Thrombectomy stent and thrombectomy device

Abstract

The invention discloses a thrombectomy stent and a thrombectomy device.The thrombectomy stent is of a self-expansion structure, the thrombectomy stent comprises a stent body, the stent body comprises a first screw rod, a second screw rod and at least five supporting structures, and the first screw rod and the second screw rod form a reverse double-helix structure; the first screw rod and the second screw rod are fixedly connected at a near-end connecting point and a far-end connecting point respectively, the near-end connecting point is close to the operation end, and the far-end connecting point is far away from the operation end; each supporting structure is fixedly connected with the first screw rod and the second screw rod, the at least five supporting structures are arranged at intervals, each supporting structure comprises at least one V-shaped structure, and an opening of each V-shaped structure faces the operation end. By means of the thrombectomy support, effective radial supporting force can be provided, the support can be conveniently cut, the thrombectomy blocks can be conveniently embedded, the thrombectomy blocks can be effectively captured, and the thrombectomy effect and the thrombectomy efficiency are improved; and meanwhile, the structure is simple, and the good storage and conveying performance is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a thrombectomy stent and a thrombectomy device. Background Art

[0002] Cerebral thrombosis is a special clinical type of cerebrovascular disease, characterized by high incidence, high disability rate, high mortality rate and high recurrence rate, and is the main disease causing death and disability in the middle-aged and elderly. The recanalization of blood vessels is the key to the treatment of ischemic stroke. At present, the conventional methods include drug thrombolysis and mechanical thrombectomy. However, the treatment effect of drug thrombolysis on large-volume thromboembolism is not ideal, and only a very small number of patients are suitable for drug thrombolysis treatment.

[0003] With the development of interventional treatment methods, in recent years, mechanical thrombectomy using a thrombectomy stent system has become a mainstream treatment method. However, if the thrombectomy stent is not properly designed and the radial force of the stent is insufficient, on the one hand, it is not conducive to the stent engaging with and capturing the thrombus, resulting in complications caused by thrombectomy treatment such as re-embolism of blood vessels; on the other hand, it makes the thrombectomy process time-consuming, leading to irreversible damage to the brain due to too long ischemia time. Summary of the Invention

[0004] In view of the above problems of the prior art, the present invention discloses a thrombectomy stent and a thrombectomy device, which can provide effective radial support force, facilitate the stent to cut the thrombus and engage with the thrombus, and can effectively capture the thrombus, improving the thrombectomy effect and thrombectomy efficiency; at the same time, the structure is simple, facilitating storage and transportation. The technical solutions disclosed by the present invention are as follows:

[0005] According to one aspect of the embodiments disclosed by the present invention, a thrombectomy stent is provided. The thrombectomy stent is a self-expanding structure, and the thrombectomy stent includes a stent body. The stent body includes a first spiral rod, a second spiral rod and at least five support structures. The first spiral rod and the second spiral rod form a reverse double spiral structure. The first spiral rod and the second spiral rod are fixedly connected at a proximal connection point and a distal connection point respectively. The proximal connection point is close to the operation end, and the distal connection point is far from the operation end;

[0006] Each of the support structures is fixedly connected to the first spiral rod and the second spiral rod. At least five of the support structures are arranged at intervals. Each of the support structures includes at least one V-shaped structure, and the opening of each V-shaped structure faces the operation end.

[0007] Optionally, the thrombectomy stent further includes at least one first protection structure. Each first protection structure is fixedly connected to the stent body, and each first protection structure is disposed between the first screw rod and the second screw rod and between the target support structures. Each first protection structure is fixedly connected to the first screw rod, the second screw rod, and the first target support structure respectively; the target support structures are adjacent support structures among at least five support structures, and the first target support structure is the support structure among the target support structures that is closer to the distal connection point.

[0008] Each first protection structure is an open mesh structure. The opening of each first protection structure faces the operating end. At least one first imaging structure is provided on each first protection structure, and each first protection structure is used to capture the thrombus blocks that fall off from the stent body.

[0009] Optionally, each first protection structure and the stent body have at least four connection points, and each first protection structure and the first target support structure have at least two connection points. The distance between the target support structures is greater than the distance between any two other support structures, and the other support structures are the support structures other than the target support structures among at least five support structures.

[0010] Optionally, the thrombectomy stent further includes a second protection structure, and the second protection structure is fixedly connected to the first screw rod and the second screw rod at the distal connection point.

[0011] The second protection structure is an open mesh structure. The mesh holes of the second protection structure are not larger than those of the first protection structure. The opening of the second protection structure faces the operating end. A second imaging structure is provided at the distal end of the second protection structure. The distal end of the second protection structure is far from the operating end, and the second protection structure is used to capture the thrombus blocks that fall off from the stent body.

[0012] Optionally, the second protection structure is fixedly connected to the first screw rod and the second screw rod at the distal connection point through at least two traction wires, and at least two traction wires converge at the distal connection point.

