Thrombus compression extraction device

Abstract

The present application relates to a kind of thrombus compression extraction device, by the way of vascular intervention is transported to embolism site and works.This device is made of thrombus blocking component, thrombus compression component and thrombus suction component;Thrombus compression component includes delivery catheter and thrombus compression balloon, thrombus compression balloon is fixed at the distal end of delivery catheter, the expansion and contraction degree of thrombus compression balloon is controllable;Thrombus suction component is tubular structure, delivery catheter can be relatively moved in the lumen of thrombus suction component, thrombus compression balloon can be retracted into the lumen of thrombus suction component with delivery catheter when in the contraction state.This device uses the mechanical property that stress will be greatly reduced when thrombus is compressed and keeps compression for a period of time, and uses thrombus compression balloon to compress thrombus and make it stress relaxation.Through thrombus suction component, thrombus can be helped to move out of body.The thrombus compression extraction device is convenient to use, makes thrombus more easily be sucked and taken out, is favorable to improve the success rate of taking out thrombus, reduces the side effect of sucking and taking out thrombus, and improves the treatment effect of acute ischemic stroke large vessel occlusion.

Description

TECHNICAL FIELD

[0001] The present application relates to a vascular interventional medical device, in particular to a thrombus compression and extraction device. BACKGROUND

[0002] Endovascular intervention thrombectomy has become an important treatment method for acute ischemic stroke large vessel occlusion. The existing cerebral thrombus extraction devices are mainly divided into two categories: thrombus extraction stents and suction catheters. The thrombus extraction stent is a super-elastic stent-shaped structure. After being delivered to the embolism site, the thrombus extraction stent is self-expanded by withdrawing the microcatheter, thereby capturing the thrombus. The thrombus captured by the thrombus extraction stent is extracted by pulling back the thrombus extraction stent. The patents of the thrombus extraction stent type include CN 111544083 B, CN 112568964 B, etc. The thrombus rich in fibrin is relatively hard in material, and has a large friction coefficient with the blood vessel wall, which makes it difficult for the thrombus extraction stent to capture and pull it, resulting in a lower success rate of the thrombus extraction stent in opening the thrombus. In addition, the interaction between the stent and the thrombus can cause cutting and pulling of the thrombus, resulting in the detachment of some thrombus fragments, which can cause embolism of the distal blood vessels.

[0003] Another type of endovascular intervention thrombectomy device is the suction catheter. The principle of action is that the negative pressure is generated in the suction catheter by the syringe or vacuum suction pump at the proximal end of the suction catheter, so as to attract the thrombus into the catheter and then remove it from the body. The disclosed patents of this type include CN 212940962 U, CN 213910408 U, etc. The problem of the suction catheter is that in order to have sufficient suction force, it must have sufficient pipe diameter. However, a large pipe diameter will affect its delivery performance. When the patient's blood vessels are relatively tortuous, the suction catheter may not be able to be delivered to the embolism site, and the opening effect will be greatly reduced at this time.

[0004] During the clinical treatment process, the thrombus extraction stent and the suction catheter are also used in combination. However, the opening rate of acute ischemic stroke large vessel occlusion can only reach about 80%-90% at present, and the blood vessels of the remaining patients cannot be effectively opened. Moreover, the proportion of patients with good recovery of neurological function 90 days after the operation is only about 50%. Therefore, in order to further improve the opening rate and the functional outcome after the operation, new thrombus extraction devices and opening methods are needed. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a thrombus compression and extraction device, to improve the success rate of blood vessel opening, and in particular to improve the opening rate of the hard thrombus embolism rich in fibrin which is relatively difficult to open.

