microcatheter

Abstract

The utility model is suitable for medical instrument technical field, disclose a kind of microcatheter, including pipe body and basket, pipe body includes outer tube and inner tube, inner tube from its distal end to its proximal end includes the head section, basket section and inlay section connected in order, inlay section is arranged in the inside of outer tube, basket section and head section are exposed from outer tube at the distal end of outer tube, inner tube is provided with infusion channel, and embolization agent or chemotherapy medicine is delivered;Basket is sleeved on the outside of basket section, the distal end of basket is connected to the distal end of basket section, and the proximal end of basket is connected to the distal end of outer tube;Inner tube can be moved relative to outer tube, to make basket can be inflated or gathered. The microcatheter of the embodiment of the application can not completely block blood, make blood flow pass through the mesh hole of basket smoothly, so that embolization agent or medicine enters tumor under the boosting action of blood flow, effectively prevent embolization agent or medicine reflux.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a microcatheter for interventional surgery. Background Technology

[0002] Interventional procedures for tumors include transarterial chemoembolization (TACE) and hepatic artery infusion chemotherapy (HAIC).

[0003] Currently, microcatheters or balloon microcatheters can be used to deliver embolic agents or chemotherapy drugs in hepatic artery chemoembolization and hepatic artery perfusion chemotherapy. Among them, balloon microcatheters are widely used in hepatic artery chemoembolization and hepatic artery perfusion chemotherapy because the balloon in the balloon can prevent reflux of embolic agents or chemotherapy drugs and avoid ectopic embolization.

[0004] However, during hepatic artery chemoembolization, the balloon in the microcatheter completely blocks blood flow, making it difficult for the embolic agent or chemotherapy drug to enter the tumor due to the lack of blood pressure-assisted propulsion. In addition, during hepatic artery perfusion chemotherapy, the perfusion time is long, up to 48 hours. The balloon in the microcatheter completely blocks blood flow for a long time, which can easily cause thrombus formation and lead to unnecessary complications.

[0005] Therefore, how to prevent the backflow of embolic agents or drugs while ensuring that blood flow is not completely blocked has become an urgent problem to be solved. Utility Model Content

[0006] The purpose of this invention is to provide a microcatheter that can prevent the backflow of embolic agents or drugs while ensuring that blood flow is not completely blocked.

[0007] To achieve the above objectives, the solution provided by this utility model is as follows:

[0008] A microcatheter, comprising:

[0009] The tube body includes an outer tube and an inner tube. The inner tube includes a head section, a basket section and an embedded section connected in sequence from its distal end to its proximal end. The embedded section passes through the interior of the outer tube. The basket section and the head section protrude from the distal end of the outer tube. The inner tube is provided with an infusion channel.

[0010] A net basket is fitted over the net basket section, with the far end of the net basket connected to the far end of the net basket section and the proximal end of the net basket connected to the far end of the outer tube.

[0011] The inner tube is movable relative to the outer tube, so that the basket can expand or contract.

[0012] Furthermore, the basket expands into a spherical shape with mesh openings.

[0013] Furthermore, the basket includes multiple first metal wires and multiple second metal wires, the multiple first metal wires are arranged along a first direction, the multiple second metal wires are arranged along a second direction, and the multiple first metal wires and the multiple second metal wires are interwoven to form the basket, wherein the first direction and the second direction intersect.

[0014] Furthermore, the far end and the near end of the net basket are provided with imaging markers; or,

[0015] The basket is designed as a fully visible structure.

[0016] Furthermore, the basket section is provided with a plurality of first development indicators along the axial direction, and the distal end of the outer tube is provided with a second development indicator.

[0017] Furthermore, the plurality of first imaging targets are distributed at equal intervals; and / or,

[0018] One of the plurality of first development indicators is disposed at the distal end of the net basket segment, one of the plurality of first development indicators is disposed at the proximal end of the net basket segment, and the remaining first development indicators are disposed between the distal end and the proximal end of the net basket segment.

[0019] Furthermore, at least one of the following conditions must be met:

[0020] The inner circumferential surface of the outer tube is provided with a first lubricating layer;

[0021] The outer peripheral surface of the embedded segment is provided with a second lubricating layer;

[0022] A gap is formed between the inner circumferential surface of the outer tube and the outer circumferential surface of the embedded section.

