WO2021136350A1

WO2021136350A1 - Thrombus retrieving stent and thrombus retrieving system

Info

Publication number: WO2021136350A1
Application number: PCT/CN2020/141281
Authority: WO
Inventors: 王永胜; 尤岩; 高国庆; 舒素云
Original assignee: 杭州德诺脑神经医疗科技有限公司
Priority date: 2019-12-30
Filing date: 2020-12-30
Publication date: 2021-07-08
Also published as: WO2021136380A1

Abstract

A thrombus retrieving stent (100, 100a, 100b, 100c, 100d, 100e) comprises a tubular and/or cage-shaped stent main body (101, 101a, 101b, 101c, 101d, 101e). The stent main body (101, 101a, 101b, 101c, 101d, 101e) comprises a first stent main body (10, 10a, 10b, 10c, 10d, 10e) and a second stent main body (30, 30a, 30b, 30c, 30d, 30e) provided at a distal end of the first stent main body (10, 10a, 10b, 10c, 10d, 10e) . The first stent main body (10, 10a, 10b, 10c, 10d, 10e) and the second stent main body (30, 30a, 30b, 30c, 30d, 30e) are in smooth transition connection. The second stent main body (30, 30a, 30b, 30c, 30d, 30e) comprises large-diameter sections (31, 31a, 31b, 31c, 31d, 31e) and small-diameter sections (33, 33a, 33b, 33c, 33d, 33e) arranged in an alternating manner and connected together.

Description

Bolt removal bracket and bolt removal system

This application requires the priority of a Chinese patent application filed with the Chinese Patent Office on December 30, 2019, with the application number CN 201911424621.1, and the invention title is "Tbolt Removal Stent and Tether Removal System" and submitted to China on December 30, 2019 The Patent Office, the application number is CN 201911423136.2, and the title of the invention is the priority of the Chinese patent application "Tbolt removal device and bolt removal system", the entire content of which is incorporated into this application by reference.

Technical field

The invention relates to the technical field of medical devices, in particular to a thrombus removal stent and a thrombus removal system.

Background technique

Thrombus is a small piece of blood that forms on the surface of the exfoliated or repaired part of the inner surface of the blood vessel of the cardiovascular system. Thrombosis spreads throughout the cardiovascular system and spreads to tissues and organs throughout the body. It is not limited to myocardial infarction, deep vein thrombosis or cerebrovascular thrombosis. Thrombosis can occur in blood vessels in any part of the body. Intracranial thrombosis is a special clinical type of cerebrovascular disease. It is easy to cause cerebral embolism. It has the characteristics of high morbidity, disability, mortality and recurrence. It is fatal and disabling for middle-aged and elderly people. The main disease.

The recanalization of blood vessels is the key to the treatment of acute ischemic stroke. At present, the conventional methods for the treatment of ischemic stroke include two categories: drug thrombolysis or mechanical thrombectomy.

Drug thrombolysis is a catheter injecting a thrombolytic agent into the attachment of the lesion in the blood vessel referred to by the lesion, and a high concentration of thrombolytic agent is formed in the local area of the lesion, thereby accelerating the speed of thrombolysis and increasing the chance of vascular recanalization. According to the findings of the National Institute of Neurological Diseases and Stroke, intravenous thrombolysis should be performed within 3 hours of onset, and the arterial thrombolysis time window is within 6 hours. Therefore, drug thrombolytic therapy is only suitable for smaller blood clots. When the volume of the thrombus is too large, a very large dose is needed to dissolve the large blood clot, and it is easy to cause various complications and the risk is high.

In order to solve the above-mentioned drug thrombolytic problem, mechanical methods are used to eliminate thrombosis. Mechanical thrombectomy includes the following methods: thrombectomy, laser thrombectomy, thrombectomy with catcher, thrombectomy with thrombectomy net. The thrombectomy is more thorough in removing the thrombus, but it damages the blood vessel wall too much, which can easily cause various concurrent inflammations. The operation of laser thrombus breaking is difficult. If the laser energy is too low, it will be ineffective. If the energy is too high, the blood vessels will be damaged, and it is also easy to cause various complications. The operation of the catcher to remove the thrombus is simple, and it does little damage to the blood vessel wall, but it often fails to catch the blood clot. The operation of the thrombus-trapping net to remove the thrombus is simple, but it cannot be used in intracranial blood vessels because of the large volume of the thrombus-trapping net. In summary, the existing mechanical thrombectomy methods fail to meet the characteristics of high thrombus capture efficiency and small mechanical damage at the same time.

Summary of the invention

In view of this, it is necessary for the present invention to provide a bolt-removing bracket and a bolt-removing system to solve the above technical problems.

