WO2022100734A1 - Thrombus-taking stent, thrombus-taking device and thrombus-taking system - Google Patents

Abstract

A thrombus-taking stent (1) comprises rigid units (11) and flexible units (12) which are connected in a staggered manner; all the rigid units (11) and the flexible units (12) are of a tubular structure capable of realizing radial compression and expansion; and the flexible units (12) are more flexible than the rigid units (11), and under an equivalent external force, the flexible units (12) are more prone to being deformed compared with the rigid units (11). A thrombus-taking device (100) comprises the thrombus-taking stent (1) and a traction guiding wire (2) connected to the thrombus-taking stent (1). Moreover, a thrombus-taking system comprises the thrombus-taking device (100), a push rod (200), a loading sheath (300) and a micro catheter (400), wherein the push rod (200) is connected to the thrombus-taking stent (1) and is used for pushing and pulling the thrombus-taking stent (1); the loading sheath (300) is used for accommodating the thrombus-taking device (100); and the micro catheter (400) is in communication with the loading sheath (300) and is used for conveying the thrombus-taking device (100). Such structure may increase the success rate of taking thrombi, and further improve the capability of catching thrombi.

Description

Thrombus Retrieval Stand, Thrombus Retrieval Device and Thrombus Retrieval System technical field

The invention relates to the technical field of medical devices, in particular to a thrombectomy bracket, a thrombectomy device and a thrombectomy system.

Background technique

Thrombosis is the abnormal aggregation of platelets and other formed components in the blood to form blood clots in the circulating blood. Thrombosis spreads throughout the cardiovascular system, affecting tissues and organs throughout the body, not limited to myocardial infarction, deep vein thrombosis or cerebrovascular thrombosis and other diseases. Thrombosis can occur in any part of the body in blood vessels. The incidence of venous thrombosis is higher than that of arterial thrombosis, and the ratio of the two can reach 4:1. Venous thrombosis accounts for 40% to 60% of the thrombosis mechanism, and the incidence of occlusive coronary thrombosis is 15% to 95%. Have atherosclerotic plaques. Thrombosis causes vascular occlusion and blood flow obstruction, causing ischemia, hypoxia and even necrosis of related vascular-dominated tissues, resulting in symptoms of corresponding tissue and organ dysfunction.

Nowadays, anticoagulant drugs and thrombolytic drugs are mostly used in clinical treatment, but the therapeutic effect is extremely insignificant. Not suitable for thrombolytic therapy.

At present, some mechanical devices are used for thrombectomy, which provides a new and efficient vascular recanalization treatment method for thrombus patients. The shape and function realization form of the thrombectomy device can be divided into: spiral, screen type, brush type, suction type, and stent type. The common defects of these mainstream products are residual thrombus after thrombectomy and thrombus falling off during retraction, resulting in unsatisfactory thrombus capture performance of the thrombectomy device as a whole. The internal carotid artery, middle cerebral artery, vertebral artery and basilar artery are the common sites of nerve thrombus. The state of acute thrombus is mostly greasy and smooth, and the existing metal thrombectomy stent is difficult to capture completely.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a thrombectomy stent, a thrombectomy device and a thrombectomy system that improve the performance of thrombus capturing.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

According to one aspect of the present invention, the present invention provides a bolus retrieval bracket, which includes rigid units and flexible units that are arranged in a line and alternately connected; both the rigid units and the flexible units are radially adjustable. A compressed and expanded tubular structure; the flexible unit is more flexible than the rigid unit, and when subjected to the same external force, the flexible unit is more easily deformed than the rigid unit.

According to another aspect of the present invention, the present invention further provides a thrombectomy device, which comprises the above-mentioned thrombus retrieval support and a traction guide wire connected to the thrombus removal support.

According to another aspect of the present invention, the present invention also provides a thrombus retrieval system, which includes the above-mentioned thrombus retrieval device, a push rod, a loading sheath and a microcatheter; The end is connected to the thrombus removal bracket for pushing and pulling the thrombus removal bracket; the loading sheath is used to accommodate the thrombus removal device in a compressed state; the microcatheter is used to communicate with the loading sheath, and the inside of the microcatheter The lumen is used to deliver the thrombectomy device.

As can be seen from the above technical solutions, the present invention at least has the following advantages and positive effects:

In the bolus removal bracket of the present invention, a bolt retrieval bracket structure in which a plurality of rigid units and flexible units are alternately connected in a straight line is used. Among them, the rigid unit has a rigid effect, and multiple rigid units can play the role of skeleton support; using the radial scalability of the rigid unit, the tubular structure of the rigid unit can cut and capture the thrombus during natural expansion, and quickly build up The blood flow channel realizes the pre-opening function of the blood flow channel.

The flexible unit is more flexible than the rigid unit, thereby improving the flexibility of the thrombectomy stent, ensuring that the thrombectomy stent always adheres to the vessel wall, preventing thrombus from falling off, and ultimately improving the thrombus capturing performance of the thrombectomy stent. During the retraction process, the risk of thrombus falling off is reduced, the success rate of thrombus removal is improved, and the thrombus capturing performance of the thrombectomy stent is further improved.

Description of drawings

FIG. 1 is a schematic structural diagram of the first embodiment of the thrombectomy device of the present invention.

FIG. 2 is a schematic structural diagram of the bolt removal device shown in FIG. 1 in a radially bent state.

FIG. 3 is a schematic structural diagram of the bolt removal device shown in FIG. 1 in an axially compressed state.

FIG. 4 is a schematic structural diagram of the stud removal device of FIG. 1 before being assembled and used.

FIG. 5 is a schematic structural diagram of the stud removal device of FIG. 4 when it is assembled and used.

FIG. 6 is a schematic diagram of the state in which the thrombectomy device in FIG. 5 is pushed in the microcatheter.

FIG. 7 is a schematic diagram of a first state of the thrombus removal device shown in FIG. 1 during a thrombus removal process.

FIG. 8 is a second state schematic diagram of the thrombus removal device shown in FIG. 1 during the thrombus removal process.

FIG. 9 is a schematic diagram of a third state of the thrombus removal device shown in FIG. 1 during a thrombus removal process.

FIG. 10 is a schematic diagram of a fourth state of the thrombus removal device shown in FIG. 1 during a thrombus removal process.

FIG. 11 is a schematic diagram of a fifth state of the thrombus removal device shown in FIG. 1 during a thrombus removal process.

FIG. 12 is a schematic diagram of a sixth state of the thrombus removal device shown in FIG. 1 during a thrombus removal process.

Fig. 13 is a schematic diagram of a conventional thrombectomy stent passing through a tortuous blood vessel.

Figure 14 is a schematic view of the thrombectomy stent shown in Figure 1 passing through a tortuous blood vessel.

15 is a schematic structural diagram of the second embodiment of the thrombectomy device of the present invention.

16 is a schematic structural diagram of the third embodiment of the thrombectomy device of the present invention.

17 is a schematic structural diagram of the fourth embodiment of the thrombectomy device of the present invention.

FIG. 18 is a schematic structural diagram of the fifth embodiment of the thrombectomy device of the present invention.

FIG. 19 is a schematic structural diagram of the sixth embodiment of the thrombectomy device of the present invention.

20 is a schematic structural diagram of the seventh embodiment of the thrombectomy device of the present invention.

FIG. 21 is a side view of the flexible unit shown in FIG. 20 .