[0023] Furthermore, the microcatheter also includes a connector, which is connected to the proximal end of the inner tube, and the connector is provided with an infusion port communicating with the infusion channel.

[0024] Furthermore, the microcatheter also includes a locking device connected to the outer tube. The locking device has a locked state and an unlocked state. When the locking device is in the locked state, it restricts the movement of the inner tube relative to the outer tube. When the locking device is in the unlocked state, the inner tube and the outer tube can move relative to each other.

[0025] Furthermore, the locking device is connected to the proximal end of the outer tube, and the microcatheter also includes a strain relief sleeve, which is sleeved at the connection between the outer tube and the locking device, as well as a portion of the outer tube.

[0026] The microcatheter provided by this utility model has the following beneficial effects:

[0027] In this embodiment, the microcatheter features a basket that fits over the basket segment of the inner tube. The basket's distal and proximal ends are connected to the distal ends of the basket segment and the outer tube, respectively. The inner tube can move relative to the outer tube, allowing it to move closer to or further away from the surgeon. This reduces or widens the distance between the distal and proximal ends of the basket, enabling it to expand or contract to adhere to the outer circumferential surface of the inner tube. When expanded, the basket conforms to the inner circumferential surface of the blood vessel, providing fixation and preventing displacement of the inner tube's tip, thus preventing displacement of the microcatheter's tip. Furthermore, the expanded basket does not completely block blood flow, allowing blood to pass smoothly through the mesh. This facilitates the entry of embolic agents or drugs into the tumor with the aid of blood flow, reducing the difficulty of tumor entry and preventing reflux. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the microcatheter provided in this embodiment of the present invention when the basket is in a retracted state;

[0030] Figure 2 yes Figure 1 A magnified view of a portion of point a;

[0031] Figure 3 This is a schematic diagram of the microcatheter provided in this embodiment of the present invention when the basket is in an expanded state;

[0032] Figure 4 yes Figure 3 A schematic cross-sectional view of the structure at point b in the middle;

[0033] Figure 5 This is a partial structural diagram of the microcatheter provided in this embodiment of the present invention in its working state;

[0034] Figure 6This is a partial structural schematic diagram of the microcatheter provided in this embodiment of the present invention when the basket is in an expanded state;

[0035] Figure 7 This is a cross-sectional view of the tube body of the microcatheter provided in this embodiment of the utility model.

[0036] Explanation of icon numbers:

[0037] 100. Microcatheter; 200. Blood vessel; 300. Solid embolic agent;

[0038] 10. Tube body; 11. Outer tube; 12. Inner tube; 121. Head section; 122. Basket section; 123. Embedded section; 124. Infusion channel;

[0039] 20. Basket; 21. Mesh; 22. First metal wire; 23. Second metal wire;

[0040] 30. Developing indicator; 40. First developing indicator; 50. Second developing indicator; 60. Gap; 70. Connecting seat; 80. Locking device; 90. Strain release sleeve. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0042] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0043] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0044] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0045] Currently, among interventional surgeries for tumors, transarterial chemoembolization (TACE) is a minimally invasive interventional treatment for liver tumors. It involves selectively or superselectively inserting a catheter into the target artery supplying the tumor and injecting an appropriate amount of embolic agent at a suitable rate to occlude the target artery, causing ischemic necrosis of the tumor tissue. Hepatic artery infusion chemotherapy (HAIC) is a local chemotherapy method for liver tumors. It involves selectively or superselectively inserting a catheter into the target artery supplying the tumor and continuously infusing chemotherapy drugs at an appropriate rate to increase the drug concentration in the tumor tissue, thereby treating hepatocellular carcinoma and reducing systemic toxicity.

[0046] In some related techniques, during hepatic artery chemoembolization (HACE) and hepatic artery infusion chemotherapy, balloon microcatheters are used to deliver embolic agents or chemotherapy drugs. The balloon in the microcatheter prevents the reflux of the embolic agent or chemotherapy drug, thus causing ectopic embolization. However, during HACE, the balloon in the microcatheter completely blocks blood flow, resulting in a lack of propellant flow for the embolic agent or chemotherapy drug, making it difficult for them to reach the tumor. During hepatic artery infusion chemotherapy, due to the long infusion time (up to 48 hours), the complete blockage of blood flow by the balloon in the microcatheter can easily lead to thrombosis and unnecessary complications.

