A suction catheter assembly

Abstract

The present invention provides an aspiration catheter assembly, which includes a catheter body and a support mechanism; wherein the catheter body includes a main section and an expansion section, the expansion section is connected to the distal end of the main section, and the expansion section is configured to be elastically deformed and radially expanded when subjected to a radially outward force; the support mechanism is used to be at least partially disposed inside the catheter body, and is configured to be able to move along the axial direction of the catheter body, and is used to apply the force to the expansion section. With such a configuration, the expansion section of the catheter body can have a smaller inner diameter during the delivery process, and the expansion section can be expanded to a larger inner diameter by the support mechanism before aspirating thrombus, thereby ensuring the suction effect and reducing the overall size of the catheter body during the delivery process, reducing the delivery resistance, and facilitating passage through tortuous blood vessels.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a suction catheter assembly. Background Art

[0002] Acute stroke is a common cerebrovascular disease, characterized by rapid onset, rapid development, severe symptoms, high disability and mortality rates, and is a critical and severe cerebrovascular disease. Stroke can be divided into two categories: hemorrhagic stroke and ischemic stroke, of which ischemic stroke accounts for as high as 70% to 80%. The pathogenesis of acute ischemic stroke is due to acute occlusion of cerebral arteries caused by thrombus or atherosclerotic plaques detached from the diseased blood vessel wall, which in turn causes a series of irreversible physiological and pathological reactions in the ischemic brain tissue, such as inflammatory response and apoptosis. If the blood perfusion of the cerebral vessels can be restored in a short period of time, the cell metabolism of the brain tissue can return to normal, avoiding further development into an infarct area.

[0003] At present, 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 3 hours after onset. However, the vast majority of patients have missed the treatment time window when they arrive at the hospital after onset, resulting in a serious decrease in the effect of intravenous thrombolysis and failure to effectively open the blocked blood vessels. Interventional thrombectomy is to introduce a thrombectomy device from the femoral artery, enter the brain blood vessels to remove the embolism, and restore blood flow. Interventional thrombectomy can extend the treatment time window for ischemic stroke to 8 hours after onset. Based on a series of clinical randomized controlled trials, relevant international organizations recommend that patients with large vessel occlusion within 6 hours should give priority to interventional thrombectomy.

[0004] Interventional thrombectomy can be roughly divided into two categories: stent retrievers and aspiration catheters. With the assistance of a micro-guidewire, a microcatheter embedded with a stent retriever is delivered into the blood vessel and passes through the thrombus or the gap between the thrombus and the blood vessel wall to reach the distal side of the thrombus. The stent retriever is then withdrawn to release the stent retriever, so that the thrombus can be trapped in the stent retriever and fixed. The stent retriever is then withdrawn into the microcatheter, and the stent retriever and microcatheter are then withdrawn to remove the thrombus out of the body. The stent retriever is in direct contact with the thrombus, and there is a mechanical squeezing and interlocking effect between the two. Therefore, secondary thrombus fragments will inevitably fall off during the operation. If the detached thrombus fragments are washed into the thinner blood vessels downstream by the blood flow, it will cause more difficult to handle vascular embolism. Unlike stent retrievers, aspiration catheters are based on negative pressure suction rather than mechanical squeezing force during thrombus removal. The specific process is that the catheter with a large inner diameter is pushed to the vicinity of the thrombus, and then the thrombus is aspirated by negative pressure. Low-hardness thrombi can be directly sucked into the catheter and expelled from the body, while high-hardness thrombi are adsorbed at the distal end of the catheter and removed from the body as the catheter is withdrawn. In order to improve the suction capacity of the suction catheter, the catheter usually has a larger inner diameter, which results in a larger overall size of the catheter, which is not conducive to the catheter passing through tortuous blood vessels, especially in the ophthalmic artery branch area, where larger catheters are easily stuck. Not only that, there is a gap between the traditional suction catheter and the blood vessel cavity. When the thrombus is sucked and adsorbed, the antegrade blood flow still impacts the thrombus, thereby reducing the suction effect. In addition, the high-hardness thrombus adsorbed at the distal end of the catheter may also be at risk of falling off due to fluctuations in negative pressure during the process of being removed from the body as the catheter is withdrawn. Summary of the invention

[0005] An object of the present invention is to provide a suction catheter assembly, aiming to solve at least one of the aforementioned problems.