[0006] To solve the above technical problems, the technical scheme of the present application is as follows:

[0007] A thrombus compression extraction device is delivered to a thrombosis site by vascular intervention for work, which is composed of a thrombus blocking component, a thrombus compression component and a thrombus suction component; the thrombus compression component includes a delivery catheter and a thrombus compression balloon, the thrombus compression balloon is fixed at the distal end of the delivery catheter, and the inflation and contraction degree of the thrombus compression balloon is controllable; the thrombus suction component is a tubular structure, the delivery catheter can move relatively in the lumen of the thrombus suction component, and the thrombus compression balloon in the contracted state can be retracted into the lumen of the thrombus suction component together with the delivery catheter.

[0008] The thrombus blocking component is located at the distal end of the thrombus compression component and the thrombus suction component, and also at the distal end of the thrombus during work. It can prevent the thrombus from being washed away by the forward blood flow during thrombectomy. Especially the thrombus compression extraction device of the present application will flatten the thrombus and cause stress relaxation, resulting in a significant reduction in the adhesion between the thrombus and the blood vessel, so the thrombus blocking component is more needed to play a safety protection role at the distal end.

[0009] Optionally, the thrombus blocking component includes a basket and a push guide wire. The basket is fixed at the distal end of the push guide wire, and the push guide wire is located in the lumen of the delivery catheter of the thrombus compression component; by controlling the push guide wire, the basket can be retracted into the delivery catheter in a compressed state, or can be pushed out of the delivery catheter to form an expanded state.

[0010] Optionally, the thrombus blocking component is a thrombus blocking balloon, which is connected to the delivery catheter and located at the distal end of the thrombus compression balloon.

[0011] The inflation and contraction of the thrombus blocking balloon and the thrombus compression balloon are independently controlled, and the delivery catheter has independent cavities respectively communicating with the two balloons. After the delivery catheter reaches the thrombosis site, it is confirmed that the thrombus blocking balloon reaches the distal end of the thrombus. Then the thrombus blocking balloon is inflated to prevent the thrombus from escaping. Then the thrombectomy operation is performed. After the thrombus is removed, the thrombus blocking balloon is contracted.

[0012] The function of the thrombus compression balloon is to exert a certain extrusion force on the thrombus after inflation, and to compress the thrombus. Through the biomechanical analysis of thrombosis, it is proved that after the thrombus is compressed and maintained in the compressed state for a period of time, the thrombus will produce stress relaxation effect, and the volume will also be reduced. This will greatly reduce the adhesion between the thrombus and the blood vessel stent, thereby reducing the difficulty of thrombectomy. When the thrombus is compressed and stress relaxation occurs, the thrombus compression balloon is contracted, which is convenient for subsequent thrombectomy operation.

[0013] Preferably, the thrombus compression balloon is in the shape of a shuttle, the outer contour of the middle region is a straight line or a wavy line, the length of the thrombus compression balloon is between 10-50 mm, and the diameter of the balloon after inflation is between 1-7 mm.

[0014] Preferably, the thrombus compression balloon has a thrombolytic drug or an anti-thrombus coating. The thrombolytic drug coating can dissolve part of the thrombus when the thrombus is too large or too hard, reducing the damage to the endothelium of the blood vessel when the balloon is inflated, and reducing the difficulty of thrombectomy. Thrombolytic drugs such as alteplase, urokinase, etc. Anti-thrombotic or anticoagulant drugs such as aspirin, clopidogrel, heparin, etc. are used to prevent the formation of new thrombus during thrombectomy.

[0015] Preferably, the thrombus compression balloon has a thrombus adhesion coating. The thrombus adhesion coating can increase the adhesion of the thrombus to the thrombus compression balloon after the thrombus is compressed, so that the thrombus can be removed by deflating and removing the thrombus compression balloon, increasing the convenience of thrombectomy. The thrombus adhesion coating can be a DNA binding compound coating.

[0016] Preferably, the thrombus compression component has a rapid exchange interface. The guide wire can pass through the rapid exchange interface.

