阅读说明：本技术 取栓支架及取栓系统 (Thrombectomy support and thrombectomy system ) 是由 王永胜 于鹏 高国庆 程舒宇 于 2020-05-30 设计创作，主要内容包括：本发明公开了一种取栓支架和取栓系统。该取栓支架包括支架本体,所述支架本体包括第一支架本体和设置在所述第一支架本体的远端的第二支架本体,所述第二支架本体包括大管径段、小管径段和过渡段,所述大管径段和所述小管径段交替相接,且所述大管径段和所述小管径段通过所述过渡段连接,所述取栓支架具有半自由状态和自由状态,在所述半自由状态下,所述第二支架本体的至少部分结构呈近似单层管状结构；在所述自由状态下,所述第二支架本体呈近似双层管状结构,从而取栓支架在所述半自由状态时可建立血流通道,以在血栓清除前就恢复阻塞血管的血液流动,提高取栓手术的安全性。(The invention discloses a thrombus taking support and a thrombus taking system. The embolectomy stent comprises a stent body, wherein the stent body comprises a first stent body and a second stent body arranged at the distal end of the first stent body, the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected through the transition section, the embolectomy stent has a semi-free state and a free state, and at least part of the structure of the second stent body is of an approximate single-layer tubular structure in the semi-free state; in the free state, the second stent body is of an approximate double-layer tubular structure, so that a blood flow channel can be established when the thrombus removal stent is in the semi-free state, the blood flow blocking the blood vessel is recovered before thrombus is removed, and the safety of a thrombus removal operation is improved.)

1. An embolectomy stent, comprising a stent body, wherein the stent body comprises a first stent body and a second stent body arranged at the distal end of the first stent body, the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected through the transition section, the embolectomy stent has a semi-free state and a free state, and at least part of the structure of the second stent body is of an approximately single-layer tubular structure in the semi-free state; in the free state, the second stent body is of an approximately double-layer tubular structure.

2. The embolectomy stent of claim 1, wherein in the free state, an orthographic projection of the large diameter segment in a first projection plane partially overlaps an orthographic projection of the small diameter segment in the first projection plane; in the semi-free state, an orthographic projection of the large-diameter section on the first projection plane does not overlap with an orthographic projection of the small-diameter section on the first projection plane; the first projection plane is a plane parallel to the central axis of the bolt taking support.

3. The embolectomy stent of claim 1 wherein the single-layered tubular structure is a continuous tubular structure formed by the co-encircling of a large-diameter section and a small-diameter section such that the single-layered tubular structure has a continuous lumen.

4. The embolectomy stent of claim 1 wherein the outer diameter of the large-diameter section of the single-layer tubular structure is less than the smallest outer diameter of the large-diameter section of the double-layer tubular structure.

5. The embolectomy stent of claim 1, wherein the large diameter section is configured as a constant diameter tubular structure having a diameter equal to the diameter of the small diameter section in the semi-free state; in the free state, the diameter of the constant diameter tubular structure is greater than the diameter of the small diameter section.

6. The embolectomy stent of claim 1, wherein the large-diameter section is configured as a reducing tubular structure in the shape of an olive-like bidirectional conical frustum large in the middle and small at both ends, and in the semi-free state, the diameter of the middle area of at least part of the large-diameter section is equal to the diameter of the small-diameter section; in the free state, the diameter of the middle region of the large-diameter section is larger than the diameter of the small-diameter section.

7. The embolectomy stent of claim 6 wherein the ratio of the maximum diameter to the minimum diameter of the large diameter section is 1.5:1 to 3: 1.

8. The embolectomy stent of claim 1 wherein the large diameter section is surrounded by a plurality of first closed loop elements, the small diameter section is surrounded by a plurality of second closed loop elements, and the transition section is surrounded by a plurality of support rods.

9. The embolectomy stent of claim 8 wherein the plurality of support struts comprises a plurality of first support struts and a plurality of second support struts, the plurality of first support struts and the plurality of second support struts each being circumferentially spaced along a second stent body, the plurality of first support struts being disposed at a proximal end of the small-diameter section and the plurality of second support struts being spaced at a distal end of the small-diameter section.

10. The embolectomy support of claim 9 wherein the first closed loop element and the second closed loop element each comprise a proximal connection point and a middle connection point, the distal end of the first strut connects to the proximal connection point of the second closed loop element, the proximal end of the first strut connects to the middle connection point of the first closed loop element; the far end of the second support rod is connected with the near end connecting point of the first closed-loop unit, and the near end of the second support rod is connected with the middle connecting point of the second closed-loop unit.

11. The embolectomy support of claim 10 wherein the first closed loop element and the second closed loop element each include a free end point directly opposite the proximal connection point, and wherein during the transition from the free state to the semi-free state, the radial distance between the free end point of the first closed loop element and the proximal connection point of the second closed loop element distally adjacent thereto gradually decreases, and the radial distance between the proximal connection point of the first closed loop element and the free end of the second closed loop element proximally adjacent thereto also gradually decreases.

12. The embolectomy stent of claim 11 wherein the free end points of the first closed-loop elements and the proximal end connection points of the second closed-loop elements adjacent to their distal ends are sequentially and alternately arranged in the circumferential direction of the second stent body to form a first annular array, and the proximal end connection points of the first closed-loop elements and the free end points of the second closed-loop elements adjacent to their proximal ends are sequentially and alternately arranged in the circumferential direction of the second stent body to form a second annular array; in the semi-free state, the proximal connection points and the free end points in the first and second annular arrays are each coplanar; in the free state, the proximal connection points and the free end points in the first and second annular arrays are not coplanar.

13. The embolectomy support of claim 9, wherein the support body is in the semi-free state, the plurality of first support rods and the plurality of second support rods each have a straight rod-like configuration; the support body is in during free state, a plurality of first bracing pieces with a plurality of second bracing pieces all are crooked column structure, and relative the inside bend of second support body or outside bend.

14. The embolectomy stent of claim 8 wherein the area of the first closed loop element is larger than the area of the second closed loop element, the shape of the first closed loop element and the second closed loop element comprising one or more of a circle, an ellipse, a triangle, a diamond, a trapezoid, and a hexagon.

15. The embolectomy stent of claim 9 wherein the distal end of the first closed loop element forms a first capture element and the distal end of the second closed loop element forms a second capture element, the first capture element alternating with and connected to the first support bar and the second capture element alternating with and connected to the second support bar.

16. The embolectomy stent of claim 15 wherein the distal end of the second stent body is fully open to form a first open end, the proximal portion of the first stent body is open to form a second open end, and an orthographic projection of the first open end on a second projection plane overlaps with an orthographic projection of the second open end on the second projection plane; the second projection plane is a plane perpendicular to the central axis of the embolectomy support.

17. The embolectomy support of claim 16, wherein the embolectomy support further comprises a third support body and a protective umbrella, the third support body is connected between the second support body and the protective umbrella, a third open end is formed at the proximal end of the third support body, a fourth open end is formed at the distal end of the third support body, an umbrella open end is formed at the proximal end of the protective umbrella, a first closed end directly opposite to the umbrella open end is formed at the distal end of the protective umbrella, and the first open end is communicated with the third open end, the fourth open end and the umbrella open end, so that a continuous channel is formed inside the embolectomy support.

18. The embolectomy stent of claim 17 wherein the third stent body comprises a capturing section and an extension section connecting between the capturing section and the umbrella, the proximal end of the capturing section being connected to the small diameter section of the second stent body by the plurality of second support struts, and the distal end of the capturing section being connected to the proximal end of the extension section.

19. The embolectomy stent of claim 18 wherein the capturing section comprises at least one capturing portion and a plurality of reinforcing portions, the at least one capturing portion and the plurality of reinforcing portions being connected side-by-side in a circumferential direction of the third stent body, and wherein the capturing portion has a different profile than the reinforcing portions.

20. The embolectomy support of claim 19 wherein the extension segment comprises a plurality of first mesh openings connected to one another; each capturing part comprises a second net opening, each reinforcing part comprises a third net opening and a skeleton rod arranged at the near end of the third net opening, or each reinforcing part comprises a plurality of third net openings which are connected in parallel along the direction of a central axis parallel to the support body, wherein the area of the second net opening is larger than the areas of the first net opening, the first closed-loop unit and the second closed-loop unit, and the area of the third net opening is equal to the area of the first net opening and the area of the first closed-loop unit.

21. The embolectomy support of claim 20 wherein the proximal end of each second mesh opening is formed with a third capture unit, the proximal end of the third capture unit is connected to the distal ends of the second support rods, the distal ends of the third capture units are configured as free ends, and the third capture unit is disposed between two adjacent second support rods.

22. The embolectomy stent of claim 21, wherein the first, second and third capture units each extend outwardly or inwardly relative to the stent body and form corresponding first, second and third receiving spaces with the stent body.

23. The embolectomy support of claim 16, further comprising a protective umbrella attached to the distal end of the second support body, the proximal end of the protective umbrella forming an umbrella port end, the distal end of the protective umbrella forming a first closed end directly opposite the umbrella port end, the umbrella port end communicating with the first open end such that the interior of the embolectomy support forms a continuous passageway.

24. The embolectomy support of any of claims 17 or 23 wherein the periphery of the first open end or the fourth open end is provided with a mounting structure and the periphery of the flared end is provided with a connecting structure which is in mating connection with the mounting structure.

25. The embolectomy support of claim 24, further comprising a connector by which the mounting structure is connected to the connecting structure to connect the flared end with the first open end or the fourth open end.

26. The embolectomy support of claim 25, wherein the connector is configured as a connector ring, the mounting structure is defined by a plurality of connector tabs having connector holes, the connector structure is defined by a plurality of connector tabs, and the connector ring passes through the connector holes of each of the connector tabs and the plurality of connector tabs to connect the umbrella to the support body.

27. The embolectomy support of claim 25 wherein the mounting structure is defined by a plurality of fixation rods, the connecting structure is defined by a plurality of connecting rods, each connecting rod is adjacent to a corresponding fixation rod, and the connecting members are configured as connecting wires that wrap around the adjacent fixation rods and connecting rods to connect the umbrella to the support body.

28. The embolectomy support of claim 1, further comprising a third support body disposed at the distal end of the second support body, the third support body being in smooth transition with the second support body, the proximal end of the third support body defining a third open end, and the distal end of the third support body defining a second closed end directly opposite the third open end.

29. An embolectomy system, comprising a pusher rod, a microcatheter, and an embolectomy support according to any of claims 1-28, wherein the embolectomy support comprises a support body, the pusher rod is connected to the proximal end of the support body, the pusher rod and the support body are press-gripped to be guided into the microcatheter, the support body can move inside and outside the microcatheter by pushing and pulling the pusher rod, and when the pusher rod moves in a direction close to the proximal end, the support body is retracted into the microcatheter; when the pushing rod moves towards the direction far away from the proximal end of the pushing rod, the stent body is pushed out of the micro-catheter.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a thrombus taking support and a thrombus taking system.

Background

Thrombi are small patches of blood flow that form on the surface of a denuded or repaired site within a blood vessel of the cardiovascular system. The thrombus formation is distributed throughout the cardiovascular system, spreads to tissues and organs of the whole body, is not limited to the pathological changes of myocardial infarction, deep venous thrombosis or cerebrovascular thrombosis and the like, and can occur in blood vessels of any part in the body. Intracranial thrombosis is a special clinical type in cerebrovascular diseases, is easy to cause cerebral embolism, has the characteristics of high morbidity, high disability rate, high mortality and high recurrence rate, and is a main disease causing death and disability of the middle-aged and the elderly.