[0013] Optionally, the stent body is spirally formed by a preset structure along a preset axis. The preset structure includes a first side rod, a second side rod, and at least five connection structures. Each connection structure is fixedly connected to the first side rod and the second side rod. At least five connection structures are arranged at intervals between the first side rod and the second side rod. Each connection structure includes at least one V-shaped structure.

[0014] The first side rod corresponds to the first screw rod, the second side rod corresponds to the second screw rod, and each of the connecting structures corresponds to each of the supporting structures.

[0015] Optionally, a third imaging structure is provided at the proximal connection point.

[0016] Optionally, at least five of the supporting structures are located within the helical surface formed between the first screw rod and the second screw rod.

[0017] Optionally, the material of the stent body is a shape memory alloy tube after heat setting treatment, and the stent body is integrally formed.

[0018] According to another aspect of the disclosed embodiments of the present invention, a thrombectomy device is provided, including a delivery assembly and the thrombectomy stent described in any one of the above. The delivery assembly is configured to deliver the thrombectomy stent to the location of the thrombus in the target blood vessel;

[0019] The delivery assembly includes a delivery guide wire, a guiding sheath, and a microcatheter. The thrombectomy stent is fixedly connected to the delivery guide wire at the proximal connection point. The thrombectomy stent is received within the guiding sheath, and the guiding sheath communicates with the microcatheter;

[0020] The microcatheter is configured to pre-determine the location of the thrombus in the target blood vessel. The guiding sheath is configured to guide the thrombectomy stent into the microcatheter, and the delivery guide wire is configured to push the thrombectomy stent to the location of the thrombus in the target blood vessel.

[0021] The technical solutions provided by the disclosed embodiments of the present invention at least bring the following beneficial effects:

[0022] The thrombectomy stent provided by the present invention is a self-expanding structure. The thrombectomy stent includes a stent body, which includes a first screw rod, a second screw rod, and at least five supporting structures. The first screw rod and the second screw rod form a reverse double-helix structure. The first screw rod and the second screw rod are fixedly connected at the proximal connection point and the distal connection point respectively. The proximal connection point is close to the operating end, and the distal connection point is far from the operating end; each supporting structure is fixedly connected to the first screw rod and the second screw rod. At least five supporting structures are arranged at intervals. Each supporting structure includes at least one V-shaped structure, and the opening of each V-shaped structure faces the operating end. The thrombectomy stent formed based on the above structure can provide effective radial support force, facilitate the stent to cut the thrombus and engage with the thrombus, can effectively capture the thrombus, improve the thrombectomy effect and efficiency, and avoid complications caused by thrombectomy treatment and irreversible damage to the brain. At the same time, the above-mentioned thrombectomy stent has a simple structure, good storage and delivery performance, and can be applied to thrombectomy treatment with higher precision requirements.

[0023] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the disclosure of the present invention, and are used together with the specification to explain the principles of the present disclosure, and do not constitute an improper limitation to the disclosure of the present invention.

[0025] Figure 1 is a schematic structural view of a thrombectomy stent provided by an embodiment of the present application from a front view perspective on the side;

[0026] Figure 2 is a schematic structural view of a thrombectomy stent provided by an embodiment of the present application from an inclined perspective on the side;

[0027] Figure 3 is a schematic structural view of a thrombectomy stent provided by an embodiment of the present application from another inclined perspective on the side;

[0028] Figure 4 is a schematic structural view of a thrombectomy stent provided by an embodiment of the present application from a front view perspective at the distal end;

[0029] Figure 5 is a schematic view of a preset structure corresponding to a thrombectomy stent provided by an embodiment of the present application;

[0030] Figure 6 is a schematic structural view of another thrombectomy stent provided by an embodiment of the present application from a front view perspective on the side;

[0031] Figure 7 is a schematic view of a local support structure of another thrombectomy stent provided by an embodiment of the present application;

[0032] Figure 8 is a schematic view of a local support structure of another thrombectomy stent provided by an embodiment of the present application from a front view perspective at the distal end;

[0033] Figure 9 is a schematic view of a local support structure of another thrombectomy stent provided by an embodiment of the present application;

[0034] Among them, the corresponding reference numerals in the drawings are: 1 - first screw rod; 2 - second screw rod; 3 - support structure; 31 - first target support structure; 4 - first protection structure; 5 - second protection structure; 51 - traction wire; 61 - first imaging structure; 62 - second imaging structure; 63 - third imaging structure; 71 - first side rod; 72 - second side rod; 73 - connection structure; 8 - delivery guide wire; 91 - proximal connection point; 92 - distal connection point. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0036] It should be noted that the "one embodiment" or "embodiment" referred to in the specification of the embodiments of the present application means a specific feature, structure or characteristic that can be included in at least one implementation manner of the present application. It should be understood that in the specification, claims and the above-mentioned drawings of the embodiments of the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. The terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system or product that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the embodiments of the present application, and are not used to limit the embodiments of the present application.