[0017] After the thrombus is compressed and stress relaxation occurs, the adhesion between the thrombus and the blood vessel wall is greatly reduced. The thrombus suction component can exert a suction force on the compressed thrombus to remove it from the body. At this time, only a small suction force is needed to remove it. Reducing the requirement for suction pipe diameter and suction vacuum can reduce the damage to the blood vessel and brain tissue caused by high-power suction.

[0018] Preferably, the thrombus suction component has a woven or coil reinforcement layer in the pipe wall to increase the flexibility and bending resistance of the thrombus suction component. The thrombus suction component has a large stiffness at the proximal end and a small stiffness at the distal end, which allows it to maintain good delivery and ability to pass through tortuous blood vessels. The proximal end can be connected to a syringe or suction pump through a Y-shaped hemostatic valve for suction.

[0019] Preferably, the thrombus blocking component, the thrombus compression component, and the thrombus suction component have radiopaque markers. The relative positions of the components can be displayed under angiography.

[0020] Preferably, the thrombus blocking component, the thrombus compression component, and the thrombus suction component have uniformly dispersed ferromagnetic particles in the material, especially in the polymer material. The movement of the permanent magnet can be controlled by an external mechanical arm. By controlling the permanent magnet, the positioning, movement, and deflection of the thrombus removal device in the blood vessel can be controlled, and the thrombus removal component has magnetic navigation capability, achieving omnidirectional steering and navigation based on the magnetic driving of the permanent magnet. It also has good maneuverability in narrow blood vessels. The mechanical arm at the end drives the permanent magnet to accurately control the deflection direction of the thrombus compression and removal device, and the structure of the optical method is used to position the permanent magnet, achieving accurate control of the device in the blood vessel and greatly increasing the accuracy and stability of the operation.

[0021] The present application is based on the biomechanical properties of thrombus that we found in our experiments, that is, the thrombus will have stress relaxation phenomenon when it is compressed and kept compression strain for a period of time, and proposes a new type of thrombus compression and extraction device. The thrombus is decompressed by the inflation of the thrombus compression balloon. After the balloon is inflated, it is kept inflated for a period of time to maintain the state of the compressed thrombus. During this period, the volume of the compressed thrombus decreases, the internal stress relaxes, the normal contact pressure between the thrombus and the blood vessel wall greatly reduces, and the tangential friction between the thrombus and the blood vessel wall also greatly reduces, reducing the difficulty of thrombus extraction. During the compression of the thrombus and the extraction of the thrombus, the distal thrombus blocking part is in the expanded state to block the thrombus from flowing distally. After the thrombus compression balloon is deflated, the thrombus suction part starts to work, and the thrombus is removed out of the body by negative pressure suction. The thrombus compression and extraction device of the present application is easy to operate and has high success rate of thrombus extraction. Especially for hard or high load thrombus, the opening effect is very good. In addition, since the adhesion between the compressed thrombus and the blood vessel wall is greatly weakened after the stress relaxation of the thrombus, the thrombus suction part only needs a small suction force to remove the thrombus out of the body. Reduces the large amount of blood loss caused by high-power suction, increases the expansion of the infarcted brain tissue, and reduces the requirements for vacuum pressure and pipe diameter of the suction catheter. The thrombus compression and extraction device of the present application can improve the success rate of thrombus extraction, improve the blood vessel opening rate, and improve the functional outcome of the patient after operation. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be further described in detail below in combination with the drawings and specific embodiments:

[0023] Figure 1 A thrombus compression and extraction device with a net form thrombus blocking part

[0024] Figure 2 A thrombus compression and extraction device with a balloon form thrombus blocking part

[0025] Figure 3 A schematic diagram of thrombus compression test

[0026] Figure 4 A stress-strain curve of the compressed thrombus

[0027] Figure 5 A schematic diagram of the thrombus extraction process of the thrombus compression device

[0028] Figure 6 A thrombus compression balloon with thrombus adhesion coating DETAILED DESCRIPTION

