Extensible nerve intervention guide wire

Abstract

The invention provides an extendable nerve intervention guide wire, and relates to the technical field of medical guide wires. A one-way extension cylinder is aligned with a clamping head at the tail end of a main guide wire through an extension groove in the outer wall of the one-way extension cylinder, and is pushed in in the axial direction, so that the clamping head enters the extension groove; the inclined end face of the inclined elastic piece faces the far end of the continuous guide wire. When the guide wire needs to be lengthened, a doctor pulls the continuous guide wire outwards, at the moment, the continuous guide wire drives the one-way lengthening barrel to move towards the telecentric end relative to the main guide wire, the clamping head relatively slides towards the proximal end along the lengthening groove, and the inclined elastic piece is flattened and allowed to pass in a sliding mode. If the continuous guide wire is trying to be pushed inwards in the reverse direction, the tip of the inclined elastic piece can be clamped into the groove in the side face of the clamping head, reverse movement of the inclined elastic piece is prevented, and mechanical one-way locking is formed. A doctor is allowed to gradually push out the main guide wire from the interior of the continuous guide wire during an operation, the guide wire is extended, the extended part is prevented from accidentally retracting, and the operation length is kept stable.

Description

An extendable neurointerventional guidewire Technical Field

[0001] This invention relates to the field of medical guide wire technology, specifically an extendable neurointerventional guide wire. Background Technology

[0002] Neurointerventional guidewires are key instruments in cerebrovascular interventional surgery. Their core function is to establish a minimally invasive channel from the puncture site to the intracranial target vessel, and to provide support and guidance for the delivery of subsequent catheters, stents, and other therapeutic devices. With the advancement of surgical techniques, especially the increasing use of long-distance and tortuous anatomical pathways such as the radial artery approach, higher demands are placed on the length, maneuverability, and intraoperative adaptability of the guidewire.

[0003] Most clinically used neurointerventional microguidewires are designed with a fixed length, commonly ranging from 200 to 300 centimeters. In ultra-long pathways via the radial artery to distal intracranial vessels, fixed-length guidewires often fail to reach the target point due to insufficient length, or cannot be flexibly extended intraoperatively as needed. To address the length issue, existing technologies employ two approaches: one is to use a single, ultra-long guidewire, but this increases torque transmission efficiency, push resistance, and control precision; the other is to use an external connection device to mechanically connect two guidewire segments externally during the procedure. This method not only increases surgical steps and time but also introduces infection risks due to the connection point being exposed to a non-sterile environment, and the connection node may affect the overall passability and flexibility of the guidewire.

[0004] Therefore, an extendable neurointerventional guidewire is provided. Summary of the Invention

[0005] To address the problems mentioned in the background art, the present invention provides the following technical solution: an extendable neurointerventional guidewire, comprising a main guidewire, the end of which is unidirectionally extendable and detachably connected to a continuing guidewire, the extension end of which has a transition section, the continuing guidewire being hollow and the transition section having a constricted opening; a unidirectional extension cylinder is internally engaged with the continuing guidewire, a locking head is fixedly connected to the end of the main guidewire, the outer wall of the unidirectional extension cylinder has symmetrically formed extension grooves parallel to the axis and penetrating at both ends, the end of the main guidewire is fixedly connected to a locking head that slides in connection with the extension groove; several inclined spring pieces are evenly distributed on both sides of the interior of the extension groove, and the inclined end face of the inclined spring piece forms a barbed structure between the locking head and the spring piece, allowing only unidirectional sliding of the locking head.

[0006] Furthermore, the end of the unidirectional extension tube is provided with a snap ring, and the end of the guide wire is provided with a snap groove that snaps into the snap ring.

[0007] Furthermore, several limiting blocks are evenly provided on both sides of the inner wall of the extension groove to center and limit the position of the card head.

[0008] Furthermore, the end of the guide wire is fixedly connected to a rotary pusher, which includes a housing fixed to the end of the guide wire. The housing has a limiting cylinder inside, and the conical end face of the limiting cylinder is supported by a snap ring. The other end of the housing is threadedly connected to a locking cap.

[0009] Furthermore, a magnet is fixedly connected to the end of the main guide wire, and a control magnet is provided inside the limiting cylinder. The conical end of the control magnet is magnetically connected to the magnet, and a control rod is fixedly connected to the control magnet, which passes through the middle of the locking cap.