[0006] To achieve the above object, the present invention provides a suction catheter assembly, comprising a catheter body and a support mechanism; wherein:

[0007] The catheter body comprises a main body section and an expansion section, wherein the expansion section is connected to the distal end of the main body section, and the expansion section is configured to generate elastic deformation and expand radially when subjected to a radially outward force;

[0008] The support mechanism is used to be at least partially disposed inside the catheter body, and is configured to be movable along the axial direction of the catheter body, and is used to apply the force to the expansion section.

[0009] Optionally, the support mechanism and the catheter body are split structures.

[0010] Optionally, the supporting mechanism comprises a pushing portion and a supporting portion, and the supporting portion is connected to the distal end of the pushing portion;

[0011] The support portion is configured such that when the support portion is located inside the main body section, the support portion is in a compressed state, and when the support portion is located inside the expansion section and expands into a circular ring shape and is coaxially arranged with the expansion section, the support portion applies the force to the expansion section.

[0012] Optionally, the pushing portion includes at least one pushing rod, a distal end of the pushing rod is fixedly connected to the supporting portion, and when the supporting portion is in a natural state, the axes of the pushing rod and the supporting portion are parallel to each other.

[0013] Optionally, the pushing portion includes two pushing rods, which are symmetrically arranged in the circumferential direction of the support portion; the pushing rod includes a rod body and a connecting ring connected to the distal end of the rod body, the connecting ring is sleeved on the support portion, and enables the pushing rod to rotate relative to the support portion.

[0014] Optionally, a first developing element is provided at the distal end of the expansion section, and a second developing element is provided on the supporting mechanism, and the second developing element and the first developing element are used to indicate the position of the distal end of the supporting mechanism within the catheter body.

[0015] Optionally, a limiting portion is provided on the inner wall of the distal end of the expansion section, and the limiting portion is used to limit the distal end of the supporting mechanism inside the catheter body.

[0016] Optionally, in a natural state, the cross-section of the expansion segment gradually decreases from the proximal end to the distal end.

[0017] Optionally, the catheter body includes a first tube body and a second tube body, the second tube body is arranged on the inner side of the first tube body, and a distal end segment of the second tube body extends from the distal end of the first tube body and constitutes the expansion segment.

[0018] Optionally, the catheter body further includes a lubricating layer, which is disposed on the inner surface of the second tube body, and a distal end surface of the lubricating layer is flush with a distal end surface of the first tube body.

[0019] Compared with the prior art, the suction catheter assembly of the present invention has the following advantages:

[0020] The aforementioned suction catheter assembly includes a catheter body and a support mechanism; wherein the catheter body includes a main body section and an expansion section, the expansion section is connected to the distal end of the main body section, and the expansion section is configured to be elastically deformed and radially expanded when subjected to a radially outward force; the support mechanism is used to be at least partially arranged on the inner wall of the catheter body, and is configured to be able to move along the axial direction of the catheter body, and is used to apply the force to the expansion section. In this way, the expansion section of the catheter body can have a smaller inner diameter during the delivery process, and the expansion section can be expanded to a larger inner diameter by the support mechanism before the thrombus is aspirated, that is, the suction effect is ensured, and the overall size of the catheter body during the delivery process is reduced, the delivery resistance is reduced, and it is easy to pass through the tortuous blood vessels. In addition, by reasonably selecting the size of the support mechanism, when the force is applied to the expansion section to expand the expansion section, the outer diameter of the expansion section can be increased to match the inner diameter of the blood vessel, thereby temporarily blocking the blood flow during the suction process, avoiding the blood flow impacting the thrombus and reducing the suction efficiency.

[0021] Furthermore, the support mechanism and the catheter body are split structures, so that during the operation, the operator can first deliver the catheter body and then deliver the support mechanism. In this way, during the process of delivering the catheter body, the catheter body is not affected by the support mechanism, has better flexibility, and is easier to pass through tortuous blood vessels.

[0022] Furthermore, in a natural state, the cross-section of the expansion section gradually decreases from the proximal to the distal direction. That is, after the catheter body absorbs the thrombus into the expansion section, it can release the force applied to the expansion section by the supporting mechanism, and make the expansion section radially retract and tend to return to the natural state, so that the expansion section exerts actual radial squeezing force on the thrombus to keep the thrombus in the expansion section and reduce the possibility of the thrombus falling off. 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 suction catheter assembly provided according to an embodiment of the present invention, in which the expansion section is in a natural state;

[0025] Figure 2 is a schematic structural diagram of a suction catheter assembly provided according to an embodiment of the present invention, in which the expansion section expands radially;

[0026] Figures 3a to 3d It is a schematic diagram of the use process of the suction catheter assembly provided according to one embodiment of the present invention.

