Chronic occlusion opening guide wire

Abstract

The invention provides a chronic occlusion opening guide wire, and belongs to the technical field of interventional medical instruments. The opening guide wire comprises a guide wire body, the guide wire body is provided with an equal-diameter core, a supporting layer and a lubricating coating are sequentially arranged on the outer side of the core, the lubricating coating is used for reducing friction force generated when the guide wire body advances in a blood vessel, and the supporting layer is sequentially provided with a pushing section and a hardness adjusting section from the near end to the far end. The hardness adjusting section is configured to have high flexibility when the guide wire body advances along a blood vessel, and the hardness of the hardness adjusting section is increased to meet the penetration requirement when a blocked part needs to be penetrated; the guide wire is mainly used for solving the technical problems that in the prior art, the far end of a guide wire cannot give consideration to flexibility and occlusion penetrating capacity at the same time, and the far-end supporting force conduction effect is poor.

Description

Technical Field

[0001] This invention belongs to the field of interventional medical device technology, specifically relating to a guidewire for opening chronic occlusion. Background Technology

[0002] As a fundamental instrument in interventional surgery, the guidewire is an extremely delicate and complex filamentous structure. Its core value in surgery lies in providing precise guidance for subsequent therapeutic interventional devices such as microcatheters, balloons, and stents to reach the lesion site, making it a key instrument for ensuring the smooth implementation of interventional procedures. In the treatment of coronary artery disease and peripheral vascular disease, especially in the opening of chronically occluded lesions, the performance of the guidewire directly determines the success rate and safety of the procedure.

[0003] In a specific chronic occlusion recanalization procedure, the surgeon first uses a guidewire to travel along the blood vessel to the lesion site. Then, the surgeon attempts to penetrate the occlusion from different angles. Once the guidewire has passed the lesion, the surgeon uses angiography at multiple projection angles to observe whether the guidewire tip travels naturally, in order to determine whether it is in the true lumen of the blood vessel or has entered the dissection of the blood vessel wall (false lumen). Once it is confirmed that the guidewire is in the distal true lumen, the surgeon continues to advance the guidewire, allowing its distal end to pass through the occlusion site by an appropriate distance. Then, along this guidewire that has successfully passed through the occlusion site, a balloon is inserted for dilation, and finally a stent is implanted to reopen the blood vessel.

[0004] The support performance of currently used guidewires mainly relies on their integrated core structure. The guidewire's passage through tortuous blood vessels and its maneuverability are also directly determined by the core's structural design. To avoid damage to blood vessels at the distal end (also known as the "distal end") during guidewire movement and to flexibly adapt to the vessel's course, the current mainstream design adopts a stepped diameter gradient structure at the distal end of the core. This means the radial dimension of the core gradually decreases from the proximal end to the distal end. This design, by reducing the amount of core material used at the distal end, effectively reduces the rigidity of the guidewire, allowing it to better conform to the natural course of the blood vessel, reducing mechanical stimulation of the vessel wall, lowering the risk of vascular injury, and thus meeting the basic requirements for flexibility during surgical procedures.

[0005] However, while this structure meets the flexibility requirements of the distal end of the guidewire, the stepped, gradually decreasing structure, while improving flexibility by reducing the diameter of the distal core, inevitably leads to a significant decrease in the rigidity of the distal end. The tissue in areas of chronic vascular occlusion is typically hard and dense, requiring sufficient distal rigidity of the guidewire to penetrate the lesion barrier. The current design, which prioritizes distal flexibility, directly results in insufficient distal rigidity of the guidewire. During advancement, the tip is prone to instability or bending, failing to generate effective penetration force. This makes it difficult for the operator to control the guidewire to penetrate the occluded segment, not only prolonging the operation time but also potentially leading to serious complications such as vascular dissection and perforation due to repeated attempts.