[0029] Figure 1A thrombus compression extraction device is shown, which includes a thrombus blocking component 10, a thrombus compression component 20 and a thrombus suction component 30. The thrombus compression component 20 includes a thrombus compression balloon 21 and a delivery catheter 22. In this embodiment, the delivery catheter 22 is composed of an outer tube 23 and an inner tube 21, the inner tube 21 is inside the outer tube 23, and the distal end of the inner tube is longer than the outer tube. Contrast agent for inflating the balloon can flow into and out of the thrombus compression balloon 21 from the proximal end of the delivery catheter through the gap between the outer tube and the inner tube. The thrombus compression balloon is a compliant balloon, the range of its expansion and contraction can be controlled by the amount of contrast agent injected. The delivery catheter 22 has a radiopaque marker 23 near the connection end of the thrombus compression balloon, which is used to mark the position of the thrombus compression balloon 21 under an angiography machine. The thrombus compression balloon is fusiform, the length of the thrombus compression balloon is between 10-50 mm, and the diameter of the balloon after expansion is between 1-7 mm. In Figure 1 the embodiment, the outer contour of the middle region of the thrombus compression balloon is straight. In other embodiments, the outer contour line of the middle region of the thrombus compression balloon can be wavy, i.e. the outer contour of the balloon is wavy, which is used to increase the contact area with the thrombus.

[0030] In Figure 1 the embodiment, the thrombus blocking component 10 includes a basket 11 and a push wire 12. The basket 11 is fixed on the push wire 12 by a collar 13, and can slide on the push wire, the sliding range is limited by a limiting device 14. The basket 11 is located at the distal end of the thrombus compression balloon 21. The push wire is located in the lumen of the inner tube 24. By pulling the push wire 12, the basket 11 can be compressed and retracted into the inner tube 24. In operation, the basket 11 is in an open state, which can prevent the thrombus from being washed away by the forward blood flow to the distal end.

[0031] The thrombus suction component 30 is tubular, and has a radiopaque marker 31 at the distal end. When the thrombus compression balloon 21 is in a retracted state, the thrombus compression component 20 can be retracted into the thrombus suction component 30 by pulling the delivery catheter 22. The proximal end of the thrombus suction component 30 is located outside the body, and can be connected to a syringe or a suction pump through a Y-shaped hemostatic valve. The thrombus suction component 30 is used to extract the compressed and stress-relaxed thrombus out of the body. The thrombus suction component 30 has a woven or coil reinforcement layer in the pipe wall, which increases the flexibility and bending resistance of the thrombus suction component. The proximal end of the thrombus suction component is rigid, and the distal end is less rigid, which makes it have good deliverability and the ability to pass through tortuous blood vessels.

[0032] Figure 2Another embodiment of the thrombus compression extraction device is shown. The thrombus compression balloon 21 is fixed on the delivery catheter 22. The delivery catheter is a triple lumen catheter, the three lumens 17 inside are independent of each other. Two of the lumens are connected to the thrombus compression balloon 21 and the thrombus blocking balloon 15 respectively, for filling with contrast agent. The other lumen is for passing the guide wire. The delivery catheter 22 can also have a rapid exchange interface connected to the lumen for passing the guide wire, for rapid exchange of the guide wire.

[0033] In Figure 2 embodiments, the thrombus blocking component 10 is a thrombus blocking balloon 15, which is fixed on the delivery catheter 22 and located at the distal end of the thrombus compression balloon 21. The thrombus blocking balloon has radiopaque markers 16 on both sides, for marking the position of the thrombus blocking balloon 15 under the angiography machine. The thrombus blocking balloon 15 is a compliant balloon, and its inflation degree can be controlled by injecting contrast agent. Figure 2 The thrombus aspiration component 30 in the embodiment is consistent with the embodiment in Figure 1 .