[0010] Furthermore, the tilting spring is made of nickel-titanium alloy. One end of the tilting spring is fixed to the side wall of the extension groove, and the other end is tilted in the opposite direction of the sliding direction of the chuck. The tilting angle of the tilting spring is 30° to 60°.

[0011] Furthermore, the cross-sectional shape of the chuck is rectangular, matching the shape of the extension groove, and the surface of the chuck is coated with a polymer lubricating layer.

[0012] Furthermore, the transition section is 5-15cm long, and the outer diameter of the transition section gradually decreases axially from the guide wire end to the main guide wire end, with an outer diameter change rate not exceeding 0.001 inches / cm.

[0013] Furthermore, the transition section is made of a composite of polymer and nickel-titanium alloy wire, and its stiffness gradually increases along the axial direction, changing synchronously with the change in outer diameter.

[0014] Furthermore, the main guide wire length is 2m, and the subsequent guide wire length is 1m.

[0015] Beneficial Effects The present invention has the following beneficial effects: (1) The present invention first aligns the one-way extension tube with the end cap of the main guide wire through the extension groove on its outer wall and pushes it in axially so that the cap enters the extension groove. The inclined end face of the inclined spring faces the distal end of the guide wire. When the guide wire needs to be extended, the doctor pulls the guide wire outward. At this time, the guide wire moves the one-way extension tube relative to the main guide wire toward the distal end, and the cap slides relative to the proximal end along the extension groove. The inclined spring is flattened and allows it to slide through. If an attempt is made to push the guide wire inward in the opposite direction, the tip of the inclined spring will be stuck in the groove on the side of the cap, preventing it from moving in the opposite direction and forming a mechanical one-way lock. This allows the doctor to gradually push the main guide wire out from inside the guide wire during the operation, thereby extending the guide wire and preventing the extended part from accidentally retracting, thus maintaining a stable operating length.

[0016] (2) This invention features a radially protruding snap-fit ​​ring at the proximal end of the unidirectional extension tube. A snap-fit ​​groove is machined into the inner wall of the proximal end of the guidewire. During assembly, the unidirectional extension tube is inserted into the guidewire and then snapped into the groove via the snap-fit ​​ring, achieving circumferential fixation and axial positioning between the two. During disassembly, the unidirectional extension tube can be removed from the guidewire by using the snap-fit ​​ring to disengage from the groove. This snap-fit ​​method allows the unidirectional extension tube to rotate while fixed together with the guidewire, transmitting torsional force and facilitating rapid assembly and disassembly in non-sterile areas, providing convenience for pretreatment and maintenance.

[0017] (3) This invention provides several limiting blocks evenly distributed on the inner walls of both sides of each extension groove to center and limit the movement of the clamping head. The limiting blocks protrude from the inner wall of the extension groove, and the gap between two limiting blocks is slightly smaller than the width of the clamping head. When the clamping head slides in the extension groove, the limiting blocks are located in the gaps on both sides of the clamping head, which does not hinder axial movement but prevents the clamping head from radially shifting or rotating in the groove. This ensures that the clamping head always slides smoothly along the center line of the extension groove, avoiding problems such as increased friction, poor movement, or damage to the tilting spring caused by clamping head misalignment, and improving the smoothness and reliability of the extension process.

[0018] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] Figure 1 is a partial isometric view of the entire invention.

[0020] Figure 2 is a partial cross-sectional view of the entire invention.

[0021] Figure 3 is a partial isometric view of the unidirectional extension tube of the present invention.

[0022] Figure 4 is an enlarged view of section A in Figure 3 of the present invention.

[0023] Figure 5 is a partial isometric view of the guidewire of the present invention.

[0024] Figure 6 is a partial isometric view of the unidirectional extension tube of the present invention.

[0025] Figure 7 is a partial isometric view of the main guide wire of the present invention.

[0026] Figure 8 is an isometric view of the snap ring of the present invention.