[0027] Figure 4is a schematic structural diagram of a support mechanism of a suction catheter assembly provided according to another embodiment of the present invention, in which the support portion is in a compressed state;

[0028] Figure 5 is a schematic structural diagram of a support mechanism of a suction catheter assembly according to another embodiment of the present invention, in which the support portion is expanded to form a circular ring;

[0029] Figure 6 yes Figure 4 A is an enlarged schematic diagram;

[0030] Figure 7a and Figure 7b It is a schematic diagram of the use status of the suction catheter assembly provided according to another embodiment of the present invention.

[0031] [Description of reference numerals is as follows]:

[0032] 100-catheter body, 110-main tube section, 120-expansion section;

[0033] 200 - supporting mechanism, 210 - supporting part, 220 - pushing rod, 220a - first pushing rod, 220b - second pushing rod, 221 - rod body, 222 - connecting ring, 230 - clamp;

[0034] 1- Micro guide wire;

[0035] 10-Thrombosis. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The core idea of ​​the present invention is to provide a suction catheter assembly to solve the problem that the suction performance is improved by increasing the inner diameter of the suction catheter in the prior art, but the bending performance of the suction catheter is reduced and it is not conducive to pushing. The suction catheter assembly provided by the present invention includes a catheter body and a support mechanism. Among them, the catheter body includes a main section and an expansion section, the expansion section is connected to the distal end of the main section, and the expansion section is configured to be elastically deformed and expand radially outward when subjected to a radially outward force. The support mechanism is used to be at least partially arranged inside the catheter body, and is configured to be able to move along the axial direction of the catheter body, and is used to apply the force to the expansion section. When in use, the suction catheter assembly has two processes, one is the conveying process, and the other is the suction process. When the suction catheter assembly is in the conveying process, the expansion section is in a natural state, with a smaller inner diameter and a smaller outer diameter, which is conducive to the catheter body passing through a tortuous blood vessel and can improve its pushing performance. When the suction catheter assembly is in the suction process, the supporting mechanism applies the force to the expansion segment and makes the expansion segment have a larger inner diameter and a larger outer diameter, which is beneficial to improving the suction force, and when the outer diameter of the expansion segment matches the inner diameter of the blood vessel, it can also temporarily block the blood flow to prevent the blood flow from impacting the thrombus and weakening the suction effect.

[0040] 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 accompanying drawings are all in a very simplified form and are not in 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 accompanying drawings represent the same or similar components.

[0041] Figure 1 and Figure 2 FIG. 1 is a schematic diagram showing the structure of a suction catheter assembly provided by an embodiment of the present invention. Figure 1 and Figure 2 , the suction catheter assembly includes a catheter body 100 and a support mechanism 200. The catheter body 100 includes a main section 110 and an expansion section 120, wherein the expansion section 120 is connected to the distal end of the main section 110, and the expansion section 120 is configured to be elastically deformed and radially expanded when subjected to a radially outward force. Here, the elastic deformation refers to a recoverable deformation, that is, when the force is canceled, the expansion section 120 can recover the deformation. The support mechanism 200 is used to be at least partially disposed inside the catheter body 100, and is configured to be able to move along the axial direction of the catheter body 100, and is used to apply the force to the expansion section 120 so that the expansion section 120 expands radially.

[0042] In the embodiment of the present invention, the expansion section 120 can radially expand to have a larger inner diameter and a larger outer diameter after being subjected to the force from the support mechanism 200. That is, when the expansion section 120 is not subjected to the force, it has a smaller inner diameter and a smaller outer diameter. In this way, the thrombus 10 (such as thrombus 10) in the blood vessel can be sucked out by the suction catheter assembly. Figures 3a to 3d ), during the pushing process, the support mechanism 200 may first be made not to apply the force to the expansion section 120 to improve the pushing performance of the catheter body 100 so that it can smoothly pass through the tortuous blood vessels. When the distal end of the catheter body 100 reaches the vicinity of the thrombus 10, the support mechanism 200 is used to apply the force to the expansion section 120 to increase the inner diameter of the expansion section 120, thereby increasing the suction force and improving the suction effect on the thrombus 10. In addition, the expansion section 120 may also be expanded to an outer diameter that matches the inner diameter of the blood vessel, so that the expansion section 120 temporarily closes the upstream blood vessel of the thrombus 10 during the suction process to block the blood flow, prevent blood from impacting the thrombus 10, and reduce the suction effect.