FIG. 22 is another schematic structural diagram of the flexible unit shown in FIG. 20 .

FIG. 23 is another schematic structural diagram of the flexible unit shown in FIG. 20 .

Fig. 24 is a schematic structural diagram of the bolt removal device shown in Fig. 20 in a radially bent state.

FIG. 25 is a schematic structural diagram of the eighth embodiment of the thrombectomy device of the present invention.

FIG. 26 is a schematic view of the structure of the pulling wire shown in FIG. 25 .

FIG. 27 is a schematic structural diagram of the ninth embodiment of the thrombectomy device of the present invention.

The reference numerals are explained as follows:

100/100a/100b/100c/100d/100e/100f/100g/100h, thrombectomy device; 200, push rod; 300, loading sheath; 400, microcatheter; 500, sheath tube; 600, connector; 700, perforation guide wire;

1/1a/1b/1c/1e/1d/1f/1g/1h, bolt retrieval bracket; 11/11a/11b/11d, rigid unit; 111, first wave circle; 1111, crest; 1112, trough; 12/ 12c/12d/12e/12f, flexible unit; 121/121e, strut; 1211, first winding segment; 1212, second winding segment; 1211e, first arc segment; 1212e, second arc segment; 122, the second wave ring; 1221, the crest; 1222, the trough; 123, the connecting piece; 124, the annular ring; 13, the connecting arm; 14, the proximal tube; 15, the distal tube; 16, the connecting rod;

2/2f/2g/2h, pulling guide wire; 201, limiting part; 21/21h, guide wire core; 22/22h, heating part; 23, insulating layer; 24, elastic part.

Detailed ways

Exemplary embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and drawings therein are essentially used for illustration rather than limitation this invention.

The thrombectomy stent and the thrombectomy device provided by the embodiments of the present invention are used to clear the blocked blood vessel and capture the thrombus in the blocked blood vessel when the blood vessel blocks the blood vessel. The thrombus removal device includes a thrombus removal bracket and a pulling guide wire. The pulling guide wire is connected with the thrombus removal bracket and can be passed through the thrombus retrieval bracket. The thrombus retrieval support has radial expansion and contraction properties, so that there are collapsed states and natural expansion states between thrombus retrieval. In the collapsed state, the thrombectomy stent can be easily delivered through the microcatheter in the blood vessel and delivered to the lesion site. After reaching the lesion site, withdrawing the microcatheter can restore the natural expansion state of the thrombectomy stent, then cut and capture the thrombus at the lesion site, and finally withdraw the captured thrombus to dredge the blocked blood vessel.

For ease of description and understanding, "proximal end" as defined herein refers to the end close to the operator, and "distal end" refers to the end away from the operator.

The following is a specific introduction through several embodiments of the thrombectomy device.

For the first embodiment, please refer to the structures and usage states shown in FIG. 1 to FIG. 3 .

Referring first to FIG. 1 , the thrombectomy device 100 of this embodiment includes a thrombectomy bracket 1 and a pulling guide wire 2 .

Wherein, the bolt removal support 1 has a hollow tubular structure, and its outer peripheral wall can have a grid or mesh structure, and the grid or mesh structure can be an irregular hole-like structure. The guide wire 2 is pulled through the proximal end of the thrombus removal stent 1 and extended into the thrombus removal stent 1 , and the distal end of the pulling guide wire 2 is connected with the distal end of the thrombus removal stent 1 . The proximal end of the pulling guide wire 2 can be connected to the outside world, and the thrombectomy stent 1 can be driven to withdraw toward the proximal end of the blood vessel by pulling the guiding wire 2 to move toward the proximal end of the blood vessel.

The thrombectomy stent 1 has a collapsed state and a natural expanded state. In the collapsed state, the radial dimension of the thrombectomy stent 1 is the smallest, which is convenient for delivery in the blood vessel, so that the thrombectomy stent 1 is delivered to the lesion site.

The bolus retrieval stent 1 can be made of a metal material such as memory. When there is no external pressure in the radial direction, the bolus retrieval stent 1 expands by itself, and the radial dimension becomes larger. In the state of natural expansion, the thrombectomy stent 1 distracts the thrombus at the diseased site, and uses the mesh or mesh structure on the peripheral wall to cut the thrombus, so that the thrombus enters the thrombectomy stent 1 and is removed. Bracket 1 capture. As the pulling wire 2 moves toward the proximal end of the blood vessel, the thrombectomy stent 1 can be controlled to drive the thrombus captured therein to withdraw, so as to clear the blocked blood vessel.

The thrombectomy stent 1 of this embodiment includes a rigid unit 11 , a flexible unit 12 , a connecting arm 13 , a proximal tube 14 and a distal tube 15 .

The rigid units 11 and the flexible units 12 are arranged in a line and are alternately connected, and the rigid units 11 and the flexible units 12 are connected by a connecting arm 13 . Both the proximal end and the distal end of the thrombectomy stent 1 are rigid units 11 . The rigid unit 11 has a rigid effect, and a plurality of rigid units 11 can play the role of skeleton support. Both the head and the tail are rigid units 11 to improve the support performance and propulsion performance of the bolt retrieval bracket 1 . The flexible unit 12 is flexible and can be bent and compressed. Both the rigid unit 11 and the flexible unit 12 have a radially retractable tubular structure, and the rigid unit 11 and the flexible unit 12 can communicate with each other. The outer peripheral wall of the rigid unit 11 is in a grid or mesh structure, and the outer peripheral wall of the flexible unit 12 is provided with an opening connecting the inside and outside of the tubular structure of the flexible unit 12, or the outer peripheral wall of the flexible unit 12 has mesh holes, so the rigid unit 11 and the When the flexible unit 12 is deployed, it can cut the thrombus around it, so that the cut part of the thrombus enters its tubular structure and is captured by the rigid unit 11 or the flexible unit 12 .

The rigid unit 11 of this embodiment has a strong rigid effect, and itself has a large radial support force. In the natural expanded state, the diameter of the rigid unit 11 is smaller than that of the blood vessel and the flexible unit 12 . Therefore, when the rigid unit 11 is unfolded, the blood vessel will not be injured, and the blood flow channel can be quickly established, so as to realize the pre-opening function of blocking the blood flow channel at the blood vessel.

Referring to FIG. 1 , the rigid unit 11 in this embodiment is a grid unit, and the grid unit has a network tube-like structure.

Further, the grid unit in this embodiment mainly includes a plurality of first wave rings 111 connected in the axial direction. Each of the first wave circles 111 has crests 1111 and troughs 1112 that are staggered in the circumferential direction. The wave crest 1111 faces the distal end, and the wave trough 1112 faces the proximal end. The wave crests 1111 of the first wave circle 111 at the proximal end are correspondingly connected with the wave troughs 1112 of the first wave circle 111 at the distal end to form a grid structure.

Specifically, as shown in FIG. 1 , the rigid unit 11 has two first wave rings 111 , and each of the first wave rings 111 can be regarded as a closed-loop structure formed by continuous bending and extending of a rod in a Z-shape or a W-shape. The trough 1112 of the first wave ring 111 at the proximal end is connected to the connecting arm 13 , or is convergently connected to the proximal tube 14 . The wave crest 1111 of the first wave circle 111 located at the distal end is connected to the connecting arm 13 , or is convergently connected to the distal tube 15 . The grid structure between two adjacent first wave circles 111 is a rhombus grid, and can also form grids of other shapes, such as triangles, rectangles or polygons.

