Thrombectomy device system

Abstract

The present invention provides a thrombus removal device system, which includes a thrombus removal bracket, and the thrombus removal bracket includes an inner layer part, an outer layer part and a fishing device. The thrombus removal device system also includes a distal developing spring and a proximal developing spring, a pushing guide wire and a loading sheath, which is used for removing thrombi in the vascular cavity of ischemic stroke. It can better embed into thrombi or clots, has a higher capture rate, has higher axial support force and performance, meets rigidity requirements, better adheres to the vessel wall in the vascular cavity, optimizes the design of indicators in various aspects, meets mechanical properties, and significantly improves the immediate recanalization rate of target blood vessels after surgery.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and specifically relates to a device for removing thrombi from blood vessels in ischemic stroke. Background Art

[0002] Stroke is a major cause of death and disability. Acute ischemic stroke (acute cerebral infarction) is the most common type of stroke. Intravenous thrombolysis is an effective treatment for acute ischemic stroke. However, the recanalization rate for acute large vessel occlusive ischemic stroke is low, and the efficacy of intravenous thrombolysis is poor.

[0003] Therefore, since the 1980s, doctors have been exploring the use of mechanical thrombectomy to open blocked blood vessels. The first-generation thrombectomy device, the Merci thrombectomy device, was approved by the US Food and Drug Administration in 2004. The MERCI and Multi-MERCI trials demonstrated that this first-generation thrombectomy device achieved a vascular patency rate exceeding 45%, but the clinical outcomes were suboptimal.

[0004] The second-generation thrombectomy device is the stent retriever, represented by the Solitaire. The Solitaire with the Intention for Thrombectomy (SWIFT) trial, published in The Lancet in 2012, demonstrated that the Solitaire group had significantly higher vascular patency rates than the Merci group (60.7% vs. 24.1%), a significantly better rate of favorable outcomes (modified Rankin Scale score 0-2) (58.2% vs. 33.6%), and a lower mortality rate (17.2% vs. 38.2%). In 2015, five randomized studies comparing mechanical thrombectomy with intravenous thrombolysis were published in the New England Journal of Medicine. These included the MR CLEAN ESCAPE, EXTEND IA, SWIFT PRIME, and REVASCA trials. All of these studies demonstrated that mechanical thrombectomy was superior to intravenous thrombolysis alone for patients with acute ischemic stroke within 6 hours of onset, marking the advent of the thrombectomy era.

[0005] However, the second-generation thrombectomy stent also has some problems that need to be improved. The single-layer thrombectomy stent basically relies on the radial support force of the metal mesh of the stent to embed the thrombus between the meshes and attach to the stent. Then, the guidewire drags the stent to pull the thrombus out of the body. Therefore, the radial support force of the thrombectomy stent must be large enough to embed the thrombus into the mesh. However, clinical studies have shown that the radial support force of the thrombectomy stent will damage the blood vessel wall, affect the later prognosis, and lay the hidden danger for subsequent stroke recurrence. In addition, during the withdrawal process of the single-layer stent, it passes through the tortuous blood vessels and its ability to resist extrusion is insufficient. The stent is flattened and dragged, and the captured thrombus or clot is severely detached. The detached thrombus floats to farther and smaller blood vessels, causing embolism again, affecting the thrombectomy effect. Summary of the Invention

[0006] The purpose of the present invention is to provide a thrombus removal device system for removing thrombi in the vascular cavity of ischemic stroke, improving the thrombus capture rate, meeting the rigidity requirements and optimizing the design of various indicators, and having the technical effect of significantly improving the immediate recanalization rate.