The recanalization of blood vessels is the key to the treatment of acute ischemic stroke. Currently, conventional methods for treating ischemic stroke include two main categories: dissolving thrombus with medicine or mechanically taking out thrombus.

The drug thrombolysis is that the catheter injects the thrombolysis agent into the focus accessory in the blood vessel pointed by pathological changes, and the local part of the focus forms very high thrombolysis agent concentration instantly, thereby accelerating the thrombolysis speed and further increasing the chance of recanalization of the blood vessel. According to the research results of national institute of neurological diseases and stroke, venous thrombolysis should be performed within 3 hours of onset and arterial thrombolysis should be performed within 6 hours, so that drug thrombolysis treatment is only applicable to small-sized thrombi. When the volume of the thrombus is too large, a very large dose is required to dissolve the large blood clot, and various complications are easily caused with high risk.

In order to solve the problem of drug thrombolysis, the thrombus is eliminated by adopting a mechanical mode. The mechanical embolectomy comprises the following steps: thrombectomy, laser thrombus breaking, thrombus taking by a catcher and thrombus taking by a thrombus catching net. Thrombectomy is thorough in thrombus removal, but has excessive damage to blood vessel walls, and is very easy to cause various complicated inflammations. The operation difficulty of laser thrombus breaking is high, the laser energy is ineffective when the laser energy is too low, the blood vessel is damaged when the laser energy is too high, and various complications are easy to cause. The operation of taking the thrombus by the catcher is simple, the injury to the blood vessel wall is small, but the blood clot can not be sleeved frequently. The operation of taking thrombus by the thrombus-capturing net is simple, but the thrombus-capturing net cannot be used in intracranial blood vessels because of large volume.

In summary, the conventional mechanical thrombus removal method needs to remove the thrombus before the normal blood flow of the blood vessel can be restored. However, for "stroke" patients, there is often a need to quickly restore normal blood flow to prevent exacerbations. Therefore, most of the existing mechanical thrombus removal methods fail to restore the blood flow blocking the blood vessel before the thrombus is removed, thereby increasing the risk of thrombus removal.

Disclosure of Invention

In view of the above, the present invention is directed to a bolt fetching bracket and a bolt fetching system to solve the above technical problems.

In a first aspect, the embodiment of the invention provides a thrombus removal stent, which comprises a stent body, wherein the stent body comprises a first stent body and a second stent body arranged at the distal end of the first stent body, the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected through the transition section, the thrombus removal stent has a semi-free state and a free state, and at least part of the structure of the second stent body is in an approximately single-layer tubular structure in the semi-free state; in the free state, the second stent body is of an approximately double-layer tubular structure.

In a second aspect, an embodiment of the present invention provides a thrombus removal system, including a push rod, a microcatheter, and the thrombus removal holder, where the thrombus removal holder includes a holder body and a protective umbrella disposed at a distal end of the holder body, the push rod is connected to a proximal end of the holder body, the push rod, the holder body, and the protective umbrella are pressed and guided into the microcatheter, the holder body and the protective umbrella can move inside and outside the microcatheter by pushing and pulling the push rod, and when the push rod moves in a direction close to the proximal end of the push rod, the holder body and the protective umbrella are retracted into the microcatheter; when the push rod moves towards the direction far away from the near end of the push rod, the bracket body and the protective umbrella are pushed out of the micro-catheter.

Compared with the prior art, the invention discloses a thrombus removal support and a thrombus removal system. The embolectomy stent comprises a stent body, wherein the stent body comprises a first stent body and a second stent body arranged at the distal end of the first stent body, the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected through the transition section, the embolectomy stent has a semi-free state and a free state, and at least part of the structure of the second stent body is of an approximately single-layer tubular structure in the semi-free state; in the free state, the second stent body is of an approximate double-layer tubular structure, so that a blood flow channel can be established when the thrombus removal stent is in the semi-free state, the blood flow blocking the blood vessel is recovered before thrombus is removed, and the safety of a thrombus removal operation is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a structural schematic view of the thrombectomy support provided by the first embodiment of the invention in the free state.

Fig. 2 is an enlarged view of a part of the structure of the embolectomy stent in fig. 1.

Fig. 3 is a schematic view of the thrombectomy stent of fig. 1 in use in a blood vessel.

Fig. 4 is a cross-sectional view of the embolectomy stent of fig. 3 taken in the direction IV-IV.

Fig. 5 is a schematic structural view of the thrombectomy stent in fig. 1 in the semi-free state.

Fig. 6 is a schematic structural view of a thrombectomy support according to a second embodiment of the present invention.

Fig. 7 is a structural schematic diagram of a part of the structure of the embolectomy stent in fig. 6.

Fig. 8 is a schematic view of another angle of the thrombectomy stent of fig. 6.

Fig. 9 is a schematic structural view of a thrombectomy support according to a third embodiment of the present invention.

Fig. 10 is a schematic view of another angle of the thrombectomy stent of fig. 8.

Fig. 11 is a schematic structural view of a thrombectomy support according to a fourth embodiment of the present invention.

Fig. 12 is a schematic structural view of a thrombectomy support according to a fifth embodiment of the present invention.

Fig. 13 is a schematic structural view of a thrombectomy support according to a sixth embodiment of the present invention.

FIG. 14 is a schematic view of the stent body of the thrombectomy stent of FIG. 13.

Fig. 15 is a schematic view of the structure of the protective umbrella of the thrombectomy holder of fig. 13.

Fig. 16 is a schematic view of the structure of the net body of the umbrella of the thrombectomy holder of fig. 15.

Fig. 17 is a bottom view of the net body of the umbrella of the thrombectomy holder of fig. 16.

Fig. 18 is a schematic structural diagram of a thrombus removal system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the field of interventional medicine, the end of the instrument relatively close to the operator is generally referred to as the proximal end, and the end of the instrument relatively far from the operator is generally referred to as the distal end. In particular, distal end refers to the end of the instrument that is freely insertable into the animal or human body. Proximal end refers to the end that is intended for operation by a user or machine or for connection to other devices.

It is to be understood that the terminology used in the description and claims of the present invention, and the appended drawings are for the purpose of describing particular embodiments only, and are not intended to be limiting of the invention. The terms "first," "second," "third," "fourth," and the like in the description and in the claims, and in the above-described drawings, are used for distinguishing between different objects and not for describing a particular order. The singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "comprises" and any variations thereof is intended to cover non-exclusive inclusions. Furthermore, the present invention may be embodied in many different forms and is not limited to the embodiments described in the present embodiment. The following detailed description is provided for the purpose of providing a more thorough understanding of the present disclosure, and the terms used to indicate orientation, top, bottom, left, right, etc. are merely used to describe the illustrated structure as it may be positioned in the corresponding figures. The term "axial" refers to the direction in which the thrombectomy stent of the present invention is advanced, i.e., the longitudinal axis of the thrombectomy stent, also coincides with the longitudinal axis of the blood vessel. The term "close" does not mean that a certain element structure is a completely sealed object, and the structure of the element structure only indicates one characteristic of the element structure, namely, the mesh body can form a containing space for containing thrombus, and the thrombus is not easy to escape from the sealing structure of the mesh body.

The description which follows is a preferred embodiment of the present invention, however, the foregoing description is given for the purpose of illustrating the general principles of the invention and is not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims.

Referring to fig. 1, 3 and 4, fig. 1 is a schematic structural view of a thrombectomy support 100 according to a first embodiment of the present invention; FIG. 3 is a schematic view of the use of the thrombectomy stent 100 in a blood vessel 200; FIG. 4 shows a cross-sectional view of the embolectomy stent 100 of FIG. 3 taken along the direction IV-IV. The thrombectomy stent 100 includes a stent body 101. The stent body 101 includes a first stent body 10 and a second stent body 30 disposed at a distal end of the first stent body 10. The second stent body 30 includes a large-diameter section 31, a small-diameter section 33, and a transition section 35. The large-diameter sections 31 and the small-diameter sections 33 are alternately connected, and the large-diameter sections 31 and the small-diameter sections 33 are connected by transition sections 35. The thrombectomy stent 100 has a semi-free state in which at least a part of the structure of the second stent body 30 has a single-layered tubular structure, and a free state in which the second stent body 30 has a double-layered tubular structure.

Thus, in the semi-free state, at least part of the structure of the stent body 101 is of an approximate single-layer tubular structure, and the grid space on the single-layer tubular structure is small, so that the problem of blocking of the inner cavity caused by the fact that thrombus completely enters the inner cavity of the thrombus removal stent 100 can be avoided, and the single-layer tubular structure can be used as a blood flow channel. In addition, when the thrombectomy stent 100 is in the semi-free state, the single-layer tubular structure ensures the radial supporting force of the whole thrombectomy stent 100, so that the thrombectomy stent 100 can quickly establish a blood flow channel to restore the blood flow blocking the blood vessels before thrombus is cleared, and the function of pre-communicating the blood flow channel is realized at the early stage of thrombectomy to improve the safety of the thrombectomy. In the free state, the stent body 101 is of an approximately double-layer tubular structure, the large-diameter section 31 has a larger grid structure, and a certain space is formed between the large-diameter section 31 and the small-diameter section 33, so that thrombus is allowed to completely enter the inner cavity of the thrombus removal stent 100, and the thrombus removal efficiency is improved. Further, the thrombus removal support 100 adopts a sectional type design, namely, the large-diameter section 31 and the small-diameter section 33 are sequentially spaced and uniformly arranged, so that the flexibility of the thrombus removal device can be improved, the thrombus removal support 100 can be ensured to adapt to blood vessels with different bending forms, and meanwhile, the anchoring effect on thrombus blocks can be enhanced, for example, when the thrombus removal support 100 is extruded in the blood vessel, the thrombus removal support 100 can be greatly deformed.

It should be noted that, in this embodiment, the semi-free state (i.e., the partially released state) refers to an operating state in which at least a part of the structure of the thrombectomy stent 100 is not fully expanded, for example, an operating state in which the stent body 101 is pressed by thrombus at an early stage of implantation of the thrombectomy stent 100 into a blood vessel; or the working state that the bracket body 101 of the thrombectomy bracket 100 is restrained by other restraining elements. The free state (i.e., fully released state) refers to the stent body 101 of the embolectomy stent 100 being in a fully expanded working state or in a working state that is fully free (i.e., not constrained by other constraining elements). In some embodiments, as shown in fig. 3, in the semi-free state, a portion of the structure of the stent body 101 is compressed by the thrombus or constrained by the constraining element. In other embodiments, as shown in fig. 5, in the semi-free state, the entire structure of the stent body 101 is constrained by thrombus compression or by a constraining element.

As shown in fig. 1, in the present embodiment, in the free state, an orthographic projection of the large-diameter section 31 on the first projection plane partially overlaps with an orthographic projection of the small-diameter section 33 on the first projection plane. So, guarantee the intravascular radial holding power of thrombectomy support 100 at different diameters to effectively prevent thrombectomy support 100 from taking place to sink when passing through blood vessel completely, and then improved thrombus and caught efficiency, and reduced the damage that thrombectomy support 100 led to the fact the vascular wall at the thrombectomy in-process. As shown in fig. 3, in the semi-free state, an orthographic projection of the large-diameter section 31 on the first projection plane does not overlap with an orthographic projection of the small-diameter section 33 on the first projection plane. The first projection plane is a plane parallel to the central axis L of the thrombectomy support 100. Thus, the embolectomy stent 100 is in a partial release state, the whole structure or partial structure of the stent body 101 is a single-layer tubular structure with an approximate closed-loop structure, so that thrombus is reduced from entering the inside of the single-layer tubular structure, the embolectomy stent is provided with a cavity for blood flow to flow in the partial release state, and the safety of embolectomy is improved.