[0038] In order to solve the problems of poor ability to capture and engage thrombus due to improper design of the thrombectomy stent and insufficient radial force of the stent, and the long time-consuming thrombectomy process, the present invention proposes a thrombectomy stent with a reverse double-helix structure with V-shaped struts, which can provide effective radial support force, facilitate the stent to cut the thrombus and engage with the thrombus, can effectively capture the thrombus, improve the thrombectomy effect and efficiency, and at the same time has a simple structure, is convenient for storage and transportation, and can be applied to thrombectomy treatment with higher precision requirements.

[0039] The following will introduce the technical solutions in the embodiments of the present application in conjunction with the attached Figures 1-9 figures.

[0040] Please refer to Figures 1-9 , a thrombectomy stent provided by an embodiment of the present application, the thrombectomy stent is a self-expanding structure, the thrombectomy stent includes a stent body, the stent body includes a first screw rod 1, a second screw rod 2 and at least five support structures 3, the first screw rod 1 and the second screw rod 2 form a reverse double-helix structure, the first screw rod 1 and the second screw rod 2 are fixedly connected at a proximal connection point 91 and a distal connection point 92 respectively, the proximal connection point 91 is close to the operating end, and the distal connection point 92 is far from the operating end; each support structure 3 is fixedly connected to the first screw rod 1 and the second screw rod 2, at least five support structures 3 are arranged at intervals, each support structure 3 includes at least one V-shaped structure, and the opening of each V-shaped structure faces the operating end.

[0041] Specifically, the proximal end (close to the operating end) and the distal end (far from the operating end) of the stent body are closed, that is, the head and tail of the first screw rod 1 and the second screw rod 2 are correspondingly connected, and there are only two connection points at the head and tail (proximal connection point 91 and distal connection point 92). Each support structure 3 can be used to cut the thrombus in the target blood vessel and engage with the thrombus, and the target blood vessel can be a blood vessel in which a thrombus is formed inside and thrombectomy operation is required; each support structure 3 can be a single V-shaped structure or a multi-V-shaped structure, such as a W-shaped structure, etc.

[0042] Specifically, each support structure 3 can be symmetric or asymmetric along the center line of the reverse double-helix structure formed by the first screw rod 1 and the second screw rod 2. Multiple support structures 3 can be arranged at equal intervals or non-equal intervals between the first screw rod 1 and the second screw rod 2. The sizes of the multiple support structures 3 can be the same or different, or the sizes of some support structures 3 are the same and the sizes of some support structures 3 are different. The size of each support structure 3 and the interval distance between adjacent support structures 3 can be set according to actual application requirements. For example, the size of each support structure 3 can be specifically set according to the thickness of the blood vessel or the position of the blood vessel in the human body, and the size of each support structure 3 and the interval distance between adjacent support structures 3 can be set according to the state of the stent body after being crimped, so that after the stent body is crimped, the multiple support structures 3 do not overlap as much as possible, thereby reducing the thickness of the stent body after crimping and facilitating storage and transportation.

[0043] In practical applications, compared with the traditional barrel-shaped thrombectomy stent that converts the circumferential force into a radial force and then cuts the thrombus, the V-shaped support structure 3 can generate a direct radial force on the thrombus. Therefore, in the case of having the same radial force as the traditional barrel-shaped thrombectomy stent, the double-helix stent with the V-shaped support structure 3 uses less metal and has a simpler structure, and thus can be inserted into a thinner microcatheter for easy transportation, and can be applied to thrombectomy treatment with higher precision requirements.

[0044] In the above embodiments, the support structure 3 with a V-shaped structure can increase the radial supporting force of the thrombectomy stent, which is beneficial to thrombus cutting and will not cut the thrombus too finely. The double-helix stent with the V-shaped support structure 3 can increase the contact area with the thrombus, which is beneficial to the fitting of the stent and the thrombus. At the same time, sufficient radial force can be obtained without tight winding, avoiding the problem of obvious stent shortening rate caused by tight winding.

[0045] Optionally, a third imaging structure 63 is provided at the proximal connection point 91.

[0046] Specifically, the above-mentioned third imaging structure 63 can be an imaging ring or an imaging coil, etc., which is made of a material that does not transmit X-rays. This material includes but is not limited to platinum-tungsten alloy. The proximal imaging structure can visually display the effective working area of the thrombectomy stent.

[0047] In some embodiments, the stent body is helically formed from a preset structure along a preset axis. The preset structure includes a first side rod 71, a second side rod 72, and at least five connecting structures 73. Each connecting structure 73 is fixedly connected to the first side rod 71 and the second side rod 72. The at least five connecting structures 73 are arranged at intervals between the first side rod 71 and the second side rod 72. Each connecting structure 73 includes at least one V-shaped structure. The first side rod 71 corresponds to the first screw rod 1, the second side rod 72 corresponds to the second screw rod 2, and each connecting structure 73 corresponds to each support structure 3.