In the first aspect, an embodiment of the present invention provides a plug-removing stent, which includes a stent body having a tubular and/or cage-like structure. The stent body includes a first stent body and a distal end of the first stent body. A second stent body, the first stent body and the second stent body are smoothly transitionally connected, and the second stent body includes a large pipe diameter section and a small pipe diameter section that are alternately connected.

In the second aspect, an embodiment of the present invention provides a thrombus removal system, including a microcatheter, a push rod, and the thrombus removal stent as described above, the push rod is connected to the proximal end of the thrombus removal stent, and the push rod The rod and the thrombus removal stent are crimped and introduced into the microcatheter. The thrombus removal stent can be pushed and pulled by the push rod to move inside and outside the microcatheter. When the push rod moves toward the proximal end thereof When the time, the thrombus retrieval stent is recovered into the micro catheter; when the push rod moves in a direction away from its proximal end, the thrombus retrieval stent is pushed out of the micro catheter.

Compared with the prior art, the bolt removal stent and bolt removal system provided by the embodiments of the present invention are based on the smooth transition connection between the first stent body and the second stent body, and the second stent body includes alternately connected Large pipe diameter section and small pipe diameter section. In this way, while the thrombus removal stent has flexibility, it also has a certain radial and axial support force, and effectively prevents the thrombus removal stent from collapsing when it completely passes through the blood vessel, thereby improving the efficiency of thrombus capture and the process of thrombus removal. It reduces the damage to the blood vessel caused by the embolization stent.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

Fig. 1 is a schematic diagram of the structure of the bolt removal bracket provided by the first embodiment of the present invention.

Fig. 2 is a three-dimensional development view of the bolt removal bracket in Fig. 1 in a plane.

Fig. 3 is a schematic diagram of the structure of the bolt removal bracket provided by the second embodiment of the present invention.

Fig. 4 is a schematic diagram of the structure of the bolt removal bracket provided by the third embodiment of the present invention.

Fig. 5 is a schematic diagram of the structure of the bolt removal bracket provided by the fourth embodiment of the present invention.

Fig. 6 is a schematic structural diagram of a bolt removal bracket provided by a fifth embodiment of the present invention.

Fig. 7 is a schematic structural diagram of a bolt removal bracket provided by a sixth embodiment of the present invention.

Fig. 8 is a schematic structural diagram of a bolt removal system provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that in the field of interventional medicine, the end of the instrument close to the operator is usually called the proximal end, and the end of the instrument far away from the operator is called the distal end. Specifically, the distal end refers to the end of the instrument that can be freely inserted into the animal or human body. The near end refers to the end used for user or machine operation or the end used to connect to other devices.

It can be understood that the terms in the specification and claims of the present invention and the above-mentioned drawings are only for describing specific embodiments, and are not intended to limit the present invention. The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific sequence. Unless the context clearly states otherwise, the singular forms "a" and "the" are also intended to include the plural forms. The term "including" and any variations of them are intended to cover non-exclusive inclusion. In addition, the present invention can be implemented in a variety of different forms, and is not limited to the embodiment described in this embodiment. The purpose of providing the following specific embodiments is to facilitate a clearer and thorough understanding of the disclosure of the present invention, wherein the words indicating directions such as up, down, left, and right are only for the position of the structure shown in the corresponding drawings.

The following descriptions of the specification are preferred embodiments for implementing the present invention. However, the above description is for the purpose of explaining the general principles of the present invention and is not intended to limit the scope of the present invention. The protection scope of the present invention shall be subject to those defined by the appended claims.

Please refer to FIG. 1 and FIG. 2 together. FIG. 1 is a schematic structural diagram of a bolt removing bracket 100 provided by a first embodiment of the present invention, and FIG. 2 is a planar three-dimensional expanded view of the bolt removing bracket 100. The plug-removing stent 100 includes a stent body 101 having a tubular and/or cage-like structure. The stent body 101 includes a first stent body 10 and a second stent body 30 provided at the distal end of the first stent body 10. The first bracket body 10 and the second bracket body 30 are integrally formed and smoothly transitioned. The second bracket body 30 includes a large pipe diameter section 31 and a small pipe diameter section 33 that are alternately connected. In this way, while the thrombus removal stent 100 has flexibility, it also has a certain radial and axial support force, and effectively prevents the thrombus removal stent 100 from collapsing when it passes through the blood vessel completely, thereby improving the efficiency of thrombus capture, and During the embolization process, the damage to the blood vessel of the embolization stent is reduced.

Specifically, in some embodiments, the first bracket body 10 and the second bracket body 30 are integrally formed so as to improve the stability and reliability of the connection between the first bracket body 10 and the second bracket body 30. In some other embodiments, the first bracket body 10 and the second bracket body 30 may also be fixedly connected together by technical means commonly used in the art, such as pressing, hot melting, bonding, welding, or pressure riveting.

