Thrombectomy device

Abstract

The present invention provides a thrombus removal device, which includes a softening mechanism and a thrombus removal mechanism, wherein the softening mechanism is used to soften the thrombus, and the thrombus removal mechanism is used to capture the softened thrombus. The thrombus removal device overcomes the problem that the thrombus removal device in the prior art has insufficient radial force and cannot effectively capture hard and large thrombi, cardiac leukothrombi and plaque thrombi, thereby improving the treatment effect.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a thrombus removal device. Background Art

[0002] Acute stroke is a common cerebrovascular disease with rapid onset, rapid development, severe symptoms, high disability and mortality rates. It is an acute and critical disease among cerebrovascular diseases. Generally speaking, stroke can be divided into two types: hemorrhagic and ischemic, of which ischemic stroke accounts for 70% to 80%. The pathogenesis of acute ischemic stroke is that thrombus or arteriosclerotic plaque detached from the diseased blood vessel wall causes acute occlusion of cerebral arteries, which in turn causes a series of physiological and pathological reactions such as inflammation and apoptosis in ischemic brain tissue. If the blood perfusion of the occluded cerebral artery is restored in a short period of time, the cell metabolism of brain tissue can return to normal and avoid the development of infarction area.

[0003] In the prior art, the main treatments for acute ischemic stroke are intravenous thrombolysis and interventional thrombectomy. Intravenous thrombolysis is the intravenous injection of thrombolytic drugs, and its treatment time window is within three hours after onset. However, most patients miss the treatment time window when they arrive at the hospital after onset, resulting in a serious decline in the thrombolytic effect and failure to effectively open up blocked blood vessels. Interventional thrombectomy is the process of introducing a thrombectomy device through the femoral artery and using the thrombectomy device to remove the embolism. The time window for interventional thrombectomy is within eight hours after onset. In recent years, interventional treatment of acute ischemic stroke has developed rapidly. Based on a series of clinical randomized controlled trials, relevant international organizations have recommended that patients with large vessel occlusion within six hours should give priority to interventional thrombectomy.

[0004] Interventional thrombectomy can be roughly divided into two categories: mechanical thrombectomy and aspiration thrombectomy. Among them, mechanical thrombectomy has gone through the iterations of the first-generation thrombectomy device MERCI, the second-generation thrombectomy device Penumbra (consisting of a reperfusion catheter and a separator) and Solitaire FR (a closed-loop stent engraved by a laser), and the third-generation thrombectomy device Treo (fully visualized) and Revive (distal closed basket). The current mainstream mechanical thrombectomy method is to deliver a microcatheter with an embedded thrombectomy stent into the body with the assistance of a microguidewire, and pass through the thrombus or through the gap between the thrombus and the blood vessel wall to reach the distal side of the thrombus, and then withdraw the microcatheter and release the thrombectomy stent. In this way, the thrombus can be trapped in the thrombectomy stent, and then the thrombectomy stent is withdrawn into the microcatheter, and the thrombus is carried into the microcatheter. Finally, the thrombectomy stent and microcatheter are withdrawn to move the thrombus out of the body. This thrombectomy method mainly utilizes the radial squeezing and interlocking action of the thrombus retriever stent to capture the thrombus. When the radial force of the thrombus retriever stent is insufficient, the thrombus capture effect is poor. Therefore, this method has limitations for large hard thrombi, large-sized cardiac leukocytosis or plaque thrombi that exceed the treatment time window. Summary of the invention

[0005] The purpose of the present invention is to provide a thrombus removal device, which first softens the thrombus and then performs the thrombus removal operation. It can be applied to hard large thrombus, large-sized cardiac leukothrombus or plaque thrombus.

[0006] To achieve the above-mentioned purpose, the present invention provides a thrombus removal device, comprising a softening mechanism and a thrombus removal mechanism, wherein the softening mechanism is used to soften the thrombus, and the thrombus removal mechanism is used to capture the softened thrombus.

[0007] Optionally, the softening mechanism comprises a first tube body, a balloon and a softening coating; the first tube body has a first channel axially penetrating; the balloon is sleeved on the outer surface of the distal end of the first tube body, and the softening coating is provided on at least a part of the outer surface of the balloon;

[0008] The thrombus removal mechanism is used to be movably disposed in the first channel, and comprises a pushing rod and a thrombus removal bracket, wherein the thrombus removal bracket is connected to the distal end of the pushing rod.