As shown in fig. 2 and 3, the second stent body 30 may include both a first portion in the semi-free state and a second portion in the free state, the first portion of the second stent body 30 being temporarily in the semi-free state due to being pressed by the thrombus. Wherein the first part is of a single-layer tubular structure, and the second part is of a double-layer tubular structure. The metal coverage rate of the outer peripheral surface of the single-layer tubular structure is greater than that of the outer peripheral surface of the double-layer tubular structure. The metal coverage is an area ratio of the metal constituting the second stent body 30 to the outer peripheral surface of the second stent body 30. In the first part in the semi-free state, the large pipe diameter section 31 is not completely opened, the diameter of the large pipe diameter section 31 is close to the diameter of the small pipe diameter section 33, the free end point 3113 of the large pipe diameter section 31 is close to the proximal end connection point 3311 of the small pipe diameter section 33, and the proximal end connection point 3111 of the large pipe diameter section 31 is close to the free end point 3313 of the small pipe diameter section 33, so that the cross section of the first part of the stent body 101 is in an approximately closed-loop structure 1011 (refer to fig. 4), namely the cross section of the single-layer tubular structure is in an approximately closed-loop structure 1011, therefore, a cavity for blood flow can be kept inside or on one side of thrombus, blood flow is opened before thrombus removal, and brain or other tissues are prevented from being damaged due to unsmooth blood flow for a long time.

Referring to fig. 3 and 4 together, a blood vessel 200 includes a vessel wall 201, a blood vessel lumen 202, and a thrombus 203 occluding the blood vessel lumen 202. When the thrombectomy stent 100 is released to the blood vessel 200 with the thrombus 203, the structure of the thrombectomy stent 100 not compressed by the thrombus 203 can be rapidly expanded to be in a completely released state, and the structure of the thrombectomy stent 100 compressed by the thrombus 203 can not be expanded to be in a partially released state. Specifically, the proximal and distal ends of the thrombectomy stent 100 are not compressed by the thrombus 203, and thus the proximal and distal ends of the thrombectomy stent 100 are brought into a fully released state. In the fully released state, the proximal and distal ends of the stent body 101 conform to the vessel wall 201. At this time, the mesh of the stent body 101 is larger, and the proximal end and the distal end of the embolectomy stent 100 are communicated with the blood vessel cavity 202. The middle portion of the thrombectomy stent 100 is pressed by the thrombus 203, so that the middle portion of the thrombectomy stent 100 cannot be completely deployed and is in a partially released state. In the partially released state, there is a gap between the middle of the stent body 101 and the vessel wall 201 of the vessel 200. At this time, the mesh of the stent body 101 is small, the middle part of the stent body 101 can form a continuous single-layer tubular structure with an approximate closed-loop structure, and the inner cavity 1012 of the single-layer tubular structure is communicated with the blood vessel cavity 202, i.e. the thrombus removal stent 100 quickly establishes a blood flow channel, thereby realizing the function of pre-communicating the blood flow channel, and improving the safety of thrombus removal operation. When the middle portion of the stent body 101 is expanded to enter the completely released state, the middle portion of the thrombectomy stent 100 is expanded in the thrombus until the middle portion of the thrombectomy stent 100 comes into contact with the blood vessel wall 201, so that the thrombus 203 is inserted into the stent body 101, and the thrombectomy stent 100 is withdrawn to remove the thrombus 203 from the blood vessel 200.

Referring again to fig. 1, 3 and 4, in the present embodiment, the single-layer tubular structure is a continuous tubular structure formed by the large-diameter section 31 and the small-diameter section 33 enclosing together, so that the single-layer tubular structure has a continuous inner cavity 1012, wherein the maximum diameter of the large-diameter section 31 is approximately equal to the maximum diameter of the small-diameter section 33, thereby realizing the pre-communicating function of the blood flow channel during the early stage of thrombus removal. The double-walled tubular structure comprises a discontinuous inner tubular structure of small diameter sections 33 and a discontinuous outer tubular structure of large diameter sections 31, wherein the maximum diameter of the large diameter sections 31 is greater than the maximum diameter of the small diameter sections 33.

Wherein the outer diameter of the large-diameter section 31 of the single-layer tubular structure is smaller than the minimum outer diameter of the large-diameter section 31 of the double-layer tubular structure. The outer diameter of the large diameter section 31 of the single-layer tubular structure is approximately equal to the outer diameter of the small diameter section 33 of the single-layer tubular structure. The small-diameter section 33 of the single-layer tubular structure has an outer diameter smaller than that of the small-diameter section 33 of the double-layer tubular structure, i.e., the outer diameter of the single-layer tubular structure is smaller than that of the inner tubular structure of the double-layer tubular structure. The large-diameter section 31, the small-diameter section 33, and the transition section 35 are coaxially arranged. In some embodiments, the large diameter section 31, the small diameter section 33, and the transition section 35 are integrally formed to improve stability and reliability of the second stent body 30. In other embodiments, the large-diameter section 31, the small-diameter section 33, and the transition section 35 may be fixedly connected together by crimping, heat fusing, bonding, welding, or riveting, which are well-known in the art.

In some embodiments, the proximal end and the distal end of the second stent body 30 are configured as large-diameter sections 31, the small-diameter sections 33 are disposed between two adjacent large-diameter sections 31, and the large-diameter sections 31 are sleeved outside the transition section 35. In other embodiments, the proximal end of the second stent body 30 is configured as a large-diameter section 31 and the distal end of the second stent body 30 is configured as a small-diameter section 33. In the present embodiment, the second stent body 30 includes 4 large-diameter sections 31 and 3 small-diameter sections 33. Wherein 2 large diameter sections 31 are located at the proximal and distal ends of the second stent body 30, respectively, and wherein the other 2 large diameter sections 31 are located at the middle of the second stent body 30. The small-diameter section 33 is located between two adjacent large-diameter sections 31. Thus, the structural design of the large-diameter section 31, the small-diameter section 33 and the transition section 35 can improve the flexibility of the thrombus removal stent 100, and can enhance the anchoring effect on thrombus. Further, the thrombus removal support 100 has certain radial and axial supporting force, so that the thrombus removal support 100 is effectively prevented from collapsing when completely passing through a blood vessel, the thrombus capture efficiency is improved, and the damage to the blood vessel wall caused by the thrombus removal support 100 is reduced in the thrombus removal process. In addition, when receiving the extrusion in the blood vessel, the thrombectomy support 100 can make great deformation to adaptable different crooked form and the blood vessel of different diameters, and can guarantee the laminating nature of support body 101 and vascular wall, with further improvement thrombectomy efficiency. Therefore, the conventional stent for embolectomy is required to have a large radial dimension inside the catheter and cannot pass through a tortuous intracranial blood vessel, whereas the stent for embolectomy 100 of the present application is required to have a small radial dimension inside the catheter and is suitable for a smaller blood vessel such as an intracranial blood vessel.

It should be noted that the number of the large-diameter sections 31 and the small-diameter sections 33 can be set according to actual requirements, and the present invention is not limited thereto.

In some embodiments, the large-diameter section 31 is configured as a constant-diameter tubular structure, and in the semi-free state, the diameter of the large-diameter section 31 is approximately equal to the diameter of the small-diameter section 33; in the free state, the diameter of the large-diameter section 31 is larger than the diameter of the small-diameter section 33. So, conveniently get integral type laser cutting shaping of embolus support 100, and increased the accommodating space between big footpath section 31 and the little footpath section 33 to the thrombus gets into the passageway 1010 of the inside of getting embolus support 100 easily, and avoids the cutting to the thrombus, and then has improved the efficiency of catching to the thrombus.

In other embodiments, the large-diameter section 31 is configured as a reducing tubular structure, the reducing tubular structure is an olive-like bidirectional conical frustum with a large middle and small two ends, and in the semi-free state, the diameter of the middle area of at least part of the large-diameter section 31 is approximately equal to the diameter of the small-diameter section 33; in the free state, the diameter of the middle region of the large-diameter section 31 is larger than the diameter of the small-diameter section 33. Therefore, the flexibility of the thrombus removal stent 100 in sliding in the blood vessel is further improved, so that the injury of the thrombus removal stent 100 to the blood vessel wall can be reduced in the thrombus removal process. Wherein, in order to take account of the flexibility of the thrombectomy stent 100, the capturing efficiency of the thrombectomy stent 100 and the radial and axial supporting force of the thrombectomy stent 100, the ratio of the maximum diameter to the minimum diameter of the large-diameter section 31 is 1.5:1 to 3: 1.

Referring to fig. 1 and 2, fig. 2 is an enlarged view of a portion of the bolt-removing holder 100. In the present embodiment, the large-diameter section 31 is surrounded by a plurality of first closed-loop units 311. The small-diameter section 33 is surrounded by a plurality of second closed-loop units 331. The transition section 35 is surrounded by a plurality of support rods 350.

Specifically, the plurality of support bars 350 includes a plurality of first support bars 351 and a plurality of second support bars 352. The plurality of first support bars 351 and the plurality of second support bars 352 are each provided at intervals along the circumferential direction of the second stent body 30. A plurality of first support bars 351 are disposed at the proximal end of the small diameter section 33 and a plurality of second support bars 352 are spaced at the distal end of the small diameter section 33.

The first closed-loop element 311 includes a proximal connection point 3111, a middle connection point 3112 and a free end point 3113, and the second closed-loop element 331 includes a proximal connection point 3311, a middle connection point 3312 and a free end point 3313. The distal end of the first support rod 351 is connected to the proximal connection point 3311 of the second closed-loop element 331, and the proximal end of the first support rod 351 is connected to the middle connection point 3112 of the first closed-loop element 311; the distal end of the second support bar 352 is connected to the proximal connection point 3111 of the first closed-loop element 311, and the proximal end of the second support bar 352 is connected to the middle connection point 3312 of the second closed-loop element 331. The free end 3113 of the first closed-loop element 311 is directly opposite the proximal connection 3111, and the free end 3313 of the second closed-loop element 331 is directly opposite the proximal connection 3311. The free end points 3113, 3313 can be embedded into the thrombus, improving the capture rate of the thrombus.

In the process of switching from the semi-free state to the free state, a radial distance between the free end point 3113 of the first closed-loop element 311 and a proximal end connection point 3311 of the second closed-loop element 331 which is opposite to the distal end of the first closed-loop element 311 and adjacent to the first closed-loop element 311 gradually increases, and a radial distance between the proximal end connection point 3111 of the first closed-loop element 311 and the free end point 3313 of the second closed-loop element 331 which is opposite to the proximal end of the first closed-loop element 311 and adjacent to the first closed-loop element 311 also gradually increases.