[0048] Specifically, a preset torsional force can be applied to both sides of the above preset structure and fixed on a heat setting tooling, and then it is placed in a high-temperature furnace for heat setting to obtain the above stent body. The size of the above preset axis and torsional force can be set according to actual application requirements. For example, the preset axis can be the midline corresponding to the first side rod 71 and the second side rod 72. The multiple connecting structures 73 can be symmetric or asymmetric along the midline corresponding to the first side rod 71 and the second side rod 72. After helical winding, the asymmetric support structures 3 can be formed based on the asymmetry of the connecting structure 73 itself, or the helical axis is not the midline corresponding to the first side rod 71 and the second side rod 72, etc.

[0049] Optionally, the material of the stent body is a shape memory alloy tube after heat setting treatment, and the stent body is integrally formed.

[0050] Specifically, the materials used for the stent body include but are not limited to metal materials, elastic polymer materials, or elastic plastic materials, such as nickel-titanium alloy.

[0051] In some embodiments, at least five support structures 3 are located within the helical surface formed between the first screw rod 1 and the second screw rod 2.

[0052] Optionally, each support structure 3 can be shaped within the helical surface formed between the first screw rod 1 and the second screw rod 2, or can be shaped into a structure deviating from the helical surface. Specifically, the tip of the V-shaped structure included in each support structure 3 can deviate from the helical surface at a preset angle, and the preset angle can be set according to actual application requirements. When each support structure 3 is shaped within the helical surface formed between the first screw rod 1 and the second screw rod 2, the above preset structure is a planar structure.

[0053] Optionally, the thrombus removal bracket also includes at least one first protective structure 4, each first protective structure 4 is fixedly connected to the bracket body, each first protective structure 4 is arranged between the first spiral rod 1 and the second spiral rod 2, and is arranged between the target support structure, and each first protective structure 4 is fixedly connected to the first spiral rod 1, the second spiral rod 2, and the first target support structure 31 respectively; each first protective structure 4 is an open mesh structure, the opening of each first protective structure 4 faces the operating end, and each first protective structure 4 is provided with at least one first developing structure 61.

[0054] Specifically, the target support structure is an adjacent support structure 3 among at least five support structures 3, the first target support structure 31 is a support structure 3 among the target support structures close to the distal connection point 92, and each first protective structure 4 is used to capture a thrombus block that has fallen off from the stent body, thereby reducing the risk of thrombus block falling off and then causing embolism.

[0055] In a specific embodiment, each first protective structure 4 can be a hemispherical mesh bag structure, which can be obtained by laser cutting or weaving. The material of the first protective structure 4 includes but is not limited to metal materials, elastic polymer materials or elastic plastic materials, such as nickel-titanium alloy. Multiple first protective structures 4 can be arranged at preset intervals, and there are multiple support structures 3 between adjacent first protective structures 4. Specifically, the preset interval can be set according to actual application requirements. For example, the intervals between multiple adjacent first protective structures 4 can be the same.

[0056] Optionally, each first protective structure 4 has at least four connection points with the bracket body, each first protective structure 4 has at least two connection points with the first target support structure 31, the distance between the target support structures is greater than the distance between any two other support structures, and the other support structures are support structures 3 other than the target support structure among at least five support structures 3.

[0057] Specifically, each connection point between the first protective structure 4 and the support body can be set as a developing point, and the bottom center of each first protective structure 4 can also be set as a developing point, so as to intuitively reflect the contact between the thrombus removal support and the thrombus block. In the case where there are four connection points between a first protective structure 4 and the support body, it has one connection point with the first spiral rod 1 and the second spiral rod 2 respectively, and has two connection points with the first target support structure 31. Each first protective structure 4 can be connected to the first spiral rod 1 and the second spiral rod 2 at the maximum opening, and the straight-line distance between the connection points between it and the first spiral rod 1 and the second spiral rod 2 can be the diameter of the maximum opening of the first protective structure 4. Each first protective structure 4 can be symmetrically arranged along the center line of the support body.

[0058] Optionally, the thrombectomy stent further includes a second protection structure 5, which is fixedly connected to the first screw rod 1 and the second screw rod 2 at the distal connection point 92; the second protection structure 5 is an open mesh structure, and the mesh holes of the second protection structure 5 are not larger than those of the first protection structure 4. The opening of the second protection structure 5 faces the operating end, and a second imaging structure 62 is provided at the distal end of the second protection structure 5, and the distal end of the second protection structure 5 is far from the operating end.

[0059] Specifically, the second protection structure 5 can be a hemispherical mesh bag structure, which can be obtained by weaving; the size of the second protection structure 5 can be the same as that of the first protection structure 4, and the second protection structure 5 can be finer than the first protection structure 4. The second imaging structure 62 can be an imaging ring or an imaging spring coil, etc., which is arranged at the center of the bottom of the second protection structure 5. The imaging structure arranged at the distal end can facilitate observing the actual position where the farthest end of the thrombectomy stent reaches the blood vessel.