[0009] Optionally, the material of the softening coating includes a matrix-degrading enzyme.

[0010] Optionally, the matrix degrading enzyme is selected from at least one of matrix metalloproteinases, serine elastase, trypsin, neutral protease, chymotrypsin, aspartase, cysteine ​​enzyme, and clostripain.

[0011] Optionally, the balloon includes a filling cavity; the first tube body further has an axially penetrating second channel, the second channel is isolated from the first channel, and a perfusion hole communicating with the filling cavity is provided on a side wall of the second channel.

[0012] Optionally, the balloon includes a filling cavity; the softening mechanism also includes a second tube body, which is sleeved on the outside of the first tube body and forms a third channel between the second tube body and the first tube body, the distal end of the second tube body is connected to the proximal end of the balloon, and the third channel is connected to the filling cavity.

[0013] Optionally, the balloon is a compliant balloon, a semi-compliant balloon or a non-compliant balloon; and / or, the thrombectomy stent is a self-expanding structure.

[0014] Optionally, the proximal end of the thrombus retrieval stent is a closed end, and the distal end of the thrombus retrieval stent is a closed end or an open end.

[0015] Optionally, the softening mechanism and the thrombus removal mechanism are separate structures.

[0016] Compared with the prior art, the thrombus removal device of the present invention has the following advantages:

[0017] The aforementioned thrombus removal device includes a softening mechanism and a thrombus removal mechanism; wherein the softening mechanism is used to soften the thrombus, and the thrombus removal mechanism is used to capture the softened thrombus. The thrombus removal device can be used to treat hard and large thrombi, large-sized cardiac leukothrombi or plaque thrombi, and has a good thrombus capture effect.

[0018] Furthermore, the softening mechanism includes a first tube body, a balloon and a softening coating; the first tube body has a first channel axially extending therethrough; the balloon is arranged on the outer surface of the distal end of the first tube body, and the softening coating is arranged on at least a partial area of ​​the outer surface of the balloon; the thrombus removal mechanism is used to be movably arranged in the first channel, and includes a pushing rod and a thrombus removal bracket, and the thrombus removal bracket is connected to the distal end of the pushing rod, has a simple structure, and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0020] Figure 1 is a schematic structural diagram of a thrombus removal device according to an embodiment of the present invention, in which the balloon and the thrombus removal stent are both in a compressed state;

[0021] Figure 2 is a schematic structural diagram of a thrombus removal device provided according to an embodiment of the present invention, in which the balloon is in an expanded state;

[0022] Figure 3 is a schematic structural diagram of a thrombus removal device provided according to an embodiment of the present invention, in which the thrombus removal stent is in an expanded state;

[0023] Figures 4a to 4d FIG. 4 is a schematic diagram of the use process of the thrombus removal device provided according to an embodiment of the present invention.

[0024] [Description of reference numerals is as follows]:

[0025] 100-softening mechanism, 110-first tube body, 111-first channel, 120-balloon, 130-softening coating;

[0026] 200 - thrombus removal mechanism, 210 - pushing rod, 220 - thrombus removal bracket;

[0027] 10-Thrombosis. DETAILED DESCRIPTION

[0028] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the present embodiment only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the figure instead of being drawn according to the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be a random change, and the component layout type may also be more complicated.

[0029] In addition, each embodiment of the following description has one or more technical features, but this does not mean that the user of the present invention must implement all the technical features in any embodiment at the same time, or can only implement part or all of the technical features in different embodiments separately. In other words, under the premise that implementation is possible, those skilled in the art can selectively implement part or all of the technical features in any embodiment according to the disclosure of the present invention and according to the design specifications or implementation requirements, or selectively implement a combination of part or all of the technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0030] As used in this specification, the singular forms "a", "an", and "the" include plural objects, and the plural form "plurality" includes more than two objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used to include the meaning of "and / or", unless the content clearly indicates otherwise, and the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and it can be a connection between the internal parts of two elements or an interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0031] As described in the background technology, the thrombus removal stent in the prior art is difficult to effectively capture hard and large thrombi, cardiac leukothrombi or plaque thrombi when the radial force is insufficient. In view of this situation, the embodiment of the present invention proposes a thrombus removal device, which is used to soften the thrombus first and then mechanically remove the thrombus, so as to overcome the problem of poor thrombus removal effect caused by insufficient radial force of the thrombus removal stent. To achieve this purpose, the thrombus removal device provided by the embodiment of the present invention includes a softening mechanism and a thrombus removal mechanism, wherein the softening mechanism is used to soften the thrombus, and the thrombus removal mechanism is used to capture the softened thrombus. Specifically, the softening mechanism may include a first tube body, a balloon and a softening coating. The first tube body has an axially through first channel, the balloon is arranged on the outer surface of the distal end of the first tube body, and the softening coating is arranged on at least a part of the outer surface of the balloon. The thrombus removal mechanism includes a push rod and a thrombus removal stent, and the thrombus removal stent is connected to the distal end of the push rod. The thrombus removal device has the advantages of simple structure and convenient use.

