Electrified micro guide wire thrombectomy stent based on radio frequency magnetic field and application method thereof

Abstract

According to the electrified micro guide wire thrombus extraction stent based on the radio frequency magnetic field and the application method thereof, after the stent is placed at the thrombus position, the thrombus is adsorbed to a bone beam of the stent through the radio frequency magnetic field established after electrification through positive and negative electrodes preset in the stent, so that the adsorption capacity of the thrombus is greatly improved, and the thrombus extraction efficiency is improved. The thrombus can be completely taken out of the body at a time, the thrombus taking efficiency is improved, the thrombus taking technical difficulty is reduced, the popularization of the thrombus taking technology is facilitated, more stroke patients can be treated, and the social burden is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of medical device technology, and in particular to an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field and an application method thereof. Background Art

[0002] 1. Application Background of Thrombectomy Stent

[0003] In recent years, major progress has been made in large-scale clinical studies (ESCAPE, EXTEND-IA, SWIFTPRIME, MR CLEAN) on the use of stent-type thrombectomy devices to treat cerebral infarction, further confirming the effectiveness of stent thrombectomy, ushering in the spring of endovascular treatment of acute cerebral infarction. Revascularization is the strongest predictor of good functional prognosis and reduced mortality. my country updated the guidelines for endovascular treatment of acute cerebral infarction in 2018 and recommended it at the highest level. From the launch of the first generation of stent retriever Merci in 2001 to the widespread use of the second generation of self-expanding thrombectomy stent represented by Solitaire in 2009, and the birth of the third generation of adjustable thrombectomy stent, with the continuous accumulation of surgeons' experience, the continuous improvement of interventional surgical instruments, and the continuous improvement of surgical concepts, including the use of combined technologies, the success rate of thrombectomy (Table 1) and good prognosis rate have been greatly improved. In the ASTER study, even if the stent retriever group underwent three thrombectomies, the rate of achieving a good prognosis (mTICI 2b / 3) was only 67.7%, which means that nearly 1 / 3 of the patients need more thrombectomies. Therefore, even if the surgical method is changed, such as combined with aspiration, the one-time recanalization rate is not satisfactory (Table 2), and there is no mismatch between the good prognosis rate and the success rate of thrombectomy.

[0004] Bracket brand <![CDATA[ Merci ]]> Solitaire TREVO Final recanalization rate 60％ 89％ 86％ Good prognosis rate 22％ 46％ 40％

[0005] Table 1

[0006] Surgical method <![CDATA[ So′Iu′m′b′ra ]]> ARTS Technology SAVE Recanalization rate 37％ 43％ 72％ Final recanalization rate 88％ 97.6％ 100％

[0007] Table 2

[0008] 2. Working Principle of Thrombectomy Stent

[0009] The principle of stent thrombectomy is that under the guidance of imaging technology, the doctor passes a guide wire through the thrombus, inserts a microcatheter, sends in the thrombectomy stent, and then withdraws the microcatheter. The memory alloy stent will automatically release and open, and the stent ribs (Strut) will be combined with the thrombus, embedding the thrombus into the mesh structure of the stent. The thrombus and the stent are then taken out of the body together, completing a thrombectomy operation.

[0010] Therefore, the tightness of the combination of thrombus and stent (including chimerism and adhesion) is the key to whether the stent thrombectomy can be successfully completed.

[0011] 3. Technical Pain Points of Thrombectomy Stents

[0012] In the process of opening the occluded intracranial large vessels, all previous generations of thrombectomy stents are to open the stent, wait for 5 minutes, use the combination of the stent beam and the thrombus, and then use the stent to remove the thrombus from the body. Here, the van der Waals force between the beam and the thrombus molecules is used. However, this force is very limited and weak, so the thrombus will break and escape, and multiple thrombus removals are required. The one-time recanalization rate is relatively high (as shown in Table 1 and Table 2 above), so the efficiency is low. So far, no matter how the structure and grid of the stent are changed, the essence of using van der Waals force to remove and bind the thrombus has not changed.