The first wave ring 111 and the entire rigid unit 11 can expand and contract in the radial direction, so that adjacent wave crests 1111 and adjacent wave troughs 1112 between each first wave ring 111 can be close to or away from each other. During natural expansion, the diameter of the first wave ring 111 becomes larger, the axial interval between the wave crest 1111 and the wave trough 1112 becomes smaller, and the circumferential interval becomes larger at the same time. When the thrombectomy stent 1 reaches the thrombus at the diseased site, the rigid unit 11 is opened by the self-expansion of the first wave ring 111, which can stretch the thrombus, establish a blood flow channel, and realize the pre-opening function; 111 cuts the thrombus, and the cut thrombus part enters the first wave circle 111 and is captured by the grid unit.

In this embodiment, the flexible unit 12 is more flexible than the rigid unit 11 , and when subjected to the same external force, the flexible unit 12 is more easily deformed than the rigid unit 11 .

Referring to FIG. 2 , when subjected to the same radial force, the flexible unit 12 of this embodiment is easier to bend and deform than the rigid unit 11 , so that the bolt removal bracket 1 can be bent at the flexible unit 12 . Therefore, that is, The thrombectomy stent 1 can ensure the effect of capturing the thrombus, while taking into account the overall flexibility of the thrombectomy stent 1, so that the thrombectomy stent 1 can be delivered and withdrawn in a circuitous blood vessel.

Referring to FIG. 3 , when subjected to the same axial force, the flexible unit 12 of this embodiment is easier to perform axial compression than the rigid unit 11 ; and when the flexible unit 12 is axially compressed, its maximum radial dimension D1 is synchronized increase.

In the natural expansion state, the maximum radial dimension D1 of the flexible unit 12 is larger than the maximum radial dimension D2 of the rigid unit 11 . A section of space 10 may be formed between two adjacent flexible units 12. The thrombus located in the space 10 is distributed on the peripheral side of the corresponding rigid unit 11 and is not cut by the grid structure of the rigid unit 11. Therefore, maintain its own integrity.

During the withdrawal of the stent 1 for thrombectomy, the flexible unit 12 can push the complete thrombus in the space 10 to withdraw, thereby reducing the risk of thrombus falling off, thereby improving the success rate of thrombus removal. At the same time, since the uncut thrombus is mainly confined in the space 10, the thrombectomy stent 1 exerts force on the thrombus in a direction parallel to the blood vessel when it is withdrawn, which means that the thrombectomy stent 1 exerts force on the thrombus. The action of the tau is not used to increase the force required to remove the thrombus from the blood vessel, thereby protecting delicate blood vessels, such as cerebral vessels, from harmful radial and tensile forces.

It should be noted that, if the maximum radial dimension D1 of the flexible unit 12 is smaller than the maximum radial dimension D2 of the rigid unit 11, the space 10 is formed between the two adjacent rigid units 11. When the bolt holder 1 During the retraction process, when the flexible unit 12 bends and protrudes to one side when passing through the curved blood vessel, the thrombus in the space 10 between the two rigid units 11 will be pushed out of the space 10, which is not conducive to the grasping of the thrombus. Catch and Retract, as shown in Figure 13 and Figure 14. Therefore, a solution is chosen in which the maximum radial dimension D1 of the flexible unit 12 is larger than the maximum radial dimension D2 of the rigid unit 11 .

It should also be noted that, in the state of natural expansion, the maximum radial dimension D1 of the flexible unit 12 can also be smaller than the maximum radial dimension D2 of the rigid unit 11, and only after the flexible unit 12 is axially compressed, its maximum radial dimension D1 If the dimension D1 is larger than the maximum radial dimension D2 of the rigid units 11 , the space 10 can be formed between the adjacent flexible units 12 .

Still referring to FIG. 3 , under the action of the pressing force at the opposite ends of the bolt removal bracket 1 in the axial direction, the maximum radial dimension D1 of the flexible unit 12 of this embodiment becomes larger, and the axial dimension becomes smaller; The maximum radial dimension D2 and the axial dimension remain unchanged. Therefore, based on the variable feature of the maximum radial dimension D1 of the flexible unit 12, when the thrombectomy stent 1 is withdrawn from the distal end of the blood vessel to the proximal end of the blood vessel, if the diameter of the blood vessel gradually increases, the maximum radial dimension D1 of the flexible unit 12 can be adjusted by adjusting the maximum diameter of the blood vessel. The radial dimension D1 enables the flexible unit 12 of the thrombectomy stent 1 to always maintain an adherent state in different blood vessel segments, so that both the thrombus inside the thrombectomy stent 1 and the bulk thrombus in the interval space 10 can be removed during retraction , thereby improving the effect and success rate of thrombus removal, and reducing the risk of thrombus shedding.

In addition, the thrombectomy stent 1, which is alternately formed by the rigid units 11 and the flexible units 12, is a segmented structure. When the thrombectomy stent 1 captures the thrombus and withdraws it to the guiding catheter or the intermediate catheter, the proximal end structure of the thrombectomy stent 1 is due to The entry guide catheter or the intermediate catheter is compressed without changing the structure of the rear end, thereby avoiding the thrombus falling off due to the overall compression of the thrombectomy stent 1 during retraction.

In this embodiment, the flexible unit 12 includes a plurality of struts 121 , and the plurality of struts 121 are arranged at intervals in the circumferential direction to form a cylindrical structure. The space between adjacent struts 121 forms openings or meshes on the outer peripheral wall of the flexible unit 12 ; two ends of the struts 121 are respectively connected to a connecting arm 13 . The ends of the adjacent struts 121 may be arranged at intervals, so that the space intervals between the adjacent struts 121 are evenly distributed. The ends of the adjacent struts 121 are also partially connected so as to be connected with the connecting arm 13 . When the flexible unit 12 is axially compressed, each strut 121 can expand radially outward so that the radial dimension of the flexible unit 12 gradually increases.

Please refer to FIG. 1 for details. The support rod 121 in this embodiment is a helical rod, and a plurality of support rods 121 are spirally wound clockwise or counterclockwise in the same direction, so that the flexible unit 12 forms a helical unit. The helical rod can be understood as a filament or rod-like structure and is wound in a helical shape, and the interval between adjacent helical rods forms openings or meshes on the outer peripheral wall of the flexible unit 12 . The helical winding angle from the proximal end to the distal end of the helical rod does not exceed 360°, wherein the larger the winding angle, the better the flexibility and the weaker the support.

According to the distance from the screw rod to the center line of the helical unit, the screw rod can be divided into a first winding section 1211 and a second winding section 1212. The first winding section 1211 and the second winding section 1212 are connected at one end and in the same direction Spiral wound. The connection between the first winding section 1211 and the second winding section 1212 is the outermost of the flexible unit 12 in the radial direction. In the direction of the first winding section 1211 being gradually away from the second winding section 1212, the distance from the central axis of the flexible unit 12 is gradually reduced. In the direction of the second winding section 1212 being gradually away from the first winding section 1211, the distance from the central axis of the flexible unit 12 is gradually reduced.

The helical unit can not only be bent under the action of radial pressure, but also can be axially compressed under axial pressure. When axially compressed, the helical unit expands synchronously and radially to achieve full fit with the vessel wall and full contact with the thrombus to achieve the maximum fitting effect. At the same time, the diameter of the expanded flexible unit 12 is larger than that of the rigid unit 11, so that the rigid unit 11 does not come into contact with the blood vessel wall.