[0032] In order to make the purpose, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar components.

[0033] Figures 1 to 3 Schematic diagram of the thrombus removal device provided by the embodiment of the present invention in different states. Figures 1 to 3 The thrombus removal device includes a softening mechanism 100 and a thrombus removal mechanism 200. The softening mechanism 100 is used to remove the thrombus 10 (such as Figures 4a to 4d The thrombus 10 is softened by the thrombus removal mechanism 200, and the thrombus removal mechanism 200 is used to capture the softened thrombus 10. When the thrombus removal device is used to treat a hard large thrombus, a cardiogenic leukothrombus, or a plaque thrombus, the thrombus softening step is first performed by the thrombus softening mechanism 100, and then the thrombus removal mechanism 200 is used to capture the thrombus, which can effectively overcome the problem of poor capture effect caused by the high hardness of the thrombus.

[0034] In a non-limiting embodiment, the softening mechanism 100 includes a first tube body 110, a balloon 120 and a softening coating 130. The first tube body 110 has an axially through first channel 111, and the first channel 111 is used for the thrombus removal mechanism 200 to pass through. The balloon 120 is sleeved on the distal outer surface of the first tube body 110, and the softening coating 130 is provided on at least a part of the outer surface of the balloon 120, and the softening coating 130 is used to soften the thrombus 10 and reduce the hardness of the thrombus 10. The thrombus removal mechanism 200 is used to be movably passed through the first channel 111, and the thrombus removal mechanism 200 includes a push rod 210 and a thrombus removal bracket 220, and the thrombus removal bracket 220 is connected to the distal end of the push rod 210. When the thrombus removal device provided in this embodiment is used for thrombus removal, the balloon 120 is first expanded to allow the softening coating 130 to act on the thrombus 10, and then the thrombus is captured by the thrombus removal stent 220 after the thrombus 10 is softened.

[0035] Optionally, the material of the softening coating 130 includes at least one matrix degrading enzyme. When the softening coating 130 contacts the thrombus 10, the matrix degrading enzyme contained therein can soften the extracellular matrix components constituting the thrombus, so that the thrombus 10 is softened. The matrix degrading enzyme is selected from matrix metalloproteinase, serine elastase, trypsin, neutral protease, chymotrypsin, aspartase, cysteine ​​enzyme, clostripain. It is understandable that when the material of the softening coating 130 includes multiple matrix degrading enzymes, no chemical reaction occurs between the multiple matrix degrading enzymes. Furthermore, the material of the softening coating 130 may also include a carrier, which is mixed with the matrix degrading enzyme and helps the matrix degrading enzyme to attach to the outer surface of the balloon 120. The optional carrier includes angiographic contrast agent substances such as at least one of iopromide, iopamidol, and iohexol, a hydrophilic material such as urea, shellac, and polysorbate, an aliphatic polyester polymer such as polylactic acid, polyglycolide, polyglycolide-lactide copolymer, and polycaprolactone, and any liposome derived from humans, eggs, or soybeans, such as phospholipid 80H for liposomes, phospholipid 90H for liposomes, lipoid EPC, lipoid E80, intralipid 20, lipoid S75, lipoid E75, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, phosphatidic acid, cardiolipin, phosphatidylethanolamine, etc.

[0036] In the embodiment of the present invention, the softening coating 130 may be uniformly or non-uniformly attached to a portion of the outer surface of the balloon 120, or may be attached to the entire outer surface of the balloon 120. In the softening coating 130, the matrix degrading enzyme may be in the form of crystalline particles or in the form of amorphous particles.