[0013] Simple stent thrombectomy cannot prevent the escape of emboli during surgery. Whether in the process of stent opening to capture thrombus (which will cause cutting of thrombus) or in the process of removing thrombus from the body (thrombus will slide between stent and blood vessel wall, and the existence of blood vessel bends will cause thrombus to fall off), thrombus will be broken, unloaded and escape. Especially in patients with intracranial arterial atherosclerotic occlusion (ICAS), there are fresh (brittle) thrombi in the lumen at both the distal and proximal ends of the occluded segment. In the process of retrieving the stent, especially the thrombus at the distal end of the occluded segment, even if it is captured by the stent, it will be squeezed out again when passing through the stenosis, resulting in ectopic embolism. Repeated thrombectomy is often required, which not only increases the risk of surgery, but also delays the time of vascular recanalization. Although new technologies such as assisted aspiration or simple aspiration have been added, including the use of balloon guide catheters (BGC), which can to a certain extent prevent the thrombus from breaking or falling off during the process of being pulled out of the body, and prevent the broken thrombus from moving forward, there are still risks such as the thrombus being cut by the stent, the thrombus being segmented and requiring multiple removals, and tiny thrombi widely blocking the microcirculation. Whether it is a simple stent thrombectomy technique, or a combined aspiration technique represented by the Solumbra technique, or a simple aspiration (Adapt) technique, it is impossible to avoid thrombus fragmentation and escape. In the clinical work of simple aspiration, the incidence of distal blockage is as high as 16%. The fragmentation and escape of thrombi block the collateral compensation of potentially salvageable tissues and even cause ischemia in previously unaffected areas. These fragments are associated with worse clinical outcomes. Studies have shown that the incidence of distal embolism during thrombectomy is as high as 12%, while in studies that mainly studied stent thrombectomy, the incidence was 5%-22%. The presence of distal embolism was not significantly correlated with poor prognosis at 3 months, however, there was a trend of increased mortality (OR 2.73 95%CI 0.875–8.512, p=0.084), and distal embolism was significantly associated with cerebral hemorrhage (OR 12.794 95%CI 1.995–82.05, p=0.013). This may be related to the nature of the thrombus. Studies have shown that white thrombi larger than 6 mm cannot be captured by any stent currently available. Other studies have also shown that the low efficiency of stent thrombectomy is related to the degree of coagulation between the thrombus and the stent and the presence of a larger core blood clot. Therefore, increasing the overall toughness and adhesion of the thrombus is a clinical problem that urgently needs to be solved.

[0014] 4. Necessity of solving the overall problem of thrombosis

[0015] In recent randomized controlled trials and registries, successful reperfusion (mTICI score 2b-3) was achieved in 80%-90% of patients with acute LVO treated with EVT. However, successful or complete reperfusion does not always correlate with good functional outcomes. Even if the occluded vessel is completely recanalized by endovascular treatment, approximately 50% of patients still have a poor prognosis, which is called clinically ineffective reperfusion (CIR).

[0016] Liu Liping et al. analyzed the possible causes and mechanisms of CIR: 1. Infarct volume and cerebral edema before recanalization; 2. Degree of vascular recanalization, mTICI grade 2b or 3; 3. No-reflow phenomenon after EVT. No-reflow phenomenon means that the occluded artery has achieved timely and complete recanalization, but the blood supply tissue of the occluded artery has not yet obtained sufficient blood flow, and there is a serious phenomenon of insufficient perfusion. This phenomenon has been widely studied in the recanalization of coronary artery occlusion, and the incidence rate is as high as about 50%. The most essential reason is microcirculatory disorders and secondary tissue perfusion insufficiency. 4. Reperfusion injury. Reperfusion injury is another important mechanism of CIR. The academic community has accumulated a large number of basic research results in the field of cerebral ischemia and reperfusion. Possible injury mechanisms include blood-brain barrier destruction, microcirculatory disorders, microthrombosis, harmful toxic substances such as free radical damage, oxidative stress response, etc.