[0007] First, the thrombectomy stent in the thrombectomy device system includes an inner layer, an outer layer and a fishing device. The thrombectomy stent has a thrombectomy stent length C, and the thrombectomy stent length C satisfies C>=22mm and <=58mm; the thrombectomy stent has an effective working length B, and the effective working length B satisfies>=13mm and <=48mm; the thrombectomy stent has a maximum diameter A, and the maximum diameter A of the thrombectomy stent satisfies A>=4.5mm and <=7.0mm; the thrombectomy stent also has a radial support force RF, and after the thrombectomy stent is released from the loading sheath or microcatheter, it is in the applicable lumen. Within the inner diameter range, the stent can return to its original shape. As the thrombectomy stent expands, the minimum radial support force RF should meet RF ≥ 0.010 N / mm, and the maximum radial support force RF should meet RF ≥ 0.020 N / mm. The radial support force RF is obtained as follows: using a stent radial force tester and a circumferential compression method, the thrombectomy stent is compressed to an initial diameter of 1 mm at 37 ± 2 ° C, and then the diameter is gradually increased at a rate of 0.2 mm / s until the thrombectomy stent is completely released. The curve of the thrombectomy stent diameter and outward support force is recorded. The radial support force RF = test support force F 测 / Effective working length B of the thrombectomy device; the thrombectomy stent also has a shape recovery performance rate P, which satisfies P<=10%, and the shape recovery performance rate P is obtained as follows: the upper and lower plates are used to compress the thrombectomy stent towards each other to compress the diameter of the thrombectomy stent to a diameter of 1.5 mm. After releasing the pressure, the maximum diameter A of the thrombectomy device is reduced by a rate of <=10%; the thrombectomy stent also has a shortening rate C, which satisfies shortening rate C<=20%, and the shortening rate C is obtained as follows: the thrombectomy stent is loaded into the loading sheath, and its total length C0 is measured using a vernier caliper with a resolution of 0.01 mm. Then, the thrombectomy stent is pushed out of the loading sheath to restore it to a freely released state, and its total length C1 is measured again. The shortening rate is calculated according to the following formula: Total length shortening rate = (C0-C1) / C0×100%.

[0008] In an alternative embodiment,

[0009] The thrombus removal device system includes a distal development spring and a proximal development spring; wherein the length E of the distal development spring satisfies E>=3.5mm and <=5.5mm, the length F of the proximal development spring satisfies F>=16mm and <=22mm, and the peak tension F of the distal development spring (4) satisfies 拉 Satisfy F 拉 >=0.3N, peak pressure F 压 Satisfy F 压 <=0.1N, peak tensile force F 拉 The tension is obtained as follows: stretch the developing spring along the farthest end of the distal developing spring until the spring wire is partially straightened, clamp the spring wire with the upper clamp and clamp the push guide wire with the lower clamp, and keep the entire test section vertical during the process; stretch the test section at a rate of 10mm / min until it breaks or separates, and record the maximum force during the stretching process, which is the peak tension F of the distal developing spring. 拉 , peak pressure F 压 It is obtained by the following method: push the distal development spring out of the loading sheath, clamp the loading sheath with the upper clamp, and the point where the distal end of the distal development spring touches the lower plate is the "zero point". Press down 2mm at a speed of 10mm / min, and record the peak pressure F. 压 , which is the peak tension F of the distal development spring 压 .

[0010] In an alternative embodiment,

[0011] The thrombectomy device system includes a push guide wire. The maximum stent OD1 of the push guide wire meets the requirement of OD1>=0.42mm and <=0.60mm. The surface of the push guide wire is also coated. The friction force of the coating should meet the mean friction force F of the coating. 摩 <=300g, single value of coating friction F 摩max <=320g, average friction force of coating F摩 and coating friction single value F 摩max It is obtained as follows: On a friction force tester, the straight section of the guide wire is compressed with a fixed force of 300g, with the test section length ≥150mm. The friction force during the pumping process is tested, repeated 25 times, and the mean and single values ​​are calculated.

[0012] In an alternative embodiment,

[0013] The thrombectomy device system includes a loading sheath, and the thrombectomy stent is pre-installed in the loading sheath.

[0014] In an alternative embodiment,

[0015] Peak tensile force F of the thrombectomy device system 系统拉力 Should satisfy F 系统拉力 ≥3N, peak tensile force F 系统拉力 The test section is obtained as follows: a section of the thrombectomy device system is placed in a loading sheath cut to a length of approximately 1 cm. The section of the thrombectomy device system placed in the loading sheath is clamped in the upper chuck of a universal material testing machine, and the lower chuck clamps the push guide wire, keeping the entire test section vertical during the process; the test section is stretched at a rate of 10 mm / min until it breaks or separates, and the maximum force during the stretching process is recorded, which is the peak tensile force F of the thrombectomy device system. 系统拉力 .