[0037] Similar to the balloon in the prior art, the material of the balloon 120 in the embodiment of the present invention is selected from a block copolymer of polyether and polyamide (Pebax), polyethylene, polyamide, etc. It can be a compliant balloon, a semi-compliant balloon, or a non-compliant balloon, but preferably a compliant balloon. The balloon 120 includes a filling cavity, which is used to accommodate a filling agent to expand the balloon 120. The first tube 110 also has a second channel that penetrates along its axial direction and is isolated from the first channel 111. The side wall of the second channel is provided with a perfusion hole connected to the filling cavity, so that the filling agent can flow through the second channel and the perfusion hole and then be perfused into the filling cavity. Alternatively, the first tube 110 does not have the second channel, but the softening mechanism 100 also includes a second tube (not shown in the figure), the second tube is sleeved on the outside of the first tube 110, and a third channel is formed between the inner wall of the second tube and the outer wall of the first tube. The distal end of the second tube is connected to the proximal end of the balloon 120, and the distal end of the third channel is connected to the filling cavity, so that the filling agent flows through the third channel and enters the filling cavity. Those skilled in the art should know that the filling agent can be a liquid as long as it is filled into the filling cavity and can exert a radial outward force on the balloon 120 to expand the balloon 120.

[0038] In fact, the softening mechanism 100 described in the embodiment of the present invention can be obtained by directly providing the softening coating 130 on the basis of the balloon catheter in the prior art, and the manufacturing process is simple and mature.

[0039] In addition, the thrombus removal stent 220 of the thrombus removal mechanism 200 is preferably a self-expanding structural member. The so-called self-expanding structural member refers to a structural member made of a material with high elasticity, which deforms when subjected to external pressure, but can restore the deformation under its own elasticity after the external pressure is removed. Usually, self-expanding structural members are made of shape memory alloy materials such as Nitinol alloy. The proximal end of the thrombus removal stent 220 is a closed end, and the distal end is a closed end or an open end. It should be noted that the closed end mentioned here refers to the proximal end of the thrombus removal stent 220 being folded. The thrombus removal stent 220 can be a braided stent or a cutting stent, which is not limited in the embodiments of the present invention.

[0040] Furthermore, the thrombus removal mechanism 200 and the softening mechanism 100 are preferably of separate structures. In actual use, the softening mechanism 100 can be delivered separately first, and then the thrombus removal mechanism 200 can be delivered through the first channel after the thrombus is softened. Compared with delivering the softening mechanism 100 and the thrombus removal mechanism 200 at the same time, the advantage of this arrangement is that this delivery method can ensure that the softening mechanism 100 and the thrombus removal mechanism 200 have good flexibility during the delivery process, so that they can pass through the tortuous blood vessels to reach the area where the thrombus is located.

[0041] Next, the method of using the thrombus removal device is introduced through a simulation experiment, but the following description should not constitute an improper limitation to the present invention.

[0042] Experimental preparation:

[0043] First, a thrombus removal device is provided: PTFE is used as the material of the first tube body 110, and Pebax is used as the material of the balloon 120. The first tube body 110 and the balloon 120 are formed by a co-extrusion and blow molding process. The molding process is well known to those skilled in the art and will not be described in detail here. Then, a matrix metalloproteinase aqueous solution with a concentration of 10 mg / ml is prepared, and the matrix metalloproteinase aqueous solution is sprayed onto the outer surface of the expanded balloon using an ultrasonic sprayer. After the base metalloproteinase solution is dried, the softening coating 130 is formed, and the softening mechanism 100 is obtained. The thrombus removal bracket 220 is obtained after cutting, heat treatment, shaping, polishing, and cleaning the nitinol tube, and then the thrombus removal bracket 220 is welded to a push rod 210 composed of a nitinol core wire to obtain the thrombus removal mechanism 200.

[0044] Next, prepare a vascular model, which is an intracranial vascular model in which the brain segment is opened. Take an experimental rabbit and collect 5 ml of blood from its ear vein. Mix the collected blood with thrombin and inject it into the midbrain segment of the intracranial vascular model. Wait for 3 to 5 minutes to ensure that the blood has coagulated into a block and formed a thrombus for 10 minutes, then reconnect the processed vascular model.