[0017] Therefore, we try to analyze that the ultimate reason for the mismatch between the vascular recanalization rate and the good prognosis rate is that the microcirculation that affects brain cell metabolism has not been fully restored. This may be related to the fact that the thrombus was not cleaned up during the thrombectomy or the microthrombus escaped, blocking the perforator and the compensatory side branch, resulting in the loss of the ischemic penumbra and the expansion of the infarct area, multiple distal embolism, and worse functional prognosis. In vitro experiments have shown that a large number of clot fragments can be released during thrombectomy, but most of these clot fragments are very small, about 10 μm in size. The resulting small occlusions may not be understood, and the actual incidence of distal embolism may be higher than reported. Although some people are trying to remedy (CHOICE study), using the reverse bridging method, trying to open small blood vessels with drugs after opening large blood vessels to improve prognosis, there is a lack of evidence from large RCT studies.

[0018] Therefore, improving the ability to clear initial thrombi (including attached new thrombi) is the most important step, which requires improving the ability of the stent to embed thrombi and coagulate thrombi.

[0019] The stents currently available also focus on improving the ability to capture blood clots, including changes in shape, support, etc. However, there is a common drawback, that is, the ability of the stent to capture blood clots only depends on the natural adhesion of blood clots (van der Waals force), which is why the stent must be placed for 5 minutes during thrombus removal, that is, to give the blood clot and the stent sufficient time to combine. However, some studies have shown that time is only a relative concept, and some blood clots still cannot combine with the stent after 5 minutes, which leads to ineffective thrombus pulling and increases the risk of endothelial damage and perforator rupture.

[0020] Therefore, improving the overall density of the thrombus and enhancing the ability of the stent to combine with the thrombus may be an effective way to solve this problem. This will allow the thrombus to be captured as a whole, reduce the risk of translocation embolism, save surgical time, increase the rate of successful recanalization in one go, and reduce microthrombi, which may also improve the good prognosis rate.

[0021] 5. Theoretical basis for improving the overall density of thrombus

[0022] Thrombosis is based on platelet aggregation, which is essentially the process of blood coagulation. How to speed up this process is described in the People's Health Edition textbook "Physiology" as follows:

[0023] Methods to accelerate blood coagulation: ① Add Ca2+ to the blood, because Ca2+ is an important factor involved in blood coagulation; ② Use coagulants, vitamin K, hemostatic aromatic acid, VitK to promote the liver to synthesize factors II, VII, IX, and X; ③ Appropriate heating, because the right temperature is conducive to increasing the activity of coagulation factors; ④ Let the blood contact the rough surface, because the rough surface is conducive to platelet adhesion, aggregation and release reaction, and exert its coagulation function.

[0024] Because (①, ②) both affect the whole body's coagulation function, they are not suitable for use in thrombectomy. However, using (③, ④), we can consider designing a stent with a rough surface (providing sufficient contact area) that can be electrically heated to provide a platform for thrombus adhesion, aggregation and release reaction, thereby solving the application defects of the above-mentioned thrombectomy stent. Summary of the invention

[0025] In order to solve the above problems, the present application proposes an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field and an application method thereof.

[0026] In one aspect, the present application provides an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field, comprising:

[0027] Bracket body 1;

[0028] An energized micro-guidewire, used for generating a radio frequency magnetic field when energized, and arranged on the stent body 1;

[0029] The power supply module is used for power supply, wherein the positive electrode is connected to the tail end of the stent body 1, the negative electrode is connected to the needle end of the stent body 1, and the power supply module is connected in series with the energized micro-guidewire to form a power supply circuit.

[0030] As an optional implementation scheme of the present application, optionally, the support structure of the support body 1 is formed by cross-combining multiple groups of DNA double helix structure supports.

[0031] As an optional embodiment of the present application, optionally, multiple groups of adjacent tail ends of the DNA double helix structure are respectively compositely formed into corresponding positive electrodes 2, and multiple groups of needle ends are gathered and extended to form a negative electrode 3.

[0032] As an optional implementation scheme of the present application, optionally, the outer side surface of the stent body 1 is coated with an insulating layer, wherein the energized micro guidewire is arranged in the inner cavity of the stent body 1.

[0033] As an optional implementation scheme of the present application, optionally, the outer side surface of the powered micro-guidewire is wrapped with an insulating layer, wherein the powered micro-guidewire is arranged on the inner side of the stent body 1 away from the blood vessel wall.