[0027] In the diagram: 1. Main guide wire, 11. Clamp, 12. Magnet, 2. Continuing guide wire, 21. Slot, 3. Transition section, 4. Rotary push section, 41. Outer shell, 42. Limiting cylinder, 43. Control magnet, 431. Control rod, 44. Locking cap, 5. One-way extension cylinder, 51. Clamping ring, 52. Extension groove, 53. Limiting block, 54. Inclined spring. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please refer to Figures 1 to 8. This embodiment of the invention provides a technical solution: an extendable neurointerventional guidewire, including a main guidewire 1. The end of the main guidewire 1 can extend unidirectionally and is detachably connected to a continuing guidewire 2. The extension end of the continuing guidewire 2 is provided with a transition section 3. The continuing guidewire 2 is hollow, and the transition section 3 is designed with a constricted opening to prevent the clamping head 11 from passing through, thus preventing dislodgement. A unidirectional extension cylinder 5 is clamped inside the continuing guidewire 2. The end of the main guidewire 1 is fixedly connected to the clamping head 11. The outer wall of the unidirectional extension cylinder 5 is symmetrically provided with extension grooves 52 that are parallel to the axis and pass through both ends. The end of the main guidewire 1 is fixedly connected to the clamping head 11 that is slidably connected to the extension groove 52. Preferably, three pairs of clamping heads 11 are provided.

[0030] Several inclined spring pieces 54 are evenly distributed on both sides of the inside of the extension groove 52. The inclined end face of the inclined spring piece 54 and the clamp 11 form a barbed structure that allows the clamp 11 to slide in only one direction.

[0031] During the extension process, the guide wire 2 is pulled outward. At this time, since the main guide wire 1 has been fully pushed in, when the guide wire 2 is pulled outward, the guide wire 2 moves outward, causing the one-way extension cylinder 5 to move outward. The clamp 11 moves relative to the guide wire 11. When it is pushed inward again, the main guide wire 1 located inside the guide wire 2 has already extended forward (the relative movement of the guide wire 2 pulls backward).

[0032] The unidirectional extension tube 5 is designed to facilitate assembly and processing.

[0033] The structure of the extension groove 52 and the inclined spring piece 54 can be machined simply by milling the outer wall of the unidirectional extension cylinder 5.

[0034] After the main guide wire 1 has been fully extended from the inside of the continuation guide wire 2, the main guide wire 1 is reassembled from the end of the continuation guide wire 2 by removing the unidirectional extension tube 5.

[0035] In practice, the one-way extension tube 5 is first aligned with the clasp 11 at the end of the main guidewire 1 through the extension groove 52 on its outer wall, and pushed axially so that the clasp 11 enters the extension groove 52. The inclined end face of the tilting spring 54 faces the distal end of the continuing guidewire 2. When it is necessary to extend the guidewire, the doctor pulls the continuing guidewire 2 outward. At this time, the continuing guidewire 2 drives the one-way extension tube 5 to move towards the distal end relative to the main guidewire 1, and the clasp 11 slides towards the proximal end along the extension groove 52. The tilting spring 54 is flattened, allowing it to slide through. If an attempt is made to push the continuing guidewire 2 inward in the opposite direction, the tip of the tilting spring 54 will engage in the groove on the side of the clasp 11, preventing its reverse movement and forming a mechanical one-way lock. This allows the doctor to gradually push the main guidewire 1 out from inside the continuing guidewire 2 during the operation, thereby extending the guidewire and preventing the extended portion from accidentally retracting, maintaining a stable operating length.

[0036] Furthermore, the end of the unidirectional extension tube 5 is provided with a snap ring 51, and the end of the guide wire 2 is provided with a snap groove 21 that snaps into the snap ring 51.

[0037] In practical implementation, the unidirectional extension tube 5 has a radially protruding snap ring 51 near its proximal end. The inner wall of the continuation guide wire 2 near its proximal end is machined with a snap groove 21. During assembly, the snap block on the inner end face of the snap ring 51 is snapped into the inside of the snap groove 21, or an annular snap groove 21 is opened on the proximal end of the continuation guide wire 2 to snap into the snap ring 51, so as to achieve circumferential fixation and axial limitation between the two.

[0038] During disassembly, use a special tool or pinch the corresponding area of ​​the snap-fit ​​ring 51 to deform it and disengage it from the slot 21, then the unidirectional extension tube 5 can be removed from the guide wire 2. The snap-fit ​​connection is firm, can transmit torsional force, and facilitates rapid assembly and disassembly in non-sterile areas, providing convenience for pretreatment and maintenance.

