Thrombectomy device and medical device

Abstract

The present invention provides a thrombus removal device and a medical device, wherein the medical device comprises the thrombus removal device, the thrombus removal device comprises a push shaft, a thrombus removal bracket and an auxiliary mechanism, wherein the thrombus removal bracket is a self-expanding bracket and is fixedly connected to the distal end of the push shaft; the auxiliary mechanism is partially arranged inside the thrombus removal bracket and is used to apply a radial outward expansion force to the thrombus removal bracket, so that the thrombus removal bracket can also perform a second expansion in the radial direction after self-expansion. The thrombus is captured by the thrombus removal device. If the radial force of the thrombus removal bracket is insufficient and the thrombus cannot be effectively captured, the auxiliary mechanism can be used to apply the expansion force to the thrombus removal bracket, so that the thrombus removal bracket expands a second time and enhances the radial force, thereby improving the thrombus capture effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a thrombus removal device and a medical 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 object of the present invention is to provide a thrombus removal device and a medical device. The thrombus removal stent of the thrombus removal device can be expanded twice by an auxiliary mechanism when the radial force is insufficient due to self-expansion, so as to increase the radial force and improve the thrombus capture effect.

[0006] To achieve the above object, the present invention provides a thrombus removal device, comprising:

[0007] Push shaft;

[0008] The thrombectomy stent is a self-expanding stent and is fixedly connected to the distal end of the pushing shaft; and

[0009] The auxiliary mechanism is partially disposed inside the thrombus retrieval stent and is used to apply a radially outward expansion force to the thrombus retrieval stent so that the thrombus retrieval stent can perform a second expansion in the radial direction after self-expansion.

[0010] Optionally, the auxiliary mechanism comprises an auxiliary bracket and an expansion rod, wherein the auxiliary bracket is at least partially disposed inside the thrombus removal bracket; and the expansion rod is connected to the auxiliary bracket;

[0011] The auxiliary mechanism is configured such that when the expansion rod moves in a predetermined direction and generates an axial relative motion with the pushing shaft, the expansion rod drives the auxiliary stent to expand in a radial direction, so that the auxiliary stent applies the expansion force to the thrombectomy stent.

[0012] Optionally, the proximal end of the auxiliary bracket is fixedly connected to the distal end of the pushing shaft and / or the proximal end of the thrombus removal bracket, and the distal end of the auxiliary bracket is fixedly connected to the distal end of the expansion rod and moves synchronously with the expansion rod;

[0013] The auxiliary mechanism is configured such that when the expansion rod moves in the axial direction of the pushing shaft from the distal end to the proximal end, the auxiliary stent expands in the radial direction.

[0014] Optionally, the pushing shaft has a first inner cavity extending axially therethrough, and the expansion rod is partially disposed in the first inner cavity and is configured to be movable along the first inner cavity.

[0015] Optionally, the pushing shaft is a cylindrical helical spring structure.

[0016] Optionally, the expansion rod is arranged in parallel with the pushing shaft.

[0017] Optionally, the proximal end and the distal end of the thrombus removal stent are both closed ends.

[0018] Optionally, the proximal end of the thrombus removal stent is a closed end, and the distal end is an open end.

[0019] Optionally, the thrombus removal stent is a braided stent or a cutting stent.

[0020] To achieve the above objectives, the present invention further provides a medical device, comprising a microcatheter and a thrombus removal device as described in any of the preceding items; the microcatheter has a second inner cavity extending axially therethrough, the thrombus removal device is used to be partially disposed in the second inner cavity and is configured to be able to move along the second inner cavity.

[0021] Compared with the prior art, the thrombus removal device and medical device of the present invention have the following advantages:

[0022] The aforementioned thrombus removal device includes a push shaft, a thrombus removal stent and an auxiliary mechanism, wherein the thrombus removal stent is a self-expanding stent and is fixedly connected to the distal end of the push shaft; the auxiliary mechanism is partially arranged inside the thrombus removal stent and is used to apply a radial outward expansion force to the thrombus removal stent, so that the thrombus removal stent can also perform a second expansion in the radial direction after self-expansion. When the thrombus removal device is used to capture hard large thrombi, large-sized cardiac leukothrombi or plaque thrombi, and the radial force of the thrombus removal stent self-expansion is insufficient, the auxiliary mechanism can be used to drive the thrombus removal stent to expand for a second time and improve the interlocking effect between the thrombus removal stent and the thrombus, so as to achieve the purpose of effectively capturing the thrombus. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0024] Figure 1 is a schematic structural diagram of a thrombus removal device according to an embodiment of the present invention, in which the thrombus removal bracket and the auxiliary bracket are both in a compressed state;