[0034] As an optional implementation scheme of the present application, optionally, the power supply module adopts a 9V battery.

[0035] On the other hand, the present application provides an application method of an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field, comprising the following steps:

[0036] Determine the location of the thrombus;

[0037] The guidewire is introduced into the vessel and passed through the thrombus;

[0038] Inserting a microcatheter, and delivering the energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field to a preset position;

[0039] withdrawing the microcatheter to release and open the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field;

[0040] Powering on to activate the radio frequency magnetic field of the powered micro-guidewire in the powered micro-guidewire thrombectomy stent based on radio frequency magnetic field, so as to generate an adsorption magnetic force on the thrombus;

[0041] Insert the negative electrode into the patient's groin skin and observe the forward blood flow every 1-2 minutes based on the smoke in the blood vessels;

[0042] When the forward blood flow stops and a smoking state occurs, the power is turned off, and the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field is withdrawn to remove the thrombus and the stent from the body together;

[0043] Clean the bracket.

[0044] Technical effects of the present invention:

[0045] The present application utilizes a stent that is placed at the location of the thrombus and, through the positive and negative electrodes prefabricated in the stent, establishes a radio frequency magnetic field after power is applied, and adsorbs the thrombus to the bone beams of the stent, thereby greatly increasing the adsorption capacity of the thrombus. The thrombus can be completely removed from the body at one time, improving the efficiency of thrombectomy and reducing the difficulty of thrombectomy technology, which is conducive to the promotion of thrombectomy technology, saving more stroke patients, and reducing social burden.

[0046] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0048] Figure 1 The figure shows the change of the thrombus state during the stent electrification process (vertical version);

[0049] Figure 2 Shown is a schematic diagram of thrombus cross-linking after radiofrequency induction;

[0050] Figure 3 Shown is a schematic diagram of the application of the double-helix stent structure of the present invention. DETAILED DESCRIPTION

[0051] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0052] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0053] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present disclosure.

[0054] The present invention places a stent at the location of the thrombus and establishes a radio frequency magnetic field through positive and negative electrodes pre-installed in the stent after power is turned on, so that the thrombus is adsorbed to the bone beam of the stent, thereby greatly increasing the adsorption capacity of the thrombus. The thrombus can be completely removed from the body at one time, the efficiency of thrombectomy is improved, and the difficulty of thrombectomy technology is reduced, which is conducive to the promotion of thrombectomy technology, the treatment of more stroke patients, and the reduction of social burden.

[0055] The description of the theory and practical experience of the changes in thrombus after power-on is as follows:

[0056] The research results of Chang Jin et al. show that the pitting potential of spring coils made of metal alloy (Cr18Ni9Ti) is higher than that of Cr18Ni9, indicating that the Ti element can increase the pitting potential level; the melting capacity increases with the increase of current only within a certain current range (<3mA), and high current can reduce the melting capacity. Based on this, it can be seen that the electrochemical reaction intensity is not a simple linear relationship with the current size. Material differences and passivation reactions on the coil surface can affect the electrochemical reaction intensity by changing the pitting potential level.

[0057] Padolecchia et al. performed diagnostic angiography on 5 patients with acute subarachnoid hemorrhage. During the angiography, 24 ml of arterial blood was drawn for in vitro electrolysis and degrouping experiments. They found that the energized GDC was wrapped by blood components, while the non-energized GDC had no thrombus formation.

[0058] Henkes et al. evaluated the different factors affecting electrocoagulation thrombosis in more detail based on the design principles of Padolecchia et al. The results showed that: ① In the in vivo experiment, thrombosis was more significant than in the in vitro experiment, which may be related to the sustainable acquisition of the components required for thrombosis; ② Except for the in vivo heparinization experiment, which showed almost no thrombosis, thrombosis occurred on the surface of the other coils; ③ The human anticoagulation experiment suggested that aspirin may be beneficial to electrocoagulation thrombosis. ④ The microciliary coil has excellent thrombogenicity, which may be due to its large effective contact area with blood.

[0059] In the field of intracranial aneurysm treatment, there is already a lot of basic and clinical evidence for the related electrocoagulation treatment method.