[0039] Furthermore, the inner walls on both sides of the extension groove 52 are evenly provided with a number of limiting blocks 53 that center and limit the position of the card head 11.

[0040] In practical implementation, several limiting blocks 53 are evenly arranged on the inner walls of both sides of each extension groove 52 to center and limit the movement of the clamping head 11. The limiting blocks 53 protrude from the inner wall of the extension groove 52, and the gap between two limiting blocks 53 is slightly smaller than the width of the clamping head 11. When the clamping head 11 slides in the extension groove 52, the limiting blocks 53 are located in the gaps on both sides of the clamping head 11, which does not hinder axial movement, but prevents the clamping head 11 from radially shifting or rotating in the groove. This ensures that the clamping head 11 always slides smoothly along the center line of the extension groove 52, avoiding problems such as increased friction, poor movement, or damage to the tilting spring 54 caused by the clamping head 11 being misaligned, thus improving the smoothness and reliability of the extension process.

[0041] Furthermore, the end of the guide wire 2 is fixedly connected to a rotary push part 4, which includes a housing 41 fixed to the end of the guide wire 2. The housing 41 has a limiting cylinder 42 inside, and the conical end face of the limiting cylinder 42 is supported on the snap ring 51. The other end of the housing 41 is threadedly connected to a locking cap 44.

[0042] In practice, the outer shell 41 of the rotary pusher 4 is fixedly connected to the proximal end of the guide wire 2. The limiting cylinder 42 is placed inside the outer shell 41, with its conical end abutting against the end face of the snap ring 51 of the one-way extension cylinder 5 that has been snapped into the guide wire 2. The locking cap 44 is connected to the distal end of the outer shell 41 by threads.

[0043] When the locking cap 44 is tightened, it presses inward against the limiting cylinder 42, causing the conical surface of the limiting cylinder 42 to press tightly against the locking ring 51, thereby enhancing the axial fixation of the unidirectional extension cylinder 5 within the guide wire 2 and preventing it from loosening during operation.

[0044] The connection pair can be tightened with a simple rotation action, ensuring the stability of the core connection mechanism during operation.

[0045] Furthermore, a magnet 12 is fixedly connected to the end of the main guide wire 1, and a control magnet 43 is provided inside the limiting cylinder 42. The conical end of the control magnet 43 is magnetically connected to the magnet 12. A control rod 431 is fixedly connected to the control magnet 43, and the control rod 431 passes through the middle of the locking cap 44.

[0046] In practice, a magnet 12 is fixed to the end of the main guide wire 1.

[0047] The limiting cylinder 42 of the rotary push part 4 is embedded with a control magnet 43. The magnetic poles of the two are set opposite each other and are initially attached by magnetic attraction.

[0048] The control rod 431 connected to the control magnet 43 extends backward through the locking cap 44. When it is necessary to fully release the main wire 1, the operator pulls the control rod 431 outward, causing the control magnet 43 to move backward against the magnetic force, thereby breaking the attraction with the magnet 12.

[0049] At this time, the main guide wire 1 and the continuing guide wire 2 are connected by a one-way mechanical connection only through the one-way extension tube 5, which allows for extension operations.

[0050] When fixation is required, releasing control lever 431 causes the magnetic force to re-engage the two, providing additional axial restraint. This magnetic control mechanism provides the operator with a quick, tool-free method for locking and unlocking, facilitating flexible control of the guidewire state at different stages of the procedure.

[0051] When extension is not required, the magnet 43 can be engaged with the magnet 43, preventing the main guide wire 1 and the continuing guide wire 2 from being extended.

[0052] Furthermore, the tilting spring 54 is made of nickel-titanium alloy. One end of the tilting spring 54 is fixed to the side wall of the extension groove 52, and the other end is tilted in the opposite direction to the sliding direction of the chuck 11. The tilting angle of the tilting spring 54 is 30° to 60°.

[0053] In practical implementation, the tilting spring 54 is made of super-elastic nickel-titanium alloy wire, and one end of it is welded and fixed to the side wall of the extension groove 52. The free end of the spring is tilted in the opposite direction of the sliding direction of the clamp 11, and the angle between it and the bottom plane of the groove is set to 45° (within the range of 30°-60°).