[0045] Thrombus capture experiment:

[0046] First, the balloon 120 is delivered into the blood vessel model using conventional techniques, and the balloon 120 is made to reach the area where the thrombus 10 is located (eg, Figure 4a As shown), during this process the balloon 120 is in a compressed state.

[0047] Next, a filling agent is injected into the balloon 120 to make the pressure inside the balloon 120 about 6 atm, and the balloon 120 is expanded until the softening coating 130 contacts the surface of the thrombus 10 (eg, Figure 4b), and maintained for several minutes to allow the softening coating 130 to act on the thrombus 10.

[0048] After determining that the thrombus 10 is softened, the filling agent is allowed to flow out of the balloon 120 and the balloon 120 is deflated.

[0049] Then, the thrombus removal stent 220 is delivered along the first channel 111 to the area where the thrombus 10 is located (eg, Figure 4c As shown), during this process, the thrombus removal bracket 220 is in a compressed state.

[0050] Next, the softening mechanism 100 is withdrawn to allow the thrombus removal stent 220 to extend out of the first channel 111 and expand to engage with the thrombus 10 (eg, Figure 4d shown).

[0051] After confirming that the thrombus 10 has been captured by the thrombus removal bracket 220, the thrombus removal mechanism 200 is withdrawn to allow the thrombus 10 to be carried by the thrombus removal bracket 220 and recovered into the first channel 111. Finally, the thrombus removal device is withdrawn as a whole.

[0052] It should be noted that, in some embodiments, after the softening coating 130 contacts the surface of the thrombus 10 and the balloon 120 contracts, at least part of the matrix degrading enzyme in the softening coating 130 can be transferred to the surface of the thrombus 10, so that the balloon 120 can be contracted without waiting for the thrombus 10 to soften. Then, after confirming that the thrombus 10 is softened, the thrombus removal stent 220 is introduced to remove the thrombus.

[0053] The thrombus removal device provided in the embodiment of the present invention comprises a softening mechanism and a thrombus removal mechanism; wherein the softening mechanism is used to soften the thrombus, and the thrombus removal mechanism is used to capture the softened thrombus. The thrombus removal device can be used to treat hard and large thrombi, large-sized cardiac leukothrombi or plaque thrombi, and has a good thrombus capture effect.

[0054] Although the present invention is disclosed as above, it is not limited thereto. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A thrombus removal device, characterized in that: It comprises a split softening mechanism and a thrombus removal mechanism, wherein the softening mechanism comprises a first tube body, a balloon and a softening coating; the first tube body has a first channel axially extending therethrough; the balloon is sleeved on the outer surface of the distal end of the first tube body, and the softening coating is provided on at least a part of the outer surface of the balloon, the softening coating is used to contact with the thrombus to soften the thrombus, the thrombus removal mechanism is used to be movably arranged in the first channel, and comprises a pushing rod and a thrombus removal bracket, the thrombus removal bracket is connected to the distal end of the pushing rod, and is used to engage with the softened thrombus to capture the thrombus.

2. The thrombus removal device according to claim 1, characterized in that: The material that softens the coating includes a matrix-degrading enzyme.

3. The thrombus removal device according to claim 2, characterized in that: The matrix degrading enzyme is selected from at least one of matrix metalloproteinases, serine elastase, trypsin, neutral protease, chymotrypsin, aspartase, cysteine ​​enzyme, and clostripain.

4. The thrombus removal device according to claim 1, characterized in that: The balloon includes a filling cavity; the first tube body also has an axially penetrating second channel, the second channel is isolated from the first channel, and a perfusion hole communicating with the filling cavity is provided on the side wall of the second channel.

5. The thrombus removal device according to claim 1, characterized in that: The balloon includes a filling cavity; the softening mechanism also includes a second tube body, which is sleeved on the outside of the first tube body and forms a third channel with the first tube body. The distal end of the second tube body is connected to the proximal end of the balloon, and the third channel is connected to the filling cavity.

6. The thrombus removal device according to claim 1, characterized in that: The balloon is a compliant balloon, a semi-compliant balloon or a non-compliant balloon; and / or the thrombectomy stent is a self-expanding structure.

7. The thrombus removal device according to claim 1, characterized in that: The proximal end of the thrombus retrieval stent is a closed end, and the distal end of the thrombus retrieval stent is a closed end or an open end.

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