[0006] Furthermore, the stepped diameter gradient core structure creates weak points in force transmission at the abrupt changes in diameter. When the surgeon applies pushing force from the proximal guidewire, the force attenuates as it passes through these abrupt changes in the core, failing to efficiently transmit it to the distal tip of the guidewire. This reduced force transmission efficiency makes it difficult for the surgeon to accurately perceive the resistance feedback from the distal lesion. This prevents precise penetration through fine-tuning of the operative force and may also cause the guidewire tip to suddenly shift due to excessive pushing force, increasing the risk of accidental femoral artery dissection or perforation of the vessel wall, further reducing the safety and controllability of the surgical procedure.

[0007] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0008] The purpose of this invention is to provide a chronic occlusion opening guidewire, so as to at least solve the technical problem that the distal end of existing guidewires cannot simultaneously achieve both flexibility and occlusion penetration capability.

[0009] To achieve the above objectives, the chronic occlusion recanalization guidewire of the present invention provides the following technical solution: A guidewire for opening chronic occlusion includes a guidewire body with a core of uniform diameter. A support layer and a lubricating coating are sequentially disposed on the outer side of the core. The lubricating coating is used to reduce the friction of the guidewire body when traveling in the blood vessel. The support layer is provided with a pushing section and a stiffness adjustment section from the proximal end to the distal end. The stiffness adjustment section is configured such that: when the guidewire body travels along the blood vessel, the stiffness adjustment section has high flexibility; when it is necessary to penetrate the occlusion site, the stiffness adjustment section increases to meet the penetration requirement.

[0010] As a further optimized technical solution, the stiffness adjustment section includes a first adjustment section and a second adjustment section that cooperate with each other from the proximal end to the distal end; when the guidewire body travels along the blood vessel, the first adjustment section and the second adjustment section separate from each other; when the guidewire body passes through the occlusion site, the first adjustment section and the second adjustment section interlock with each other to increase the stiffness of the distal end of the guidewire body.

[0011] As a further optimized technical solution, the first adjustment section is a spiral spring structure, and the second adjustment section is a sleeve structure. The sleeve structure has a spiral groove structure on its side wall, and the first adjustment section can be inserted into the spiral groove structure of the second adjustment section by rotating around its axis.

[0012] As a further optimized technical solution, the overall winding length of the spiral spring structure is equal to the overall winding length of the spiral groove structure.

[0013] As a further optimized technical solution, all the pitches of the spiral spring structure are equal, and the spiral groove structure is adapted to the shape of the spiral spring structure.

[0014] As a further optimized technical solution, the pitch of the spiral spring structure gradually decreases from the near end to the far end, and the spiral groove structure is adapted to the shape of the spiral spring structure.

[0015] As a further optimized technical solution, all the pitches of the spiral spring structure are equal, and the pitch of the spiral groove structure gradually decreases from the near end to the far end.

[0016] As a further optimized technical solution, both the first adjustment section and the second adjustment section are spiral spring structures, and the pitch of the second adjustment section is equal to the diameter of the spiral spring winding wire of the first adjustment section.

[0017] As a further optimized technical solution, the hardness adjustment section is made of a developing material.

[0018] As a further optimized technical solution, the push section is a sleeve structure.

[0019] Beneficial effects: This invention, by setting a switchable stiffness adjustment section, allows the distal end of the guidewire to maintain good flexibility when passing through tortuous blood vessels, while increasing stiffness when penetrating hard occluded tissue. This effectively solves the technical problem in the prior art where the distal end of the guidewire cannot simultaneously maintain both flexibility and occlusion penetration capability. In addition, the constant-diameter core ensures efficient and attenuated transmission of thrust, allowing the operator to obtain clear tactile feedback. Combined with the increased stiffness of the distal end, the guidewire body has more stable guidance when penetrating occluded tissue, greatly improving the success rate of penetrating chronic total occlusion lesions and reducing complications such as vascular damage caused by repeated operations.

[0020] Furthermore, during guidewire travel, the first and second adjustment segments of the stiffness adjustment zone remain separate, ensuring excellent compliance and flexibility at the distal end. This allows for safe and non-invasive passage through tortuous vascular pathways. When lesion penetration is required, manipulation (such as rotation) allows the first and second adjustment segments of this zone to interlock, transforming the flexible structure into a rigid one, providing sufficient tip support and penetration power to overcome chronic total occlusion lesions. This switchable working mode allows a single guidewire to simultaneously possess the compliance for navigation and the stiffness for penetration, meeting the needs of different working conditions.