[0025] Figure 2 is a schematic structural diagram of a thrombus removal device according to an embodiment of the present invention, in which the thrombus removal stent is in an expanded state and the auxiliary stent is in a compressed state;

[0026] Figure 3 is a schematic structural diagram of a thrombus removal device according to an embodiment of the present invention, in which the thrombus removal stent and the auxiliary stent are both in an expanded state;

[0027] Figure 4 is a schematic structural diagram of a thrombus removal device provided according to an embodiment of the present invention, in which the auxiliary mechanism is not assembled with the thrombus removal bracket and the pushing shaft;

[0028] Figure 5a to Figure 5d A schematic diagram showing the process of thrombus removal using the medical device provided by an embodiment of the present invention is shown.

[0029] [Description of reference numerals is as follows]:

[0030] 100-push shaft, 200-thrombectomy bracket, 300-auxiliary mechanism, 310-auxiliary bracket, 320-expansion rod;

[0031] 10-microcatheter, 20-microguidewire;

[0032] 1-Thrombosis. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Figures 1 to 4 FIG. 2 shows a schematic diagram of the structure of a thrombus removal device provided by an embodiment of the present invention. Figures 1 to 4 The thrombus removal device includes a push shaft 100, a thrombus removal stent 200 and an auxiliary mechanism 300. The thrombus removal stent 200 is a self-expanding stent and is fixedly connected to the distal end of the push shaft 100. The auxiliary mechanism 300 is partially disposed inside the thrombus removal stent 200 and is used to apply a radially outward expansion force to the thrombus removal stent 200 so that the thrombus removal stent 200 can perform a second radial expansion after self-expansion. The thrombus removal device is used to capture the thrombus 1 (such as Figure 5a to Figure 5d (marked), especially when capturing large hard thrombi, large-sized cardiac leukothrombi or plaque thrombi that exceed the treatment time window, if the radial force generated by the self-expansion of the thrombus retriever stent 200 is insufficient, resulting in insufficient fit between the thrombus retriever stent 200 and the thrombus 1, and the thrombus cannot be effectively captured, the operator can apply a radial outward expansion force to the thrombus retriever stent 200 by operating the auxiliary mechanism 300, so that the thrombus retriever stent 200 can be expanded a second time, thereby improving the fit between the thrombus retriever stent 200 and the thrombus 1 and improving the capture effect. It should be noted that the so-called self-expanding stent means that the thrombus retriever stent 200 is made of a highly elastic material, which can be deformed when subjected to pressure, and when the pressure is removed, it can automatically restore the deformation under the action of its own elastic force. The thrombus retriever stent 200 can be made of a shape memory alloy such as Nitinol alloy, and it can be a cutting stent or a braided stent, which is not limited in the embodiments of the present invention.

[0038] In a specific embodiment, the auxiliary mechanism 300 includes an auxiliary bracket 310 and an expansion rod 320, wherein the auxiliary bracket 310 is at least partially arranged inside the thrombus removal bracket 200, and the expansion rod 320 is connected to the auxiliary bracket 310, and when the expansion rod 320 moves along a predetermined direction and generates an axial relative movement with the pushing shaft 100, the expansion rod 320 drives the auxiliary bracket 310 to expand radially, and when the auxiliary bracket 310 continues to expand after radially expanding to a predetermined degree, the auxiliary bracket 310 squeezes the thrombus removal bracket 200 inside the thrombus removal bracket 200 and applies the expansion force to the thrombus removal bracket 200 to promote the secondary expansion of the thrombus removal bracket 200, thereby enhancing the interlocking effect between the thrombus removal bracket 200 and the thrombus 1 and improving the thrombus removal effect.

[0039] Preferably, the proximal end of the auxiliary stent 310 is fixedly connected to the distal end of the push shaft 100 by welding or any other suitable means, and the distal end of the auxiliary stent 310 is fixedly connected to the distal end of the expansion rod 320 by welding or any other suitable means. When the expansion rod 320 moves, the distal end of the auxiliary stent 310 moves synchronously therewith. In this embodiment, when the expansion rod 320 moves from the distal end to the proximal end in the axial direction of the push shaft 100 (that is, the aforementioned predetermined direction is the direction from the distal end to the proximal end), the auxiliary stent 310 expands radially, and conversely, when the expansion rod 320 moves from the proximal end to the distal end in the axial direction of the push shaft 100, the auxiliary stent 310 contracts radially. It is understandable that the proximal end of the auxiliary stent 310 can also be fixedly connected to the proximal end of the thrombectomy stent 200. And, the auxiliary stent 310 can be made of shape memory alloy (such as Nitinol alloy) or highly elastic polymer material and is pre-shaped into an expansion shape such as a spherical or ellipsoidal shape.