In the process of switching from the free state to the semi-free state, a radial distance between the free end point 3113 of the first closed-loop element 311 and a proximal end connection point 3311 of the second closed-loop element 331 which is opposite to the distal end of the first closed-loop element 311 and adjacent to the first closed-loop element 311 gradually decreases, and a radial distance between the proximal end connection point 3111 of the first closed-loop element 311 and the free end point 3313 of the second closed-loop element 331 which is opposite to the proximal end of the first closed-loop element 311 and adjacent to the first closed-loop element 311 also gradually decreases. Therefore, in the semi-free state, the first closed-loop unit 311 and the second closed-loop unit 331 form a continuous tubular structure with a large metal coverage rate and close to a closed loop, so that a blood flow channel is formed in the thrombus for blood flow to pass through, and the safety of the embolectomy is improved.

At the intersection of the large-diameter section 31 and the small-diameter section 33, the free end points 3113 of the first closed-loop units 311 and the proximal end connection points 3311 of the second closed-loop units 331 adjacent to the distal ends thereof are alternately arranged in sequence along the circumferential direction of the second stent body 30 to form a first annular array 3010, and the proximal end connection points 3111 of the first closed-loop units 311 and the free end points 3313 of the second closed-loop units 331 adjacent to the proximal ends thereof are alternately arranged in sequence along the circumferential direction of the second stent body 30 to form a second annular array 3012.

In this embodiment, the radial distance is a straight line distance between the adjacent free end point 3113 and the proximal connection point 3311 at the intersection of the large and small diameter sections 31, 33 or a straight line distance between the adjacent free end point 3313 and the proximal connection point 3111 at the intersection of the large and small diameter sections 31, 33. Specifically, the radial distance is a straight-line distance between adjacent free end points 3113 and the proximal connection point 3311 in the first annular array 3010; or the linear distance between adjacent free end points 3313 and proximal connection points 3111 in the second annular array 3012.

In the semi-free state, the proximal connection point 3311 and the free end point 3113 in the first annular array 3010 are coplanar, and the proximal connection point 3111 and the free end point 3313 in the second annular array 3012 are also coplanar, so as to ensure that the whole of the thrombectomy stent 100 has radial and axial supporting force, and to ensure that the first closed-loop unit 311 and the second closed-loop unit 331 have relatively small areas, so as to avoid the thrombus from entering the channel 1010 inside the thrombectomy stent 100, thereby realizing the pre-circulation function of the blood flow channel. It should be noted that the proximal connection points 3311 and the free end points 3113 of the first annular array 3010 are coplanar, which means that the proximal connection points 3311 of the first annular array 3010 are connected to each other to form a first plane, and the free end points 3113 of the first annular array 3010 are connected to each other to form a second plane, where the first plane and the second plane are coplanar, that is, the first plane and the second plane are located on the same plane and coincide with each other. The proximal connection points 3111 and the free end points 3313 in the second circular array 3012 are coplanar, meaning that the proximal connection points 3111 in the second circular array 3012 are connected to each other to form a third plane, and the free end points 3313 in the second circular array 3012 are connected to each other to form a fourth plane, the third plane and the fourth plane being coplanar, i.e., the third plane and the fourth plane are located on the same plane and coincide with each other. The first plane, the second plane, the third plane and the fourth plane are perpendicular to a central axis L of the embolectomy support 100.

In the free state, the proximal connection point 3311 and the free end point 3113 in the first annular array 3010 are not coplanar, and the proximal connection point 3111 and the free end point 3313 in the second annular array 3012 are not coplanar, so that smoothness of switching of the thrombectomy stent 100 from the free state to the semi-free state is improved, radial and axial supporting force of the whole thrombectomy stent 100 is ensured, and meanwhile, the first closed-loop unit 311 and the second closed-loop unit 331 are ensured to have relatively large areas so that thrombi enter the channel 1010 inside the thrombectomy stent 100, and therefore thrombus capture efficiency is improved. It should be noted that the proximal connection points 3311 and the free end points 3113 of the first annular array 3010 are not coplanar, which means that the proximal connection points 3311 of the first annular array 3010 are connected to each other to form a first plane, and the free end points 3113 of the first annular array 3010 are connected to each other to form a second plane, where the first plane and the second plane are not coplanar, that is, the first plane and the second plane are located on different planes and are parallel to each other. The proximal connection points 3111 and the free end points 3313 in the second circular array 3012 are not coplanar, meaning that the proximal connection points 3111 in the second circular array 3012 are connected to each other to form a third plane and the free end points 3313 in the second circular array 3012 are connected to each other to form a fourth plane, the third plane and the fourth plane being non-coplanar, i.e., the third plane and the fourth plane are located on different planes and are parallel to each other.

In the process of switching from the semi-free state to the free state, the length of the embolectomy support 100 is gradually reduced, the outer diameter of the embolectomy support 100 is gradually increased, and the area of the first closed-loop unit 311 and the area of the second closed-loop unit 331 are also gradually increased. Specifically, in the semi-free state, the embolectomy support 100 is radially compressed to stretch the length of the embolectomy support 100, and the embolectomy support 100 has a relatively small outer diameter, with the area of the first closed-loop element 311 and the area of the second closed-loop element 331 being relatively small. In the free state, the embolectomy stent 100 is radially expanded to shorten the length of the embolectomy stent 100, and the embolectomy stent 100 has a relatively large outer diameter, and the area of the first closed-loop element 311 and the area of the second closed-loop element 331 are relatively large.

When the stent body 101 is in the semi-free state, the plurality of first support rods 351 and the plurality of second support rods 352 are in a straight rod-shaped structure; when the holder body 101 is in the free state, the plurality of first support bars 351 and the plurality of second support bars 352 are each in a curved structure and are curved inward or outward with respect to the second holder body 30. So, under free state, because a plurality of first bracing pieces 351 and a plurality of second bracing piece 352 all are curved structure to can reduce the cutting to the thrombus, and can provide more accommodation space for the thrombus, so that the thrombus gets into the inner chamber of getting and tying support 100, and then improved the efficiency of arresting of getting and tying support 100 to the thrombus. In the semi-free state, the plurality of first support rods 351 and the plurality of second support rods 352 are all in a straight rod-shaped structure, and the plurality of first support rods 351 and the plurality of second support rods 352 are approximately parallel to the axial direction of the second stent body 30, so that the whole embolectomy stent 100 can be compressed to form a single-layer tubular structure with a closed-loop structure 1011 and approximately the same outer diameter, a pre-communicating function of a blood flow channel is realized, and brain injury in the operation process is reduced.

The area of the first closed-loop cell 311 is larger than that of the second closed-loop cell 331. The shapes of the first closed-loop cell 311 and the second closed-loop cell 331 include one or more of a diamond shape, a circular shape, an elliptical shape, a triangular shape, a trapezoidal shape, and a hexagonal shape.

In the present embodiment, the first closed-loop unit 311 and the second closed-loop unit 331 are both diamond-shaped or approximately diamond-shaped structures. The large-diameter section 31 is surrounded by 4 first closed-loop units 311 to form a tubular structure. Each first closed-loop element 311 has 2 middle connection points 3112. The adjacent two first closed-loop elements 311 are connected together by a middle connection point 3112. The small-diameter section 33 is surrounded by 3 second closed-loop units 331 to form a tubular structure. Each second closed-loop element 331 has 2 middle connection points 3312. The adjacent two second closed-loop elements 331 are connected together by a middle connection point 3312. Wherein, the area of the first closed-loop unit 311 is larger than that of the second closed-loop unit 331. The plurality of first closed-loop units 311 are staggered from the plurality of second closed-loop units 331, so that the second closed-loop units 331 are arranged between two adjacent first closed-loop units 311, so that the thrombectomy stent 100 is easier to compress, is more adaptable to small vessels, and is easier to introduce into a microcatheter.

The distal end of the first closed-loop unit 311 forms a first capturing unit 3114, and the distal end of the second closed-loop unit 331 forms a second capturing unit 3314. The first catching units 3114 and the first support rods 351 are alternately arranged and connected with each other, and the second catching units 3314 and the second support rods 352 are alternately arranged and connected with each other, so that not only is the flexibility of the thrombectomy stent 100 ensured, but also a certain supporting force is provided for the thrombectomy stent 100 in the radial direction and the axial direction, and the efficiency of the thrombectomy stent 100 in catching thrombus is improved.

Here, the 2 middle connection points 3112 of the first closed-loop element 311 are connected to the free end point 3113 to form a first catching element 3114. The 2 middle connection points 3312 of the second closed-loop element 331 are connected to the free end point 3313 to form a second catching element 3314. The first catching unit 3114 and the second catching unit 3314 may have a V-shaped, W-shaped, zigzag, or U-shaped structure to improve the efficiency of catching thrombus.

The first catching units 3114 and the second catching units 3314 are alternately arranged, that is, the second catching units 3314 are arranged between two adjacent first catching units 3114, so as to be fully distributed in the radial direction of the thrombectomy stent 100, thereby improving the effect of anchoring thrombi. The first catching unit 3114 and the second catching unit 3314 form a first accommodating space 3115 and a second accommodating space 3315, respectively, in correspondence with the holder body 101. Both the first 3114 and second 3314 capture units extend outwardly or inwardly relative to the stent body 101. The bending directions of the first catching unit 3114 and the second catching unit 3314 are opposite to the bending directions of the first support bar 351 and the second support bar 352. Thus, the space of the first accommodating space 3115 and the second accommodating space 3315 is increased, so that more accommodating spaces can be provided for thrombus, so that thrombus can enter the inner cavity of the thrombus taking support 100, and the capturing efficiency of the thrombus taking support 100 on thrombus is further improved. When the thrombectomy stent 100 is in the free state (i.e., the expanded state), the first catching unit 3114 and the second catching unit 3314 are inserted into the thrombus or the thrombus is clamped in the first housing space 3115 and the second housing space 3315, thereby improving the anchoring of the thrombectomy stent 100 to the thrombus. Because the first catching unit 3114 and the second catching unit 3314 are uniformly distributed in the circumferential direction of the stent body 101, the flexibility of the embolectomy stent 100 is enhanced, and the efficiency of catching thrombus is also improved.

The first capture unit 3114 and the second capture unit 3314 are movable in a direction perpendicular to the axis L of the embolectomy stent 100. In this way, when the embolectomy stent 100 is prevented from moving within a blood vessel, the first catching unit 3114 and the second catching unit 3314 do not come into direct contact with the blood vessel wall, thereby preventing damage to the tissue of the blood vessel wall.

Further, the distal end of the first capturing unit 3114 and the distal end of the second capturing unit 3314 are both provided with rounded chamfers to further avoid damage to the vessel wall by the distal end of the first capturing unit 3114 and the second capturing unit 3314.

In some embodiments, the first bracket body 10 is integrally formed with the second bracket body 30 so as to improve stability and reliability of the connection of the first bracket body 10 with the second bracket body 30. In other embodiments, the first bracket body 10 and the second bracket body 30 can be fixedly connected together by means of crimping, heat fusing, bonding, welding or riveting, which are commonly used in the art.

In the present embodiment, the distal end of the second stent body 30 is completely open to form a first open end 301, the proximal end portion of the first stent body 10 is open to form a second open end 15, and an orthographic projection of the first open end 301 on the second projection plane is partially overlapped with an orthographic projection of the second open end 15 on the second projection plane; the second projection plane is a plane perpendicular to the central axis L of the embolectomy support 100. In this manner, the proximal and distal compliances of the thrombectomy stent 100 are enhanced.