Wherein, both the proximal end and the distal end of the second stent body 30 are configured as large diameter sections 31. The small pipe diameter section 33 is arranged between two adjacent large pipe diameter sections 31. The second bracket body 30 includes a plurality of first closed loop units 311, a plurality of second closed loop units 312 and a plurality of third closed loop units 331. The plurality of first closed loop units 311 and the plurality of second closed loop units 312 are connected to each other to form a large pipe diameter section 31. The plurality of third closed-loop units 331 are connected to each other to form a small pipe diameter section 33.

In this embodiment, the second stent body 30 includes two large diameter sections 31 and one small diameter section 33. The two large diameter sections 31 are located at the proximal and distal ends of the second stent body 30. The small pipe diameter section 33 is arranged in the middle of the second bracket body 30 and is located between two adjacent large pipe diameter sections 31.

Optionally, the area of the first closed-loop unit 311 is smaller than the area of the second closed-loop unit 312 and larger than the area 331 of the third closed-loop unit, so that the thrombus removal stent 100 can provide a certain pulling force during the thrombus removal process, and effectively prevent thrombosis. Move, and then facilitate the removal of the thrombus. In addition, since the area of the second closed-loop unit 312 is relatively large, it is suitable for blood vessels of different sizes, that is, the second closed-loop unit 312 can be fully expanded for large blood vessels, and the second closed-loop unit 312 can be overlapped for small blood vessels. Thereby, the thrombus can be captured more firmly. Since the area of the area 331 of the first closed loop unit 311 and the third closed loop unit is relatively small, the contact area with the blood vessel wall is reduced, and the damage to the blood vessel wall is reduced.

As shown in FIG. 2, in this embodiment, the first closed-loop unit 311 surrounds the second closed-loop unit 312, and two adjacent second closed-loop units 312 are arranged at intervals along the circumferential direction of the second bracket body 30. The second closed loop unit 312 is evenly distributed along the axial and circumferential directions of the second stent body 30 so that the thrombus can enter the thrombus removal stent 100. Optionally, a plurality of second closed-loop units 312 are located on the same layer in the radial direction of each large pipe diameter section 31. In other embodiments, the plurality of second closed-loop units 312 are located on different layers in the radial direction of each large pipe diameter section 31, and the plurality of second closed-loop units 312 of two adjacent layers are along the line of the second stent body 30. Circumferentially staggered settings in order to firmly capture the thrombus, thereby increasing the effective capture rate of the thrombus.

The shapes of the first closed-loop unit 311 and the third closed-loop unit 331 include, but are not limited to, one or more of a circle, an ellipse, a triangle, a diamond, a trapezoid, and a hexagon. The second closed-loop unit 312 is approximately in the shape of an hourglass, so that when the second stent unit 30 is squeezed in the blood vessel, it can make a large deformation, so that the second stent unit 30 has better flexibility, thereby improving thrombus. Capture efficiency, and reduce the damage to the blood vessel of the embolization stent during the embolectomy process. In addition, since the second closed-loop unit 312 is in the shape of an hourglass, the second closed-loop unit 312 can adapt to thrombus of different sizes, which improves the effective capture rate of thrombus.

In this embodiment, both the first closed-loop unit 311 and the third closed-loop unit 331 are composed of a closed grid. The second closed loop unit 312 is enclosed by two semi-closed grids. A plurality of grids are arranged in a row in sequence, and the grids of two adjacent rows are arranged in a staggered manner. Two adjacent grids are connected together by connecting ribs 103. In the axial direction parallel to the bolt removal stent 100, in two adjacent rows, the grid of one row faces the gap between the two adjacent grids in the other row, so that the bolt removal stent 100 is more easily compressed and more adaptable Small blood vessels, and easy to introduce into the micro catheter 300 (refer to Figure 8).

Specifically, the second closed loop unit 312 includes a first grid 3121, a second grid 3122, and a channel 3123 connecting the first grid 3121 and the second grid 3122. The first grid 3121 and the first closed-loop unit 311 are sequentially arranged in a row, the second grid 3122 is also sequentially arranged in a row with the first closed-loop unit 311, and the channel 3123 is also sequentially arranged in a row with the first closed-loop unit 311. The multiple second closed-loop units 312 on the same layer are symmetrically distributed from the central axis of the second bracket body 30. The extending direction of the channel 3123 is parallel to the central axis of the second bracket body 30. In the radial direction of the large pipe diameter section 31 of the same layer, the channel 3123 and the connecting rib 103 are directly opposite.