[0060] In practical applications, vascular imaging devices such as DSA (Digital Subtraction Angiography) can be used to monitor the positions of multiple imaging structures, so as to understand the condition and progress position of the stent. During the thrombectomy process, the shapes of the thrombectomy stent and the thrombus are clarified, the effective thrombectomy length of the thrombectomy stent is accurately marked, it is judged whether the thrombectomy stent is completely released and expanded, the contact situation between the thrombectomy stent and the thrombus is intuitively reflected, and it is further judged whether there is in-situ stenosis in the diseased blood vessel, which is beneficial to the doctor's surgical operation and judgment.

[0061] In the above embodiment, the second protection structure 5 is used to grab the thrombus that falls off from the stent body, especially the thrombus that falls off from the distal end of the stent body. It can be combined with the first protection structure 4 to enhance the thrombus grabbing ability of the thrombectomy stent and reduce the risk of re-embolism caused by thrombus escape.

[0062] Optionally, the second protection structure 5 is fixedly connected to the first screw rod 1 and the second screw rod 2 at the distal connection point 92 through at least two traction wires 51, and the at least two traction wires 51 converge at the distal connection point 92.

[0063] Specifically, the second protection structure 5 can be symmetrically connected by four traction wires 51, and the four traction wires 51 converge at the distal connection point 92 to make the second protection structure 5 more stable during the thrombectomy process. The materials of the traction wires 51 include but are not limited to nitinol and stainless steel, etc.

[0064] In practical applications, multiple thrombectomy stents can be connected in sequence for thrombectomy operations. Each thrombectomy stent can include at least five support structures 3, and the number of thrombectomy stents can be determined according to the length of the thrombectomy stent required in practical applications.

[0065] The following introduces the specific embodiments of the present application based on the above technical solutions.

[0066] Example 1

[0067] Please refer to Figures 1-5 , Example 1 provides a thrombectomy stent. The thrombectomy stent is a self-expanding structure. The thrombectomy stent includes a stent body. The stent body includes a first screw rod 1, a second screw rod 2, and a plurality of support structures 3. The first screw rod 1 and the second screw rod 2 form a reverse double helix structure. The first screw rod 1 and the second screw rod 2 are fixedly connected at a proximal connection point 91 and a distal connection point 92 respectively. The proximal connection point 91 is close to the operating end, and the distal connection point 92 is far from the operating end; each support structure 3 is fixedly connected to the first screw rod 1 and the second screw rod 2. The plurality of support structures 3 are arranged at intervals. Each support structure 3 is a single V-shaped structure, and the opening of the V-shaped structure faces the operating end.

[0068] Specifically, the proximal end (close to the operating end) and the distal end (far from the operating end) of the stent body are closed, that is, the head and tail of the first screw rod 1 and the second screw rod 2 are correspondingly connected, and there are only two connection points at the head and tail (the proximal connection point 91 and the distal connection point 92). Each support structure 3 is used to cut the thrombus in the target blood vessel and engage with the thrombus. The target blood vessel can be a blood vessel in which a thrombus is formed inside and thrombectomy operation is required.

[0069] Specifically, each support structure 3 and the above-mentioned reverse double helix structure are both symmetric along Figure 1 the central axis, and this axis is the center line of the reverse double helix structure. The sizes of the plurality of support structures 3 are the same.

[0070] Optionally, a third imaging structure 63 is provided at the proximal connection point 91.

[0071] Specifically, the above-mentioned third imaging structure 63 is an imaging ring, which is made of a non-fluoroscopic ray material, platinum-tungsten alloy.

[0072] In some embodiments, the stent body is spirally formed by a preset structure along a preset axis. As Figure 5 shown, the preset structure includes a first side rod 71, a second side rod 72, and a plurality of connection structures 73. Each connection structure 73 is fixedly connected to the first side rod 71 and the second side rod 72. The plurality of connection structures 73 are arranged at intervals between the first side rod 71 and the second side rod 72. Each connection structure 73 is a single V-shaped structure; the first side rod 71 corresponds to the first screw rod 1, the second side rod 72 corresponds to the second screw rod 2, and each connection structure 73 corresponds to each support structure 3.

[0073] Specifically, a preset torsional force of a preset magnitude can be applied to both sides of the above-mentioned preset structure, and it is fixed to a heat-setting tooling, and then placed in a high-temperature furnace for heat setting, so as to obtain the above-mentioned bracket body. The above-mentioned preset axis is the midline corresponding to the first side rod 71 and the second side rod 72, and a plurality of connecting structures 73 are symmetric along the midline corresponding to the first side rod 71 and the second side rod 72.

[0074] Optionally, the material of the bracket body is a shape memory alloy tube after heat setting treatment, and the bracket body is integrally formed.

[0075] Specifically, the materials used for the bracket body include but are not limited to metal materials, elastic polymer materials or elastic plastic materials, such as nitinol alloy.

[0076] Specifically, a plurality of support structures 3 are located within the helical surface formed between the first screw rod 1 and the second screw rod 2, and the above-mentioned preset structure is a planar structure.