[0016] In an alternative embodiment,

[0017] The inner layer of the thrombectomy stent is provided with 3 or 4 mesh holes on its circumference.

[0018] In an alternative embodiment,

[0019] The thrombectomy device system includes multiple imaging marking points made of platinum-iridium alloy. The operator can clearly observe the deployment of the thrombectomy stent. The imaging marking points on each segment of the thrombectomy stent are distributed vertically at 90°, so the operator can easily observe whether the thrombectomy stent is deployed without adjusting the angle of the imaging equipment.

[0020] In an alternative embodiment,

[0021] The thrombectomy device system is advanced in the established microcatheter pathway. The embolus is positioned within the effective working length of the thrombectomy stent by aligning the proximal developing mark point of the thrombectomy stent with the proximal edge of the embolus. The thrombectomy stent is positioned within the embolus by advancing it until the proximal developing spring is N mm away from the proximal edge of the embolus, where N>=2. Then, the guide wire is fixed and the microcatheter is withdrawn to deploy the thrombectomy stent within the embolus. Once the distal tip of the microcatheter has been withdrawn to the position above the proximal developing spring, the thrombectomy stent will be fully deployed.

[0022] In an alternative embodiment,

[0023] Maximum pushing force F of the thrombectomy stent in the microcatheter 推 Less than 1.5N, the maximum retraction force F of the thrombectomy stent in the microcatheter 撤 Should be less than 1.5N. Maximum pushing force F 推 and the maximum retracement force F 撤 It is obtained in the following way: in a 37°C water bath, the microcatheter is delivered to the farthest end of the simulated vascular tooling through a microguidewire, and the distal end of the microcatheter is flush with the distal end of the simulated vascular tooling. The thrombectomy system is pushed through the microcatheter until the thrombectomy bracket is completely exposed from the microcatheter and released. The thrombectomy system is withdrawn a corresponding distance, and the pushing distance is set. At this position, the thrombectomy system is pushed and withdrawn three times at a speed of 200 mm / min using a push-and-withdrawal force tester, and the force-displacement curve and the maximum pushing force and maximum withdrawing force are recorded.

[0024] The present invention provides a new generation of thrombus removal device system. After being released, the thrombus removal stent of the present invention can be better embedded in the thrombus or clot, has a higher capture rate, has higher axial support force and performance, meets the rigidity requirements, and is better attached to the vessel wall in the vascular cavity. The indicators in various aspects are optimized and designed to meet the mechanical properties, and the immediate recanalization rate of the target vessel after surgery is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the structure of a thrombus removal device system with three mesh holes on the circumference of the inner layer provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the structure of a thrombus removal device system with four mesh holes on the circumference of the inner layer provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the clamping position during a peak tensile test of a thrombus removal device system according to an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the position of the thrombus removal device system provided by an embodiment of the present invention in the lumen. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The thrombectomy device system involved in the present invention is an intra-arterial thrombus removal device that can be re-entered into a sheath, and restores blood flow by removing blood clots in occluded blood vessels. The thrombectomy device system includes multiple components such as a thrombectomy stent and a push guide wire, which are pre-installed in a loading sheath. The radiopaque marker can provide an image for guidance under fluoroscopy. The proximal marker band of the push guide wire provides fluoroscopic guidance for starting. The thrombectomy stent is delivered to the embolic site through a matching microcatheter. With the assistance of medical imaging equipment, the microcatheter is withdrawn to position and release the thrombectomy stent. After a period of time, the thrombectomy stent is embedded in the thrombus. After that, the thrombectomy stent that captures the thrombus is recovered together with the microcatheter into the intermediate catheter or balloon catheter, and then withdrawn from the body to achieve the purpose of restoring blood flow. During the process of withdrawing the thrombectomy stent, the catching net device at the distal end of the thrombectomy stent can capture the detached thrombus to prevent the distal blood vessel from embolism again.