In some embodiments, the first stent body 10 is configured in a funnel structure, and the second stent body 30 is configured in a straight tube structure, so that the thrombus removal stent 100 avoids falling off of the thrombus when retracting toward the proximal end of the thrombus removal stent 100. Specifically, the first bracket body 10 includes a plurality of fourth closed-loop units 11. A plurality of fourth closed-loop units 11 are connected to each other to form the funnel structure. Wherein, the tube diameter of the first stent body 10 gradually increases from its proximal end to the distal direction, so as to prevent the proximal end of the first stent body 10 from being removed due to bolt removal during the process of retreating the bolt removal stent 100 toward its proximal direction. The influence of the withdrawal force of the stent 100 causes the overall diameter of the stent 100 to be reduced or kinked, thereby improving the efficiency of capturing thrombus and reducing the damage to the blood vessel caused by the thrombus removal stent 100. In this way, a smooth transitional connection between the first stent body 10 and the second stent body 30 is ensured, thereby reducing the damage to the blood vessel caused by the thrombus removal stent during the thrombus removal process.

In some embodiments, the area of the fourth closed-loop unit 11 is equal to the area of the first closed-loop unit 311, thereby reducing the contact area between the first stent body 10 and the second stent body 30 and the blood vessel wall, thereby reducing the impact on the blood vessel wall. damage.

Please refer to FIG. 3, which is a schematic structural diagram of a bolt-removing bracket 100 a provided by the second embodiment of the present invention. In the second embodiment, the structure of the bolt removal bracket 100a is similar to the structure of the bolt removal bracket 100 of the first embodiment. The difference is that the proximal end of the first stent body 10a is configured as an oblique cone-shaped structure. The proximal end of the first stent body 10a forms a sloped entrance 15a. The shape of the inlet 15a is cone-shaped, like a drop shape. In this embodiment, the shape of the inlet 15a is a fusiform. In this way, based on the gradient design of the entrance 15a of the first stent body 10a, not only can the withdrawal force of the withdrawal bolt removal stent 100a be effectively prevented from being transmitted to the entire circumference of the bolt removal stent 100a, but also the pipe diameter of the first stent body 10a can be avoided. It becomes smaller during the withdrawal of the thrombus removal stent 100a, so as to ensure that the thrombus is not easy to fall off when the thrombus removal stent 100a is withdrawn.

Please refer to FIGS. 1 and 2 again. Optionally, the bracket body 101 further includes a plurality of connecting ribs 103 connecting the first closed loop unit 311, the second closed loop unit 312, the third closed loop unit 331 and the fourth closed loop unit 11. The plurality of connecting ribs 103 are parallel to the central axis of the bracket body 101. The proximal end of the first stent body 10 is also provided with a connecting head 13. The connector 13 extends in the direction of the central axis of the bracket body 101. When the thrombus removal stent 100a is withdrawn, the traction force will be concentrated on the extension line where the connecting head 13 is located, ensuring that the diameter of the distal end of the stent body 101 remains unchanged, thereby improving the efficiency of thrombus capture.

In some embodiments, the connecting head 13 is provided with a developing positioning element 102 so as to indicate the position of the plug-removing bracket 100 through the position of the developing positioning element 102 under the detection of the instrument. The developing positioning member 102 is made of a radiopaque material. The radiopaque material is preferably a precious metal material such as gold, platinum, or tantalum. The developing positioning element 102 can take various forms such as ring shape, wire shape, ribbon shape, or dot shape, and is fixed to the bolt removal bracket 100 by pressing, hot melting, bonding, welding or pressure riveting and other common technical means in the art. on. In some embodiments, the developing positioning element 102 may be ring-shaped, and the developing positioning element 102 is sleeved outside the connecting head 13.

In this embodiment, two visualization positioning elements 102 are respectively provided at the distal and proximal positions of the thrombus removal stent 100 to accurately locate the position of the thrombus, so that the thrombus can be detected during the thrombus removal process using the thrombus removal stent 100 To capture the thrombus and determine whether the thrombus is separated from the thrombus retrieval stent 100 during the withdrawal process of the thrombus retrieval stent 100 for real-time observation, and then guide the specific microscopic operation of thrombus retrieval, that is, to guide the thrombus retrieval stent 100 to switch between the compressed state and the released state , Which makes the bolt removal more accurate. In some other embodiments, the middle part of the thrombus removal stent 100 may also be provided with multiple visualization positioning elements to more accurately locate the position of the thrombus.

In this embodiment, both the first stent body 10 and the second stent body 30 are made of a metal material with a memory effect or a polymer material with elasticity, so that the stent body 101 self-expands to form a tube and/or a cage. structure. The metal material is, for example, but not limited to nickel-titanium alloy or cobalt-based alloy. Specifically, the first stent body 10 and the second stent body 30 can be formed by laser cutting a plate-shaped nickel-titanium alloy to form a tubular or cage-like structure with a hollow structure, and then be crimped, heat-treated and shaped. In another embodiment, the first stent body 10 and the second stent body 30 can also form a tubular or cage-like structure with the hollow structure by weaving a wire-like Nitinol alloy. In other embodiments, the first bracket body 10 and the second bracket body 30 may also be processed by using elastic plastic materials.