[0021] Furthermore, the hardness adjustment section of the present invention achieves the hardness switching function through various helical mechanical interlocking structures (such as helical-groove interlocking, double helical interlocking, etc.), which is simple to operate, reliable in action, and easy to promote and apply in clinical practice.

[0022] Furthermore, by using a preferred imaging material (such as platinum-iridium alloy) to manufacture the hardness adjustment section, this invention provides excellent visibility of the guidewire under X-ray fluoroscopy. The surgeon can observe the position and state (separation or embedding) of the hardness adjustment section in real time and clearly, thereby enabling more precise positioning of the guidewire tip at the lesion and confirmation of the switching operation, further ensuring the safety and effectiveness of the surgical procedure. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram showing the separation of the first and second adjustment sections in Embodiment 1 of the chronic occlusion opening guidewire of the present invention. Figure 2 This is a schematic diagram showing the interlocking of the first and second adjustment sections in Embodiment 1 of the chronic occlusion opening guidewire of the present invention; Figure 3 This is a schematic diagram of the structure of the guidewire for opening chronic occlusion in embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the structure of the chronic occlusion opening guidewire of the present invention, Example 3; Figure 5 This is a schematic diagram of the structure of Example 4 of the chronic occlusion opening guidewire of the present invention.

[0024] In the diagram: 100, guide wire body; 110, core; 120, support layer; 121, pushing section; 122, hardness adjustment section; 1221, first adjustment section; 1222, second adjustment section; 1223, spiral groove structure; 130, lubricating coating. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0026] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, the term "proximal end" uniformly refers to the end closer to the operator, while "distal end" refers to the end farther from the operator.

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0028] The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions of the product; they are only intended to illustrate the content of the invention.

[0029] To address the technical problems of existing guidewires that cannot simultaneously achieve both flexibility and penetration capability at the distal end, and that exhibit poor distal support force transmission, this invention provides a guidewire for opening chronic occlusions. This guidewire includes a guidewire body 100 with a core 110 of equal diameter. A support layer 120 and a lubricating coating 130 are sequentially arranged on the outer side of the core 110. The distal end of the support layer 120 has a stiffness adjustment section 122, which is configured to have two working states: maintaining flexibility while traveling within the blood vessel; and increasing stiffness when penetrating the occlusion site. Specifically, this section achieves dynamic stiffness switching through the interlocking of a first adjustment section 1221 and a second adjustment section 1222 (e.g., interlocking a helical spring with a cannula with helical grooves, or interlocking two helical spring structures). This invention, through its variable stiffness design, effectively solves the technical problem of traditional guidewires being unable to simultaneously achieve distal flexibility and penetration stiffness, significantly improving the success rate and safety of opening procedures for chronic complete occlusion lesions.

[0030] Example 1 like Figure 1 , Figure 2As shown, the chronic occlusion recanalization guidewire includes a guidewire body 100, which has a core 110 of uniform diameter. This uniform diameter design ensures that the pushing force is transmitted from the proximal end to the distal end without attenuation, allowing the operator to accurately perceive changes in resistance at the distal end, thereby improving the controllability of the operation. In this embodiment, the core 110 is made of a superelastic nickel-titanium alloy or stainless steel, ensuring excellent pushing force transmission and support performance.

[0031] The core 110 is provided with a support layer 120 and a lubricating coating 130 on its outer side. The lubricating coating 130 is a hydrophilic coating or a hydrophobic coating. The hydrophilic coating is preferably made of polyethylene glycol, which can form a super-slippery surface after contact with blood, reducing the coefficient of friction to 0.01-0.03. The hydrophobic coating can be made of polytetrafluoroethylene, which can also effectively reduce the frictional resistance of the guidewire when it travels in the blood vessel.

