The embolectomy device of claim 11, wherein the visualization structure is disposed on the scaffold at a location having a maximum diameter.

13. The embolectomy device of claim 10, further comprising a proximal visualization structure and a distal visualization structure made of a visualization material, the proximal visualization structure being disposed at a proximal end of the embolectomy device and the distal visualization structure being disposed at a distal end of the embolectomy device.

14. An embolectomy system comprising a delivery device and an embolectomy device as defined in any of claims 10-13;