[0040] In some implementations, the proximal end and the distal end of the thrombectomy stent 200 are both closed ends, the auxiliary stent 310 is completely disposed inside the thrombectomy stent 200, and the length of the auxiliary stent 310 is less than or equal to the length of the thrombectomy stent 200. In other implementations, the proximal end of the thrombectomy stent 200 is a closed end and the distal end is an open end, the auxiliary stent 310 can be completely disposed inside the thrombectomy stent 200, or the length of the auxiliary stent 310 is greater than the length of the thrombectomy stent 200, and the auxiliary stent 310 is partially disposed inside the thrombectomy stent 200, that is, the distal end of the auxiliary stent 310 extends to the outside of the thrombectomy stent 200. It can be understood that the closed end mentioned here refers to the corresponding end of the thrombectomy stent 200, such as the proximal end, which is gathered, so that the proximal end of the thrombectomy stent 200 forms a tapered structure. In addition, the auxiliary stent 310 can be either a braided stent or a cutting stent.

[0041] Optionally, the expansion rod 320 may be a solid structure or a hollow structure, and may be composed of a single strand of wire or a plurality of strands of wire, which is not limited in the embodiment of the present invention. The expansion rod 320 may be arranged in parallel with the push shaft 100, so that the push shaft 100 may be a solid rod. The materials of the push shaft 100 and the expansion rod 320 may be selected from metal materials or polymer materials, and the optional metal materials include but are not limited to Nitinol alloys, and the optional polymer materials include but are not limited to nylon, PTFE (polytetrafluoroethylene), and Pebax (block polyetheramide elastomer).

[0042] Preferably, the push shaft 100 has a first inner cavity extending axially through, and the expansion rod 320 is partially disposed in the first inner cavity and is configured to be movable along the first inner cavity so that the auxiliary stent 310 can be radially expanded or contracted. In some implementations, the push shaft 100 is a tube, which can be a single-lumen tube or a multi-lumen tube, which can be selected according to actual needs. In other implementations, the push shaft 100 is a cylindrical helical spring structure formed by a wire around an axis, which has the advantages of having good pushability and flexibility, and is easier to pass through tortuous blood vessels.

[0043] It should be noted that, when the distal end of the thrombus removal stent 200 is a closed end, and the expansion rod 320 is partially and movably disposed in the first inner cavity of the pushing shaft 100, the distal end of the auxiliary stent 310 can be fixedly connected to the distal end of the thrombus removal stent 200, and the proximal end of the auxiliary stent 310 is fixedly connected to the distal end of the expansion rod 320. When the expansion rod 320 moves in the direction from the proximal end to the distal end (that is, the predetermined direction is the direction from the proximal end to the distal end), the auxiliary stent 310 can radially expand, and when the expansion rod 320 moves in the direction from the distal end to the proximal end, the auxiliary stent 310 can radially contract.

[0044] Furthermore, the present invention also provides a medical device, including a microcatheter 10 (such as Figure 5a to Figure 5d As shown in the figure, and as the thrombus removal device described above, the microcatheter 10 has a second inner cavity extending axially therethrough, and the thrombus removal device is used to be partially disposed in the second inner cavity and is configured to be movable along the second inner cavity.

[0045] Next, this article will introduce the use process of the medical device in combination with a simulation experiment.

[0046] Experimental preparation:

[0047] Open the middle brain segment of the intracranial vascular model. Take an experimental rabbit, collect 5 ml of blood from the rabbit's ear vein, mix the collected blood with thrombin and immediately inject it into the middle brain segment of the vascular model. Wait for about 3 to 5 minutes to confirm that the blood has coagulated and formed a thrombus, and then close the middle brain segment of the intracranial vascular model.

[0048] Thrombectomy experiment:

[0049] First, a micro guide wire 20 is introduced into the location where the thrombus 1 is formed in the blood vessel model.

[0050] Then, the distal end of the microcatheter 10 is transported along the microguide wire 20 to the distal end side of the thrombus 1 (such as Figure 5a shown).