[0077] Optionally, the thrombus-removing bracket further includes a plurality of first protection structures 4. Each first protection structure 4 is fixedly connected to the bracket body. Each first protection structure 4 is arranged between the first screw rod 1 and the second screw rod 2 and between the target support structures. Each first protection structure 4 is fixedly connected to the first screw rod 1, the second screw rod 2, and the first target support structure 31 respectively; each first protection structure 4 is an open mesh structure, the opening of each first protection structure 4 faces the operating end, and at least one first imaging structure 61 is arranged on each first protection structure 4.

[0078] Specifically, the target support structure is an adjacent support structure 3 among the plurality of support structures 3, the first target support structure 31 is the support structure 3 close to the distal connection point 92 among the target support structures, and each first protection structure 4 is used to grab the thrombus blocks falling off from the bracket body.

[0079] In a specific embodiment, each first protection structure 4 is a hemispherical mesh structure, and this mesh structure can be obtained by laser cutting or weaving. The material of the first protection structure 4 includes but is not limited to metal materials, elastic polymer materials or elastic plastic materials, such as nitinol alloy. A plurality of first protection structures 4 are arranged at equal intervals with a preset spacing, and there are a plurality of support structures 3 between adjacent first protection structures 4. Specifically, the above-mentioned preset spacing can be set according to actual application requirements.

[0080] Optionally, each first protection structure 4 has four connection points with the stent body, each first protection structure 4 has two connection points with the first target support structure 31, and each has one connection point with the first screw rod 1 and the second screw rod 2 respectively. The distance between the target support structures is greater than the distance between any two other support structures. The other support structures are the support structures 3 among the multiple support structures 3 except the target support structures. The distances between the target support structures corresponding to the multiple first protection structures 4 are the same. Among the other support structures, the adjacent support structures 3 are arranged at equal intervals between the first screw rod 1 and the second screw rod 2.

[0081] Specifically, the connection points of each first protection structure 4 with the stent body are all set as imaging points, and the bottom center point of each first protection structure 4 is set as an imaging point, which can intuitively reflect the contact situation between the thrombectomy stent and the thrombus mass. Each first protection structure 4 is connected to the first screw rod 1 and the second screw rod 2 at the maximum opening. Each first protection structure 4 is symmetrically arranged along the center line of the stent body. The straight-line distance between the connection points of it with the first screw rod 1 and the second screw rod 2 is the diameter at the maximum opening of the first protection structure 4.

[0082] Optionally, the thrombectomy stent further includes a second protection structure 5. The second protection structure 5 is fixedly connected to the first screw rod 1 and the second screw rod 2 at the distal connection point 92; the second protection structure 5 is an open mesh structure, and its opening faces the operating end. The distal end of the second protection structure 5 is provided with a second imaging structure 62, and the distal end of the second protection structure 5 is far from the operating end.

[0083] Specifically, the second protection structure 5 is a hemispherical mesh structure, which can be obtained by weaving; the size of the second protection structure 5 is the same as that of the first protection structure 4, but the mesh holes of the second protection structure 5 are finer than those of the first protection structure 4. The second imaging structure is an imaging ring, which is arranged at the center of the bottom of the second protection structure 5. The imaging structure arranged at the distal end can facilitate observing the actual position where the farthest end of the thrombectomy stent reaches the blood vessel.

[0084] Specifically, the second protection structure 5 is fixedly connected to the first screw rod 1 and the second screw rod 2 at the distal connection point 92 through four traction wires 51. The second protection structure 5 is symmetrically connected through the four traction wires 51, and the four traction wires 51 converge at the distal connection point 92. The materials of the traction wires 51 include but are not limited to nitinol and stainless steel, etc.

[0085] Embodiment 2

[0086] The difference between Embodiment 2 and Embodiment 1 lies in the setting of the support structure 3. The similarities with Embodiment 1 will not be elaborated here. Now, the differences between Embodiment 2 and Embodiment 1 are described as follows:

[0087] AsFigure 6 As shown Figure 6 and Figure 1 have the same perspective, both being the side front view perspective. Each support structure 3 is asymmetric along the axis (the dotted line in the figure), that is, the center line of the reverse double helix structure formed by the first screw rod 1 and the second screw rod 2. This reverse double helix structure is axisymmetric along the axis in the figure. Correspondingly, each connecting structure 73 in the spiral front plane structure is asymmetric along the axis, that is, the midline corresponding to the first side rod 71 and the second side rod 72.

[0088] Embodiment 3

[0089] The difference between Embodiment 3 and Embodiment 1 lies in the different settings of the support structure 3. The similarities with Embodiment 1 will not be elaborated here. Now, the differences between Embodiment 3 and Embodiment 1 are described as follows:

[0090] As Figure 7 and Figure 8 shown, each support structure 3 is shaped into a structure deviating from the spiral surface formed between the first screw rod 1 and the second screw rod 2. Correspondingly, each connecting structure 73 in the non-planar structure before the spiral deviates from the plane where the two side rods are located. The position marked "the position of the support structure in the spiral surface" in the figure indicates the position of the support structure 3 if the support structure 3 is shaped on the spiral surface formed between the first screw rod 1 and the second screw rod 2. The support structure 3 deviating from the spiral surface in the figure can be regarded as tilting a certain angle in the Figure 7 perspective direction.