In this embodiment, the flexible units 12 forming the helical unit and the rigid units 11 forming the grid unit are sequentially spaced and alternately arranged, so that the bolt removal bracket 1 forms a segmented structure as a whole, which improves the flexibility of the bolt removal bracket 1 , able to adapt to different curved vessels. The grid structure of the rigid unit 11 embedded in the thrombus can open the inside of the thrombus through its own radial support force, quickly establish a blood flow channel, and block the pre-canalization function of the blood vessel in real time; the grid structure of the rigid unit 11 can also form a capture structure, The thrombus is cut and captured as it is deployed. The helical unit is a flexible structure that is compressed when deployed inside the thrombus. At this time, the external force is used to compress, and the guide wire 2 is retracted to the proximal end relative to the thrombectomy stent 1, so that the helical unit is fully expanded, and the helical rod cuts the thrombus, so that the helical unit and the thrombus are fitted to the greatest extent, and adhere to the vessel wall. combine. The diameter of the helical element in the expanded state is larger than that of the grid element, and a space 10 is formed between adjacent helical elements. The thrombus located in the space 10 that is not cut by the grid unit can maintain high integrity, and the risk of thrombus falling off during the withdrawal process can be reduced, thereby improving the effect and success rate of thrombus removal.

In this embodiment, both the helical unit and the mesh unit can be made of memory alloy or polymer material. Specifically, it can be formed by braiding or laser-cutting nickel-titanium pipes, or by laser-cutting nickel-titanium sheets and then crimping and heat-setting, or by weaving nickel-titanium wires, or by processing elastic plastic materials. into and so on.

Specifically, as shown in FIG. 1 , the bolt removal bracket 1 of this embodiment is alternately connected by four rigid units 11 and three flexible units 12 . It should be noted that the numbers of the rigid units 11 and the flexible units 12 are not limited, and may be increased accordingly and designed as required.

The rigid unit 11 and the flexible unit 12 are connected through the connecting arm 13 . One end of the connecting arm 13 is connected with the rigid unit 11 , and the other end is connected with the flexible unit 12 . The connecting arm 13 may be parallel to the central axis of the bolt-removing bracket 1 , and the connecting arm 13 is rod-shaped and extends along the axial direction of the bolt-removing bracket 1 . The connecting arm 13 can also be a curved or helical helical arm. Using the connecting arm 13 can make the transition between the rigid unit 11 and the flexible unit 12 better, so as to allow the bending between the two adjacent rigid units 11 in the bolt retrieval bracket 1 to not damage the expansion of the flexible unit 12 as much as possible, and The ability of the flexible unit 12 to be well apposed and adherent to the vessel wall is maintained.

Specifically, one end of the connecting arm 13 can be connected to the wave crest 1111 or the wave trough 1112 of the first wave circle 111 in the grid unit, and the other end of the connecting arm 13 can be connected to one end of one or more helical rods in the helical unit. Between adjacent rigid units 11 and flexible units 12, a plurality of connecting arms 13 may be provided. A plurality of connecting arms 13 are arranged at intervals around the axial direction of the rigid unit 11 . In the specific embodiment, as shown in FIG. 1 , there are four connecting arms 13 , one end of each connecting arm 13 is connected with a screw rod, and the other end is connected with the wave crest 1111 or the wave trough 1112 of the first wave ring 111 .

On the thrombectomy stent 1 , the proximal end of the rigid unit 11 located at the proximal end adopts a conical structure, and is convergently connected to the proximal end tube 14 . The use of the conical structure can improve the overall flexibility of the proximal end structure of the thrombectomy stent 1, which facilitates the entry of the thrombectomy stent 1 into the guide catheter or sheath 500 when the thrombus removal stent 1 is withdrawn.

On the thrombectomy stent 1 , the distal end of the rigid unit 11 located at the most distal end adopts a conical structure, and is convergently connected to the distal tube 15 . The distal end of the most distal rigid unit 11 has a tapered structure, which can reduce the damage to the thrombus during the advancement of the thrombectomy stent 1 and reduce the risk of the broken thrombus flowing to the distal end of the blood vessel.

In the present embodiment, the proximal tube 14 is a hollow tube, and the guide wire 2 is pulled through the proximal tube 14 and passed through the rigid unit 11 and the flexible unit 12 in sequence; the distal end of the guide wire 2 and the distal tube 15 are pulled connected.

The distal tube 15 can also be a hollow tube, and the distal end of the pulling guide wire 2 is provided with a limiting portion 201 , and the limiting portion 201 can adopt a spherical structure. After the distal end of the guide wire 2 is pulled through the distal tube 15 of the hollow structure, it is clamped to the distal end of the distal tube 15 through the limiting portion 201 . Furthermore, when the pulling guide wire 2 is withdrawn, the pulling guide wire 2 can drive the thrombus removal bracket 1 to withdraw. It can be understood that the distal end of the pulling wire 2 can also be welded on the distal tube 15 .

Referring to FIGS. 4 to 6 , the thrombectomy device 100 according to the embodiment of the present invention is loaded into the thrombectomy system in a collapsed state before use. The thrombectomy system further includes the push rod 200 , the loading sheath 300 , and the microcatheter 400 . and sheath 500.

The proximal end of the thrombectomy stent 1 is convergently connected to the proximal tube 14 through the rigid unit 11, and the hollow proximal tube 14 is communicated with the push rod 200. The proximal end passes through the proximal tube 14 and the push rod 200 in sequence.

The loading sheath 300 is sheathed on the outside of the push rod 200, and the thrombus removal stent 1 is pre-compressed and introduced into the loading sheath 300 before use, as shown in FIG. 4 .

When thrombectomy needs to be performed, the loading sheath 300 can be connected to the microcatheter 400 through a connector 600 (eg, a luer connector), as shown in FIG. 5 . Then, the proximal tube 14 and the thrombectomy stent 1 are pushed into the lumen of the microcatheter 400 by the push rod 200, as shown in FIG. 6 . Then, the thrombectomy device 100 will be delivered through the microcatheter 400 to the lesion location of the thrombus determined according to angiography or other diagnostic means, so that the thrombectomy stent 1 can be released at the vascular lesion location and the push rod 200 can be used to achieve precise alignment of the push-pull action. , so that the bolus retrieval bracket 1 can be switched between the compressed state and the released state.

The sheath tube 500 is sheathed outside the microcatheter 400, and the sheath tube 500 extends into the blood vessel along with the microcatheter 400, and is transported to the proximal end of the thrombus at the diseased site, for accommodating the thrombus captured by the thrombectomy stent 1 when withdrawing. thrombus.