[0047] In some related techniques, conventional microcatheters are used to deliver chemotherapy drugs during hepatic artery infusion chemotherapy, allowing for normal blood flow. However, during hepatic artery infusion chemotherapy, due to the prolonged infusion time, patients may move to varying degrees. The tip of a conventional microcatheter is prone to displacement or even detachment from the tumor-feeding artery during the infusion procedure. Once the microcatheter detaches from the tumor-feeding artery, the chemotherapy drugs cannot flow to the tumor-feeding artery, rendering them ineffective and potentially damaging healthy tissue. Re-insertion of the catheter is also very troublesome.

[0048] Therefore, as Figure 1 , Figure 4 and Figure 5As shown, this embodiment of the application provides a microcatheter 100. By setting the inner tube 12 to move relative to the outer tube 11, a basket 20 is also placed outside the basket segment 122 of the inner tube 12, and the distal end of the basket 20 is connected to the distal end of the basket segment 122, while the proximal end of the basket 20 is connected to the distal end of the outer tube 11. This reduces the distance between the distal end and the proximal end of the basket 20 when the inner tube 12 moves relative to the outer tube 11, allowing the basket 20 to expand and open. Moreover, the expanded basket 20 can not only conform to the inner circumferential surface of the blood vessel 200, but also partially block the blood flow, allowing blood to flow smoothly through the mesh 21 of the basket 20. Thus, the embolic agent or drug enters the tumor under the impetus of the blood flow, effectively preventing the embolic agent or drug from flowing back.

[0049] The following is in conjunction with Appendix 1 to Figure 7 The following describes some embodiments of this application in detail. Unless otherwise specified, the embodiments and features described below can be combined with each other.

[0050] It should be noted that in the following embodiments, the proximal end can be understood as the end closer to the surgeon, and the distal end can be understood as the end farther away from the surgeon.

[0051] like Figure 1 , Figure 4 and Figure 5 As shown, the microcatheter 100 provided in this embodiment includes a tube body 10 and a basket 20. The tube body 10 includes an outer tube 11 and an inner tube 12. The inner tube 12 includes a head segment 121, a basket segment 122, and an embedded segment 123 connected in sequence from its distal end to its proximal end. The embedded segment 123 passes through the interior of the outer tube 11. The basket segment 122 and the head segment 121 protrude from the distal end of the outer tube 11. The inner tube 12 is provided with an infusion channel 124 for delivering embolic agents or chemotherapy drugs. The basket 20 is sleeved on the outside of the basket segment 122. The distal end of the basket 20 is connected to the distal end of the basket segment 122, and the proximal end of the basket 20 is connected to the distal end of the outer tube 11. The inner tube 12 is movable relative to the outer tube 11 so that the basket 20 can expand or contract.

[0052] In this embodiment, the microcatheter 100 includes a basket 20 fitted over the basket segment 122 of the inner tube 12. The basket 20 has its distal and proximal ends connected to the distal ends of the basket segment 122 and the outer tube 11, respectively. The inner tube 12 moves relative to the outer tube 11. Under external force, the inner tube 12 moves relative to the outer tube 11 towards or away from the surgeon, reducing or widening the distance between the distal and proximal ends of the basket 20. This allows the basket 20 to expand and open or retract to adhere to the outer circumference of the inner tube 12. Therefore, when the basket 20 retracts... The folded basket 20 does not impede the advancement of the microcatheter 100, allowing it to be delivered to the lesion site via a guide device. When inflated, the basket 20 conforms to the inner circumferential surface of the vessel 200, providing fixation and preventing displacement of the tip 121 of the inner tube 12, thereby preventing displacement of the tip of the microcatheter 100. Furthermore, the inflated basket 20 does not completely block blood flow, allowing blood to pass smoothly through the mesh 21 of the basket 20. This allows the embolic agent (such as a solid embolic agent 300) or medication to be propelled along the direction of blood flow (e.g., ...). Figure 5 (As shown in the y direction) enters the tumor, reducing the difficulty for embolizing agents or drugs to enter the tumor, and can also prevent the backflow of embolizing agents or drugs.

