Self-unloading twisted tension device during cerebral vascular stent release process and interventional surgical instrument

Abstract

This invention belongs to the field of interventional surgical instrument technology, and provides a self-relieving torsional tension device and interventional surgical instrument during the release of a cerebral vascular stent. A rotating inner sheath is rotatably installed inside the catheter, and a rotor block is rotatably installed on the guidewire. During operation, the rotating inner sheath contacts the outer wall of the stent to be intervened in, and the rotor block engages with the inner wall of the stent. When torsional tension occurs during the release of the stent in the cerebral blood vessel, the stent rotates around the catheter and guidewire in real time under the action of the rotating inner sheath and the rotor block, realizing the self-relieving of torsional tension during stent release. This automatically removes the torsional tension generated during the release of the cerebral vascular stent, improves the stress distribution within the stent mesh, ensures complete stent opening and good apposition to the vessel wall, avoids abnormal stent opening after release, and prevents serious consequences such as thrombosis between the stent and the vessel wall due to poor stent apposition, thus making the patient safer.

Description

Technical Field

[0001] This invention belongs to the field of interventional surgical instruments technology, and particularly relates to a self-releasing torsion tension device and interventional surgical instruments during the release of a cerebral vascular stent. Background Technology

[0002] In the body, cerebral blood vessels are significantly more tortuous than peripheral vessels, especially from the cavernous segment of the internal carotid artery to the supraclinoid segment and the main trunk of the middle cerebral artery, where the vessels are relatively fixed and large. After stent placement in these vessels, deformation is minimal. During stent deployment, the vessel's morphology and course become tortuous and twisted to some extent, generating torsional tension within the stent mesh. This tension, if not released, makes stent deployment difficult, resulting in poor apposition and incomplete opening. This weakens blood flow to the carrier vessel, leading to secondary thrombosis, perforator occlusion, and even acute occlusion of the carrier vessel or failure of the stent to open, resulting in serious consequences.

[0003] The inventors discovered that the torsional tension during the deployment of cerebral vascular stents was not effectively managed. Even if the stent opened smoothly or was successfully opened and adhered to the vessel wall after remedial measures, the torsional tension within the stent affected its stability and its effect on the vascular intima. The action of the stent mesh on the vascular intima is not simply an outward radial force, but also involves a lateral pulling force caused by torsional tension. In actual clinical practice, when encountering tortuous vessels, stent opening is often unsatisfactory, requiring adjustments and remedial measures. This is mainly because the torsional tension within the stent cannot be released in time, easily leading to stent torsion, poor apposition, and incomplete opening. Remedial measures are required by the surgeon, such as massage with microguidewires, massage and pushing with microcatheters or intermediate catheters, and balloon dilation, which are time-consuming, laborious, and increase surgical risks. Sometimes, poor stent apposition can cause thrombus formation between the stent and the vessel wall. The thrombus can extend into the stent through the stent mesh, not only blocking perforators but also severely affecting blood flow in the carrier artery, leading to serious consequences. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a self-releasing torsional tension device and interventional surgical instrument for the release of cerebral vascular stents. Through the design of the catheter and guidewire for delivering the stent, this invention can automatically release the torsional tension generated during the release of cerebral vascular stents, improve the stress distribution within the stent mesh, ensure thorough stent opening and good apposition to the stent wall, and avoid abnormal opening after stent release, thereby making the patient safer.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a self-releasing torsional tension device during the release of a cerebral vascular stent, comprising:

[0007] A self-releasing torsion tension device during the release of a cerebral vascular stent includes a catheter and a guidewire sleeved inside the catheter;

[0008] The catheter is rotatably equipped with a rotating inner sheath, which contacts the outer wall of the stent to be intervened in; the guidewire is rotatably equipped with a rotor block, which is engaged with the inner wall of the stent to be intervened in; when the stent experiences torsional tension during its release in the cerebral blood vessels, the stent can rotate around the catheter and guidewire under the action of the rotating inner sheath and the rotor block, thereby achieving self-relieving of the torsional tension during the stent release process.

[0009] Furthermore, the rotating inner sleeve is located at the distal end of the catheter.

[0010] Furthermore, an installation groove is provided on the inner wall of the conduit, and the rotating inner sleeve is rotatably disposed within the installation groove.

[0011] Furthermore, the inner diameter of the rotating inner sleeve is equal to the inner diameter of the conduit.

[0012] Furthermore, the rotor block is a cylindrical tube with a connecting hole in the middle.

[0013] Furthermore, the guide wire is provided with a variable diameter section whose diameter is smaller than that of other parts, and the rotor block is sleeved on the variable diameter section through a connecting hole; the inner diameter of the connecting hole is larger than the diameter of the variable diameter section of the guide wire, but smaller than the diameter of other parts of the guide wire.