Please refer to FIG. 7 to FIG. 12 , during interventional thrombectomy, referring to FIG. 7 , the perforated guide wire 700 is used to pass through the thrombus at the lesion site in advance to establish a vascular access in the thrombus. Referring to FIG. 8 , the microcatheter 400 and the sheath 500 are transported along the perforated guide wire 700 to the thrombus at the lesion site, and the microcatheter 400 passes through the thrombus, the microcatheter 400 is fixed, and the perforated guide wire 700 is withdrawn. Referring to FIG. 9 , the thrombectomy device 100 is pushed to the location of the thrombus determined according to angiography or other diagnostic means through the push rod 200 . Referring to FIG. 10 , stop the front push rod 200, fix the push rod 200, and withdraw the microcatheter 400, so that the thrombectomy stent 1 is released at the distal end of the microcatheter 400. According to the position of the imaging point on the image, ensure that the thrombus is located in the The thrombectomy device 100 is in the effective area, and the thrombectomy stent 1 is completely released in the blood vessel. Referring to FIG. 11 , the guide wire 2 can be adjusted according to the thickness of the vessel wall to expand the helical unit and anchor the helical unit to the vessel wall, so as to fully attach the helical unit to the vessel wall and capture the thrombus. Referring to FIG. 12 , the pulling guide wire 2 and the push rod 200 are simultaneously pulled to withdraw the thrombectomy stent 1 with the captured thrombus into the sheath 500 to complete the removal of the thrombus.

Please refer to FIG. 13 , when the traditional one-piece thrombectomy stent 1 is withdrawn in a continuous tortuous blood vessel, due to the extrusion effect of the rounded corners, the thrombectomy stent 1 is compressed into a linear shape during the withdrawal process, and the thrombus retrieving stent 1 is compressed into a linear shape. Chimerism reduces the volume and increases the probability of thrombus falling off, thereby reducing the effect and success rate of thrombectomy.

Referring to FIG. 14 , the thrombectomy stent 1 provided in this embodiment is under the combined action of the elastic release of the shape memory material and the pulling of external force, the thrombectomy stent 1 can be radially expanded and completely embedded in the thrombus. Due to its own flexibility and the variable diameter of its inner helical unit, it can be fully expanded at the tortuous part of the blood vessel, and remains relatively static with the thrombus during retraction, effectively preventing the thrombus from falling off, thereby improving the effect and success rate of thrombectomy. . In addition, when the thrombectomy stent 1 is withdrawn from the distal blood vessel to the proximal blood vessel, the diameter of the blood vessel wall gradually increases, and the diameter of the helical unit can be adjusted to keep the thrombectomy device 100 always adhered to the wall at different sections of the blood vessel. Further reduce the risk of thrombus shedding and improve the effect and success rate of thrombectomy.

For the second embodiment, refer to the structure shown in FIG. 15 .

The thrombectomy device 100a of this embodiment is similar in structure to the first embodiment, and the difference lies in the design of the rigid unit 11a. Specifically, in the thrombus retrieval bracket 1a of the present embodiment, in the rigid unit 11a except for the two rigid units 11a located at the proximal end and the most distal end, in the direction from the proximal end to the distal end of the thrombus retrieval bracket 1a, The axial lengths of the plurality of rigid units 11a are successively reduced. The axial length of the rigid unit 11a can be adjusted by changing the number of the first wave coils 111 .

The maximum radial dimension D1 of the flexible unit 12a is larger than the maximum radial dimension D2 of the rigid unit 11a, so that between two adjacent flexible units 12a, a space 10 can be formed to capture the thrombus. The axial dimension of the space 10 may vary with the axial length of the rigid unit 11a. Therefore, in the direction from the proximal end to the distal end, as the axial length of each rigid unit 11a decreases successively, the axial dimension of each interval space 10 also decreases synchronously, thereby reducing the thrombus in each interval space 10. The size is regular from large to small.

When the thrombectomy stent 1a is withdrawn in the tortuous blood vessel, the distal space 10 cannot accommodate the proximal large thrombus, so it can effectively prevent the large thrombus located in the proximal space 10 from moving to the distal space 10 migration, preventing its escape to further distances, further reducing the risk of thrombus shedding.

It should be noted that the axial dimension of each interval space 10 may be changed in other ways, for example, in the direction from the proximal end to the distal end, the axial dimension of each interval space 10 becomes larger in turn, or alternately arranged in size and structure, and Or randomize the size, etc.

For the third embodiment, refer to the structure shown in FIG. 16 .

The structure of the thrombus removal device 100b of this embodiment is similar to that of the first embodiment, and the difference lies in the design of the rigid unit 11b.

Specifically, in the thrombectomy stent 1b of the present embodiment, in the rigid units 11b of the 11b except the two rigid units located at the proximal end and the most distal end, the radial width of each rigid unit 11b itself varies from the proximal end to the distal end gradually increases in the direction of the end. The radial width of the rigid unit 11b can be adjusted by changing the distance from each first wave ring 111 in the rigid unit 11b to the central axis of the rigid unit 11b.

In the direction from the proximal end to the distal end, since the radial width of the rigid unit 11b gradually increases, the surface of the rigid unit 11b can exhibit a tapered structure, so that the size of the correspondingly formed space 10 also decreases gradually. Structure. Corresponding to the large thrombus formed in the space 10, the size gradually decreases from the proximal end to the distal end. This can effectively prevent the large thrombus in the space 10 from migrating to the distal side, preventing it from escaping to a further distance, and further reducing the risk of thrombus falling off.

For the fourth embodiment, refer to the structure shown in FIG. 17 .

The thrombectomy device 100c of this embodiment is similar in structure to the first embodiment, and the difference lies in the design of the flexible unit 12c.

Specifically, in the thrombus removal stent 1c of the present embodiment, in the natural expansion state, in the direction from the proximal end to the distal end of the thrombus removal stent 1c, the maximum radial dimension D1 of each flexible unit 12c increases sequentially, so that The flexible unit 12c on the distal side can be compressed in the axial direction to adjust its maximum radial dimension D1 to accommodate larger blood vessels.

During the retraction of the thrombectomy stent 1c, as the blood vessel gradually becomes larger, the distal flexible unit 12c can have a larger maximum radial dimension D1 to fit with the blood vessel wall and avoid thrombus in the space 10. Escape to the distance, further effectively reducing the risk of thrombus shedding.

For the fifth embodiment, refer to the structure shown in FIG. 18 .

The structure of the bolt removal device 100d of this embodiment is similar to that of the first embodiment, except that the structure of the connecting arm 13 is omitted between the rigid unit 11d and the flexible unit 12d. At this time, the rigid unit 11d of the bolt removal bracket 1d is omitted. It is directly connected to the flexible unit 12d.

In this embodiment, the end of the screw rod of the flexible unit 12d is directly connected to the wave crest 1111 or the wave trough 1112 of the first wave ring 111 of the rigid unit 11d.

For the sixth embodiment, refer to the structure shown in FIG. 19 .

The thrombectomy device 100e of this embodiment is different from the first embodiment in that the structure of the flexible unit 12e is different.

In this embodiment, the flexible unit 12e of the bolt-removing bracket 1e includes a plurality of struts 121e, and the plurality of struts 121e are arranged at intervals in the circumferential direction to form a cylindrical structure. The space gap between adjacent struts 121e forms openings or meshes on the outer peripheral wall of the flexible unit 12e; both ends of the struts 121e are connected to a connecting arm 13 respectively.

Please refer to FIG. 19 for details. In the natural expansion state, the support rod 121e is an arc-shaped rod. The arc-shaped rod extends along the axial direction of the bolt-removing bracket 1e, and the middle part of the arc-shaped rod is an arc along the radial direction of the bolt-removing bracket 1e. A plurality of arc-shaped rods are circumferentially spaced around the axis of the bolt-removing bracket 1e, so that the flexible unit 12e is approximately spherical or ellipsoidal in a natural expansion state. When the flexible unit 12e is axially compressed, the axial distance between the two ends of the arc-shaped rod gradually decreases, and the middle part of the arc-shaped rod expands radially outward, and the degree of outward convexity becomes larger, so that the maximum radial direction of the flexible unit 12e is increased. The size D1 gradually increases to achieve full fit with the vessel wall and full contact with the thrombus to achieve the maximum fit effect.