[0054] The elasticity of the nickel-titanium alloy allows the tilting spring 54 to be easily pressed down when the chuck 11 slides forward, and to quickly rebound when the chuck 11 has a reverse tendency, with its tip embedding into a pre-set micro-dimple on the surface of the chuck 11.

[0055] The unidirectional locking mechanism is sensitive and durable enough to withstand repeated operation cycles, while the biocompatibility of the material meets the requirements for long-term implants.

[0056] Furthermore, the cross-sectional shape of the chuck 11 is rectangular, matching the shape of the extension groove 52, and the surface of the chuck 11 is coated with a polymer lubricating layer.

[0057] In practice, the cross-section of the card head 11 is machined into a rectangle, and its dimensions are closely matched with the rectangular cross-section of the extension groove 52, with the gap controlled at 0.002 inches.

[0058] The surface of the card head 11 is coated with a uniformly thick polytetrafluoroethylene lubricating coating.

[0059] The rectangular cross-section prevents the chuck 11 from rotating within the slot, ensuring that the torque is transmitted in the same direction from the main guide wire 1 to the continuing guide wire 2.

[0060] The polytetrafluoroethylene coating significantly reduces the coefficient of sliding friction between the card head 11 and the metal wall of the extension groove 52, making the extension operation feel light and smooth, reducing operating resistance and possible metal particles.

[0061] Furthermore, the transition section 3 is 5-15cm long, and the outer diameter of the transition section 3 gradually decreases along the axial direction from the end of the guide wire 2 to the end of the main guide wire 1, with the outer diameter change rate not exceeding 0.001 inches / cm.

[0062] In practical implementation, the transition section 3 is 10 cm long. Its outer diameter is 0.016 inches at the end of the guide wire 2 and 0.014 inches at the end of the main guide wire 1, decreasing linearly and uniformly along the axial direction. The outer diameter change rate is 0.0002 inches / cm, which is less than the requirement of 0.001 inches / cm. This structure is achieved through a precision extrusion molding process.

[0063] When the guidewire system passes through tortuous blood vessels or narrow areas, the smooth and continuous gradual change in outer diameter avoids sudden step-like changes, significantly reducing the scraping resistance and potential damage risk to the inner wall of the blood vessel as the guidewire advances, and improving the passage of blood vessels.

[0064] Furthermore, the transition section 3 is made of a composite of polymer and nickel-titanium alloy wire, and its stiffness gradually increases along the axial direction, changing synchronously with the change in outer diameter.

[0065] In practice, the matrix of transition section 3 is made of polyurethane polymer material, in which nickel-titanium alloy wires with gradually varying diameters are embedded.

[0066] At the second end of the guide wire, the nickel-titanium wire has a thicker diameter and a higher braiding density; towards the first end of the main guide wire, the nickel-titanium wire gradually becomes thinner and the braiding density gradually decreases.

[0067] This design allows the bending stiffness of transition segment 3 to gradually decrease from the end of guidewire 2 to the end of main guidewire 1. This ensures that the guidewire has sufficient pushing force while its tip (on the side of main guidewire 1) remains flexible, allowing it to conform to complex vascular pathways, reducing the risk of perforation, and fulfilling the clinical operational requirement of strong proximal support and flexible distal tracking.

[0068] Furthermore, the length of the main guide wire 1 is 2m, and the length of the secondary guide wire 2 is 1m.

[0069] In practice, the total length of the main guidewire 1 is set to 200 cm, and the total length of the secondary guidewire 2 is set to 100 cm. This results in an initial system length of 200 cm, which can be extended to a total working length of approximately 300 cm via an extension mechanism. This length range covers the typical path length from the radial artery approach to the distal intracranial target vessel, allowing a single guidewire system to meet the needs of most neurointerventional surgeries. This avoids the need to replace the entire guidewire system due to insufficient length during the procedure, simplifying the surgical steps and shortening the operation time.

[0070] In the disassembly embodiment, unscrew the locking cap 44, remove the control magnet 43, and then remove the limiting cylinder 42. At this time, the end of the one-way extension cylinder 5 is exposed. By pushing the main guide wire 1 in the opposite direction into the interior of the continuing guide wire 2, the main guide wire 1 pushes the one-way extension cylinder 5 out of the interior of the continuing guide wire 2. After the one-way extension cylinder 5 is completely removed, maintenance is completed, such as disinfection and sterilization.