[0014] Furthermore, two sets of fixing blocks are spaced apart on the inner wall of the bracket, and the rotor block is engaged between the two sets of fixing blocks.

[0015] Furthermore, two sets of fixing blocks are installed at one end of the support near the operating end of the catheter.

[0016] Furthermore, each set of fixing blocks includes multiple fixing blocks, which are evenly distributed circumferentially on the inner wall of the bracket.

[0017] Secondly, the present invention also provides an interventional surgical instrument, comprising:

[0018] An interventional surgical instrument employs a self-releasing torsional tension device during the release of a cerebral vascular stent as described in the first aspect.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] This invention features a rotating inner cannula within the catheter and a rotating rotor block on the guidewire. During operation, the rotating inner cannula contacts the outer wall of the stent to be intervened in, while the rotor block engages with the inner wall of the stent. When torsional tension arises during stent deployment within the cerebral blood vessel, the stent rotates in real-time around the catheter and guidewire under the action of the rotating inner cannula and rotor block, achieving self-release of torsional tension during stent deployment. This automatic release of torsional tension generated during stent deployment improves the stress distribution within the stent mesh, ensuring thorough stent opening and good apposition to the vessel wall. It solves the problem of untimely release of torsional tension within the stent, thus avoiding abnormal stent opening after deployment and preventing serious consequences such as thrombosis between the stent and the vessel wall due to poor stent apposition, thereby enhancing patient safety. Attached Figure Description

[0021] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0022] Figure 1 This is a schematic diagram of the stent delivery and catheter according to Embodiment 1 of the present invention;

[0023] Figure 2 This is a schematic diagram of the stent delivery, catheter, and stent according to Embodiment 1 of the present invention;

[0024] Figure 3 This is a schematic diagram of the stent release process in Embodiment 1 of the present invention;

[0025] Figure 4 As in Embodiment 1 of the present invention Figure 3 Schematic diagram of the cross-section at point F;

[0026] Figure 5 As in Embodiment 1 of the present invention Figure 3 Schematic diagram of the cross-section at point G;

[0027] Figure 6 As in Embodiment 1 of the present invention Figure 3 Schematic diagram of the cross-section at point H;

[0028] Figure 7 As in Embodiment 1 of the present invention Figure 3 Schematic diagram of the cross-section at point I;

[0029] Figure 8 As in Embodiment 1 of the present invention Figure 3 Schematic diagram of the cross-section at point J;

[0030] Among them, 1. catheter; 2. guidewire; 21. guidewire tail end; 22. guidewire head end; 23. reducing section; 3. support; 31. fixing block; 32. support mesh wire; 4. rotor block; 5. rotating inner sleeve. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] Example 1:

[0034] With the advancement of new interventional materials and technologies, the field of cerebrovascular intervention is developing rapidly. Among these, cerebrovascular stents are increasingly widely used in interventional cerebrovascular treatment due to their effectiveness and convenience. Whether it's large cerebral aneurysms, wide-necked aneurysms unsuitable for simple coil embolization, stenting for cerebral venous sinus stenosis, or interventional treatments of carotid-cavernous fistulas that preserve the parent artery, these self-expanding cerebrovascular stents are increasingly used, especially the dense mesh stents of recent years. These cerebrovascular stents typically have the following characteristics: 1. Relatively long. Most of these stents are braided stents. While their diameter and length parameters are relatively stable under tension-free conditions, their length changes significantly when released within tortuous or unevenly sized blood vessels under varying tension. Furthermore, the stent undergoes various deformations similar to a spring, such as sliding, rebounding, contraction, and extension, under stress. To adapt to the curvature of the blood vessel and the specific lesion, these stents are generally quite long, sometimes reaching 6-7 cm. 2. Weak self-expanding property. These types of stents are delivered to the target location via a pathway catheter or stent delivery / deployment microcatheter, and then pushed out from the microcatheter containing the stent until deployment is complete. Some types of stents are equipped with a dedicated matching microcatheter, which is delivered through a larger diameter microcatheter or intermediate catheter for placement, deployment, and release of the stent. Unlike balloon-expandable stents, which rely on balloon injection to open after placement, self-expanding stents rely on their own elasticity to open, which has limited force. The stent's adherence to the wall depends to some extent on the radial force generated by its own elastic outward expansion. Within the braided stent, adjacent segments are influenced by the mutual restraint of the mesh fibers, with the denser the mesh, the greater this influence tends to be. If the stent is not fully opened due to external vascular conditions or its own internal tension, it will affect the opening of subsequent stent segments or even the entire stent. If the stent cannot be fully opened or opened at all, multiple push-pull release systems, in-stent microwire massage, microcatheter massage, pushing, and balloon dilation are required. These remedial measures inevitably prolong the operation time and significantly increase the risk of vascular intimal damage and embolic events, affecting the patient's treatment outcome to some extent. If these measures fail and the stent still cannot be opened, the stent placement has failed. Although open-loop stents do not have the same effect of mutual restraint between adjacent segments as braided stents, they still have the possibility of opening obstacles. If similar procedures are used for braided stents, these procedures are more complex for open-loop stents, and remedial measures to open the stent bring greater risks. It is often very difficult to pass through the stent lumen again with microwires and other devices, with risks of entering the stent mesh, the outer gap of the stent, the stent mesh or network being pushed and pulled deformed, or even tilting out of the lumen, causing more dangers. 3. Weak resistance to torsion. This type of stent can be opened completely and immediately without external force when opened externally, and the stent's own memory shape is well restored.However, within the body, cerebral blood vessels are significantly more tortuous than peripheral vessels, especially in the region from the cavernous segment of the internal carotid artery to the supraclinoid segment and the main trunk of the middle cerebral artery, where the vessel shape is relatively fixed and large. After stent placement, these vessels undergo minimal deformation. During stent release within the cerebral vessels, the vessel's course and shape undergo bending, twisting, and expansion. The tension cannot be fully released as it would be outside the body. If the accumulated torsional tension within the stent is not released, it affects stent opening, leading to incomplete stent opening, poor apposition, or incomplete opening. This can weaken blood flow to the carrier vessel, cause secondary thrombosis, perforator occlusion, or even stent failure to open or acute occlusion of the carrier vessel, resulting in serious consequences.