[0053] In practical applications, the microcatheter 100 of this embodiment is used in transarterial chemoembolization (TACE). The expanded basket 20 allows blood flow to pass through the mesh 21 of the basket 20, facilitating the smooth delivery of the solid embolic agent 300 with the assistance of blood flow. This reduces the difficulty of the solid embolic agent 300 entering the tumor and prevents backflow of the solid embolic agent 300. In hepatic artery infusion chemotherapy (HAIC), the expanded basket 20 conforms to the inner circumferential surface of the blood vessel 200, fixing the position of the tip 121 and preventing displacement of the tip of the microcatheter 100. This allows the infused drug to flow to the tumor-feeding artery for a long period, while blood flow can still pass through the expanded basket 20. Moreover, compared to the method of delivering chemotherapy drugs using a conventional microcatheter 100, this method effectively prevents displacement of the tip of the microcatheter 100 or even detachment from the tumor-feeding artery, avoids damage to normal tissue, and reduces or even eliminates the need for re-insertion.

[0054] It should be noted that the tip of the microcatheter 100 can be understood as the head segment 121 of the inner tube 12, which can be inserted into the tumor-supplying target artery of the patient.

[0055] like Figure 1 and Figure 3 As shown, for example, the inner tube 12 and the outer tube 11 can be arranged coaxially, which helps the basket 20 to expand radially along the inner tube 12 to form a spherical shape.

[0056] like Figure 2 , Figure 4 and Figure 5 As shown, in one application embodiment, when placing the microcatheter 100, after the microcatheter 100 is delivered to the tumor feeding artery along the guidewire, with the outer tube 11 stationary, the inner tube 12 is pulled back to move the inner tube 12 toward the surgeon, thereby shortening the distance between the distal end and the proximal end of the basket 20, causing the basket 20 to expand and adhere to the inner wall of the blood vessel 200. Then, the guidewire is withdrawn, and embolic agents or chemotherapy drugs are delivered from the guidewire / infusion lumen (infusion channel 124).

[0057] like Figure 5 and Figure 6 As shown, in some embodiments, the basket 20 expands into a spherical shape with mesh 21, so that the spherical surface of the basket 20 fits against the inner peripheral wall of the blood vessel 200 in the radial direction of the basket segment 122, thereby increasing the adhesion between the basket 20 and the inner peripheral wall of the blood vessel 200.

[0058] like Figure 5 and Figure 6 As shown, in some embodiments, the basket 20 includes multiple first metal wires 22 and multiple second metal wires 23. The multiple first metal wires 22 are arranged along a first direction, and the multiple second metal wires 23 are arranged along a second direction. The first direction and the second direction intersect, and the multiple first metal wires 22 and multiple second metal wires 23 are interwoven to form the basket 20.

[0059] Understandably, the basket 20 is woven from multiple first metal wires 22 and multiple second metal wires 23, enabling the basket 20 to switch between an expanded and a contracted state. Furthermore, the metal wires (first metal wires 22 and second metal wires 23) can withstand external forces without easily deforming or breaking. Therefore, the expanded basket 20 can prevent the embolic agent or medication from moving towards the operator, thereby effectively preventing reflux of the embolic agent or medication. For example, the first metal wires 22 and second metal wires 23 can be made of titanium-nickel alloy.

[0060] For example, the basket 20 can expand radially along the basket segment 122 to form a tennis ball shape to fit the inner peripheral wall of the blood vessel 200, which can both allow blood flow and effectively prevent the backflow of embolic agents and drugs.

[0061] like Figure 2 As shown, in some embodiments, the distal end and proximal end of the basket 20 are provided with imaging markers 30, so that under X-ray irradiation, by observing the distance between the imaging markers 30 at the distal end and the imaging markers 30 at the proximal end of the basket 20, it can be determined whether the basket 20 is in an expanded state or a contracted state, thereby ensuring that the basket 20 can be seen within the patient's blood vessels 200 when it expands and opens.

[0062] like Figure 3As shown, in some other embodiments, the basket 20 is configured as a fully developable structure, realizing the fully developable design of the basket 20, so that the shape and position of the basket 20 can be clearly displayed under X-ray irradiation, thereby improving the developing effect of the basket 20.

[0063] like Figure 6 As shown, for example, a developing material is coated on the metal wires (first metal wire 22, second metal wire 23) of the basket 20. For example, a developing coating (not shown) is provided on the outer wall of the metal wires of the basket 20. This developing coating can be developed under X-ray irradiation, so that the shape and position of the basket 20 can be clearly displayed under X-ray irradiation, thereby enhancing the developing effect of the basket 20.