[0032] The thrombus removal device system includes an inner layer portion 1 and an outer layer portion 2, wherein the inner layer portion 1 and the outer layer portion 2 together constitute the thrombus removal bracket of the thrombus removal device system. Figure 1 、 2 As shown, the thrombectomy stent adopts a multi-segment open-loop outer frame and forms an inner and outer double-layer basket pattern, which can enable the thrombectomy stent to better adhere to the wall of the tortuous blood vessels to embed thrombi, and the proximal and distal ends of the thrombectomy stent are closed to form a dense closed loop. At the same time, the thrombectomy stent has an open mesh. The design of the open mesh allows the thrombi in the blood vessel cavity to enter and be captured, and these open meshes also form a channel within the dense closed loop. The channel within the dense closed loop can immediately establish a blood flow channel and achieve immediate recanalization.

[0033] The thrombectomy stent composed of the inner layer 1 and the outer layer 2 has a thrombectomy stent length C, which satisfies C>=22mm and <=58mm. Preferably, the thrombectomy stent length C is 25mm, 32mm, 40mm, 41mm, 47mm, 50mm, or 56mm.

[0034] The thrombectomy stent composed of the inner layer 1 and the outer layer 2 also has an effective working length B of the thrombectomy stent. The effective working length B of the thrombectomy stent satisfies >=13mm and <=48mm. Preferably, the effective working length B of the thrombectomy stent is 15mm, 22mm, 30mm, 37mm, or 45mm.

[0035] The thrombectomy stent formed by the inner layer 1 and the outer layer 2 also has a maximum diameter A of the thrombectomy stent. The maximum diameter A of the thrombectomy stent satisfies A>=4.5 mm and <=7.0 mm.

[0036] The thrombectomy stent composed of the inner layer part 1 and the outer layer part 2 is made of shape memory alloy. Preferably, the material is nickel-titanium alloy. After the thrombectomy stent is released from the loading sheath, it can return to its original shape within the inner diameter range of the applicable blood vessel. As the stent expands, the minimum value of the radial support force RF should meet RF≥0.010N / mm, and the maximum value of the radial support force RF should meet RF≥0.020N / mm, to ensure that the thrombectomy stent is prevented from collapsing due to factors such as the vascular wall, blood flow, and red blood cells during the thrombectomy process.

[0037] It should be noted that the radial support force RF here is obtained by the following method: using a stent radial force tester, the stent is compressed to an initial diameter of 1mm at 37±2°C using the circumferential compression method, and then the diameter is gradually increased at a rate of 0.2mm / s until the stent is completely released. The curve of stent diameter and outward support force is recorded. The radial support force RF = test support force F 测 / Effective working length B of the thrombectomy device.

[0038] In addition, the thrombectomy stent is pre-installed in the loading sheath, that is, the thrombectomy stent is highly compressed into a relatively small space before it is released. After the thrombectomy stent is released from the loading sheath, microcatheter and other access instruments, it should expand immediately. Therefore, the thrombectomy stent should meet the deformation requirements, mainly in two aspects: shape recovery performance P and shortening rate C, among which the shape recovery performance rate P <= 10% and the shortening rate C <= 20%.

[0039] It should be noted that the shape recovery rate P is obtained as follows: the diameter of the thrombectomy stent is compressed to 1.5 mm using two upper and lower plates. After releasing the pressure, the diameter A of the thrombectomy stent is reduced by less than or equal to 10%, which is the shape recovery rate P mentioned in the present invention. The shortening rate C is obtained as follows: the stent is loaded into a loading sheath and its total length C0 is measured using a vernier caliper with a resolution of 0.01 mm. The stent is then pushed out of the loading sheath to return to its free state, and its total length C1 is measured again. The shortening rate is calculated using the following formula: Total length shortening rate = (C0 - C1) / C0 × 100%.