[0060] Jiang Yuhua et al., who first reported the use of electrocoagulation technology, used intravascular guidewire electrocoagulation to treat 5 patients with perforating artery blister aneurysms. After 4 V and 1 mA of electrocoagulation for 4 minutes, the aneurysm was successfully occluded. The average follow-up after surgery was 10.4 months, and no aneurysm recurrence was observed. This was the first clinical success, proving the effectiveness of electrocoagulation. At the same time, it was proposed that electrocoagulation treatment includes two microscopic processes: ① thrombus formation, a certain range of constant current direct current can attract negative factors in the blood and induce thrombus formation; ② thrombus organization, which promotes thrombus formation through the electrothermal effect, and further leads to thrombus denaturation and organization, preventing the fibrinolysis process and turning fresh thrombi into stable thrombi.

[0061] The effectiveness of electrocoagulation may be related to the exposed area of ​​the conductive material.

[0062] Therefore, it can be concluded that the microguidewire, at an appropriate voltage and for an appropriate period of time, can promote blood coagulation and increase the stability of thrombus.

[0063] Wu Tao et al. conducted a preliminary exploration of the electrocoagulation and the duration of the current used in electrocoagulation using the New Zealand white rabbit animal model. Figure 1 The results showed that: ① Scanning electron microscope observation showed that there was obvious thrombus attachment on the surface of the micro-guidewire after power-on, and the thrombus was denser when the voltage was higher. ② Under the same power-on time, the higher the voltage, the more rabbit aneurysm cavities were completely occluded in the micro-guidewire electrocoagulation treatment group. Under the same voltage, the longer the power-on time, the better the quality of the thrombus formed. The thrombus initially formed after power-on was a loose solid-liquid mixed state. At this time, the thrombus was not tightly combined with the aneurysm cavity. After continued power-on, the thrombus became a dense solid state and was not easy to separate from the blood vessel wall. ③ The incidence of brain tissue ischemic foci and embolism time only occurred in the micro-guidewire electrocoagulation treatment group with a voltage>9V. The length of power-on time was not related to the incidence of embolic events, and there was a positive correlation with voltage, but no correlation with power-on time.

[0064] The quality of the thrombus in this experiment was evaluated based on its density, solid or liquid state, and the degree of tightness of the thrombus combination with the tumor. The specific standards were: +: The thrombus is soft, loose, and a combination of solid and liquid, and can fall off naturally in the tumor cavity; ++: The thrombus is soft, tight, and completely solid, and can be easily peeled off, with no liquid blood components; +++: The thrombus is hard, tight, and completely solid, and is not easy to peel off from the tumor.

[0065] Through preliminary experimental exploration of animal models, the mutual influence of factors such as voltage, power-on time, and thrombus quality were comprehensively analyzed. In the design of stent thrombectomy, a thrombus of ++ quality can achieve the expected goal. Because the previous experience came from animals and a single micro-guidewire, the voltage and power-on time of the stent equivalent to a combination of multiple micro-guidewires need further exploration.

[0066] In a preliminary Raman spectroscopy study, it was found that the concentration of thrombus proteins increased with the increase of radiofrequency time, and the radiofrequency-induced thrombus cross-linking increased the thrombus stiffness by as much as 8 times.

[0067] like Figure 2 The experimental diagrams of the adhesion between thrombus and stent after RF power-on are shown. A, B, C, and D are schematic diagrams of the adsorption force field caused by the RF magnetic field of thrombus at different frequencies, and the height and bottom of the thrombus shape and tip (outlined triangle) after RF treatment and after being pulled to a uniform height of 1.8 mm. Therefore, the results prove that the RF magnetic field can reduce the interface slip between the stent and the thrombus, thereby completely removing the thrombus from the body.

[0068] Based on the above application theory of radio frequency magnetic field, the present invention utilizes the energized micro-guidewire on the stent to generate a radio frequency magnetic field after being energized, so as to assist in thrombus removal.