[0064] like Figure 6 As shown, in some embodiments, the basket segment 122 is provided with a plurality of first imaging markers 40 along the axial direction, and the distal end of the outer tube 11 is provided with a second imaging marker 50. It can be understood that in the axial direction of the microcatheter 100 (e.g., Figure 3 In the direction shown (i), the inner tube 12 has a plurality of first development indicators 40 on the basket section 122. At the same time, a second development indicator 50 is provided at the far end of the outer tube 11. Thus, when the inner tube 12 is displaced relative to the outer tube 11, the degree of opening of the basket 20 can be determined according to the degree of overlap between the different first development indicators 40 and the second development indicators 50.

[0065] like Figure 6 As shown, in some embodiments, the plurality of first development marks 40 are distributed at equal intervals. Compared with unequal intervals, this helps to observe the degree of overlap between the first development marks 40 and the second development marks 50 under X-ray irradiation, thereby improving the development effect.

[0066] like Figure 1 , Figure 5 and Figure 6 As shown, in some embodiments, when the basket 20 is in the retracted state, one of the plurality of first imaging markers 40 is located at the distal end of the basket segment 122, another of the plurality of first imaging markers 40 is located at the proximal end of the basket segment 122, and the remaining first imaging markers 40 are located between the distal end and the proximal end of the basket segment 122. In specific applications, by pulling the inner tube 12 relative to the outer tube 11 a certain distance toward the surgeon, it can be observed under X-ray irradiation that the first imaging marker 40 located at the proximal end of the basket segment 122 is contained within the outer tube 11, and among the remaining first imaging markers 40 located between the distal end and the proximal end of the basket segment 122, one first imaging marker 40 overlaps with a second imaging marker 30, and it can also be observed that the basket 20 expands and opens.

[0067] For example, when the basket 20 is retracted onto the inner tube 12, the number of first developing marks 40 can be set according to the actual axial length of the basket segment 122. For instance, two first developing marks 40 can be set between the distal end and the proximal end of the basket segment 122, one first developing mark 40 can be set at the distal end of the basket segment 122, and one first developing mark 40 can be set at the proximal end of the basket segment 122. It should be understood that the distal end of the basket segment 122 is the end where the basket segment 122 connects to the head segment 121, and the proximal end of the basket segment 122 is the end where the basket segment 122 connects to the inner segment 123.

[0068] like Figure 7 As shown, in some embodiments, the inner circumferential surface of the outer tube 11 is provided with a first lubricating layer (not shown). In this embodiment, a lubricating material is coated on the inner circumferential surface of the outer tube 11 to form a first lubricating layer, which helps to reduce the difficulty of pushing and pulling the inner tube 12 in the outer tube 11.

[0069] like Figure 4 and Figure 7 As shown, in some embodiments, the outer peripheral surface of the embedded segment 123 is provided with a second lubricating layer (not shown). In this embodiment, the second lubricating layer is formed by coating the outer peripheral surface of the embedded segment 123 with lubricating material, which helps to reduce the difficulty of pushing and pulling the inner tube 12 in the outer tube 11.

[0070] like Figure 4 and Figure 7 As shown, in some embodiments, a gap 60 is formed between the inner circumferential surface of the outer tube 11 and the outer circumferential surface of the inner section 123, which helps to reduce the difficulty of pushing and pulling the inner tube 12 in the outer tube 11.

[0071] like Figure 4 and Figure 7 As shown, for example, the inner circumferential surface of the outer tube 11 is provided with a first lubricating layer, the outer circumferential surface of the inner section 123 is provided with a second lubricating layer, and a small gap 60 is formed between the inner circumferential surface of the outer tube 11 and the outer circumferential surface of the inner section 123, so as to facilitate the inner tube 12 to be pushed and pulled back in the outer tube 11.

[0072] like Figure 3 and Figure 4 As shown, in some embodiments, the microcatheter 100 further includes a connector 70, which is connected to the proximal end of the inner tube 12. The connector 70 can connect the microcatheter 100 to an external medical device (such as an interventional device). The connector 70 is provided with an infusion port that communicates with the infusion channel 124, and embolic agents and drugs can be introduced into the infusion channel 124 from the infusion port.

[0073] For example, the connector 70 includes a locking connector and a Luer connector with an infusion port. The Luer connector may be a standard Luer inner cone. The Luer connector may be connected to an external medical device (such as a high-pressure injector). The locking connector is used to lock the Luer connector to the external medical device to prevent the Luer connector from leaking or loosening.