[0040] As a preferred embodiment, when capturing emboli within the vascular lumen, to further capture more emboli, prevent their escape, and ensure the success rate of the embolectomy process, the embolectomy system further includes a fishing device. The fishing device is located at the distal end of the embolectomy system. As a preferred solution, the distal end of the outer layer 2 and the fishing device are connected with equal diameters to form an integral structure. That is, the distal end of the outer layer 2 is directly gathered into a mesh structure, which serves as the fishing device. In addition, the arrangement and layout of the inner layer 1, outer layer 2, and fishing device can be found in the related patent CN213963546U filed by the applicant. The relevant contents of the inner layer 1, outer layer 2, and fishing device of this patent are incorporated into the embodiments of the present invention and form part of the present specification, and will not be repeated here.

[0041] The thrombus removal device system also includes a distal developing spring 4 and a proximal developing spring 5. The distal developing spring 4 converges with the distal ends of the inner layer 1 and outer layer 2 at a point, while the proximal developing spring 5 converges with the proximal ends of the inner layer 1 and outer layer 2 at a point. The length E of the distal developing spring 4 satisfies E>=3.5 mm and <=5.5 mm, and the length F of the proximal developing spring 5 satisfies F>=16 mm and <=22 mm. The distal developing spring 4 and the proximal developing spring 5 are made of a developable material, preferably platinum-tungsten alloy, to ensure clear visibility under X-rays.

[0042] It should be noted that during the delivery of the thrombus removal stent, the distal development spring 4 at its distal end will be the first to be affected by the complex environment in the blood vessel cavity. In order to ensure that the distal development spring 4 does not fail and does not damage the blood vessel cavity wall, the requirements of deformation and flexibility should be met. Specifically, the peak tension F of the distal development spring 4 is 拉 >=0.3N, peak pressure F 压 <=0.1N.

[0043] It should be noted that the peak tension F 拉 The peak tension F of the distal developing spring of the thrombus removal stent is obtained by stretching the developing spring along its distal end until the spring wire is partially straightened. The upper clamp is used to clamp the spring wire and the lower clamp is used to clamp the push guide wire, while keeping the entire test section vertical during the process. The test section is stretched at a rate of 10 mm / min until it breaks or separates. The maximum force during the stretching process is recorded, which is the peak tension F of the distal developing spring of the thrombus removal stent. 拉 The peak pressure F 压 The pressure F is obtained by pushing the distal end of the developing spring 4 of the thrombus removal device out of the loading sheath. The upper clamp clamps the loading sheath. The lower carrier is a flat plate with an area greater than 10 cm2. When the distal end of the developing spring contacts the lower carrier, it is the "zero point". Press down 2 mm at a speed of 10 mm / min and record the peak pressure F. 压And the deformation of the distal development spring.

[0044] There are multiple developing marking points 3 on the thrombectomy stent. These developing marking points 3 are made of platinum-iridium alloy. The operator can clearly observe the deployment of the thrombectomy stent. The developing points of each segment are distributed vertically at 90°, so it is convenient to observe whether the stent is deployed without adjusting the DSA angle. At the same time, through the role of these developing marking points, the removal path of the embolus can also be clearly determined.

[0045] The development marking point 3 , the distal development spring 4 and the proximal development spring 5 together form the radiopaque marker of the present invention.

[0046] The thrombectomy device system also includes a push guide wire 6, the maximum diameter OD1 of which satisfies OD1>=0.42mm and <=0.60mm. The push guide wire 6 is made of a mixture of nickel-titanium alloy, polytetrafluoroethylene, and Pebax. During the delivery process, the push guide wire 6 will come into contact with the loading sheath, microcatheter, blood vessel wall, etc. Therefore, in order to facilitate delivery, a coating is also applied on the surface of the push guide wire 6. However, it should be ensured that the coating does not fall off during delivery, otherwise it will enter the blood system and cause an accident. The coating friction should meet the coating friction mean F 摩 <=300g, single value of coating friction F 摩max <=320g.

[0047] It should be noted that the average friction force of the coating here is F 摩 and coating friction single value F 摩max It is obtained as follows: On a friction tester, the straight section of the guide wire is compressed with a fixed force of 300g. The length of the test section is ≥150mm. The friction force during the pumping process is tested. After repeating the test 25 times, the mean and single values ​​are calculated. After 25 tests, the appearance of the test section is observed under a 20x microscope to confirm whether the coating has fallen off.