According to the distance from the arc rod to the center line of the flexible unit 12e, the arc rod can be divided into a first arc segment 1211e and a second arc segment 1212e, and one end of the first arc segment 1211e and the second arc segment 1212e are connected. The connection between the first arc-shaped segment 1211e and the second arc-shaped segment 1212e is the outermost of the flexible unit 12e in the radial direction. In the direction of the first arc-shaped segment 1211e being gradually away from the second arc-shaped segment 1212e, the distance from the central axis of the flexible unit 12e is gradually reduced. In the direction of the second arc-shaped segment 1212e being gradually away from the first arc-shaped segment 1211e, the distance from the central axis of the flexible unit 12e becomes gradually smaller.

Further, the flexible unit 12e also includes annular rings 124 located at both ends of the arc-shaped rod. The two annular rings 124 are arranged at intervals, and the annular rings 124 are arranged around the axis of the bolt retrieval bracket 1e. Both ends of the arc-shaped rod are respectively connected to an annular ring 124 , and the annular ring 124 can be directly connected to the rigid unit 11 or connected to the rigid unit 11 through the connecting arm 13 . The annular ring 124 may have elasticity so as to contract and expand as a whole with the bolt retrieval support 1e.

For the seventh embodiment, refer to the structures shown in FIGS. 20 to 24 .

Compared with the first embodiment, the thrombectomy device 100f of this embodiment is different in that the structures of the flexible unit 12f and the pulling guide wire 2f are different.

In this embodiment, the outer peripheral wall of the flexible unit 12f of the bolt-removing bracket 1f has a mesh structure. The flexible unit 12f has the same mesh-like structure as the rigid unit 11, and the mesh structure forms an opening on the outer peripheral wall of the flexible unit 12f.

In a specific embodiment, please refer to FIG. 20 and FIG. 21 , the flexible unit 12f includes a connecting piece 123 and a second wave ring 122 which are axially correspondingly connected. The connecting piece 123 is located on the distal side of the second wave ring 122 .

The connecting piece 123 and the corresponding second wave ring 122 can be arranged in multiple groups, and the connecting piece 123 and the second wave ring 122 between the multiple groups are alternately connected in turn, which can increase the length of the flexible unit 12f, as shown in FIG. 22 and FIG. 23 . shown.

Each of the second wave circles 122 has crests 1221 and troughs 1222 that are staggered in the circumferential direction. The wave crest 1221 faces the distal end, and the wave trough 1222 faces the proximal end.

In the second wave ring 122, some of the wave crests 1221 are in contact with the proximal end of the connecting piece 123, and some of the wave crests 1221 are suspended. Further, the flexible unit 12f is formed into a grid structure as a whole, and a gap can be formed at the suspended wave crest 1221 .

Specifically, the connecting member 123 may adopt a plurality of rod members bent in a V-shape. The tip of each V-shaped connecting piece 123 is the proximal end, and is in contact with the wave crest 1221 of the second wave ring 122 . The two ends of the V-shaped connecting piece 123 opposite to the tip are distal ends, and the two distal ends are respectively connected to a connecting arm 13; the connecting piece 123 and the second wave ring 122 between the groups are alternately connected in turn. , the two distal ends can also be used to connect with the trough 1222 of another adjacent second wave ring 122 . The plurality of connecting pieces 123 are arranged at intervals around the circumference, and cooperate with the second wave ring 122 to form a tubular structure. A grid or mesh structure may be formed between the connecting member 123 and the wave crests 1221 or wave troughs 1222 of the second wave ring 122 . Referring to FIG. 24, under the action of radial external force, the flexible unit 12f can be bent at the gap formed by the suspended wave crest 1221, thereby improving the flexibility of the thrombectomy stent 1f and adapting to the curved blood vessel.

Referring to FIG. 21 , in the direction from the proximal end to the distal end, the distance between the second wave ring 122 and the centerline of the flexible unit 12f is gradually increased, so that the dangling wave crest 1221 of the second wave ring 122 can expand outward. the free end. The maximum width of the flexible unit 12f at the free end is the maximum radial dimension D1 of the flexible unit 12f, and the maximum radial dimension D1 is larger than the maximum radial dimension D2 of the rigid unit 11 . Between the adjacent two groups of the second wave circles 122, the free ends formed by the dangling wave crests 1221 may be located at the same position or cross distributed, as shown in FIG. 22 and FIG. 23 .

The flexible unit 12f can expand and contract in the radial direction, so that the adjacent wave crests 1221 and the adjacent wave troughs 1222 between the second wave circles 122 can be close to or away from each other. When the flexible unit 12f expands naturally in the thrombus, the free end formed by the dangling wave peaks 1221 can be embedded in the thrombus and fit with the vessel wall. The space 10 is formed between the corresponding dangling wave crests 1221 of the adjacent flexible units 12f. When the thrombectomy stent 1f is withdrawn, the free end formed by the dangling wave crest 1221 can push the complete thrombus in the space 10 to withdraw, thereby improving the success rate of thrombus removal. At the same time, the free end formed by the suspended wave crest 1221 extends from the proximal end to the distal end, so it will not prevent the thrombectomy stent 1f from being retracted into the sheath tube 500 during retraction.

It should be noted that the maximum radial dimension D1 of the flexible unit 12f is larger than the maximum radial dimension D1 of the rigid unit 11 , which can be adjusted and controlled by the diameter of the second wave ring 122 at the wave crest 1221 .

Further, in the second wave ring 122 , the wave crests 1221 corresponding to the proximal end of the connecting piece 123 and the suspended wave crests 1221 are arranged at staggered intervals.

Notably, the flexible unit 12f of this embodiment is not capable of radial expansion through axial compression.

Please refer to FIG. 20 for details. The flexible unit 12f has a second wave ring 122 and a connecting piece 123 . Wherein, the connecting member 123 is formed by two opposite V-shaped rod members. The second wave ring 122 can be regarded as a closed-loop structure formed by a Z-shaped or W-shaped continuous bending extension of the rod, which has four wave crests 1221 at the distal end and four wave troughs 1222 at the proximal end. Two wave crests 1221 are in contact with the connecting piece 123 , and the other two wave crests 1221 form suspended free ends. The wave crests 1221 in contact with the connecting piece 123 are arranged at intervals from the suspended wave crests 1221 .

20 and 24, the distal end of the pulling guide wire 2f in this embodiment is directly connected to the proximal end of the thrombus retrieval bracket 1f, that is, connected to the proximal tube 14, and the pulling guide wire 2f does not need to be inserted into the thrombus retrieval bracket Arranged within 1f. The proximal end of the pulling guide wire 2f can be connected to the outside world, and by moving the pulling guide wire 2f toward the proximal end of the blood vessel, the whole thrombectomy stent 1f can be driven to withdraw toward the proximal end.

For the eighth embodiment, refer to the structures shown in FIGS. 25 and 26 .

The thrombectomy device 100g of this embodiment is similar in structure to the first embodiment, except that the design of the pulling wire 2g is different.

The pulling guide wire 2 g of this embodiment includes a guide wire core 21 and a heating portion 22 provided on the guide wire core 21 .