[0074] like Figure 1 and Figure 3 As shown, in some embodiments, the microcatheter 100 further includes a locking device 80 connected to the outer tube 11. The locking device 80 has a locked state and an unlocked state. When the locking device 80 is in the locked state, the locking device 80 restricts the movement of the inner tube 12 relative to the outer tube 11. When the locking device 80 is in the unlocked state, the inner tube 12 and the outer tube 11 can move relative to each other to open or close the basket 20.

[0075] In this embodiment, by setting a locking device 80, the inner tube 12 can be locked when the basket 20 expands, so that the inner tube 12 does not move relative to the outer tube 11, thereby maintaining the expanded state of the basket 20. The inner tube 12 can also be locked after the basket 20 is closed, so that the inner tube 12 does not move relative to the outer tube 11, thereby maintaining the closed state of the basket 20.

[0076] like Figure 1 and Figure 3 As shown, in some embodiments, the locking device 80 is connected to the proximal end of the outer tube 11. The microcatheter 100 also includes a strain relief sleeve 90, which is sleeved at the connection between the outer tube 11 and the locking device 80, as well as a portion of the outer tube 11. It can be understood that the locking device 80 is located between the strain relief sleeve 90 and the connecting seat 70, and the strain relief sleeve 90 is sleeved on the outer circumferential surface of a portion of the outer tube 11. The end of the strain relief sleeve 90 furthest from the basket 20 is sleeved at the end of the locking device 80 closest to the basket 20. In this embodiment, the area where the strain relief sleeve 90 is located serves as a stress buffer zone, effectively dispersing stress concentration during catheter operation.

[0077] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A microcatheter, characterized in that, include: The tube body includes an outer tube and an inner tube. The inner tube includes a head section, a basket section and an embedded section connected in sequence from its distal end to its proximal end. The embedded section passes through the interior of the outer tube. The basket section and the head section protrude from the distal end of the outer tube. The inner tube is provided with an infusion channel. A net basket is fitted over the net basket section, with the far end of the net basket connected to the far end of the net basket section and the proximal end of the net basket connected to the far end of the outer tube. The inner tube is movable relative to the outer tube, so that the basket can expand or contract.

2. The microcatheter according to claim 1, characterized in that, The basket expands into a spherical shape with mesh openings.

3. The microcatheter according to claim 1, characterized in that, The basket includes multiple first metal wires and multiple second metal wires. The multiple first metal wires are arranged along a first direction, and the multiple second metal wires are arranged along a second direction. The multiple first metal wires and the multiple second metal wires are interwoven to form the basket, and the first direction and the second direction intersect.

4. The microcatheter according to claim 1, characterized in that, The far end and the near end of the net basket are provided with imaging markers; or, The basket is designed as a fully visible structure.

5. The microcatheter according to claim 4, characterized in that, The basket section is provided with a plurality of first development indicators along the axial direction, and the outer tube is provided with a second development indicator at its distal end.

6. The microcatheter according to claim 5, characterized in that, The plurality of first imaging markers are equally spaced; and / or, One of the plurality of first development indicators is disposed at the distal end of the net basket segment, one of the plurality of first development indicators is disposed at the proximal end of the net basket segment, and the remaining first development indicators are disposed between the distal end and the proximal end of the net basket segment.

7. The microcatheter according to claim 1, characterized in that, At least one of the following conditions must be met: The inner circumferential surface of the outer tube is provided with a first lubricating layer; The outer peripheral surface of the embedded segment is provided with a second lubricating layer; A gap is formed between the inner circumferential surface of the outer tube and the outer circumferential surface of the embedded section.

8. The microcatheter according to claim 1, characterized in that, The microcatheter also includes a connector, which is connected to the proximal end of the inner tube, and the connector is provided with an infusion port that communicates with the infusion channel.

9. The microcatheter according to claim 1, characterized in that, The microcatheter also includes a locking device connected to the outer tube. The locking device has a locked state and an unlocked state. When the locking device is in the locked state, the locking device restricts the movement of the inner tube relative to the outer tube. When the locking device is in the unlocked state, the inner tube and the outer tube can move relative to each other.

10. The microcatheter according to claim 9, characterized in that, The locking device is connected to the proximal end of the outer tube, and the microcatheter also includes a strain relief sleeve, which is sleeved at the connection between the outer tube and the locking device and a portion of the outer tube.

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