[0048] The thrombus removal device system also includes a loading sheath 7, and the thrombus removal stent is pre-installed in the loading sheath 7. Due to the function of the loading sheath 7, the thrombus removal stent is compressed into the space defined by the loading sheath 7. The thrombus removal stent will only be deformed after it is separated from the loading sheath 7. The loading sheath 7 plays an effective protective role for the thrombus removal stent.

[0049] The entire thrombectomy device system is installed in the packaging coil. In order to better position the thrombectomy device system in the packaging coil and prevent it from escaping from the coil, the thrombectomy device system needs to be limited. During the long period of time between the thrombectomy device leaving the factory and entering the hospital for use, the effectiveness of the thrombectomy device system, especially the effectiveness of the core components of the thrombectomy device system, must be guaranteed. An important criterion for judging this effectiveness is the peak tensile force F of the thrombectomy device system. 系统拉力, peak tensile force F of the thrombectomy device system 系统拉力 Should satisfy F 系统拉力 ≥3N.

[0050] It should be noted that the peak tension F 系统拉力 Obtained by:

[0051] like Figure 3 As shown, the P2 segment of the thrombectomy device is placed in a loading sheath cut to a length of approximately 1 cm. The P2 segment placed in the loading sheath is clamped in the upper chuck of a universal material testing machine, and the lower chuck clamps the push guide wire, keeping the entire test segment vertical during the process. The test segment is stretched at a rate of 10 mm / min until it breaks or separates. The maximum force during the stretching process is recorded, which is the peak tensile force F of the thrombectomy device system. 系统拉力 , and record the failure location.

[0052] For the thrombectomy device system involved in the present invention, the total length D of the thrombectomy device system should satisfy: D>=180 cm and <=220 cm, so as to meet the operator's operation requirements.

[0053] The working principle of the thrombus removal device system of the present invention is as follows:

[0054] like Figure 4 As shown, the thrombus removal device system is advanced in the established microcatheter 8 passage, and the thrombus is positioned within the effective working length of the thrombus removal stent by aligning the proximal imaging point 3 of the stent with the proximal edge of the thrombus;

[0055] When the thrombectomy device or the proximal marker is not visible, the thrombectomy stent is positioned within the thrombus by advancing it until the proximal imaging spring 5 is approximately N mm away from the proximal edge of the thrombus, where N>=2;

[0056] Then fix the guide wire and withdraw the microcatheter 8 to deploy the stent in the thrombus. Once the distal end of the microcatheter 8 has been withdrawn to a position above the proximal developing spring 5 of the thrombus removal device, the stent will be fully deployed.

[0057] The stent is allowed to embed into the thrombus for 3-5 minutes before withdrawal.

[0058] In order to ensure that the thrombectomy stent does not damage the lumen wall and that the mesh openings of the thrombectomy stent securely capture the embolus when pushing and withdrawing the thrombectomy stent of the thrombectomy device system of the present invention, it is necessary to ensure that the pushing force and the retracting force of the thrombectomy stent in the microcatheter 8 meet the requirements. For the thrombectomy stent of the present invention, the maximum pushing force F of the thrombectomy stent in the microcatheter 8 is 1. 推 The maximum retraction force F of the thrombectomy stent in the microcatheter 8 should be less than 1.5N. 撤 Should be less than 1.5N.

[0059] It should be noted that the maximum thrust F 推 and the maximum retracement force F 撤 It is obtained by the following method: in a 37°C water bath, the microcatheter 8 is delivered to the farthest end of the simulated vascular tooling via a microguidewire, and the distal end of the microcatheter 8 is flush with the distal end of the simulated vascular tooling. The thrombectomy device of the present invention is pushed through the microcatheter 8 until the thrombectomy bracket completely exposes the microcatheter 8 and is released. The thrombectomy device is withdrawn a corresponding distance, and the pushing distance is set. At this position, the thrombectomy device is pushed and withdrawn three times at a speed of 200 mm / min using a pushing and withdrawing force tester, and the force-displacement curve and the maximum pushing force and maximum withdrawing force are recorded.