[0091] Embodiment 4

[0092] The difference between Embodiment 4 and Embodiment 1 lies in the different settings of the support structure 3. The similarities with Embodiment 1 will not be elaborated here. Now, the differences between Embodiment 4 and Embodiment 1 are described as follows:

[0093] As Figure 9 shown, each support structure 3 is a W-shaped structure. Correspondingly, each connecting structure in the spiral front plane structure is also a W-shaped structure.

[0094] The embodiments of the present application further provide a thrombectomy device, including a delivery assembly and the above-mentioned thrombectomy stent. The delivery assembly is used to deliver the thrombectomy stent to the position of the thrombus in the target blood vessel;

[0095] The delivery assembly includes a delivery guide wire 8, a guiding sheath (not shown), and a microcatheter (not shown). The thrombectomy stent is fixedly connected to the delivery guide wire 8 at the proximal connection point 91. The thrombectomy stent is received in the guiding sheath, and the guiding sheath is communicated with the microcatheter;

[0096] The microcatheter is used to pre-determine the location of the thrombus in the target blood vessel, the guiding sheath is used to guide the thrombectomy stent into the microcatheter, and the delivery guide wire 8 is used to push the thrombectomy stent to the location of the thrombus in the target blood vessel.

[0097] Specifically, the raw material used for the delivery guide wire 8 can be a material with good mechanical properties and biological properties, such as stainless steel, nitinol alloy, etc. The delivery guide wire 8 is coated with a lubricating coating, which can reduce the resistance during the pushing and pulling process of the delivery guide wire 8 and enhance the controllability. The lubricating coating can be a PTFE coating or a hydrophilic coating. The inner diameter of the guiding sheath can be equal to the inner diameter of the microcatheter, and it can send the thrombectomy stent into the microcatheter. The material of the guiding sheath can be a polymer material, such as polytetrafluoroethylene, which has a small friction coefficient and can reduce the resistance during the pushing process.

[0098] In practical applications, clinicians use DSA (Digital Subtraction Angiography) to perform angiography on patients to determine the location of the target thrombus in the target blood vessel. Using conventional vascular puncture intervention techniques, the end of the microcatheter far from the operating end is delivered to a certain distance beyond the target thrombus, and then an appropriate amount of contrast agent is injected into the microcatheter to perform angiography on the blood vessel distal to the thrombus to judge the approximate length of the target thrombus and select a thrombectomy stent of appropriate specifications. Then, based on the guiding function of the guiding sheath, the thrombectomy stent is sent into the microcatheter and gradually pushed. When the imaging structure far from the operating end in the thrombectomy stent reaches the most distal end of the microcatheter, keep the thrombectomy stent stationary relative to the human body and retract the microcatheter towards the operating end. As the microcatheter is retracted, the thrombectomy stent will expand at the target thrombus location. The support structure of the thrombectomy stent itself cuts into the target thrombus and fits with the thrombus. At the same time, the open mesh structure parts arranged in the middle and distal sections of the thrombectomy stent will also expand and open by self-expansion to form a protective net to capture the thrombus that falls off from the support structure. The most distal end of the microcatheter is retracted to the position of the imaging ring at the proximal connection point of the thrombectomy stent. After the thrombectomy stent is fully expanded, when the doctor judges that the capture of the target thrombus is good, quickly retract the thrombectomy stent and the microcatheter. During the retraction process, if there is any fallen thrombus, it will be captured by the open mesh structure in the middle and distal sections of the thrombectomy stent. Finally, the thrombectomy device wrapped with the target thrombus is withdrawn from the body to complete the entire thrombectomy process.

[0099] As can be seen from the technical solutions provided in the embodiments of this specification above, the thrombectomy stent in this specification has the following technical effects:

[0100] 1) The stent adopts a double-helical structure, which includes a plurality of V-shaped support structures arranged at intervals, which can increase the radial support force of the stent, facilitate thrombus cutting, and will not cut the thrombus into very small pieces, improving the thrombectomy effect;

[0101] 2) The V-shaped support structure enables the stent to obtain sufficient radial force without being tightly wound, avoiding the problem of obvious stent shortening rate caused by tight winding;

[0102] 3) The double - helix stent with a V - shaped support structure can increase the contact area with the thrombus block, which is more conducive to the fitting of the stent and the thrombus block, effectively capturing the thrombus block, and improving the thrombus removal effect and efficiency.

[0103] 4) Compared with the traditional barrel - shaped thrombus removal stent that converts the circumferential force into radial force and then cuts the thrombus block, the V - shaped support structure can generate a direct radial force on the thrombus block. Therefore, under the condition of having the same radial force as the traditional barrel - shaped thrombus removal stent, the double - helix stent with a V - shaped support structure rod can use less metal material, saving costs.

[0104] 5) The V - shaped support structure uses less metal and has a simpler structure. Furthermore, the stent can be inserted into a smaller micro - catheter, and its delivery performance is better than that of the traditional barrel - shaped thrombus removal stent, and it can be applied to thrombus removal treatment with higher precision requirements.