The guide wire core 21 is made of conductive material, and is inserted into the bolt retrieval support 1g. One end of the guide wire core 21 protrudes outward from the bolt-removing bracket 1g, and can be electrically connected to an external power source; the heating part 22 is located in the bolt-removing bracket 1g; when the guide wire core 21 is energized, the heating part 22 can generate Joule heat, so that the The thrombus in the area around the heating part 22 is dehydrated and coagulated, and it is tightly bonded with the heating part 22 to improve the thrombus capturing effect, and then when the thrombectomy stent 1g and the pulling wire 2g are withdrawn, it can effectively prevent The thrombus falls off, improving the effect and success rate of thrombus removal.

The external power source can be a radio frequency power source. When the guide wire core 21 is supplied with radio frequency current, a radio frequency thermal ablation effect can be formed around the heating part 22 .

The guide wire core 21 is covered with an insulating layer 23 in areas other than the heat generating portion 22 . The insulating layer 23 is a layer of insulating material wrapped on the guide wire core 21 , and can be sleeved or bonded on the guide wire core 21 .

The heat generating part 22 is a layer of heat conducting medium. The heating part 22 can be integrally formed with the guide wire core 21 , and the heating part 22 can also be glued or welded on the guide wire core 21 .

The heating portion 22 protrudes from the outer peripheral wall of the guide wire core 21 in the radial direction, so as to increase the heating area thereof, thereby further improving the ability to capture the thrombus. Of course, the heat generating portion 22 may not protrude from the outer peripheral wall of the guide wire core 21 .

The radial width of the heating part 22 gradually increases from the two ends to the middle, so as to form a structure with small size at both ends and large size in the middle, and further reduce the flow resistance of the heating part 22 to blood flow after the blood flow channel is opened. Specifically, the heating portion 22 may adopt an elliptical sphere structure, and the two ends of the elliptical sphere are arranged corresponding to the proximal end and the distal end of the thrombus retrieval bracket 1g, respectively. The outer peripheral wall of the heating part 22 is in a streamlined shape with smooth transition, that is, the proximal end and the distal end of the heating part 22 are designed in a streamlined shape.

In the bolus removal bracket 1g of this embodiment, the heating part 22 can be arranged in the rigid unit 11 or the flexible unit 12 correspondingly. A plurality of heat-generating parts 22 may be provided, and the plurality of heat-generating parts 22 are arranged at intervals.

As a preferred solution, the heating part 22 may be arranged corresponding to the rigid unit 11 , so as to enhance the ability to catch large thrombus falling in the interval area between two adjacent flexible units 12 .

For the ninth embodiment, refer to the structure shown in FIG. 27 .

The thrombectomy device 100h of this embodiment is similar in structure to that of the eighth embodiment, and the difference lies in the design of the pulling guide wire 2h.

The pulling guide wire 2h of this embodiment includes a guide wire core 21h, a heating portion 22h disposed on the guide wire core 21h, and an elastic portion 24 disposed on the guide wire core 21h and arranged at intervals from the heating portion 22h.

The elastic portion 24 has a segment-like structure and is correspondingly disposed in the flexible unit 12 . The heat generating portion 22h is correspondingly provided in the rigid unit 11 .

The bolt removal bracket 1h of this embodiment further includes a plurality of connecting rods 16 . Both ends of the elastic portion 24 are respectively connected to the peripheral side wall of the bolt-removing bracket 1h through one or more connecting rods 16 . That is, the inner end of each connecting rod 16 is connected to the end of the elastic portion 24 , and the outer end of the connecting rod 16 can be connected to the peripheral side wall of the rigid unit 11 or the flexible unit 12 , or connected to the connecting arm 13 . Both ends of the elastic portion 24 are relatively fixed to the bolt-removing bracket 1h through the connecting rod 16 , so that the elastic portion 24 is aligned and restricted in the corresponding flexible unit 12 , and the heating portion 22h is correspondingly distributed in the rigid unit 11 .

The elastic portion 24 may be in a stretched state when the bolt retrieval bracket 1h is kept in a collapsed state. As shown in FIG. 27 , when the thrombectomy stent 1h is released in the blood vessel, the flexible unit 12 can expand by itself. And when it expands radially from self-expansion, its axial dimension is shortened. Using the restoring force of the elastic portion 24 can assist the bolus retrieval bracket 1h to expand, and realize the rapid expansion of the bolus retrieval bracket 1h; Synchronization is shortened.

The connecting rod 16 is retractable and retractable along the radial direction of the bolt-removing bracket 1h, such as a corrugated rod or an elastic telescopic member. The connecting rod 16 may be stretched when the thrombectomy stent 1h is expanded. When the bolus retrieval bracket 1h is contracted to a collapsed state, the connecting rod 16 can be compressed, so that the connecting rod 16 can be accommodated in the sheath tube 500 and maintain the collapsed state together with the bolus retrieval bracket 1h.

While the present invention has been described with reference to several exemplary embodiments, it is to be understood that the terminology used is of description and illustration, and not of limitation. Since the invention can be embodied in many forms without departing from the spirit or spirit of the invention, it is to be understood that the above-described embodiments are not limited to any of the foregoing details, but are to be construed broadly within the spirit and scope defined by the appended claims Therefore, all changes and modifications that come within the scope of the claims or their equivalents should be covered by the appended claims.

Claims (39)

1. A bolt-removing bracket, characterized in that it comprises rigid units and flexible units that are arranged in a line and alternately connected;

   Both the rigid unit and the flexible unit are radially compressible and expandable tubular structures;

   The flexible unit is more flexible than the rigid unit, and when subjected to the same external force, the flexible unit is more easily deformed than the rigid unit.
2. The bolus retrieval bracket according to claim 1, wherein when subjected to the same radial force, the flexible unit is easier to bend and deform than the rigid unit;
3. The bolus retrieval bracket according to claim 1, wherein when subjected to the same axial force, the flexible unit is easier to perform axial compression than the rigid unit, and when the flexible unit is axially compressed When the radial dimension increases simultaneously, the maximum radial dimension of the flexible unit after being axially compressed can be larger than the radial dimension of the rigid unit.
4. The bolt removal bracket according to claim 3, wherein the flexible unit comprises a plurality of struts arranged at intervals in the circumferential direction, and two ends of each of the struts are respectively connected with one of the rigid units;

   When the flexible unit is axially compressed, each of the struts can expand radially outward to gradually increase the radial dimension of the flexible unit.
5. The bolus retrieval stent according to claim 4, wherein, in a natural expansion state, the support rod is an arc rod;

   The arc-shaped rod extends along the axial direction of the bolt-removing bracket, and the middle portion of the arc-shaped rod protrudes outward along the radial direction of the bolt-removing bracket;

   When the flexible unit is axially compressed, the axial distance between the two ends of the arc-shaped rod becomes gradually smaller, and the middle portion of the arc-shaped rod expands radially outward so that the radial dimension of the flexible unit gradually increases.
6. 5. The bolus retrieval bracket according to claim 5, wherein the flexible unit comprises two annular rings arranged at intervals, and the annular rings are distributed around the axis of the bolt retrieval bracket;

   Both ends of the arc-shaped rod are respectively connected with one of the annular rings;

   The two annular rings are respectively connected with one of the rigid units.
7. The bolt removal bracket according to claim 4, wherein the support rod is a screw rod, and a plurality of the screw rods are spirally wound in the same direction;