Specifically, the proximal end of the first stent body 10 is constructed in a tapered conical cylinder type structure. In this embodiment, the proximal end of the first stent body 10 forms a second open end 15 having a slope. The second open end 15 is tapered in shape, such as a drop. In the present embodiment, the second open end 15 is shaped like a shuttle. So, based on the slope design of the second open end 15 of first support body 10, not only can the effective separation withdraw and get the circumference of embolus support 100 of withdrawing power transmission to whole embolus support 100 of getting on, and avoid the pipe diameter of first support body 10 to diminish at the in-process that the embolus support 100 was got in the withdrawal to ensure that the thrombus is getting the difficult phenomenon that drops that appears of embolus support 100 in the process of withdrawing.

In other embodiments, the proximal end of the first stent body may be configured as a funnel structure and the second stent body may be configured as a straight tube structure, thereby preventing thrombus from falling off during withdrawal of the thrombectomy stent in a direction proximal to the proximal end thereof. The pipe diameter of the first support body is gradually increased from the near end to the far end, so that the pipe diameter of the whole first support body is prevented from being reduced or kinked due to the influence of the withdrawing force of the thrombus taking support in the process that the thrombus taking support is withdrawn towards the near end, the thrombus catching efficiency is improved, and the damage of the thrombus taking support to the vascular wall is reduced. Therefore, smooth transition connection between the first stent body and the second stent body is ensured, and then the damage of the thrombus removal stent to the blood vessel wall is reduced in the thrombus removal process.

In some embodiments, the proximal end of the first stent body 10 is provided with a visualization positioning element 102 to facilitate indicating the position of the embolectomy stent 100 by the position of the visualization positioning element 102 under instrumental detection. The visualization positioning element 102 is made of a radiopaque material. The radiopaque material is preferably a noble metal material such as gold, platinum or tantalum. The development positioning element 102 may take various forms such as a ring, a wire, a belt, or a dot, and is fixed to the thrombectomy support 100 by a means commonly used in the art, such as pressing, heat fusing, bonding, welding, or riveting. In some embodiments, the visualization positioning element 102 may be ring-shaped, and the visualization positioning element 102 is sleeved on the proximal end of the thrombectomy stent 100.

In some embodiments, the proximal end of the first stent body 10 is also provided with a connector. The connector extends in a direction parallel to the axis L of the thrombectomy stent 100. In the process that the thrombus taking support 100 is withdrawn, the traction force is concentrated on the extension line where the connector is located, the pipe diameter of the far end of the support body 101 is guaranteed to be unchanged, and therefore the thrombus catching efficiency is improved. The development positioning member 102 is fixed to the joint.

In this embodiment, since the proximal end of the thrombectomy support 100 is provided with the visualization positioning element 102 to accurately position the position of the thrombus, the thrombus can be caught during the thrombectomy process using the thrombectomy support 100, and whether the thrombus is separated from the thrombectomy support 100 is determined during the retraction process of the thrombectomy support 100 for real-time observation, so as to guide the specific thrombectomy operation, that is, guide the thrombectomy support 100 to switch between the compression state and the release state, so that the thrombectomy is more accurate. In other embodiments, multiple visualization positioning elements may be provided in the middle of the thrombectomy stent 100 to more accurately locate the position of the thrombus.

In the present embodiment, the first stent body 10 and the second stent body 30 are made of a metal material having a memory effect or a polymer material having elasticity, so that the stent body 101 self-expands to form a tubular and/or cage-like structure. The metallic material is, for example, but not limited to, a nickel titanium alloy or a cobalt based alloy. Specifically, the first stent body 10 and the second stent body 30 may be formed into a tubular or cage structure having a hollow structure by laser cutting a plate-shaped nickel-titanium alloy, and then crimped and heat-treated to shape. In another embodiment, the first stent body 10 and the second stent body 30 may also be formed into a tubular or cage structure having an open structure by weaving a filamentous nitinol. In other embodiments, the first and second stent bodies 10 and 30 may also be manufactured by using a plastic material having elasticity.

Referring to fig. 5, fig. 5 is a schematic structural view illustrating the whole structure of the thrombectomy support 100 in fig. 1 in the semi-free state. As shown in fig. 5, in the semi-free state, the plurality of first support bars 351 and the plurality of second support bars 352 are parallel to the central axis L of the embolectomy holder 100. The free end points 3113 corresponding to the first closed-loop elements 311 in the first annular array 3010 are coplanar with the near end points 3311 corresponding to the second closed-loop elements 331, and the near end points 3111 corresponding to the first closed-loop elements 311 in the second annular array 3012 and the free end points 3313 corresponding to the second closed-loop elements 331 are also coplanar.

The invention discloses a thrombus taking stent which comprises a stent body with a tubular and/or cage-shaped structure, wherein the stent body comprises a first stent body and a second stent body arranged at the far end of the first stent body, the first stent body is in smooth transition connection with the second stent body, the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected together through the transition section, the stent body is in a single-layer tubular structure in a semi-free state, and the stent body is in a double-layer tubular structure in the free state, so that a blood flow channel can be established in the semi-free state of the thrombus taking stent, blood flow blocking blood vessels can be recovered before thrombus is cleared, and the safety of a thrombus taking operation is improved. Further, the distal end of the thrombectomy stent is not formed with a large mesh opening, thereby avoiding the problem of blockage of the blood flow path caused by thrombus entering the internal channel 1010 of the thrombectomy stent 100 through the large mesh opening.

Referring to fig. 6, 7 and 8, fig. 6 is a schematic structural view of a thrombectomy support 100b according to a second embodiment of the present invention; FIG. 7 is a schematic structural view of a portion of a embolectomy support 100b according to a second embodiment of the present invention; fig. 8 is a schematic structural view of another angle of a thrombectomy support 100b according to the second embodiment of the present invention. In the second embodiment, the construction of the thrombectomy support 100b is similar to that of the thrombectomy support 100 (see FIG. 1) of the first embodiment. In contrast, the embolectomy stent 100b further comprises a third stent body 40b and a protective umbrella 6, and the distal end of the second stent body 30b is a small-diameter section 33.

The third stent body 40b is connected between the second stent body 30b and the umbrella 6, a third open end 401b is formed at the proximal end of the third stent body 40b, a fourth open end 403b is formed at the distal end of the third stent body 40b, an umbrella end 601 is formed at the proximal end of the umbrella 6, a first closed end 603 right opposite to the umbrella end 601 is formed at the distal end of the umbrella 6, the first open end 301b is communicated with the third open end 401b, the fourth open end 403b and the umbrella end 601, so that a continuous channel 1010b is formed inside the embolectomy stent 100b, and the distal end of the second stent body 30b is configured into the small-diameter section 33.

Because the distal end of the thrombectomy support 100b is provided with the protective umbrella 6, the thrombi falling from the thrombectomy support 100b can be effectively prevented from escaping. In addition, the distal end of the stent body 101b forms a fourth opening end 403b, the proximal end of the umbrella 6 forms an umbrella opening end 601 directly opposite to the fourth opening end 403b, the distal end of the umbrella 6 forms a first sealing end 603 directly opposite to the umbrella opening end 601, and the umbrella opening end 601 is connected with the fourth opening end 403b, so that a continuous channel 1010b is formed inside the embolectomy stent 100 b. Thus, the thrombus falling from the thrombus extraction support 100b can completely enter the protective umbrella 6 without being blocked, so that the protective umbrella 6 can effectively recover the thrombus falling from the thrombus extraction support 100b, the problem of blood vessel re-embolism caused by the thrombus falling from the thrombus extraction support 100b is avoided, and the complication caused by thrombus extraction treatment is prevented, thereby increasing the blood vessel recanalization rate. In addition, because the umbrella mouth end 601 is connected with the fourth opening end 403b, that is, the protective umbrella 6 is tightly attached to the distal end of the stent body 101b, so as to prevent thrombus from escaping, and the thrombus-taking stent 100b and the protective umbrella 6 can be synchronously released, so that the protective umbrella 6 can be rapidly opened by means of the radial supporting force of the stent body 101b until the protective umbrella 6 is unfolded to the presetting state, so as to recover the thrombus falling off from the stent body 101 b.

In this embodiment, the proximal end of the third stent body 40b is smoothly transitionally connected with the distal end of the second stent body 30b, and the proximal end of the third stent body 40b is connected with the distal end of the second stent body 30b by a transition section 35.

Specifically, as shown in fig. 7 and 8, the third bracket body 40b includes a catching section 41b and an extending section 42b connecting the catching section 41b and the protective umbrella 6. The proximal end of the catching section 41b is connected to the small-diameter section 33 of the second stent body 30b by a plurality of second support bars 352, and the distal end of the catching section 41 is connected to the proximal end of the extension section 42 b. Wherein, the catching section 41b is smoothly and transitionally connected with the extending section 42b, thereby ensuring the overall flexibility of the embolectomy stent 100b and improving the safety of the embolectomy.

In some embodiments, the outer diameter of the capturing section 41b is greater than or substantially equal to the maximum outer diameter of the second stent body 30b and substantially equal to the outer diameter of the extending section 42 b. In this way, the radial and axial supporting force of the thrombectomy stent 100b is ensured, and all of the thrombi dropped or escaped from the second stent body 30b can enter the passage 1010b inside the third stent 40b from the catching section 41 b.

The catching section 41b includes at least one catching portion 43b and a plurality of reinforcing portions 44 b. At least one catching portion 43b and a plurality of reinforcing portions 44b are connected side by side in the circumferential direction of the third stent body 40b, and the outer shape of the catching portion 43b is different from that of the reinforcing portions 44 b. In some embodiments, the number of the catching portions 43b corresponds to the number of the reinforcing portions 44b, and the catching portions 43b and the reinforcing portions 44b are alternately connected in the circumferential direction of the third stent body 40 b. In the present embodiment, the catching sections 41b include two catching portions 43b and two reinforcing portions 44b that are diametrically opposed, and each catching portion 43b and each reinforcing portion 44b are arranged side by side and alternately connected in the circumferential direction of the third stent body 40 b. Thus, the capturing performance of the second net opening 411b for thrombus which is not effectively captured by the second stent body 30b, such as hard thrombus like organized thrombus, calcified thrombus and the like and thrombus with larger volume, is improved, the radial supporting force of the third stent body 40b is ensured, and the adherence of the capturing section 41b is prevented from being reduced due to excessive deformation of the third stent body 40b, that is, the collapse of the capturing section 41b of the third stent body 40b is prevented, and the adherence of the capturing section 41b is enhanced, so that the capturing efficiency for thrombus is improved.

According to the thrombus taking stent 100b provided by the embodiment of the invention, the third stent body 40b is additionally arranged, the second mesh opening 411b with a larger mesh opening area is arranged at the proximal end of the third stent body 40b, and the third capturing unit 4114b is formed at the proximal end of the second mesh opening 411b, so that the third capturing unit 4114b can anchor thrombus which is not effectively captured by the second stent body 30b, such as hard thrombus such as organized thrombus, calcified thrombus and the like and thrombus with a larger volume, so as to improve the capturing performance of the second mesh opening 411b on the hard thrombus, and further the hard thrombus can enter the channel 1010b inside the third stent body 40b from the second mesh opening 411b, so as to improve the capturing efficiency on the hard thrombus.

The number of the catching portions 43b and the reinforcing portions 44b is designed according to the diameter of the third stent body 40b, the number of the first closed-loop units 311 for surrounding the large-diameter section 31, or the number of the second closed-loop units 331 for surrounding the small-diameter section 33, and the like, and the present invention is not limited thereto.