[0032] The support layer 120 is provided with a push section 121 and a hardness adjustment section 122 from the proximal end to the distal end. The hardness adjustment section 122 is configured such that when the guidewire body 100 travels along the blood vessel, the hardness adjustment section 122 has high flexibility, and when it is necessary to penetrate the occluded site, the hardness of the hardness adjustment section 122 increases to meet the penetration requirements.

[0033] In this embodiment, the pushing section 121 adopts a stainless steel sleeve structure, which serves to provide a stable pushing force for the guidewire as a whole, and together with the core 110, provides support for the guidewire body 100, preventing the guidewire body 100 from bending or twisting during the pushing process. In addition, it is also used to provide driving force for the hardness adjustment of the hardness adjustment section 122.

[0034] The hardness adjustment section 122 is an important structure for switching between guidewire compliance and penetration. It includes a first adjustment section 1221 and a second adjustment section 1222 that work together from the proximal end to the distal end. The length of the second adjustment section 1222 is controlled between 10-30mm. This length range can ensure the rigid support effect after adjustment without affecting the overall flexibility of the distal end of the guidewire. When the guidewire body 100 travels within a tortuous blood vessel, the first adjustment segment 1221 and the second adjustment segment 1222 are separated from each other. At this time, the stiffness adjustment segment 122 maintains high flexibility and can flexibly adapt to changes in the direction of the blood vessel, avoiding damage to the vessel wall. When the distal end of the guidewire body 100 reaches the occluded lesion site and needs to penetrate, the support layer 120 at the proximal end of the guidewire body 100 is rotated to make the first adjustment segment 1221 and the second adjustment segment 1222 interlock, significantly increasing the rigidity of the stiffness adjustment segment 122. This means that the stiffness of the distal end of the guidewire body 100 is effectively increased, thereby providing sufficient penetration power to break through the occluded lesion.

[0035] In this embodiment, the first adjustment segment 1221 is a helical spring structure, with its proximal end fixedly connected to the distal end of the pushing section 121, and the distal end extending freely a set distance away from the proximal end. The second adjustment segment 1222 is a sleeve structure, with a solid component disposed at the distal end of the core 110. A helical groove structure 1223 is formed on the side wall of the sleeve structure, allowing the first adjustment segment 1221 to be inserted into the helical groove structure 1223 of the second adjustment segment 1222 by rotating around its axis.

[0036] The overall winding path length of the helical spring structure is equal to the overall winding path length of the helical groove structure 1223. This means that the straightened winding of the helical spring structure is equal to the straightened winding path length of the helical groove structure 1223. This design ensures that the helical spring of the first adjustment section 1221 remains matched with the helical groove structure 1223 of the second adjustment section 1222 throughout the entire process from initial screwing to final tightening. If the winding lengths are unequal, at some stage of the screwing process, one end will inevitably be screwed in while the other end is not, or one end will be overstretched / compressed. This invention, through its equal-length design, avoids misalignment or localized stress concentration caused by length mismatch, resulting in smooth and stable screwing action, ensuring the overall support strength of the hardness adjustment section 122 after engagement, and uniform stress distribution throughout the entire engagement length, greatly improving the reliability and durability of the structure. Furthermore, when the helical spring structure and the helical groove structure 1223 are fully engaged, the equal-length design ensures that the first adjustment section 1221 and the second adjustment section 1222 are tightly integrated throughout the contact area, forming a complete and continuous rigid composite. This maximizes the effective contact area, thereby evenly distributing the pushing force from the core 110 throughout the entire stiffness adjustment zone, achieving a smooth and consistent transmission of stiffness from proximal to distal. This avoids weak points caused by poor local contact, ensuring that the distal end of the guidewire can function as a whole when penetrating lesions, providing maximum and stable support stiffness.

[0037] Furthermore, all the threads in the helical spring structure have equal pitch, and the helical groove structure 1223 is adapted to the shape of the helical spring structure. The purpose of this design is to simplify, mature, and control the manufacturing process. Whether using precision winding or laser engraving, the equal-pitch structure makes it easier to achieve high-precision mass production, effectively ensuring the performance consistency and interchangeability of each guide wire product. Therefore, this design, while pursuing performance, also considers the feasibility and economy of production, laying a solid foundation for the commercial promotion of the product.