Please refer to FIG. 4, which is a schematic structural diagram of a bolt removal bracket 100b provided by the third embodiment of the present invention. In the third embodiment, the structure of the bolt removal bracket 100b is similar to the structure of the bolt removal bracket 100 of the first embodiment. The difference is that the second bracket body 30b includes three large diameter sections 31b and two small diameter sections 33b.

In this embodiment, the three large pipe diameter sections 31b and the two small pipe diameter sections 33b are integrally formed and smoothly transitioned. The large pipe diameter section 31b, the small pipe diameter section 33b, the large pipe diameter section 31b, the small pipe diameter section 33b, and the large pipe diameter section 31b are sequentially connected to form the second stent body 30b. Specifically, two small pipe diameter sections 33b are arranged at intervals, and each small pipe diameter section 33b is arranged between two adjacent large pipe diameter sections 31b. Both the proximal and distal ends of the second stent body 30b are configured as large diameter sections 31b. In this way, the thrombus removal stent 100b can more effectively avoid the detachment of the thrombus, and is suitable for thrombus removal from blood vessels of different sizes.

It should be noted that in some other embodiments, the number of large diameter sections and small diameter sections can be designed according to actual environmental conditions such as thrombus size or blood vessel thickness, which is not limited in the present invention.

Please refer to FIG. 5. FIG. 5 is a schematic structural diagram of a bolt removal bracket 100c provided by the fourth embodiment of the present invention. In the fourth embodiment, the structure of the bolt removal bracket 100c is similar to the structure of the bolt removal bracket 100b of the third embodiment. The difference is that the bolt removal bracket 100c further includes a plurality of capturing units 20c and a plurality of auxiliary capturing units 50c.

In this embodiment, multiple capture units 20c are arranged at the junction of the large pipe diameter section 31c and the small pipe diameter section 33c, that is, the small pipe diameter section 33c is provided with multiple capture units at the proximal and distal ends. 20c to further improve the capture efficiency of the thrombus removal stent 100c. The multiple catching units 20c are evenly distributed in the circumferential direction of the bolt removal bracket 100c. A plurality of catching units 20c are enclosed in a circle from the circumference of the bolt-removing bracket 100c. A circle can include 2-6 capture units. The bolt-removing bracket 100c can be provided with 2-4 rounds of capture units in the axial direction.

Among them, each capture unit 20c is configured as a closed loop structure. Each catching unit 20c includes a connecting part 21c and a catching part 22c opposed to each other. The connecting portion 21c is substantially in an inverted V shape, and the capturing portion 22c is substantially in a V shape. The connecting portion 21c is connected to the bracket body 101, and the capturing portion 22c can extend outward or inward relative to the bracket body 101c, so that a receiving space 201c is formed between the capturing portion 22c and the bracket body 101c. The capturing portion 22c can move in a direction perpendicular to the axis of the bolt removal bracket 100c. In this way, it is avoided that when the thrombus removal stent 100c moves in the blood vessel, the capturing portion 22c does not directly contact the blood vessel wall, thereby avoiding damage to the blood vessel wall tissue.

The distal end of the capturing portion 22c is provided with an arc-shaped chamfer to further prevent the capturing portion 22c of the capturing unit 20 from damaging the blood vessel wall. In addition, when the bolt-removing bracket 100c is in an expanded state, the capturing portion 22c of each capturing unit 20c is located outside the closed loop unit 32c of the bracket body 101c, that is, there is a gap between the capturing portion 22c and the bracket body 101c for capturing The capturing part 22c of the unit 20c is inserted into the thrombus, or the thrombus is clamped in the accommodating space 201c, thereby improving the anchoring of the thrombus by the thrombus removal stent 100c.

Specifically, each auxiliary catching unit 50c is fixed at the junction of the connecting part 21c and the catching part 22c of the catching unit 20c. In this embodiment, each auxiliary capture unit 50c is arranged between two adjacent capture units 20c.

The plurality of auxiliary catching units 50c are all configured in a barbed structure. Each auxiliary catching unit 50c includes opposite connecting ends 51c and free ends 52c. The proximal end of each auxiliary capturing unit 50c is a connecting end 51c, and the distal end of each auxiliary capturing unit 50c is a free end 52c. Each auxiliary catching unit 50c can also be directly connected to the connecting rib 103c of the bolt-removing bracket 100c. Each auxiliary catching unit 50c and the connecting rib 103c are integrally formed.

The free end 52c of the auxiliary catching unit 50c can extend outward or inward relative to the bracket body 101c, and move in a direction perpendicular to the axis of the bolt removal bracket 100c. Wherein, the auxiliary catching unit 50c can be arranged in 2-6 circles along the axial direction of the stent body 101c, and each circle has 2-6 auxiliary catching units 50c, so as to further improve the thrombus catching efficiency of the thrombus removal stent 100c.