[0035] During the operation of cerebral vascular stents, the surgeon can currently only address the following three aspects regarding the stent itself: 1. Releasing the axial tension of the stent. This is achieved by controlling the stent's placement position. The surgeon first delivers the stent to the distal side of the target area and then withdraws the delivery system to release the axial tension accumulated inside the stent, aiming to release the stent with minimal tension. However, this operation only releases the axial tension of the stent system. The stent delivery system itself accumulates a certain amount of torsional tension during its long and tortuous journey through the blood vessels, but this is currently overlooked because it cannot be assessed through fluoroscopy or the operator's tactile feedback. 2. Adjusting the tension during stent release. After the stent is in place, the surgeon continuously adjusts and releases some of the stent's tension by pushing and pulling the stent guidewire and the delivery microcatheter / catheter to fully open the stent. This operation mainly adjusts the radial tension and the tension caused by axial bending. This operation does not address the torsional tension of the stent. 3. Remedial measures when stent opening is not ideal: massage with microguidewire, massage and push with microcatheter or intermediate catheter, follow up with balloon dilation and stent removal, etc. If post-balloon dilation is required, it is often because the previous measures have been tried repeatedly without success, and the safety of the operation has been greatly affected.

[0036] The torsional tension during the stent deployment process described above is not yet adequately understood or addressed. The generation of torsional tension includes: 1. The anterior portion of the stent is opened and adhered to the vessel wall. Due to the stent's elasticity, the pressure exerted by the stent on the vessel wall provides fixation. The larger the opening and the tighter the compression, the greater the force required for passive rotation of the stent. The tortuosity of cerebral blood vessels, the varying diameters and stiffness of their lumens, and especially the spiral tortuosity of the vessels, cause torsion between different stent segments, accumulating tension. 2. During stent deployment, the operator cannot sense, assess, or remove the torsional tension generated between the delivery system and the stent. The delivery system includes the puncture sheath, various levels of delivery catheters, microcatheters, guidewires, and stents, all of which have internal frictional resistance. Furthermore, as the delivery system travels from outside the body through multiple blood vessels and over numerous bends to reach the target intracranial cerebral blood vessels, internal deformation and compression occur, increasing the system's internal frictional resistance. During surgical procedures, the microcatheters and guidewires used to deliver stents often have internal torsional tension that cannot be fully released. For example, it is frequently observed during surgery that the ends of the microcatheters and guidewires cannot rotate coaxially and at the same angle. While the operator can determine the stent's position and opening status using X-ray fluoroscopy, current technology cannot determine the internal torsional tension of the stent, let alone relieve this tension.