[0034] In Figure 1 or Figure 2 embodiments, the outer layer of the thrombus compression balloon 21 can be coated with thrombolytic drugs or anti-thrombotic coatings. The thrombolytic drugs loaded on the balloon can dissolve part of the thrombus, reduce the endothelial damage caused by the increase in the volume of the thrombus compression balloon when it is inflated, and also reduce the difficulty of thrombectomy. Thrombolytic drugs such as alteplase, urokinase, etc. Anti-coagulants such as aspirin, clopidogrel, heparin, etc. can reduce the formation of new thrombus during thrombectomy. In Figure 1 or Figure 2 embodiments, the thrombus compression balloon can also have a thrombus adhesion coating. The function of the thrombus adhesion coating is to increase the adhesion of the thrombus to the thrombus compression balloon after the thrombus is compressed, so that the thrombus can be removed by deflating and removing the thrombus compression balloon, increasing the convenience of thrombectomy. The thrombus adhesion coating can be a DNA binding compound coating.

[0035] In one embodiment, the materials of the thrombus blocking component, the thrombus compression component and the thrombus aspiration component, especially the polymer materials, have uniformly dispersed ferromagnetic microparticles. The movement of the permanent magnet can be controlled by an external mechanical arm. By controlling the permanent magnet, the positioning, movement and deflection of the thrombus extraction device in the blood vessel can be controlled, so that the thrombus extraction component has magnetic navigation capability, realizing omnidirectional steering and navigation capability based on permanent magnet magnetic drive. It also has good controllability in narrow blood vessels. The end of the mechanical arm drives the permanent magnet to accurately control the deflection direction of the thrombus compression extraction device, and the method of structured light is used to position the permanent magnet, realizing the accurate control of the device in the blood vessel, greatly increasing the accuracy and stability of the operation.

[0036] Figure 3 A is the shape of the thrombus before compression. Figure 3 A is the shape of the thrombus before compression. Figure 3 B is a schematic diagram of the compression process, the thrombus is compressed by two rigid planes from top and bottom. Figure 3 C is the shape of the thrombus after compression and holding for a period of time, the volume of the thrombus is reduced.

[0037] Figure 4 The stress change of the thrombus during compression and holding for a period of time is shown. It can be seen that in the first few seconds, the thrombus receives continuous compression, and the stress value increases continuously to reach the peak. After reaching the maximum compression state, the compression clamp remains stationary for a period of time. During this period, the stress of the thrombus decreases rapidly until it stabilizes. This indicates that the thrombus has stress relaxation. We apply this mechanical property of the thrombus to the thrombectomy process, using the thrombus compression component to compress the thrombus and cause stress relaxation of the thrombus. After the thrombus undergoes stress relaxation, its volume decreases, making it easier to be sucked into the thrombus suction component. More importantly, a large part of the normal stress is relaxed, and the contact force and friction between the thrombus and the blood vessel wall will be small, making it easy for the thrombus to be removed by suction. We found that even for hard thrombus with high fibrin content, this stress relaxation phenomenon occurs.

[0038] Figure 5 The working process of the thrombus compression and removal device is shown. In Figure 5 A, 41 is the blood vessel, and 42 is the thrombus embolized in the blood vessel. In Figure 5 B, the thrombus suction component 30 is delivered to the proximal end of the embolization site. Under the guidance of the guide wire 50, the delivery catheter 22 passes through the thrombus, and the thrombus compression balloon can cover the thrombus by visualizing the marker. Figure 5 C, by injecting contrast agent, the thrombus blocking balloon 15 is inflated to prevent the thrombus from being washed away by forward blood flow during thrombectomy. In Figure 5 D, by injecting contrast agent, the thrombus compression balloon 21 is inflated to compress the thrombus 42. The thrombus compression balloon is kept inflated for a period of time, such as 50-300 seconds, during which the compressed thrombus 42 undergoes stress relaxation, and the stress of the thrombus decreases significantly. In Figure 5 E, by withdrawing the contrast agent, the thrombus compression balloon 21 is deflated. The volume of the thrombus 42 is significantly reduced relative to before compression, and because of stress relaxation, the contact stress between the thrombus and the blood vessel wall is significantly reduced. The compressed thrombus can be in a suspended state in the blood vessel. In Figure 5In F, the negative pressure is generated in the thrombus suction member by a syringe or a suction pump, the compressed thrombus is sucked into the thrombus suction member, and thus the thrombus is removed out of the body. Then the thrombus blocking balloon can be deflated, the recanalization of the blood vessel is confirmed by angiography, and then the delivery catheter and the suction catheter can be pulled out of the body.