[0105] 6) On the double - helix stent with multiple V - shaped support structures, multiple protective mesh bags are provided, which can capture the thrombus blocks that fall off from the stent, thereby reducing the risk of re - embolism caused by thrombus block escape and avoiding complications caused by thrombus removal treatment.

[0106] It should be noted that: the above - mentioned order of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above - mentioned specific embodiments of this specification are described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be executed in a different order from that in the embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multi - tasking and parallel processing are also possible or may be advantageous.

[0107] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0108] Those of ordinary skill in the art can understand that all or part of the steps to implement the above - mentioned embodiments can be completed by hardware, or can be completed by a program instructing relevant hardware. The program can be stored in a computer - readable storage medium, and the above - mentioned storage medium can be a read - only memory, a disk, or an optical disc, etc.

[0109] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A thrombectomy stent, characterized in that, The thrombectomy stent is a self-expanding structure. The thrombectomy stent includes a stent body, and the stent body includes a first helical rod, a second helical rod, and at least five support structures. The first helical rod and the second helical rod form a reverse double-helical structure. The first helical rod and the second helical rod are fixedly connected at a proximal connection point and a distal connection point respectively. The proximal connection point is close to the operation end, and the distal connection point is far from the operation end. Each of the support structures is fixedly connected to the first helical rod and the second helical rod. At least five of the support structures are arranged at intervals. Each of the support structures includes at least one V-shaped structure, and the opening of each V-shaped structure faces the operation end.

2. The thrombectomy stent according to claim 1, wherein, The thrombectomy stent further includes at least one first protection structure. Each of the first protection structures is fixedly connected to the stent body. Each of the first protection structures is arranged between the first helical rod and the second helical rod and between the target support structures. Each of the first protection structures is fixedly connected to the first helical rod, the second helical rod, and the first target support structure respectively. The target support structure is the adjacent support structure among at least five of the support structures, and the first target support structure is the support structure among the target support structures that is close to the distal connection point. Each of the first protection structures is an open mesh structure. The opening of each of the first protection structures faces the operation end. At least one first imaging structure is arranged on each of the first protection structures. Each of the first protection structures is used to capture the thrombus blocks that fall off from the stent body.

3. The thrombectomy stent according to claim 2, wherein, Each of the first protection structures and the stent body has at least four connection points. Each of the first protection structures and the first target support structure has at least two connection points. The distance between the target support structures is greater than the distance between any two other support structures. The other support structures are the support structures among at least five of the support structures except the target support structures.

4. The thrombectomy stent according to claim 2 or 3, characterized in that, The thrombectomy stent further includes a second protection structure. The second protection structure is fixedly connected to the first helical rod and the second helical rod at the distal connection point. The second protection structure is an open mesh structure. The mesh holes of the second protection structure are not larger than those of the first protection structure. The opening of the second protection structure faces the operation end. A second imaging structure is arranged at the distal end of the second protection structure. The distal end of the second protection structure is far from the operation end. The second protection structure is used to capture the thrombus blocks that fall off from the stent body.

5. The thrombectomy stent according to claim 4, wherein, The second protection structure is fixedly connected to the first helical rod and the second helical rod at the distal connection point through at least two traction wires, and at least two of the traction wires converge at the distal connection point.

6. The thrombectomy stent according to claim 1, wherein, The stent body is formed by helically winding a preset structure along a preset axis. The preset structure includes a first side rod, a second side rod, and at least five connecting structures. Each connecting structure is fixedly connected to the first side rod and the second side rod. At least five connecting structures are arranged at intervals between the first side rod and the second side rod. Each connecting structure includes at least one V-shaped structure; The first side rod corresponds to the first screw rod, the second side rod corresponds to the second screw rod, and each connecting structure corresponds to each support structure.

7. The thrombectomy stent according to claim 1, wherein A third imaging structure is provided at the proximal connection point.

8. The thrombectomy stent according to claim 1, wherein, At least five support structures are located within the helical surface formed between the first screw rod and the second screw rod.

9. The thrombectomy stent according to claim 1, wherein The material of the stent body is a shape memory alloy tube subjected to heat setting treatment, and the stent body is integrally formed.

10. A thrombectomy device, characterized in that, It includes a delivery assembly and an embolus retrieval stent according to any one of claims 1 to 9. The delivery assembly is used to deliver the embolus retrieval stent to the position of the thrombus in the target blood vessel; The delivery assembly includes a delivery guide wire, a guiding sheath, and a microcatheter. The embolus retrieval stent is fixedly connected to the delivery guide wire at the proximal connection point. The embolus retrieval stent is housed within the guiding sheath, and the guiding sheath communicates with the microcatheter; The microcatheter is used to pre-determine the position of the thrombus in the target blood vessel. The guiding sheath is used to guide the embolus retrieval stent into the microcatheter, and the delivery guide wire is used to push the embolus retrieval stent to the position of the thrombus in the target blood vessel.

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