Wherein each catching part 43b comprises a second net opening 411b, each reinforcing part 44b comprises a third net opening 413b and a skeleton rod 415b arranged at the proximal end of the third net opening 413b, wherein the area of the second net opening 411b is larger than the areas of the first net opening 421b, the first closed-loop unit 311 and the second closed-loop unit 331, the area of the third net opening 413b is equal to the area of the first net opening 421b and the area of the first closed-loop unit 311, and the shape of the third net opening 413b is the same as the shape of the first net opening 421b and the shape of the first closed-loop unit 311, so as to enhance the overall flexibility of the thrombectomy stent 100 b. In other embodiments, each reinforcement may not include a scaffolding bar, i.e., each reinforcement may include a plurality of third mesh openings connected in parallel along a direction parallel to the central axis L of the stent body.

In this embodiment, the extension section 42b is surrounded by a plurality of first net openings 421 b. The catching section 41b is surrounded by at least one second net opening 411b, a plurality of third net openings 413b and a skeleton bar 415 b. The first net port 421b, the second net port 411b, the third net port 413b and the skeleton bar 415b are connected to each other to form a third stent body 40b having a tubular structure or a cage-like structure.

The second port 411b is opposite to the second closed-loop unit 331, that is, the second port 411b is disposed between two adjacent first closed-loop units 311. The third port 413b is opposite to the second closed-loop element 311, that is, the second port 411b is disposed between two adjacent first closed-loop elements 311. In this way, the second net opening 411b is ensured to have a relatively large area, so as to improve the capability of the thrombectomy stent 100b to capture hard thrombi such as organized thrombi and calcified thrombi and large-volume thrombi, and the axial and radial supporting forces of the thrombectomy stent 100b are ensured, and at the same time, the thrombi can be more easily introduced into the channel 1010b inside the third stent body 40b from the second net opening 411 b.

A proximal end of each second net port 411b is formed with a third catching unit 4114b, the proximal end of the third catching unit 4114b is connected to the distal end of the second support bar 352, and the distal end of the third catching unit 4114b is configured as a free end. Wherein the third capturing unit 4114b constitutes a part of the second portal 411 b.

In the present embodiment, the third catching unit 4114b is configured in a V-shaped, W-shaped, zigzag, or U-shaped configuration, and the third catching unit 4114b is disposed between two adjacent second support bars 352. The third capturing unit 4114b is directly opposite to the second capturing unit 3314, and is disposed between two adjacent first capturing units 3114. The third catching units 4114b are disposed between adjacent two second support bars 352 and connected to each other.

Specifically, the first portal 421b includes a proximal connection point 4211b and two middle connection points 4212 b. The two adjacent first net openings 421b are connected by a middle connection point 4212 b. The second port 411b includes two proximal connection points 4111b, a free end point 4112b, and a distal connection point 4113b opposite to the free end point 4112 b. The third portal 413b includes a proximal attachment point 4131b, two intermediate attachment points 4132b, and a distal attachment point 4133b directly opposite the proximal attachment point 4131 b. The middle connection point 4212b of the first portal 421b coincides with the distal connection point 4113b of the second portal 411b and the distal connection segment 4133b of the third portal 413 b. The proximal connection point 4211b of the first portal 421b coincides with the middle connection point 4132b of the third portal 413 b.

Wherein, the axial projection of each second net opening 411b is approximately heart-shaped. Each proximal connection point 4111b of the capture segment 41b connects to the distal end of a corresponding second support bar 352. The two proximal connection points 4111b and the free end point 4112b of each second port 411b are connected to form a V-shaped or U-shaped third capturing unit 4114 b. The third catching unit 4114b extends outward or inward relative to the holder body 101b, and forms a third receiving space 4115b with the holder body 101 b. In this way, thrombus that cannot be effectively caught by the second stent body 30b, for example, hard thrombus such as organized thrombus or calcified thrombus or thrombus having a large volume, can enter the protective umbrella 6 through the second net opening 411 b. In addition, thrombus falling or overflowing from the second stent body 30b easily enters the protective umbrella 6 through the second net opening 411b, so that the problem of re-embolization of blood vessels caused by thrombus falling or overflowing from the embolectomy stent 100b and not effectively captured is avoided, and complications caused by embolectomy treatment, such as vasospasm, are prevented, thereby increasing the recanalization rate of blood vessels.

In the present embodiment, the skeleton bar 415b is configured in a Y-shaped structure. The frame bar 415b includes a first reinforcement bar 4151b and a second reinforcement bar 4153b connected between the first reinforcement bar 4151b and the third portal 413 b. The first reinforcement bar 4151b is configured in a V-shaped structure. The first reinforcement rod 4151b has the same shape as the third capturing unit 4114b, and the distal end of the second port 411d has the same shape as the distal end of the third port 413d, so as to ensure the balance of radial forces of the capturing section 41b and the smoothness of the capturing section 41b, enhance the adherence of the capturing section 41b, and improve the capturing rate of thrombus. The second reinforcing bar 4153b has the same shape as the second supporting bar 352, and the third mesh port 413b has the same shape as the first mesh port 421b, so as to ensure the flexibility of the stent body 101b, provide a certain supporting force in the radial and axial directions of the stent body 101b, and improve the capturing efficiency of the stent body 101b on thrombus.

The second port 411b is opposite to the second closed-loop unit 331, that is, the second port 411b is disposed between two adjacent first closed-loop units 311. The number of the second net ports 411b is equal to the number of the second closed-loop units 331. The second capturing unit 3314 of the second stent body 30b is close to the third capturing unit 4114b of the third stent body 40b, and the bending direction of the second capturing unit 3314 is consistent with that of the third capturing unit 4114b, so that the flexibility of the thrombus taking stent 100b is ensured, and the anchoring effect on thrombus can be further improved. The two opposite sides of the second net opening 411b parallel to the central axis L of the stent body 101b are respectively connected with a third net opening 413b and a skeleton rod 415b which are connected in parallel along the central axis L direction, and each third net opening 413b is arranged between the skeleton rod 415b and the first net opening 421b, so that the radial extension space of the second net opening 411b is increased, the area of the second net opening 411b is increased, and the adherence of the capturing section 41b is enhanced, so that thrombus enters the channel 1010b inside the third stent body 40b from the second net opening 411 b.

The stent body 101b and the protective umbrella 6 may be formed into a tubular or cage-like structure having a hollow structure by laser cutting a plate-like nickel-titanium alloy, and then crimped and heat-treated to shape. In another embodiment, the stent body 101b and the protective umbrella 6 may be formed into a tubular or cage structure having an open structure by weaving a wire-like nickel-titanium alloy. In other embodiments, the bracket body 101 and the protective umbrella 6 can also be made of elastic plastic materials.

In the embodiment, the stent body 101b is formed by laser engraving of a pipe network material with a shape memory effect; the protective umbrella 6 is woven from a filamentary material having a shape memory effect. The pipe network material or the filament material includes, but is not limited to, a metal material, a polymer material with elasticity, or a plastic material with elasticity. Other possibilities are to make the stent body 101b and the protective umbrella 6 self-expandable to form a tubular and/or cage-like structure. The metallic material is, for example, but not limited to, a nickel titanium alloy or a cobalt based alloy. The stent body 101b made of the pipe network material has certain radial and axial supporting force, so that the stent body 101b is ensured to have good adherence, and therefore, thrombus can be prevented from entering gaps between the thrombus removal stent 100b and a blood vessel wall when the thrombus removal stent 100b is in a complete release state. The protective umbrella 6 woven from a thread-like material has a mesh unit with a small mesh area, so that a thrombus with a relatively small volume can be captured to improve the capturing efficiency of the thrombus. In addition, the protective umbrella 6 is relatively soft, thereby reducing damage to the vessel wall.

Referring to fig. 6 and 7 again, in the present embodiment, the mounting structure 104 is disposed on the periphery of the fourth opening 403b, and the connection structure 602 is disposed on the periphery of the umbrella opening 601 and is connected to the mounting structure in a matching manner. The attachment of the mounting structure 104 to the attachment structure 602 is, for example, but not limited to, an adhesive, a weld, a press-fit, or a snap-fit connection. The mounting structure 104 and the connecting structure 602 are directly connected together, which not only facilitates the manufacturing process, but also simplifies the overall structure of the thrombectomy support 100 b.

In some embodiments, the embolectomy support 100b also includes a connector 8. Mounting structure 104 is coupled to coupling structure 602 via coupling 8 to couple umbrella port 601 with fourth opening end 403 b. The mounting structure 104 and the connecting structure 602 are connected together by the connecting piece 8, so that the compactness and the stability of the connection between the bracket body 101b and the protective umbrella 6 are improved.

The fourth opening end 403b forms a first bending portion 105 that is continuously bent, the mounting structure 104 is disposed on the first bending portion 105, the bezel end 601 forms a second bending portion 604 that is continuously bent, and the connecting structure 602 is disposed on the second bending portion 604. The first bending portion 105 and the second bending portion 604 are wavy or zigzag. Thus, the fourth opening end 403b and the umbrella opening end 601 can provide more connection points to improve the stability and reliability of the connection of the stent body 101b and the protective umbrella 6, and ensure that the stent body 101b and the protective umbrella 6 can be synchronously released, so that the protective umbrella 6 can be rapidly opened by the protective umbrella 6 with the help of the radial supporting force of the stent body 101b, and thrombus in the blood vessel can be effectively captured.

Specifically, the fourth opening 403b is surrounded by a plurality of first openings 421b, a distal end of each first opening 421b is configured as a first bending structure 1061, and the plurality of first bending structures 1061 are connected to form the first bending portion 105. The bevel end 601 is surrounded by a plurality of first grid units 606, a proximal end of each first grid unit 606 is configured as a second bending structure 6061, and the plurality of second bending structures 6061 are connected to each other to form a second bending portion 604. In the present embodiment, the first bending structure 1061 and the second bending structure 6061 are V-shaped. The first bending portion 105 and the second bending portion 604 are both saw-toothed.

The number of the first net openings 421b is less than the number of the first grid units 606, and the area of each first net opening 421b is greater than the area of each first grid unit 606. In this way, the protective umbrella 6 can recover thrombus with a relatively small volume, so as to further improve the efficiency of capturing thrombus by the thrombus removal stent 100 b.

Specifically, the shapes of the plurality of first net openings 421b and the plurality of first grid cells 606 include, but are not limited to, one or more of a circle, an oval, a triangle, a diamond, a trapezoid, and a hexagon. In the present embodiment, the shapes of the first mesh openings 421b and the first grid cells 606 are all rhombuses.

The mounting structure 104 is surrounded by a plurality of connecting pieces 107 having connecting holes 1071, and the plurality of connecting pieces 107 are respectively provided on the plurality of first bending structures 1061. The connection structure 602 is surrounded by a plurality of connection buckles 605, each connection buckle 605 is disposed on the corresponding second bending structure 6061, and the connection member 8 is configured as a connection ring which passes through the connection hole 1071 of each connection piece 107 and the plurality of connection buckles 605 to connect the protective umbrella 6 with the bracket body 101 b. The connecting ring is made of a material with a shape memory effect. So, the shroud umbrella 6 can be opened fast to the go-between with the help of support body 101 b's radial holding power, and the design of go-between can avoid the umbrella mouth end 601 of shroud umbrella 6 to take place to collapse and strengthened the adherence of shroud umbrella 6 with the vascular wall to the efficiency of catching to the thrombus has been improved.