[0038] Furthermore, the entire rigidity adjustment section 122 is made of a radiopaque material (such as platinum-iridium alloy), which makes the guidewire highly visible under X-ray fluoroscopy. The surgeon can observe the position and state (separation or embedding) of the rigidity adjustment section in real time and clearly, thereby enabling more precise positioning of the guidewire tip at the lesion and confirmation of the switching operation, further ensuring the precise execution of the surgical steps.

[0039] The specific working principle of the guidewire for opening chronic occlusion is as follows: like Figure 1 As shown, the first adjustment segment 1221 and the second adjustment segment 1222 are separated at this time. The distal end of the guidewire is very flexible and can easily follow the tortuous blood vessel path, avoiding damage to the vascular intima.

[0040] When the guidewire tip reaches the site of the chronic occlusion lesion and penetration is required, the operator holds the proximal end of the guidewire, keeping the core 110 stationary, and gently rotates the pushing section 121 of the support layer 120. This rotational motion is transmitted to the distal end, causing the helical spring of the first adjustment section 1221 to screw into the helical groove structure 1223 of the second adjustment section 1222, as shown. Figure 2 As shown, the two are tightly interlocked to form a rigid composite, which greatly enhances the overall rigidity and bending resistance of the distal end of the guidewire, thereby enabling it to effectively penetrate relatively hard occlusive tissue.

[0041] Example 2 like Figure 3 As shown, the difference between this embodiment and Embodiment 1 is that the pitch of the spiral spring structure of the first adjustment section 1221 is designed to gradually decrease from the near end to the far end. Correspondingly, the pitch of the spiral groove structure 1223 on the sleeve of the second adjustment section 1222 also changes in the same way and is adapted to it.

[0042] This gradient pitch design, when the guidewire is in travel mode, directly relates the compliance of the spiral groove structure 1223 to its pitch: the smaller the pitch, the lower the bending stiffness of that section, and the better the compliance. In this embodiment, by making the distal pitch smaller, the tip of the guidewire body 100 has better flexibility during travel, allowing it to pass more flexibly through tortuous terminal blood vessels; while the relatively larger pitch at the proximal end provides the necessary transitional support. This gradient compliance distribution from stiff to flexible from proximal to distal significantly improves the safety and smoothness of the travel process.

[0043] Example 3 like Figure 4As shown, the difference between this embodiment and Embodiment 2 is that the helical spring structure of the first adjustment section 1221 maintains a constant pitch, while the pitch of the helical groove structure 1223 on the second adjustment section 1222 gradually decreases from the proximal end to the distal end. This design ensures the flexibility of the guidewire during travel. When the constant-pitch helical spring structure is forced into the gradually decreasing pitch helical groove structure 1223, the helical spring experiences a continuous and gradually increasing axial compressive force as it is screwed in from the proximal end to the distal end because the pitch at the distal end is smaller than the pitch of the helical spring itself. This force compresses the coils of the helical spring tightly together. This axial compression force means that after the first adjustment section 1221 and the second adjustment section 1222 are fully engaged, they are not simply conforming to each other, but are in a high-tension self-tightening state. This pre-tightening force greatly enhances the ability of the fitment to resist axial compression and radial bending, thus providing ultimate rigidity beyond simple shape matching, making it particularly suitable for lesion locations requiring tip hardness.

[0044] Furthermore, the surgeon will clearly feel a gradually increasing rotational resistance when rotating the guidewire for engagement. This resistance originates from the continuous compression of the helical spring, providing the surgeon with clear and linear progress feedback. The surgeon can directly perceive the depth and tightness of the engagement by touch, thereby avoiding potential component damage caused by excessive rotation. This tactile feedback mechanism greatly improves the controllability and safety of the surgical procedure.