Among them, the auxiliary capture unit 50c has self-expandability. The material contained in the auxiliary capture unit 50c can be the material contained in the bolt-removing bracket 100c, which will not be repeated here.

In some embodiments, a receiving space 501c is formed between the free end of each auxiliary capture unit 50c and the bracket body 101c. In this way, when the thrombus removal stent 4c is in the released state, there is a gap between the free end of each auxiliary capture unit 50c and the stent body 101c, so that the auxiliary capture unit 50c can be inserted into the thrombus, or the thrombus can be held in the containing space. 501c, thereby further improving the anchoring of thrombus by the thrombus removal stent 100c.

The distal end 52c of each auxiliary capture unit 50c is provided with an arc-shaped chamfer to avoid damage to the blood vessel wall by the auxiliary capture unit 50c. In this embodiment, multiple auxiliary capturing units 50c are located at the junction of the large diameter section 31c and the small diameter section 33c, so as to reduce the risk of the auxiliary capturing unit 50c damaging the blood vessel wall.

It should be noted that the number of capture units 20c and auxiliary capture units 50c can be set according to the diameter of the plug-removing bracket 100c, and the arrangement positions, lengths, and inclination angles of the multiple auxiliary capture units 50c can be the same as each other. They may also be different from each other, and the present invention is not limited.

Please refer to FIG. 6. FIG. 6 is a schematic structural diagram of a bolt removal bracket 100 d according to a fifth embodiment of the present invention. In the fifth embodiment, the structure of the bolt removing bracket 100d is similar to the structure of the bolt removing bracket 100c of the fourth embodiment. The difference is that the proximal end of the first stent body 10e is configured as an oblique cone-shaped structure. Please refer to the description of the second embodiment for the specific structure of the oblique cone cylindrical structure.

Please refer to FIG. 7. FIG. 7 is a schematic structural diagram of a bolt removal bracket 100 d according to a sixth embodiment of the present invention. In the sixth embodiment, the structure of the bolt removal bracket 100e is similar to the structure of the bolt removal bracket 100c of the fourth embodiment. The difference is that the bolt removal bracket 100e further includes a plurality of connecting members 53e, and the plurality of auxiliary capturing units 50e are connected to the bracket body 101e through the corresponding connecting members 53e.

In this embodiment, each connecting member 53e is configured as a curved structure, and each connecting member 53e is bent inwardly relative to the bracket body 101e to increase the receiving space 501e formed between the auxiliary catching unit 50e and the bracket body 101e. So as to provide more accommodation space for the thrombus. Specifically, a distance is formed between the inner side of each connecting piece 53e and the axis of the stent body 101e, and the outer side of each connecting piece 53e is connected to the periphery of the stent body 101e, so as to prevent the connecting piece 53e from intercepting the thrombus and preventing entry. Take the bolt inside the bracket 100e. The plurality of connecting members 53e are evenly distributed from the circumferential direction of the bracket body 101e. Each connecting member 53e can be integrally formed with the bracket body 101e. In other embodiments, each connecting member 53e can also be fixed to the bracket body 101e by a mounting structure. The mounting structure is, for example, but not limited to an adhesive, a crimping structure or a riveting structure.

In some embodiments, each auxiliary capture unit 50e is connected to the bracket body 101e through a corresponding connecting member 53e. Each auxiliary catching unit 50e is arranged at the connection between the connecting piece 53e and the catching unit 20e. Specifically, the connecting end 51e of the auxiliary capturing unit 50e is connected to the proximal end of the connecting piece 53e.

Wherein, the plurality of connecting members 53e and the plurality of catching units 20e are alternately arranged and connected to each other to ensure the flexibility of the bolt removal stent 100e and a certain supporting force in the radial and axial directions of the bolt removal stent 100e. In addition, the design of the connecting piece 53e can also increase the space between the capturing portion 22e and the stent body 101e, and provide more accommodating space for thrombus. Specifically, the proximal end of each connecting piece 53e is connected to the distal end of the connecting portion 21e of one of the catching units 20e (that is, the proximal end of the catching portion 22e), and the distal end of each connecting piece 53e is connected to the other catching unit. The proximal end of the connecting portion 21e of 20e. In this embodiment, each connecting member 53e can be integrally formed with the bracket body 101e. In some other embodiments, each connecting member 53e may also be fixed on the bracket body 101e by a mounting structure. The mounting structure is, for example, but not limited to an adhesive, a crimping structure or a riveting structure.