[0060] The thrombectomy device system involved in the present invention is suitable for acute cerebral stroke caused by neurovascular embolism, and plays a role in blood flow reconstruction. The thrombectomy device system can be used for at least the anterior cerebral circulation, such as the internal carotid artery, the M1 and M2 segments of the middle cerebral artery, and the A1 and A2 segments of the anterior cerebral artery. It has a higher capture rate, higher axial support force and performance, meets the rigidity requirements, and better adheres to the vessel wall in the vascular cavity. The indicators in various aspects are optimized and designed to meet the mechanical properties, and the immediate recanalization rate of the target vessel after surgery is significantly improved.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thrombus removal device system, comprising a thrombus removal bracket, wherein the thrombus removal bracket comprises an inner layer portion (1), an outer layer portion (2) and a fishing device, characterized in that: The thrombus retrieval stent has a thrombus retrieval stent length C, and the thrombus retrieval stent length C satisfies C>=22mm and <=58mm; The thrombectomy stent has an effective working length B, and the effective working length B satisfies a range of greater than or equal to 13 mm and less than or equal to 48 mm; The thrombectomy stent has a maximum diameter A, and the maximum diameter A satisfies A>=4.5 mm and <=7.0 mm; The thrombectomy stent also has a radial support force RF. After the thrombectomy stent is released from the loading sheath or microcatheter, it can return to its original shape within the applicable lumen diameter range. As the thrombectomy stent expands, the minimum value of the radial support force RF should satisfy RF ≥ 0.010 N / mm, and the maximum value of the radial support force RF should satisfy RF ≥ 0.020 N / mm. The radial support force RF is obtained as follows: using a stent radial force tester and a circumferential compression method, the thrombectomy stent is compressed to an initial diameter of 1 mm at 37±2°C, and then the diameter is gradually increased at a speed of 0.2 mm / s until the thrombectomy stent is completely released, and the curve of the thrombectomy stent diameter and outward support force is recorded. The radial support force RF = test support force F 测 / Effective working length B of the thrombectomy device; The thrombectomy stent also has a shape recovery rate P, which satisfies P <= 10%. The shape recovery rate P is achieved by compressing the thrombectomy stent to a diameter of 1.5 mm using upper and lower flat plates. After releasing the pressure, the maximum diameter A of the thrombectomy device is reduced by a rate of <= 10%. The thrombectomy stent also has a shortening rate C, which satisfies the shortening rate C<=20%. The shortening rate C is obtained as follows: the thrombectomy stent is loaded into the loading sheath, and its total length C0 is measured using a vernier caliper with a resolution of 0.01 mm. Then, the thrombectomy stent is pushed out of the loading sheath to restore it to a freely released state, and its total length C1 is measured again. The shortening rate is calculated according to the following formula: total length shortening rate = (C0-C1) / C0×100%.

2. The thrombus removal device system according to claim 1, characterized in that: The thrombus removal device system includes a distal development spring (4) and a proximal development spring (5); wherein the length E of the distal development spring (4) satisfies E>=3.5mm and <=5.5mm, the length F of the proximal development spring (5) satisfies F>=16mm and <=22mm, and the peak tension F of the distal development spring (4) satisfies 拉 Satisfy F 拉 >=0.3N, peak pressure F 压 Satisfy F 压 <=0.1N, the peak tension F 拉 The pulling force is obtained by stretching the developing spring along the farthest end of the distal developing spring (4) until the spring wire is partially straightened, clamping the spring wire with an upper clamp and clamping the push guide wire with a lower clamp, and keeping the entire test section vertical during the process; stretching the test section at a rate of 10 mm / min until it breaks or separates, and recording the maximum force during the stretching process, which is the peak pulling force F of the distal developing spring (4) 拉 The peak pressure F is obtained by pushing the distal developing spring (4) out of the loading sheath tube, clamping the loading sheath tube with the upper clamp, and the distal end of the distal developing spring (4) contacts the lower plate as the "zero point", pressing down 2 mm at a speed of 10 mm / min, and recording the peak pressure F 压 , which is the peak tension F of the distal developing spring (4) 压 .