[0043] Furthermore, when the expansion section 120 is in a natural state, the expansion section 120 is a conical structure whose cross section gradually decreases from the proximal end to the distal end. The advantage of such a configuration is that when the thrombus 10 is adsorbed into the expansion section 120, the force applied by the support mechanism 200 to the expansion section 120 can be canceled, so that the expansion section 120 contracts radially and tends to return to the conical structure, thereby applying a radial squeezing force to the thrombus 10 and clamping the thrombus 10, thereby reducing the possibility of the thrombus 10 falling off due to negative pressure fluctuations during removal from the body. The natural state described here refers to the state of the expansion section 120 when it is not subjected to the force provided by the support mechanism 200.

[0044] The expansion section 120 is made of elastic material, and the available materials include but are not limited to polyetheramide block copolymer, styrene, thermoplastic polyolefin elastomer, polyester elastomer, thermoplastic polyurethane elastomer, polyamide, rubber, etc. The main section 110 can be a conventional pipe, which can be a metal pipe or a polymer pipe, a single-layer pipe or a multi-layer pipe, a single-lumen pipe or a multi-lumen pipe (for example, including two lumens, one of which is used as a negative pressure channel and the other is used as a guide wire channel), which is not limited in the embodiment of the present invention. The main section 110 and the expansion section 120 can be separately formed and then connected together by any suitable method such as heat shrinkage, crimping, suturing, etc., or the expansion section 120 can also be integrally formed with the main section 110.

[0045] In an exemplary embodiment, the catheter body 100 includes a first tube body and a second tube body, the material of the first tube body is a polyetheramide block copolymer, and the material of the second tube body is a thermoplastic polyolefin elastomer. The first tube body and the second tube body are extruded and formed at one time using an extruder, and the second tube body is arranged on the inner side of the first tube body, and the distal segment of the second tube body extends from the distal end of the first tube body and then undergoes heat processing to form the tapered expansion section 120. Furthermore, the catheter 100 also includes a lubricating layer, which is arranged on the inner surface of the second tube body, and the distal end face of the lubricating layer is flush with the distal end face of the first tube body. The material of the lubricating layer can be polytetrafluoroethylene, and the purpose of providing the lubricating layer is to provide a lubricating layer between the support mechanism 200 and the micro guidewire 1 (such as Figure 3a The lubricating layer can also be extruded together with the first tube body and the second tube body. In this embodiment, the axial length of the expansion section 120 can be about 1 cm.

[0046] Preferably, the support mechanism 200 and the catheter body 100 are of a split structure. In this way, the catheter body 100 and the support mechanism 200 can be transported separately, that is, during use, the catheter body 100 is transported first, and then the support mechanism 200 is transported. Compared with the integral transport of the two, the advantage of this embodiment is that during the process of transporting the catheter body 100 alone, the catheter body 100 can maintain good flexibility and is easier to pass through tortuous blood vessels.

[0047] Please continue to refer to Figure 1 and Figure 2 The support mechanism 200 includes a push portion and a support portion 210, wherein the support portion 210 is connected to the distal end of the push portion, and the push portion is used to move along the axial direction of the catheter body 100 under the action of an external force, and drive the support portion 210 to move. The support portion 210 is configured such that when the support portion 210 is located inside the main body section 110, the support portion 210 is in a compressed state, and when the support portion 210 is located inside the expansion section 120 and expands into a circular ring and is coaxially arranged with the expansion section 120, the support portion 210 applies the force to the expansion section 120 to expand the expansion section 120 in the radial direction.

[0048] The support portion 210 is preferably a self-expanding structural member, and when it is in a natural state, it is in a circular ring shape. The self-expanding structural member refers to a structural member made of a highly elastic material and can be pre-shaped into a predetermined shape (the predetermined shape of the support portion 210 is a circular ring shape). When the self-expanding structural member is subjected to external pressure or tension, it deforms. When the external pressure or tension is cancelled, it recovers the deformation under its own elasticity. The material of the self-expanding structural member can be a shape memory alloy, such as a nitinol alloy. In one embodiment, the push portion includes at least one push rod 220, the distal end of which is fixedly connected to the support portion 210, and when the support mechanism 200 is in a natural state, the push rod 220 and the axis of the support portion 210 are parallel to each other. Of course, when the support portion 210 is in a compressed state, the push rod 220 can also be parallel to the support portion 210. The push rod 220 delivers the compressed support portion 210 into the expansion section 120 along the axial direction of the catheter body 100, and then the support portion 210 self-expands and returns to a circular ring shape to apply the force to the expansion section 120. It can be understood that the elastic force generated by the expansion section 120 when subjected to the force should be smaller than the self-expansion force of the support portion 210.