[0069] Example 1

[0070] like Figure 1 As shown, in one aspect, the present application proposes an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field, comprising:

[0071] Bracket body 1;

[0072] An energized micro-guidewire, used for generating a radio frequency magnetic field when energized, and arranged on the stent body 1;

[0073] The power supply module (9V battery) is used for power supply, with its positive pole connected to the tail end of the stent body 1, the negative pole connected to the needle end of the stent body 1, and connected in series with the energized micro-guidewire to form a power circuit.

[0074] As an optional implementation scheme of the present application, optionally, the support structure of the support body 1 is formed by cross-combining multiple groups of DNA double helix structure supports.

[0075] In the present invention, the stent as a whole adopts a curled open design. Studies have shown that such a design can better ensure that sufficient radial support is provided to the tube wall at the bend of the blood vessel, so as to better fit the thrombus. The main skeleton is designed to have weak electrical performance or even insulation, because it needs to fit the blood vessel wall to prevent damage to the blood vessel wall, and the two wires with relatively strong electrical performance are designed to have a DNA double helix structure with the same structure as the stent, which can ensure that the thrombus can be adsorbed at 360°. The surface should be designed with an irregular structure to better adapt to the manifestation of thrombus, and the grid sizes are different. Too much radial force will increase vascular damage. Too small radial support will lead to poor contact with the thrombus. Because power can ensure the capture force of the thrombus, the stent should be soft to minimize interference with the blood vessel.

[0076] Therefore, when the stent is electrified, it can cause the blood clot to combine faster and more tightly, which also provides a theoretical premise for the design of a new generation of stents.

[0077] Application method:

[0078] Connect the positive pole of a 9V battery (which can be equipped with a power controller for step-up and step-down control) to the tail end of the stent and the negative pole to a needle (the external needle can be manually operated), which is then inserted into the skin at the patient's groin. Every 1-2 minutes, smoke is emitted to observe the state of the forward blood flow (the administrator doctor can determine whether to remove the thrombus based on clinical experience with vascular smoking). Studies have shown that if the forward blood flow stops, it may be that the thrombus is fully combined with the stent. Based on this concept, in the process of using an energized stent, the method of emitting smoke at intervals of about 1 minute to confirm the forward blood flow is also used to obtain the best time to recover the stent.

[0079] The above series connection is only for the convenience of expression. In actual application, a single chip microcomputer, circuit, etc. can be used to control the opening and closing of the circuit.

[0080] As an optional embodiment of the present application, optionally, multiple groups of adjacent tail ends of the DNA double helix structure are respectively compositely formed into corresponding positive electrodes 2, and multiple groups of needle ends are gathered and extended to form a negative electrode 3.

[0081] like Figure 3 As shown, because of the use of a DNA double helix structure, if a single set of DNA double helix structure stents is used, there will be blank areas of the DNA double helix structure, and this part cannot be well combined with the blood vessel wall and cannot effectively support the blood vessel. Therefore, at least 2 sets of DNA double helix structure stents (coaxially arranged, with equal spacing between adjacent ones) are required to fill the blanks, so that the stents can form several irregular stent frames, thereby supporting the blood vessel wall. And because an energized micro-guide wire is arranged inside, it is necessary to set positive and negative electrodes at both ends of the stent, and the tail ends of multiple DNA double helix structures can be combined into a positive electrode (because there are multiple spiral branches at the tail end, the corresponding branches of multiple sets of DNA double helix structures can be combined into a positive electrode again, which can be specifically combined with the attached Figure 3 The tail end is shown as multiple composite positive electrodes as shown in the figure), and the other end is composited into a negative electrode to facilitate power control.

[0082] In this embodiment, the size of the micro guidewire is not limited and can be configured accordingly according to the stent model.

[0083] During aneurysm electrocoagulation surgery, there are reports suggesting that aneurysm neck injury and aneurysm rupture may be related to the direct contact of the microguidewire with the blood vessel wall. Therefore, the part of the stent that touches the blood vessel wall should preferably be insulated.

[0084] There are two insulation treatment methods provided below.

[0085] As an optional embodiment of the present application, optionally, the outer side of the stent body 1 is coated with an insulating layer, wherein the energized micro-guide wire is arranged in the inner cavity of the stent body 1. The energized micro-guide wire is embedded in the stent body 1 to achieve an insulating arrangement. The stent body 1 generally adopts a memory alloy, so an insulating layer is coated on the outside to achieve insulation.