[0039] Figure 6 In an embodiment, the thrombus compression balloon has a thrombus adhesion coating. After the stress relaxation of the thrombus, the thrombus compression balloon is deflated. Because of the thrombus adhesion coating, the thrombus is adhered to the balloon wall. By pulling back the delivery catheter, the thrombus compression balloon can be retracted into the thrombus suction device together with the thrombus. In this process, negative pressure suction can also be combined to increase the success rate of thrombus removal.

Claims

1. A thrombus compression and removal device, delivered to the embolism site via vascular intervention, characterized in that... The device consists of a thrombus blocking component, a thrombus compression component, and a thrombus aspiration component. The thrombus compression component includes a delivery catheter and a thrombus compression balloon. The thrombus compression balloon is fixed to the distal end of the delivery catheter. The expansion and contraction of the thrombus compression balloon are controllable. The thrombus compression balloon is spindle-shaped, with a straight or wavy outer contour in the central region. The thrombus compression balloon has a thrombus adhesion coating. The thrombus aspiration component has a tubular structure. The delivery catheter can move relative to the lumen of the thrombus aspiration component. When the thrombus compression balloon is in the contracted state, it can be retracted into the lumen of the thrombus aspiration component along with the delivery catheter.

2. The thrombus compression and removal device according to claim 1, characterized in that... The thrombus blocking component includes a basket and a pusher wire. The basket is fixed to the distal end of the pusher wire, which is located in the lumen of the delivery catheter. By controlling the pusher wire, the basket can be retracted into the delivery catheter of the thrombus compression component in a compressed state, or it can be pushed out of the delivery catheter to form an extended state.

3. The thrombus compression and removal device according to claim 1, characterized in that... The thrombus-blocking component is a thrombus-blocking balloon, which is connected to the delivery catheter and located distal to the thrombus-compressing balloon.

4. The thrombus compression and removal device according to claim 3, characterized in that... The expansion and contraction of the thrombus blocking balloon and the thrombus compression balloon are independently controlled, and the delivery catheter has independent cavities that are connected to the two balloons respectively.

5. The thrombus compression and removal device according to claim 1, characterized in that... The length of the thrombus compression balloon is between 10-50 mm, and the diameter of the balloon after inflation is between 1-7 mm.

6. The thrombus compression and removal device according to claim 1, characterized in that... The thrombus compression balloon has a thrombolytic drug coating or an antithrombus coating.

7. The thrombus compression and removal device according to claim 1, characterized in that... The delivery catheter of the thrombus compression component has a quick-exchange interface, and the tube wall of the thrombus aspiration component has a braided or coiled reinforcement layer. The thrombus aspiration component has high rigidity at the proximal end and low rigidity at the distal end. The proximal end can be connected to a syringe or aspiration pump for aspiration through a Y-shaped hemostatic valve.

8. The thrombus compression and removal device according to claim 1, characterized in that... The thrombus blocking component, thrombus compression component, and thrombus aspiration component have radiopaque markings.

9. The thrombus compression and removal device according to claim 1, characterized in that... The materials of the thrombus blocking component, thrombus compression component, and thrombus aspiration component contain uniformly dispersed ferromagnetic microparticles, and a permanent magnet is located at the end of the external robotic arm. The permanent magnet can control the positioning, movement, and deflection of the thrombus removal device within the blood vessel.

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