[0049] Next, the aspiration catheter assembly of this embodiment is tested using a blood vessel model.

[0050] Test preparation: Take an experimental rabbit and collect 5 ml of blood from its ear vein for later use. Then open the midbrain segment of the intracranial vascular model. Mix the collected blood with thrombin and immediately inject it into the vascular segment. Wait for 3 to 5 minutes for the blood to coagulate and form a thrombus. Then close the vascular model.

[0051] test:

[0052] First, the expansion section 120 of the catheter body 100 is delivered along the micro-guidewire 1 to the position where the thrombus 10 is formed in the blood vessel model (such as Figure 3a shown).

[0053] Then, the micro guide wire 1 is withdrawn from the body.

[0054] Afterwards, the support portion 210 is introduced into the interior of the catheter body 100, and the support portion 210 is pushed along the axial direction of the main tube body 110 by the push rod 220 (eg, Figure 3b shown).

[0055] When the support portion 210 enters the expansion section 120, the support portion 210 expands into a circular ring shape in the expansion section 120, and the expansion section 120 expands radially. The support portion 210 is pushed forward until the support portion reaches the distal end of the expansion section 120, at which time the expansion section 120 expands into a funnel-shaped structure with a cross section gradually increasing from the proximal end to the distal end (such as Figure 3c shown).

[0056] Subsequently, a negative pressure device is connected to the proximal end of the main tube 110 , and the thrombus 10 is started to be sucked so that the thrombus 10 enters the interior of the expansion section 120 .

[0057] Next, the support mechanism 200 is withdrawn, so that the expansion section 120 contracts radially and clamps the thrombus 10 (eg, Figure 3d As shown in FIG. 1 , it is understandable that when the support mechanism 200 is withdrawn, the support portion 210 may be compressed under the pressure of the tube wall of the main tube 110 .

[0058] Finally, the catheter body 100 entraining the thrombus 10 is withdrawn.

[0059] In this embodiment, the distal end of the expansion section 120 is also provided with a first developing element, and the support mechanism 200 may be provided with a second developing element. The relative position of the second developing element and the first developing element is used to determine the position of the support portion 210 in the catheter body 100, so as to avoid pushing the support portion 210 to the outside of the expansion section 120. Specifically, the distal end of the push rod 220 or the support portion 210 is provided with the second developing element. In the axial direction of the catheter body 100, when the second developing element and the first developing element are aligned, it indicates that the support portion 210 has reached the distal end of the expansion section 120. Alternatively, a limiting portion is provided on the inner wall of the distal end of the expansion section 120, and the limiting portion is, for example, a ring-shaped limiting protrusion. When the support portion 210 abuts against the limiting portion, it indicates that the support portion 210 has reached the distal end of the expansion section 120.

[0060] In addition, the suction catheter assembly also includes a connecting seat (not shown in the figure), and a plurality of interfaces, for example, two interfaces, are provided on the first connecting seat, one of which is used for the micro guide wire and the supporting mechanism to pass through, and the other interface is used to connect the negative pressure device.

[0061] In another embodiment, Figures 4 to 6 As shown, the push portion includes two push rods 220, and the two push rods 220 are symmetrically arranged in the circumferential direction of the support portion 210. The push rod 220 includes a rod body 221 and a connecting ring 222 connected to the distal end of the rod body 221, and the connecting ring 222 is sleeved on the support portion 210 and enables the push rod 220 to rotate relative to the support portion 210. It should be noted that a positioning mechanism is provided on the support portion 210, and the positioning mechanism is used to position the two push rods 220 at predetermined positions of the support portion 210 and maintain a symmetrical arrangement.

[0062] In this embodiment, the use process of the suction catheter assembly is as follows:

[0063] First, the expansion section of the catheter body 100 is delivered to the region where the thrombus 10 is formed in the blood vessel (such as Figure 3a shown).

[0064] Then, the support portion 210 in a compressed state is introduced into the proximal end of the catheter body 100, so that the two push rods 220 remain relatively stationary in the axial direction, for example, the two push rods 220 are clamped by a clamp 230 so that the two remain relatively stationary in the axial direction, and the two push rods 220 are used to push the support portion 220 together along the axial direction of the catheter body 100. In this process, the push rods 220 extend along the axial direction of the catheter body 100, and the distal ends of the two push rods 220 are staggered from each other and are not perpendicular to the support portion 210. For the convenience of description, the two push rods 220 are respectively referred to as the first push rod 220a and the second push rod 220b, wherein the distal end of the first push rod 220 is located at the distal end side of the second push rod 220b. The first push rod 220a applies a first force directed to the distal end to the support portion 210, and the second push rod 220b applies a second force directed to the proximal end to the support portion 210, so that the positioning portion 210 is stretched into an elliptical structure or a folded linear structure and is in a compressed state (such as Figure 7a shown).