The symmetry axis of each first net opening 421b parallel to the central axis L of the embolectomy support 100b is substantially coincident with the symmetry axis of the corresponding first grid unit 606 parallel to the central axis L of the embolectomy support 100b, so that the connection buckle 605 is aligned with the connection hole 1071, thereby facilitating the assembly.

In some embodiments, the number of connector tabs 605 is equal to the number of connector holes 1071. Each connecting buckle 605 is correspondingly disposed on each second bending structure 6061. So, can avoid the umbrella mouth end 601 of umbrella 6 to take place to collapse and lead to there being the problem in gap between umbrella 6 and the vascular wall to ensure umbrella mouth end 601's radial holding power, strengthened the adherence of umbrella 6 with the vascular wall, and then improved the efficiency of catching to the thrombus.

In other embodiments, the number of connector tabs 605 is greater than the number of connector holes 1071. Each of the connection buckles 605 is disposed at a position of the second bending structure 6061 corresponding to the connection hole 1071, thereby facilitating the assembly of the protective umbrella 6 with the bracket body 101 b.

The protective umbrella 6 comprises a net body 63 formed by weaving a plurality of ribs 61 in a staggered manner, each rib 61 is in a petal structure and is distributed in a radial manner, and the proximal end of each rib 61 protrudes outwards relative to the net body 63 to form a second bending structure 6061.

In this embodiment, the connecting buckle 605 and the second bending structure 6061 are integrally formed. The middle part of each rib 61 is crossed to form a corresponding connecting buckle 605, thereby improving the stability and reliability of the connecting buckle 605 and simplifying the processing method.

In other embodiments, a plurality of connecting buckles 605 may also be formed on the corresponding second bending structures 6061 by mechanical fastening. Mechanical fastening means are, for example, but not limited to, adhesive, welding, riveting, crimping or winding of a filamentary material.

In this embodiment, the net body 63 includes a cylindrical extension portion 62 and a conical recovery portion 64, the extension portion 62 is disposed between the holder body 101b and the recovery portion 64, and a plurality of connection buttons 605 are disposed at the proximal end of the extension portion 62. The outer diameter of the extension 62 is substantially equal to the outer diameter of the holder body 101 b. So, through being provided with extension 62 at the near-end of protection umbrella 6, increased the whole area of protection umbrella 6 to the thrombus emergence escape in having avoided thrombectomy support 100b, and then improved thrombectomy support 100b to the seizure performance of thrombus, so that thrombectomy support 100b thrombectomy totally, prevent vasospasm, and can resume blood flow speed fast. In addition, the proximal end of the protective umbrella 6 is smoothly connected with the distal end of the stent body 101b, so that the flexibility of the embolectomy stent 100b is ensured, the injury to the blood vessel wall is reduced, and the embolectomy stent 100b and the protective umbrella 6 can be synchronously released.

Specifically, the extension portion 62 is formed by a plurality of first grid units 606 and a plurality of second grid units 621. The recycling portion 64 is formed by surrounding a plurality of third grid units 641, the areas of the plurality of second grid units 621 are the same, the areas of the plurality of third grid units 641 gradually increase from the distal end to the proximal end, and the area of the second grid unit 621 is larger than the area of the third grid unit 641, smaller than the area of the first mesh opening 421b, and equal to the area of the first grid unit 606. In this way, before the embolectomy stent 100b enters the fully released state, the protective umbrella 6 is not deployed to the pre-shaped state, and at this time, the thrombus with a smaller volume can still enter the extension part 62 from the first mesh unit 606 or the second mesh unit 621 and then be recovered by the recovery part 64, so as to further improve the thrombus capturing efficiency. In addition, the mesh design of the net body 63 is gradually encrypted from the proximal end to the distal end, so that thrombus entering the net body 63 is prevented from escaping, and the thrombus falling from the thrombus removal stent 100b is recovered, so that the recanalization rate of the blood vessel is increased.

The central axis of the embolectomy support 100b is collinear with the central axis of the support body 101b and the central axis of the protective umbrella 6, so that the stability of the embolectomy support 100b is improved, and the smoothness of the movement of the support body 101b and the protective umbrella 6 in the blood vessel is ensured.

The maximum outer diameter of the protective umbrella 6 is equal to or larger than the maximum outer diameter of the thrombectomy holder 100b, so that the protective umbrella 6 can catch more thrombi falling from the thrombectomy holder 100 b. An orthographic projection of the bezel end 6 on the first open end 601 in the axial direction coincides with the fourth open end 403 b. Thus, the adherence of the protective umbrella 6 to the vessel wall is enhanced, and the thrombus capturing efficiency is improved.

In this embodiment, the protective umbrella 6 further comprises a protective sheath 65. A protective sleeve 65 is fixedly disposed over the distal end of rib 61 to wrap and constrict the distal end of rib 61. In this way, the distal ends of the ribs 61 are prevented from coming into contact with the blood vessel wall, so that damage to the blood vessel wall is reduced, and the thrombus falling or overflowing from the inside of the thrombus removal stent 100b is always kept housed in the protective umbrella 6.

In some embodiments, the protective sleeve 65 of the protective umbrella 6 may be configured as a developer positioning element. The developing positioning element is fixedly sleeved on the far end of the umbrella rib 61 to wrap and tighten the far end of the umbrella rib 61. The development positioning member is, for example, but not limited to, a development ring or a development wire. In some embodiments, the developer wire is helically wound at the distal end of the protective umbrella 6. In other embodiments, the developer ring is mounted on the distal end of the protective umbrella 6. A visualization positioning element is fixed to the distal end of the rib 61 to serve as a distal marker of the entire thrombectomy stent 100b, thereby more accurately locating the position of the thrombus. The fixing means of the developing positioning element is, for example, but not limited to, welding, pressing, heat fusing, or riveting, etc. the fixing means is commonly used in the art. In other embodiments, the protective umbrella may include both a visualization positioning element and a protective sleeve disposed at a distal end of the protective umbrella.

Referring to fig. 9 and 10 together, fig. 9 is a schematic structural view of a thrombectomy support 100d according to a third embodiment of the present invention; fig. 10 is a schematic view of another angle of the thrombectomy stent 100 d. In the third embodiment, the construction of the thrombectomy holder 100d is similar to that of the thrombectomy holder 100b of the second embodiment. In contrast, the catching section 41d of the third stent body 40d is different from the catching section 41b of the third stent body 40b in the second embodiment.

In this embodiment, the proximal end of each second net port 411d is not formed with the third catching unit. The catching section 41d does not comprise a backbone bar, i.e. a backbone bar is replaced by another third mesh opening 413 d. Specifically, each capturing portion 43d includes a second net port 411d, and each reinforcing portion 44d of the capturing section 41d includes two third net ports 413b connected in parallel in a direction parallel to the central axis L of the stent body 101 d. Each catching portion 43d is substantially olive-shaped. Each reinforcing portion 44d is substantially 8-shaped. The capturing section 41d is surrounded by at least one second net port 411d and a plurality of third net ports 413 d. The first net port 421d, the second net port 411d, and the third net port 413d are connected to each other to form a third stent body 40d having a tubular structure or a cage-like structure.

The proximal and distal end profiles of the second net port 411d are the same as the proximal and distal end profiles of the third net port 413d, so as to ensure the radial force balance of the capturing section 41d and the smoothness of the capturing section 41d, enhance the adherence of the capturing section 41d, and improve the capturing rate of thrombus. Two adjacent third ports 413 d. The shape of the third mesh port 413d is the same as that of the first mesh port 421d, so as to ensure the flexibility of the stent body 101b, ensure that the stent body 101b has a certain supporting force in the radial direction and the axial direction, and improve the capturing efficiency of the stent body 101b on thrombus.

In the present embodiment, the second net opening 411d is substantially olive-shaped. Each second portal 411d has a proximal connection point 4111d, and each proximal connection point 4111d of the capturing section 41d is connected to the distal end of the corresponding second support rod 352. In this way, the area of the second net mouth 411d is increased, and the ability of the thrombectomy stent 100d to capture hard thrombi such as organized thrombi and calcified thrombi and large-volume thrombi is further improved.

The second port 411d is opposite to the first closed-loop unit 311, that is, the second port 411d is disposed between two adjacent second closed-loop units 331. The number of the second net ports 411d is equal to that of the first closed-loop units 311, so that thrombus can be more easily introduced into the channel 1010d inside the third stent body 40d from the second net ports 411d while ensuring the axial and radial supporting force of the embolectomy stent.

In this embodiment, the third capturing unit is not disposed on the basis of the second net port 411d, and two third net ports 413d connected in parallel along the direction of the central axis L are respectively connected to two opposite sides of the second net port 411d parallel to the central axis L of the stent body 101d, so that the area of the second net port 411d is increased, so that thrombus enters the channel 1010d inside the third stent body 40d from the second net port 411d, and the radial extension space of the second net port 411d is increased, so that the area of the second net port 411d is increased, and the adherence of the capturing section 41d is enhanced.

In the thrombus removal stent 100d provided by the embodiment of the present invention, the third stent body 40d is additionally provided, and the proximal end of the third stent body 40d is provided with the second mesh opening 411d having a larger mesh opening area. Since the third capturing unit is not formed at the proximal end of the second net port 411d, the area of the second net port 411d is increased, so as to further improve the capturing performance of thrombus which is not effectively captured by the second net port 411d to the second stent body 30d, such as hard thrombus, e.g., organized thrombus, calcified thrombus, etc., and thrombus with larger volume, and further, the hard thrombus can enter the channel 1010d inside the third stent body 40d from the second net port 411d, so as to improve the capturing efficiency of the hard thrombus.

Referring to fig. 11, fig. 11 is a schematic structural view of a thrombus removal support 100f according to a fourth embodiment of the present invention. In the fourth embodiment, the construction of the thrombectomy holder 100f is similar to that of the thrombectomy holder 100d of the third embodiment. In contrast, the distal end of the third holder body 40f of the embolectomy holder 100f forms a second closed end 403f directly opposite the third open end 401 f.

In this embodiment, the embolectomy support 100f further includes a third support body 40f disposed at the distal end of the second support body 30, the third support body 40f is in smooth transition connection with the second support body 30, a third open end 401f is formed at the proximal end of the third support body 40f, and a second closed end 403f opposite to the third open end 401f is formed at the distal end of the third support body. In this way, the third stent body 40f can further capture the passage 1010f through which the thrombus falling or overflowing from the second stent body 30 can enter the third stent body 40f, thereby effectively preventing the thrombus from being detached from the inside of the thrombectomy stent 100 f.

The first bracket body 10, the second bracket body 30 and the third bracket body 40f are integrally formed, so that the bolt taking bracket 100f is convenient to manufacture, and the stability and the reliability of mutual connection of the first bracket body 10, the second bracket body 30 and the third bracket body 40f are ensured. The thrombectomy stent 100f is formed by laser cutting a nitinol material, thereby effectively preventing thrombus from escaping from the thrombectomy stent 100 f. The third stent body 40f is arranged at the far end of the thrombus removal stent 100f, the catching section 41f of the third stent body 40f is formed by jointly enclosing a third mesh 411f with a relatively large mesh area, and the extension section 42f of the third stent body 40f is formed by jointly enclosing a fourth mesh 421f with a relatively small mesh area, so that both large-volume thrombus and small-volume thrombus can enter the channel 1010f in the third stent body 40f from the third mesh 411f, and the extension section 42f can accommodate the thrombus caught by the third stent body 40f, thereby further improving the catching efficiency of the thrombus removal stent 100 f.