[0071] During reassembly, insert the head end of the main guide wire 1 through the end of the one-way extension tube 5, so that the locking head 11 enters the extension groove 52. Magnetize the control magnet 43 onto the magnet 12. Then insert the head end of the main guide wire 1 into the interior of the continuing guide wire 2. At the same time, insert the one-way extension tube 5 into the interior of the continuing guide wire 2, so that the locking ring 51 engages with the locking groove 21. Remove the control magnet 43, insert the limiting tube 42 into the interior of the outer shell 41, insert the control magnet 43 into the magnet 12, and then screw on the locking cap 44 to complete the assembly.

Claims

1. An extendable neurointerventional guidewire, comprising a main guidewire (1), characterized in that: The end of the main guide wire (1) can extend in one direction and is detachably connected to a continuing guide wire (2). The extension end of the continuing guide wire (2) is provided with a transition section (3). The continuing guide wire (2) is hollow and the transition section (3) is constricted. The continuing guide wire (2) is fitted with a one-way extension tube (5). The end of the main guide wire (1) is fixedly connected with a clamp (11). The outer wall of the one-way extension tube (5) is symmetrically provided with an extension groove (52) that is parallel to the axis and passes through both ends. The end of the main guide wire (1) is fixedly connected with a clamp (11) that slides with the extension groove (52). Several inclined spring pieces (54) are evenly distributed on both sides of the inside of the extension groove (52). The inclined end face of the inclined spring piece (54) and the clamp (11) form a barbed structure that only allows the clamp (11) to slide in one direction.

2. The extendable neurointerventional guidewire according to claim 1, characterized in that: The end of the unidirectional extension tube (5) is provided with a snap ring (51), and the end of the guide wire (2) is provided with a slot (21) that snaps into the snap ring (51).

3. The extendable neurointerventional guidewire according to claim 2, characterized in that: The inner walls on both sides of the extension groove (52) are evenly provided with a number of limiting blocks (53) that center and limit the card head (11).

4. The extendable neurointerventional guidewire according to claim 3, characterized in that: The end of the guide wire (2) is fixedly connected to a rotary push part (4). The rotary push part (4) includes a housing (41) fixed on the end of the guide wire (2). The housing (41) is provided with a limiting cylinder (42). The conical end face of the limiting cylinder (42) is supported on the snap ring (51). The other end of the housing (41) is threadedly connected to a locking cap (44).

5. The extendable neurointerventional guidewire according to claim 4, characterized in that: A magnet (12) is fixedly connected to the end of the main guide wire (1), and a control magnet (43) is provided inside the limiting cylinder (42). The conical end of the control magnet (43) is magnetically connected to the magnet (12). A control rod (431) is fixedly connected to the control magnet (43), and the control rod (431) passes through the middle of the locking cap (44).

6. The extendable neurointerventional guidewire according to claim 1, characterized in that: The tilting spring (54) is made of nickel-titanium alloy. One end of the tilting spring (54) is fixed to the side wall of the extension groove (52), and the other end is tilted in the opposite direction of the sliding direction of the card head (11). The tilting angle of the tilting spring (54) is 30° to 60°.

7. The extendable neurointerventional guidewire according to claim 1, characterized in that: The cross-sectional shape of the card head (11) is rectangular, matching the shape of the extension groove (52), and the surface of the card head (11) is coated with a polymer lubricating layer.

8. The extendable neurointerventional guidewire according to claim 1, characterized in that: The transition section (3) is 5-15cm long. The outer diameter of the transition section (3) gradually decreases from the end of the guide wire (2) to the end of the main guide wire (1) along the axial direction. The outer diameter change rate is no greater than 0.001 inches / cm.

9. The extendable neurointerventional guidewire according to claim 8, characterized in that: The transition section (3) is made of a composite of polymer and nickel-titanium alloy wire, and its stiffness gradually increases along the axial direction, changing synchronously with the change in outer diameter.

10. The extendable neurointerventional guidewire according to any one of claims 1 to 9, characterized in that: The length of the main guide wire (1) is 2m, and the length of the secondary guide wire (2) is 1m.

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