[0065] When the side of the support portion 210 close to the distal end of the catheter body reaches the distal end of the expanded section 120, the first push rod 220a is kept fixed, the clamp 230 is removed, and the second push rod 220b is continued to be controlled to move toward the distal end. At this time, the second push rod 220b rotates relative to the support portion 210, and the first push rod 220a also rotates relative to the support portion 210 until the first push rod 220a and the second push rod 220b are perpendicular to the support portion 210. At the same time, the support portion 210 gradually expands to restore to a circular ring shape, and the expanded section 120 expands radially (such as Figure 7b shown).

[0066] Afterwards, a negative pressure device is connected to the proximal end of the main body 110, and the thrombus 10 is sucked out to allow the thrombus 10 to enter the inside of the expansion section 120. During this process, the two push rods 220 can be clamped by the clamp 230 to keep the two push rods 220 relatively still, and the push rods 220 can also be fixed by other external mechanisms.

[0067] Next, the support mechanism 200 is withdrawn. When withdrawing the support mechanism 200, the user may first withdraw one of the push rods 220 to switch the support portion 210 to a compressed state, and then withdraw the support mechanism 200 as a whole.

[0068] Finally, the catheter body 100 carrying the thrombus is withdrawn.

[0069] It is understandable that in this embodiment, a first developing element may be provided at the distal end of the expansion section 120, and a second developing element may be provided at the distal end of the first pushing rod 220a, so as to determine whether the support portion 210 has reached the distal end of the expansion section 120, and to prevent the support portion 210 from extending out of the expansion section 120. Alternatively, a limiting portion may be provided on the inner wall of the distal end of the expansion section 120.

[0070] 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 suction catheter assembly, characterized in that: It comprises a catheter body and a supporting mechanism; wherein, The catheter body comprises a main body section and an expansion section, wherein the expansion section is connected to the distal end of the main body section, and the expansion section is configured to generate elastic deformation and expand radially when subjected to a radially outward force; The support mechanism is used to be partially arranged inside the catheter body, and includes a pushing part and a supporting part, the pushing part includes two pushing rods, and the two pushing rods are symmetrically arranged in the circumferential direction of the supporting part; the pushing rod includes a rod body and a connecting ring connected to the distal end of the rod body, the connecting ring is sleeved on the supporting part, and enables the pushing rod to rotate relative to the supporting part; when the supporting part is located inside the main body section, the distal ends of the two pushing rods are staggered from each other in the axial direction of the catheter body, so that the supporting part is stretched into an elliptical structure or a folded straight line configuration so that the supporting part is in a compressed state; when the supporting part is located inside the expansion section and expands into a circular ring shape, and is coaxially arranged with the expansion section, the two pushing rods are perpendicular to the supporting part, and the supporting part applies the force to the expansion section.

2. The suction catheter assembly according to claim 1, characterized in that The supporting mechanism and the catheter body are split structures.

3. The suction catheter assembly according to claim 1 or 2, characterized in that: A first developing element is disposed at the distal end of the expansion section, and a second developing element is disposed on the support mechanism. The second developing element and the first developing element are used to indicate the position of the distal end of the support mechanism within the catheter body.

4. The suction catheter assembly according to claim 1 or 2, characterized in that: A limiting portion is provided on the inner wall of the distal end of the expansion section, and the limiting portion is used to limit the distal end of the supporting mechanism inside the catheter body.

5. The suction catheter assembly according to claim 1 or 2, characterized in that: In a natural state, the cross section of the expansion section gradually decreases from the proximal end to the distal end.

6. The suction catheter assembly according to claim 1 or 2, characterized in that: The catheter body comprises a first tube body and a second tube body, wherein the second tube body is arranged inside the first tube body, and a distal end section of the second tube body extends from the distal end of the first tube body and constitutes the expansion section.

7. The suction catheter assembly according to claim 6, characterized in that The catheter body further comprises a lubricating layer, which is disposed on the inner surface of the second tube body, and a distal end surface of the lubricating layer is flush with a distal end surface of the first tube body.

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