In some embodiments, the distal end of the third stent body 40f is also provided with a visualization positioning element 102f to facilitate indicating the position of the distal end of the third stent body 40f of the embolectomy stent 100f by the position of the visualization positioning element 102f under instrumental detection.

It should be noted that the structural design of the third bracket 40f of the thrombectomy bracket 100f of the seventh embodiment is suitable for the thrombectomy bracket 100 of the first embodiment, and the description thereof is omitted here.

Referring to fig. 12, fig. 12 is a schematic structural view of a embolectomy support 100g according to a fifth embodiment of the present invention. In the fifth embodiment, the thrombectomy stent 100g has a structure similar to that of the thrombectomy stent 100b of the second embodiment. In contrast, the holder body 101g is not provided with a third holder body, and the protective umbrella 6 is directly connected to the distal end of the second holder body 30 g.

In this embodiment, the distal end of the second holder body 30 forms a first open end 301. The embolectomy support 100g comprises a protective umbrella 6 connected with the distal end of the second support body 30, the proximal end of the protective umbrella 6 forms an umbrella opening end 601, the distal end of the protective umbrella 6 forms a first sealing end 603 opposite to the umbrella opening end 601, and the umbrella opening end 601 is communicated with the first opening end 301, so that a continuous channel 1010g is formed inside the embolectomy support 100 g.

Referring to fig. 13 to 15, fig. 13 is a schematic structural view of a thrombectomy support 100h according to a sixth embodiment of the present invention, and fig. 14 is a schematic structural view of a support body 101h of the thrombectomy support 100 h; fig. 15 is a schematic structural view of the umbrella 6h of the thrombectomy holder 100 h. In the sixth embodiment, the construction of the thrombectomy holder 100g is similar to that of the thrombectomy holder 100b of the second embodiment. In contrast, the holder body 101 does not include the third holder body, the protective umbrella 6h is connected to the second holder body 30 in a manner different from the protective umbrella 6 and the second holder body 30b in the second embodiment, and the protective umbrella 6h is not provided with a cylindrical extension portion.

In this embodiment, the mounting structure 104h is surrounded by a plurality of fixing rods 107h, and the plurality of fixing rods 107h are respectively disposed on the plurality of first bending structures 1061. The connecting structure 602h is surrounded by a plurality of connecting rods 605h to form, the connecting rods 605h are dispersedly arranged on the corresponding second bending structures 6061h, each connecting rod 605h is adjacent to the corresponding fixing rod 107h, the connecting piece 8 is constructed by connecting wires 8h, and the connecting wires 8h are wound around the adjacent fixing rods 107h and connecting rods 605h to connect the protective umbrella 6h with the support body 101 h. Thus, the structure of the mounting structure 104h and the connecting structure 602h is simplified, and the bolt taking support 100 is convenient to process and manufacture. Further, by winding the adjacent fixing rod 107h and the connecting rod 605h with the connecting wire 8h, the stability and reliability of the connection of the holder body 101h and the protective umbrella 6h are enhanced.

In other embodiments, the connecting wire 8h may be omitted, i.e., the fixing rod 107h and the connecting rod 605h may be directly fixedly connected together. The fixing means of the fixing rod 107h and the connecting rod 605h is, for example, but not limited to, welding or bonding.

In some embodiments, the connecting wire 8h is a development positioning element. The developing and positioning element is arranged at the joint of the stent body 101h and the protective umbrella 6h and is used as a far-end mark of the thrombus taking stent 100h, so that the positions of thrombus and the protective umbrella 6h can be more accurately positioned. In other embodiments, the developer positioning element may be directly fixed to the connecting wire. The development positioning member is, for example, but not limited to, a development ring or a development wire. The fixing means of the developing positioning element is, for example, but not limited to, welding, pressing, heat fusing, or riveting, etc. the fixing means is commonly used in the art.

The connecting rod 605h comprises a plurality of bending sections 6051h and a straight section 6053h, and the straight section 6053h is formed by converging and weaving the plurality of bending sections 6051h to the straight section 6053 h. Thus, the opening end 601h of the protective umbrella 6h can be prevented from collapsing.

The far end of each bending section 6051h is connected to the middle of the corresponding second bending structure 6061h, the bending sections 6051h are distributed in a central symmetry manner around the straight section 6053h, and the straight section 6053h is arranged at the outer side of the joint 6062h of the two adjacent second bending structures 6061 h. So, the radial holding power that umbrella mouth end 601h of umbrella 6h received is more even, prevents that umbrella 6h from taking place to collapse to guaranteed umbrella 6 h's adherence, and can open umbrella 6h fast, and then effectively catch the thrombus in the blood vessel.

Wherein, the straight section connecting rods 6053h of the fixing rod 107h and the connecting rod 605h both extend in a direction parallel to the central axis L of the thrombectomy support 100 h. Thus, the flexibility of the whole of the embolectomy stent 100h is ensured, the smoothness of the movement of the stent body 101h and the protective umbrella 6h in the blood vessel is ensured, and the damage to the blood vessel wall is reduced.

In the present embodiment, the net body 63h is configured as a recovery structure having a conical shape. The mesh body 63h is surrounded by a plurality of first mesh units 606h and a plurality of third mesh units 641 h. The area of the third grid units 641h gradually increases from the distal end to the proximal end and is smaller than the area of the first net opening 421 b. Since the areas of the plurality of third mesh units 641h gradually increase from the distal end to the proximal end, that is, the mesh design of the mesh body 63h gradually becomes dense from the proximal end to the distal end, so as to prevent the thrombus entering the mesh body 63h from escaping, thereby recovering the thrombus falling or overflowing from the stent body 101h, and increasing the recanalization rate of the blood vessel.

Referring to fig. 16 and 17, fig. 16 is a schematic structural diagram of the net body 63 h; fig. 17 is a bottom view of the net body 63 h. The mesh body 63h is constructed in a tapered kaleidoscope pattern. Specifically, the net body 63h is formed of a plurality of layers of patterned ring structures 631h in the axial direction of the protective umbrella 6h, the plurality of layers of patterned ring structures 631h are connected to each other seamlessly, and each layer of patterned ring structures 631h is connected by a plurality of third grid cells 641h having the same mesh area. Specifically, a third grid unit 641h of one of the layers 631h faces the gap between two adjacent third grid units 641h of the other layer 631h, so that the umbrella 6 can be compressed more easily and can adapt to small blood vessels.

It should be noted that the structural design of the protective umbrella 6h and the mounting structure 104h of the bracket body 101h of the thrombectomy bracket 100h according to the sixth embodiment is applicable to the thrombectomy brackets 100b, 100d, and 100g according to the second, third, and fifth embodiments, and will not be described herein again.

Referring to fig. 18, fig. 18 is a schematic structural diagram of a bolt taking system 1000 according to an embodiment of the present invention. The thrombectomy system 1000 includes the thrombectomy stent 100 described above, as well as the push rod 200 and microcatheter 300. The thrombectomy stent 100 comprises a thrombectomy stent 100, a push rod 200 is connected to the proximal end of the thrombectomy stent 100, and the push rod 200 and the thrombectomy stent 100 are pressed and guided into a micro-catheter 300. The thrombectomy stent 100 can move inside and outside the microcatheter 300 by pushing and pulling the push rod 200. When the push rod 200 moves towards the direction close to the proximal end thereof, the thrombus removal stent 100 is retracted into the microcatheter 300; when the push rod 200 is moved away from its proximal end, the thrombectomy stent 100 is pushed out of the microcatheter 300.

In this embodiment, the connection between the proximal end of the thrombectomy stent 100 and the distal end of the pushing rod 200 includes welding, sleeving or adhesive fixation. Alternatively, the soldering includes, but is not limited to, silver soldering or gold soldering. Adhesive includes, but is not limited to, UV glue or epoxy glue. The micro-catheter 300 is sleeved outside the push rod 200. The embolectomy system 1000 also includes a loading tube 400. The loading tube 400 is used to secure the microcatheter 300.

When the thrombus removal device is used, the proximal end of the thrombus removal support 100 is connected with the distal end of the push rod 200, and then the mounted thrombus removal support 100 and the push rod 200 are compressed into the microcatheter 300 in advance. In the interventional therapy, the microcatheter 300 is delivered to the lesion of the blood vessel and passes through the thrombus, fixing the microcatheter 300. The thrombus stent 100 is pushed to the position of the thrombus determined according to the visualization positioning element 102 by the pushing rod 200, the micro-catheter 300 is retracted to release the thrombus stent 100 at the far end thereof, the thrombus stent 100 is flicked and anchored at the far end to the blood vessel wall, then the pushing rod 200 is slowly pushed forward, and simultaneously the micro-catheter 300 is retracted under the reaction force to release the tension of the micro-catheter 300, and the process is repeated for a plurality of times until the thrombus stent 100 is completely released.

Because the thrombectomy stent 100 is made of a shape memory material, the thrombectomy stent 100 has elasticity such that the thrombectomy stent 100 can be transitioned between a compressed state and a released state. By releasing the thrombectomy stent 100, the thrombectomy stent 100 can be completely embedded inside the thrombus. After waiting for a certain time, the push rod 200 is pulled back, the thrombus is captured by the thrombus taking support 100, and the thrombus taking support 100 and the micro catheter 300 are withdrawn and taken out of the body, so that the whole thrombus taking process is completed. The thrombectomy stent 1000 as a whole is crimped and introduced into the micro-catheter 300, that is, the thrombectomy stent 100 is delivered to the lesion site of the blood vessel through the micro-catheter 300.

It should be noted that the embolectomy supports 100a, 100b, 100d, 100f, 100g, and 100h in the second to ninth embodiments can be applied to an embolectomy system, and are not described herein again.

In some embodiments, the embolectomy stent further comprises a protective umbrella arranged at the distal end of the stent body, the push rod is connected to the proximal end of the stent body, the push rod, the stent body and the protective umbrella are pressed and guided into the microcatheter, the stent body and the protective umbrella can move inside and outside the microcatheter by pushing and pulling the push rod, and when the push rod moves towards the direction close to the proximal end of the push rod, the stent body and the protective umbrella are retracted into the microcatheter; when the push rod moves towards the direction far away from the near end of the push rod, the bracket body and the protective umbrella are pushed out of the micro-catheter.

The thrombus removal stent and the thrombus removal system provided by the embodiment of the invention comprise a first stent body and a second stent body arranged at the far end of the first stent body, wherein the second stent body comprises a large-diameter section, a small-diameter section and a transition section, the large-diameter section and the small-diameter section are alternately connected, the large-diameter section and the small-diameter section are connected through the transition section, the thrombus removal stent has a semi-free state and a free state, and at least part of the structure of the second stent body is of an approximate single-layer tubular structure in the semi-free state; in the free state, the second stent body is of an approximate double-layer tubular structure, so that a blood flow channel can be established when the thrombus removal stent is in the semi-free state, the blood flow blocking the blood vessel is recovered before thrombus is removed, and the safety of a thrombus removal operation is improved.

The embodiments of the present invention are described in detail, and the principles and embodiments of the present invention are explained herein by applying specific embodiments, and the descriptions of the embodiments are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in view of the above, the content of the present specification should not be construed as a limitation to the present invention.