   When the flexible unit is axially compressed, the axial distance between the two ends of the screw rod gradually decreases, and the radial dimension of the flexible unit gradually increases.
8. The bolt removal bracket according to claim 7, wherein the winding angle from one end of the screw rod to the other end of the screw rod is in the range of 0° to 360°.
9. The bolt removal bracket according to claim 7 or 8, wherein the screw rod comprises a first winding section and a second winding section, one end of the first winding section and the second winding section One end of the segment is connected, and the first winding segment and the second winding segment are both spirally wound;

   In the natural expansion state, the distance from the first winding section to the central axis of the flexible unit gradually decreases in the direction of gradually moving away from the second winding section; the second winding section is gradually moving away from In the direction of the first winding section, the distance from the central axis of the flexible unit gradually decreases; the connection between the first winding section and the second winding section is the radial distance of the flexible unit. outermost.
10. The bolus retrieval stent according to claim 2, wherein, in a natural expansion state, the maximum radial dimension of the flexible unit is larger than the radial dimension of the rigid unit.
11. The thrombectomy stent according to claim 10, wherein the flexible unit comprises at least one set of axially corresponding connecting pieces and a wave ring; the connecting piece is located on the distal side of the wave ring;

    Each of the wave circles has alternating crests and troughs in the circumferential direction; part of the wave crests of the wave circle is connected to the proximal end of the connecting piece, and part of the wave crests of the wave circle are suspended.
12. The bolus retrieval support according to claim 11, characterized in that, in the corrugated circle, the wave crests corresponding to the connecting piece and the suspended wave crests are arranged at staggered intervals.
13. The bolt removal bracket according to claim 11 or 12, wherein the connecting member comprises a plurality of V-shaped rods arranged at intervals in the circumferential direction, and the V-shaped rods are rods bent in a V-shape;

    The apex of the V-shaped rod is the proximal end, and is connected with the crest of the wave ring;

    The two ends of the V-shaped rod opposite to its apex are distal ends, and the two distal ends of the V-shaped rod are used to connect with the rigid unit or with the trough of another wave ring.
14. The bolus retrieval bracket according to any one of claims 1 to 13, wherein the bolus retrieval bracket further comprises a connecting arm, and the rigid unit and the flexible unit are connected through the connecting arm, and the The connecting arm is rod-shaped.
15. The bolt removal bracket according to claim 14, wherein a plurality of the connecting arms are provided, and the plurality of the connecting arms are distributed along the circumferential direction of the rigid unit.
16. The thrombus retrieval bracket according to any one of claims 1-15, wherein the proximalmost end and the distalmost end of the thrombus retrieval bracket are both the rigid units.
17. The thrombectomy stent according to any one of claims 1 to 15, wherein in a natural expansion state, in the direction from the proximal end to the distal end, the flexible units in the thrombectomy stent The largest radial dimension increases sequentially.
18. The bolus retrieval bracket according to any one of claims 1-15, characterized in that, for a set formed by rigid units disposed between two adjacent flexible units, the tumbler retrieval bracket is In the direction from the proximal end to the distal end, the axial lengths of the plurality of the rigid units in the set gradually decrease.
19. The bolus retrieval bracket according to any one of claims 1-15, wherein, for a set formed by rigid units disposed between two adjacent flexible units, each of the sets is The radial dimension of the rigid element gradually increases in the direction from the proximal end to the distal end.
20. A thrombus retrieval device, characterized in that it comprises the thrombus retrieval support according to any one of claims 1-19 and a traction guide wire connected with the thrombus retrieval support.
21. The thrombectomy device of claim 20, wherein the thrombectomy device further comprises a distal tube and a proximal tube;

    The most distal end of the thrombectomy bracket is convergently connected to the distal tube; the most proximal end of the thrombectomy bracket is convergently connected to the proximal tube.
22. 22. The thrombectomy device of claim 21, wherein the distal end of the pulling wire is connected to the proximal tube.
23. The thrombectomy device according to claim 22, wherein the proximal tube is a hollow tube; the traction guide wire passes through the proximal tube and sequentially passes through the rigid unit and the flexible unit , the distal end of the pulling wire is connected with the distal tube.
24. The thrombectomy device according to claim 23, wherein the distal tube is a hollow tube, and the distal end of the pulling wire passes through the distal tube and is clamped at the distal end of the distal tube. end.
25. The thrombectomy device according to claim 23, wherein a heating part is provided on the pulling wire, and the heating part is correspondingly arranged in the rigid unit or the flexible unit;

    The pulling wire can be electrically connected to an external power source; in a power-on state, the heating part can generate heat.
26. The thrombectomy device of claim 25, wherein the pulling guide wire comprises a guide wire core; the distal end of the guide wire core is connected to the distal tube, or the distal end of the guide wire core is connected to the distal tube. Passing through the distal tube and clipping on the distal end of the distal tube;

    The heating part is arranged on the guide wire core, the guide wire core is passed through the rigid unit and the flexible unit, and one end of the guide wire core can be electrically connected to an external power source.
27. The thrombus removal device according to claim 26, wherein the guide wire core is covered with an insulating layer on the area other than the heat generating part.
28. The thrombus removal device according to claim 26, wherein the heating part and the guide wire core are integrally formed.
29. The plug removal device according to claim 26, wherein the heating part is bonded or welded on the guide wire core.
30. The thrombus removal device according to claim 26, wherein the heat generating portion protrudes from the outer peripheral wall of the guide wire core in a radial direction.
31. The thrombus removal device according to any one of claims 26 to 30, wherein the radial dimension of the heat generating portion gradually increases from its two ends to the middle direction.
32. The stud removal device according to any one of claims 26-30, wherein the outer peripheral wall of the heat generating portion is a smooth transitional curved surface.
33. The thrombus removal device according to any one of claims 26-30, wherein the heating part is in the shape of an elliptical sphere.
34. The thrombus removal device according to any one of claims 26 to 30, wherein a plurality of the heat generating parts are provided, and the plurality of the heat generating parts are arranged at intervals.
35. The thrombus removal device according to any one of claims 26-30, wherein the heating part is correspondingly arranged in the rigid unit or the flexible unit.
36. The stud removal device according to any one of claims 26-30, wherein an elastic portion is provided on the guide wire core, the elastic portion and the heating portion are arranged at intervals, and the elastic portion is correspondingly provided with an elastic portion. In the flexible unit, the heating part is correspondingly arranged in the rigid unit;

    Both ends of the elastic part are respectively connected with the peripheral side wall of the bolt-removing bracket through connecting rods, so as to constrain the elastic part in the corresponding flexible unit; The radial expansion and contraction of the bracket.
37. The stud removal device according to claim 36, wherein the connecting rod is a corrugated rod extending radially along the stud removal bracket.
38. The bolt removal device according to claim 36, wherein a plurality of the connecting rods corresponding to one end of the elastic portion are provided, and the plurality of connecting rods corresponding to one end of the elastic portion are arranged at circumferential intervals.
39. A thrombectomy system, characterized in that it comprises the thrombectomy device according to any one of claims 20-38, a push rod, a loading sheath and a microcatheter;

    the push rod is connected with the proximal end of the bolus retrieval bracket, so as to push and pull the tumbler retrieval bracket;

    the loading sheath is used to accommodate the thrombectomy device in a compressed state;

    The microcatheter is used to communicate with the loading sheath, and the lumen within the microcatheter is used to deliver the thrombectomy device.

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