[0086] As an optional embodiment of the present application, optionally, the outer side surface of the energized micro-guidewire is wrapped with an insulating layer, wherein the energized micro-guidewire is arranged in the inner side of the stent body 1 away from the blood vessel wall. The purpose of insulation and providing a radio frequency magnetic field can also be achieved by embedding the insulated energized micro-guidewire in the stent body 1 or fixing it on the side of the stent body 1. This method can be preferred here. The insulated energized micro-guidewire is stuck on the inner side surface of the stent body 1 away from the blood vessel wall (inner groove), which does not affect the contact between the stent surface and the blood vessel wall, and can provide magnetic field adsorption force at the same time.

[0087] Example 2

[0088] Based on the implementation principle of Example 1, the present application, on the other hand, proposes an application method of an energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field, comprising the following steps:

[0089] Determine the location of the thrombus;

[0090] The guidewire is introduced into the vessel and passed through the thrombus;

[0091] Inserting a microcatheter, and delivering the energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field to a preset position;

[0092] withdrawing the microcatheter to release and open the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field;

[0093] Powering on to activate the radio frequency magnetic field of the powered micro-guidewire in the powered micro-guidewire thrombectomy stent based on radio frequency magnetic field, so as to generate an adsorption magnetic force on the thrombus;

[0094] Insert the negative electrode into the patient's groin skin and observe the forward blood flow every 1-2 minutes based on the smoke in the blood vessels;

[0095] When the forward blood flow stops and a smoking state occurs, the power is turned off, and the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field is withdrawn to remove the thrombus and the stent from the body together;

[0096] Clean the bracket.

[0097] The above-mentioned thrombectomy process can be understood in combination with the existing clinical thrombectomy process and principle, and will not be described in detail in this embodiment.

[0098] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An energized micro-guidewire thrombectomy stent based on radio frequency magnetic field, characterized in that: include: A support body (1); An energized micro-guidewire, used for generating a radio frequency magnetic field when energized, and arranged on the stent body (1); A power supply module is used for supplying power, wherein the positive electrode is connected to the tail end of the stent body (1), the negative electrode is connected to the needle end of the stent body (1), and the module is connected in series with the energized micro-guidewire to form a energized circuit.

2. The energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to claim 1, characterized in that: The support structure of the support body (1) is formed by cross-combining multiple groups of DNA double helix structure supports.

3. The energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to claim 2, characterized in that: Multiple groups of adjacent tail ends of the DNA double helix structure are respectively composited to form corresponding positive electrodes (2), and multiple groups of needle ends are gathered and extended to form a negative electrode (3).

4. The energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to claim 1, characterized in that: The outer side surface of the stent body (1) is coated with an insulating layer, wherein the energized micro-guidewire is arranged in the inner cavity of the stent body (1).

5. The energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to claim 1, characterized in that: The outer side surface of the energized micro-guidewire is wrapped with an insulating layer, wherein the energized micro-guidewire is arranged on the inner side of the stent body (1) away from the blood vessel wall.

6. The energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to claim 1, characterized in that: The power module adopts a 9V battery.

7. A method for using the energized micro-guidewire thrombectomy stent based on radio frequency magnetic field according to any one of claims 1 to 8, characterized in that: The steps include: Determine the location of the thrombus; The guidewire is introduced into the vessel and passed through the thrombus; Inserting a microcatheter, and delivering the energized micro-guidewire thrombectomy stent based on a radio frequency magnetic field to a preset position; withdrawing the microcatheter to release and open the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field; Powering on to activate the radio frequency magnetic field of the powered micro-guidewire in the powered micro-guidewire thrombectomy stent based on radio frequency magnetic field, so as to generate an adsorption magnetic force on the thrombus; Insert the negative electrode into the patient's groin skin and observe the forward blood flow every 1-2 minutes based on the smoke in the blood vessels; When the forward blood flow stops and a smoking state occurs, the power is turned off, and the energized micro-guidewire thrombectomy stent based on the radio frequency magnetic field is withdrawn to remove the thrombus and the stent from the body together; Clean the bracket.

Images