[0045] Example 4 like Figure 5 As shown, the difference between this embodiment and Embodiment 1 is that this embodiment provides a different interlocking scheme. In this embodiment, both the first adjustment segment 1221 and the second adjustment segment 1222 of the hardness adjustment section 122 are helical spring structures. The pitch (P) of the second adjustment segment 1222 is designed to be approximately equal to the winding diameter (d) of the first adjustment segment 1221 (P≈d). When the two are rotated relative to each other, the winding of the first adjustment segment 1221 can precisely embed into the pitch gap of the second adjustment segment 1222, achieving a similar interlocking effect and thus significantly increasing the hardness of the area.

[0046] In summary, the chronic occlusion recanalization guidewire provided by this invention achieves efficient thrust transmission through an equal-diameter core, and allows for flexible switching between compliance and penetration through an adjustable stiffness section. Combined with the design of the imaging material and lubricating coating, it significantly improves the success rate and safety of chronic occlusion lesion recanalization surgery, effectively solving the industry problem of the inability of guidewire compliance and penetration to coexist in interventional surgery, and has extremely high clinical value.

[0047] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the protection scope of the present invention.

Claims

1. A chronic total occlusion crossing guidewire, comprising: The guide wire body (100) has an equal-diameter core (110), an outer side of the core (110) is sequentially provided with a support layer (120) and a lubricating coating (130), the lubricating coating (130) is used for reducing the friction of the guide wire body (100) when traveling in the blood vessel, and the support layer (120) is sequentially provided with a pushing section (121) and a hardness adjustment section (122) from the proximal end to the distal end, the hardness adjustment section (122) is configured to have higher flexibility when the guide wire body (100) travels along the blood vessel, and the hardness of the hardness adjustment section (122) is increased to meet the penetration requirement when it is required to penetrate the occluded site.

2. The chronic total occlusion crossing guidewire of claim 1, wherein, The hardness adjustment section (122) comprises a first adjustment section (1221) and a second adjustment section (1222) which cooperate with each other from the proximal end to the distal end; the first adjustment section (1221) and the second adjustment section (1222) are separated from each other when the guide wire body (100) travels along the blood vessel; and the first adjustment section (1221) and the second adjustment section (1222) are embedded in each other to increase the hardness of the distal end of the guide wire body (100) when the guide wire body (100) passes through the occluded site.

3. The chronic total occlusion crossing guidewire of claim 2, wherein, The first adjustment section (1221) is a spiral spring structure, the second adjustment section (1222) is a sleeve structure, a spiral groove structure (1223) is formed on the side wall of the sleeve structure, and the first adjustment section (1221) can be embedded in the spiral groove structure (1223) of the second adjustment section (1222) by rotating around the axis.

4. The chronic total occlusion crossing guidewire of claim 3, wherein, The overall winding length of the spiral spring structure is equal to the overall winding length of the spiral groove structure (1223).

5. The chronic total occlusion crossing guidewire of claim 4, wherein, All of the pitches of the spiral spring structure are equal, and the spiral groove structure (1223) is matched with the shape of the spiral spring structure.

6. The chronic total occlusion crossing guidewire of claim 4, wherein, The pitches of the spiral spring structure gradually decrease from the proximal end to the distal end, and the spiral groove structure (1223) is matched with the shape of the spiral spring structure.

7. The chronic total occlusion crossing guidewire of claim 4, wherein, All of the pitches of the spiral spring structure are equal, and the pitches of the spiral groove structure (1223) gradually decrease from the proximal end to the distal end.

8. The chronic total occlusion crossing guidewire of claim 2, wherein, The first adjustment section (1221) and the second adjustment section (1222) are both spiral spring structures, and the pitch of the second adjustment section (1222) is equal to the diameter of the wire wound by the spiral spring structure of the first adjustment section (1221).

9. The chronic total occlusion crossing guidewire of any one of claims 1-8, wherein, The hardness adjustment section (122) is made of a developing material.

10. The chronic total occlusion crossing guidewire of any one of claims 1-8, wherein, The pushing section (121) is a sleeve structure.

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