In some embodiments, the free end 52e of the auxiliary capturing unit 50e is configured as a curved structure, and the bending direction of the auxiliary capturing unit 50e is opposite to the bending direction of the connecting member 53e. Wherein, each auxiliary catching unit 50e is bent outward relative to the bolt-taking bracket 100e to further increase the accommodating space 201e formed between the auxiliary catching unit 20e and the bracket body 101e and to increase the auxiliary catching unit 50e and the bracket body 101e The accommodating space 501e formed therebetween provides more accommodating space for further thrombosis. In addition, the design of the curved structure of the auxiliary capture unit 50e can hold the thrombus more firmly, and improve the safety of the thrombus removal stent 100e, prevent the free end 52e from piercing the direction of the blood vessel wall, and increase the adhesion to the blood vessel wall. Avoid damaging the blood vessel wall tissue.

It should be noted that the structural design of the bolt removal bracket 100a of the second embodiment is applicable to the

bolt removal brackets

100b, 100e in the third and sixth embodiments, and will not be repeated here.

Please refer to FIG. 8, which is a schematic structural diagram of a bolt removal system 1000 according to an embodiment of the present invention. The thrombus removal system 1000 includes the above-mentioned thrombus removal stent 100d, a push rod 200 and a micro catheter 300. The push rod 200 is connected to the proximal end of the thrombus removal stent 100d, and the push rod 200 and the thrombus removal stent 100d are crimped and introduced into the microcatheter 300. The plug-removing stent 100d can move inside and outside the microcatheter 300 by pushing and pulling the push rod 200. When the push rod 200 moves toward its proximal end, the thrombus removal stent 100d is recovered into the micro catheter 300; when the push rod 200 moves away from its proximal end, the thrombus removal stent 100d is pushed out of the micro catheter 300 .

In this embodiment, the connection between the proximal end of the bolt-removing bracket 100d and the distal end of the push rod 200 includes welding, sleeve connection, or glue-fixed connection. Optionally, welding includes, but is not limited to silver welding or gold welding. Adhesives include, but are not limited to UV glue or epoxy glue. The micro catheter 300 is sleeved outside the pushing rod 200. The bolt removal system 1000 further includes a loading tube 400. The loading tube 400 is used to fix the micro catheter 300.

When in use, first connect the proximal end of the thrombus removal stent 100d and the distal end of the push rod 200, and then compress the installed thrombus removal stent 100d and the push rod 200 into the microcatheter 300 in advance. During the interventional treatment, the microcatheter 300 is delivered to the diseased part of the blood vessel, passes through the thrombus, and fixes the microcatheter 300. Push the thrombus removal stent 100d through the push rod 200 to the position of the thrombus determined according to the imaging positioning element 102, retract the microcatheter 300 to release the thrombus removal stent 100d at its distal end, and the thrombus removal stent 100d bounces at the distal end to anchor the blood vessel Then, push the push rod 200 forward slowly, and at the same time withdraw the micro-catheter 300 under the reaction force to release the tension of the micro-catheter 300, and repeat it many times until the embolization stent 100d is fully released.

Since the plug removal stent 100d is made of a shape memory material, the plug removal stent 100d has elasticity, so that the plug removal stent 100d can switch between a compressed state and a released state. By releasing the thrombus removal stent 100d, the thrombus removal stent 100d can be completely embedded inside the thrombus. After waiting for a certain period of time, the push rod 200 is pulled back, and the thrombus removal stent 100d is retracted to capture the thrombus, until the thrombus removal stent 100d together with the microcatheter 300 is retracted out of the body to complete the entire embolization process. The thrombus removal device 1000 as a whole is crimped and introduced into the microcatheter 300, that is, the thrombus removal stent 100d is delivered to the diseased part of the blood vessel through the microcatheter 300.

It should be noted that the

bolt removal brackets

100, 100a, 100b, 100c, 100e in the first embodiment to the fourth embodiment and the sixth embodiment can all be applied to the bolt removal system, which will not be repeated here.

The bolt removal stent and bolt removal system provided by the embodiments of the present invention are based on the smooth transitional connection between the first stent body and the second stent body, and the second stent body includes alternately connected large pipe diameter sections and small pipe diameter sections. In this way, while the thrombus removal stent has flexibility, it also has a certain radial and axial support force, and effectively prevents the thrombus removal stent from collapsing when it completely passes through the blood vessel, thereby improving the efficiency of thrombus capture and the process of thrombus removal. It reduces the damage to the blood vessel caused by the embolization stent.

The embodiments of the present invention are described in detail above, and specific examples are used in this article to illustrate the principles and implementation of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; at the same time, for Those of ordinary skill in the art, based on the idea of the present invention, will have changes in the specific implementation and the scope of application. In summary, the content of this specification should not be construed as limiting the present invention.