3. The thrombus removal device system according to claim 2, characterized in that: The thrombus removal device system includes a push guide wire (6), the maximum diameter OD1 of the push guide wire (6) satisfies OD1>=0.42mm and <=0.60mm, and the surface of the push guide wire (6) is also coated with a coating, and the friction force of the coating should meet the coating friction force mean F 摩 <=300g, single value of coating friction F 摩max <=320g, the average friction force of the coating F 摩 and the single value F of the coating friction 摩max The method is as follows: on a friction tester, the straight section of the push guide wire (6) is pressed with a fixed force of 300g, the test section length is ≥150mm, the friction force during the pumping process is tested, and after repeating 25 times, the mean and single values ​​are calculated.

4. The thrombus removal device system according to claim 2, characterized in that: The thrombus removal device system comprises a loading sheath (7), and the thrombus removal bracket is pre-installed in the loading sheath (7).

5. The thrombus removal device system according to claim 4, characterized in that: The peak tensile force F of the thrombus removal device system 系统拉力 Should satisfy F 系统拉力 ≥3N, the peak tensile force F 系统拉力 Obtained by: A section of the thrombectomy device system is placed in the loading sheath (7) cut to a length of about 1 cm, and the section of the thrombectomy device system placed in the loading sheath (7) is clamped in the upper chuck of a universal material testing machine, and the lower chuck clamps the push guide wire, and the entire test section is kept vertical during the process; the test section is stretched at a rate of 10 mm / min until it breaks or separates, and the maximum force during the stretching process is recorded, which is the peak tensile force F of the thrombectomy device system. 系统拉 force.

6. The thrombus removal device system according to claim 2, characterized in that: The inner layer portion (1) of the thrombus removal bracket is provided with three mesh holes on its circumference.

7. The thrombus removal device system according to claim 2, characterized in that: The inner layer part (1) of the thrombus removal bracket is provided with four mesh holes on its circumference.

8. The thrombus removal device system according to claim 2, characterized in that: The thrombectomy device system includes a plurality of imaging marking points (3), and the material of the imaging marking points (3) is a platinum-iridium alloy. The operator can clearly observe the deployment of the thrombectomy stent, and the imaging marking points (3) on each segment of the thrombectomy stent are vertically distributed at 90 degrees, so it is convenient to observe whether the thrombectomy stent is deployed without adjusting the angle of the imaging device.

9. The thrombus removal device system according to claim 8, characterized in that: The thrombus removal device system is advanced in the established microcatheter pathway, and the embolus is positioned within the effective working length of the thrombus removal stent by aligning the developing mark point (3) at the proximal end of the thrombus removal stent with the proximal edge of the embolus; the thrombus removal stent is positioned within the embolus by advancing the thrombus removal stent until the proximal developing spring (5) is N mm away from the proximal edge of the embolus, and then the pushing guide wire is fixed, and the microcatheter is withdrawn to deploy the thrombus removal stent within the embolus. Once the distal end of the microcatheter has been withdrawn to a position above the proximal developing spring (5), the thrombus removal stent will be fully deployed.

10. The thrombus removal device system according to claim 9, characterized in that: Said N>=2.

11. The thrombus removal device system according to claim 1, 2 or 9, characterized in that: The maximum pushing force F of the thrombectomy stent in the microcatheter 推 Less than 1.5N, the maximum retraction force F of the thrombectomy stent in the microcatheter 撤 Should be less than 1.5N.

12. The thrombus removal device system according to claim 11, characterized in that: The maximum thrust force F 推 and the maximum retracement force F 撤 It is obtained by the following method: in a 37°C water bath, the microcatheter is transported to the farthest end of the simulated vascular tooling through a micro guidewire, and the distal end of the microcatheter is flush with the distal end of the simulated vascular tooling. The thrombectomy device system is pushed through the microcatheter until the thrombectomy bracket completely exposes the microcatheter and is released. The thrombectomy device system is withdrawn a corresponding distance, and a pushing distance is set. At this position, the thrombectomy device system is pushed and withdrawn multiple times at a speed of 200 mm / min using a pushing and withdrawing force tester, and the force-displacement curve and the maximum pushing force and maximum withdrawing force are recorded.

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