[0051] Afterwards, the micro-guidewire 20 is withdrawn from the blood vessel model, and the distal end of the thrombus removal device is introduced into the second inner cavity of the micro-catheter 10, and the distal end of the thrombus removal stent 200 is transported along the second inner cavity to the distal side of the thrombus 1 (such as Figure 5b As shown in FIG. 1 , it can be understood that during this process, the thrombus removal bracket 200 and the auxiliary bracket 310 are both in a contracted state.

[0052] Subsequently, the microcatheter 10 is withdrawn (ie, the microcatheter 10 is moved from the distal end to the proximal end) to allow the thrombus removal stent 200 to self-expand (eg, Figure 5c shown).

[0053] Next, the expansion rod 320 is withdrawn (i.e., the expansion rod 320 is moved from the distal end to the proximal end), so that the auxiliary stent 310 is radially expanded, and the auxiliary stent 310 is pressed against the thrombus removal stent 200 inside the thrombus removal stent 200, and a radial expansion force is applied to the thrombus removal stent 200, so that the thrombus removal stent 200 is expanded for a second time (e.g., Figure 5d as shown) and effectively captures thrombus 1.

[0054] After confirming that the thrombus removal device has completely captured the thrombus 1, the expansion rod 320 is pushed forward (i.e., the expansion rod 320 is moved from the proximal end to the distal end), and the auxiliary stent 310 is contracted radially. Then, the thrombus removal device is withdrawn until the thrombus removal device is recovered into the microcatheter 10. Finally, the microcatheter 10 and the thrombus removal device carrying the thrombus 1 are withdrawn from the blood vessel model as a whole.

[0055] It is understandable that when the radial force of the thrombus retriever stent 200 is large enough and the thrombus retriever stent 200 can effectively capture the thrombus, the auxiliary stent 310 may not be used to expand the thrombus retriever stent 200 for a second time, that is, during the process of capturing the thrombus, the auxiliary stent 310 is always in a compressed state.

[0056] In the technical solution provided by the embodiment of the present invention, when the radial force of the thrombus removal stent is insufficient and it is difficult to effectively capture the thrombus, an auxiliary mechanism can be used to provide radial expansion force to the thrombus removal stent inside the thrombus removal stent, and the thrombus removal stent can be expanded twice, thereby improving the interlocking effect between the thrombus removal stent and the thrombus, enhancing the thrombus capture ability, and improving the thrombus removal effect. The thrombus removal device provided by the embodiment of the present invention is particularly suitable for capturing hard large thrombi, large-sized cardiac thrombi, and plaque thrombi.

[0057] 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: include: Push shaft; The thrombectomy stent is a self-expanding stent and is fixedly connected to the distal end of the pushing shaft; as well as, The auxiliary mechanism comprises an auxiliary bracket and an expansion rod, wherein the auxiliary bracket is at least partially arranged inside the thrombus removal bracket; the proximal end of the auxiliary bracket is fixedly connected to the distal end of the pushing shaft and / or the proximal end of the thrombus removal bracket, and the distal end of the auxiliary bracket is fixedly connected to the distal end of the expansion rod and moves synchronously with the expansion rod; The auxiliary mechanism is configured such that when the expansion rod moves in the axial direction of the pushing shaft from the distal end to the proximal end, the auxiliary stent expands radially and applies a radially outward expansion force to the thrombus retrieval stent, so that the thrombus retrieval stent can perform a second expansion radially after self-expansion.

2. The thrombus removal device according to claim 1, characterized in that: The pushing shaft has a first inner cavity extending axially therethrough, and the expansion rod is partially disposed in the first inner cavity and is configured to be movable along the first inner cavity.

3. The thrombus removal device according to claim 2, characterized in that: The pushing shaft is a cylindrical helical spring structure.

4. The thrombus removal device according to claim 1, characterized in that: The expansion rod is arranged in parallel with the pushing shaft.

5. The thrombus removal device according to claim 1, characterized in that: The proximal end and the distal end of the thrombus removal stent are both closed ends.

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

7. The thrombus removal device according to claim 1, characterized in that: The thrombectomy stent is a braided stent or a cutting stent.

8. A medical device, characterized in that: The invention comprises a microcatheter and a thrombus removal device as described in any one of claims 1 to 7; the microcatheter has a second inner cavity extending axially therethrough, the thrombus removal device is used to be partially disposed in the second inner cavity and is configured to be movable along the second inner cavity.

Images