Claims

A plug-removing stent includes a stent body with a tubular and/or cage-like structure. The stent body includes a first stent body and a second stent body arranged at the distal end of the first stent body. The first stent The body is smoothly transitionally connected with the second bracket body, and the second bracket body includes a large pipe diameter section and a small pipe diameter section that are alternately connected.
The thrombus removal stent according to claim 1, wherein the proximal end and the distal end of the second stent body are both configured as the large tube diameter section, and the small tube diameter section is arranged at two adjacent Between large pipe diameter sections.
The bolt removal stent according to claim 1, wherein the second stent body includes a plurality of first closed loop units, a plurality of second closed loop units, and a plurality of third closed loop units, and a plurality of the first closed loops The unit and the plurality of second closed-loop units are connected to each other to form the large pipe diameter section, and a plurality of third closed-loop units are connected to each other to form the small pipe diameter section.
3. The bolt removal bracket of claim 3, wherein the area of the first closed-loop unit is smaller than the area of the second closed-loop unit and larger than the area of the third closed-loop unit.
The bolt removal stent according to claim 3, wherein the first closed-loop unit surrounds the second closed-loop unit, and two adjacent second closed-loop units are arranged at intervals along the circumferential direction of the second stent body .
3. The bolt removal stent according to claim 3, wherein the second closed loop unit is evenly distributed along the axial and circumferential directions of the second stent body.
The bolt removal stent according to claim 6, wherein a plurality of the second closed-loop units are located on the same layer in the radial direction of each of the large pipe diameter sections; or a plurality of the second closed-loop units are located on the same layer. Each of the large pipe diameter sections is located on a different layer in the radial direction, and a plurality of the second closed-loop units of two adjacent layers are staggered along the circumferential direction of the second stent body.
The bolt removal stent according to claim 3, wherein the second closed-loop unit is in the shape of an hourglass, and the shapes of the first closed-loop unit and the third closed-loop unit include a circle, an ellipse, a triangle, and a diamond. One or more of, trapezoid and hexagon.
The thrombus removal stent according to claim 1, wherein the second stent body includes at least two large pipe diameter sections and at least two small pipe diameter sections, and the large pipe diameter section and the small pipe diameter section The pipe diameter sections are sequentially connected at intervals to form the second bracket body.
The thrombus removal stent according to claim 3, the first stent body includes a plurality of fourth closed-loop units, the plurality of fourth closed-loop units are connected to each other to form a funnel structure, and the pipe diameter of the first stent body is determined by The proximal end gradually increases toward the distal end.
The bolt removal stent according to claim 10, wherein the stent body further comprises a connection connecting the first closed-loop unit, the second closed-loop unit, the third closed-loop unit, and the fourth closed-loop unit A plurality of connecting ribs, the plurality of connecting ribs are parallel to the central axis of the bracket body.
5. The bolt removal stent according to claim 1, further comprising a plurality of catching units, the plurality of catching units are arranged at the junction of the large pipe diameter section and the small pipe diameter section.
The bolt removal bracket according to claim 12, further comprising a plurality of connecting members, and the plurality of connecting members and the plurality of capturing units are alternately arranged and connected to each other.
The bolt removal bracket of claim 13, wherein each of the connecting members is configured as a curved structure, and each of the connecting members is bent inwardly with respect to the bracket body.
The bolt-removing bracket according to claim 12, wherein each of the catching units includes a V-shaped catching portion, and the catching portion can extend outward or inward relative to the stent body, and is in line with the A first accommodating space is formed between the bracket bodies.
The bolt-removing bracket according to claim 13, wherein the bracket body further comprises at least one auxiliary catching unit, and each auxiliary catching unit is provided in the connection between the connecting piece and the catching unit. Place.
The plug-removing bracket according to claim 16, wherein the distal end of each auxiliary catching unit is a free end, and the free end of the auxiliary catching unit is provided with an arc-shaped chamfer, and the The free end of the auxiliary catching unit can extend outward or inward relative to the bracket body and move in a direction perpendicular to the axis of the bolt-removing bracket.
The bolt-removing bracket according to claim 16, wherein a second receiving space is formed between the free end of each auxiliary capturing unit and the bracket body.
16. The bolt-removing bracket of claim 16, wherein each of the auxiliary catching units is configured as a curved structure, and each of the auxiliary catching units is bent outward relative to the bracket body.
16. The bolt removal stent according to claim 16, wherein the auxiliary catching unit is arranged in 2-6 circles along the axial direction of the stent body, and each circle has 2-6 auxiliary catching units.
A thrombus removal system, comprising a push rod, a micro catheter, and the thrombus removal stent according to any one of claims 1-20, the push rod is connected to the proximal end of the thrombus removal stent, and the push rod and The thrombus removal stent is crimped and introduced into the microcatheter. The thrombus removal stent can move inside and outside the microcatheter through the push and pull of the push rod. When the push rod moves toward the proximal end thereof When the time, the thrombus removal stent is recovered into the micro catheter; when the push rod moves in a direction away from its proximal end, the thrombus removal stent is pushed out of the micro catheter.