[0037] Adverse consequences may arise from the failure to release torsional tension during stent deployment. Currently, various intracranial stents are relatively mature in terms of materials and manufacturing processes. Stents placed in relatively straight vessels can often be easily and completely opened without remedial measures, and they can also be easily and completely opened in simply tortuous vessels. This can be confirmed by demonstrations of different stents in smooth in vitro catheters. However, in actual clinical practice, when encountering tortuous vessels, stent opening is often unsatisfactory, requiring adjustments and remedial measures. This is mainly because the torsional tension inside the stent cannot be released in time, affecting stent opening and easily leading to stent torsion, poor apposition, and incomplete opening. Remedial measures are required by the operator: massage with a microguidewire, massage and pushing with a microcatheter or intermediate catheter, and post-balloon dilation, etc., which are time-consuming, labor-intensive, and increase surgical risks. Sometimes, poor stent apposition can cause thrombus formation between the stent and the vessel wall. The thrombus can extend into the stent through the stent mesh, not only blocking perforators but also severely affecting blood flow in the parent artery, leading to serious consequences. Even if the stent opens smoothly or is successfully deployed and adhered to the vessel wall after remedial measures, the internal torsional tension of the stent still affects its stability and its effect on the intima. When torsional tension is present, the action of the stent mesh on the vessel wall intima is not simply an outward radial force, but also includes lateral pulling and shearing forces caused by torsional tension, which can damage both the vessel intima and perforators.

[0038] To address the issue of torsional tension not being relieved in a timely manner during stent release, such as Figure 1 and Figure 2 As shown, this embodiment provides a self-unloading torsion tension device during the release of a cerebral vascular stent, including a catheter 1 and a guidewire 2 sleeved inside the catheter 1;

[0039] The catheter 1 is rotatably equipped with a rotating inner sheath 5, which contacts the outer wall of the stent 3 to be intervened in; the guidewire 2 is rotatably equipped with a rotor block 4, which is engaged with the inner wall of the stent 3 to be intervened in; when the stent 3 experiences torsional tension during its release in the cerebral blood vessels, the stent 3 rotates around the catheter 1 and guidewire 2 in real time under the action of the rotating inner sheath 5 and the rotor block 4, thereby realizing the self-relieving of torsional tension during the release of the stent 3.

[0040] Specifically, such as Figure 3 As shown, during operation, the rotating inner cannula 5 contacts the outer wall of the stent 3 to be intervened in, and the rotor block 4 is engaged with the inner wall of the stent 3 to be intervened in. When the stent 3 experiences torsional tension during its release in the cerebral blood vessels, the stent 3 rotates around the catheter 1 and the guidewire 2 in real time under the action of the rotating inner cannula 5 and the rotor block 4, thereby realizing the self-release of torsional tension during the release of the stent 3. During the operation, the torsional tension generated during the release of the stent 3 in the cerebral blood vessels is automatically released, which improves the stress distribution between the stent mesh wires 32, so that the stent 3 opens completely and adheres well to the wall. This solves the problem that the torsional tension inside the stent 3 cannot be released in time, thereby avoiding the phenomenon of abnormal opening of the stent 3 after release, and avoiding the phenomenon of thrombosis between the stent and the vessel wall due to poor adhesion of the stent 3, which may lead to serious consequences, thus making the patient safer.

[0041] Understandably, this embodiment is an improvement on the structure of catheter 1 and guidewire 2. There are two main ways to use catheter 1 and guidewire 2 when pushing stent 3: one is that before use, they are compressed around guidewire 2 in the corresponding sheath. When in use, the stent 3 is pushed into catheter 1 through the guidewire 2 after being placed in position, and then the delivery, opening and release actions are completed; the other is that before use, stent 3 is compressed around guidewire 2 in tube 1. When in use, catheter 1 is pushed into position through the established catheter path, and then the guidewire 2 at the end of the catheter is manipulated to complete the opening and release actions of stent 3.

[0042] The rotating inner sleeve 5 is located at the distal end of the catheter. It can be understood that the distal end of the catheter is used to place the support 3 or the end located at the guidewire tip 22 during actual operation.

[0043] One implementation of the rotating inner sleeve 5 rotatably disposed within the conduit 1 is as follows: an installation groove is provided on the inner wall of the conduit 1, and the rotating inner sleeve 5 is rotatably disposed within the installation groove; the inner diameter of the rotating inner sleeve 5 is equal to the inner diameter of the conduit 1.

[0044] One implementation of the rotatable rotor block 4 of the guide wire 2 is to set the rotor block 4 as a circular tube with a connecting hole in the middle; the guide wire 2 is provided with a variable diameter section 23 with a diameter smaller than other parts, and the rotor block 4 can be sleeved on the variable diameter section 23 through the connecting hole; the inner diameter of the connecting hole is larger than the diameter of the variable diameter section 23 of the guide wire 2, but smaller than the diameter of other parts of the guide wire 2.

[0045] In order to enable the guidewire 2 and the rotor block 4 to push and pull the stent 3 in the axial direction, optionally, two sets of fixing blocks are provided at intervals on the inner wall of the stent 3, and the rotor block 4 is engaged between the two sets of fixing blocks; the two sets of fixing blocks can be set at one end of the stent 3 near the operating end of the catheter 1; it can be understood that the operating end here can be understood as the last end of the stent 3 to be released during the process of releasing the stent 3 into the cerebral blood vessels.

[0046] Each set of fixing blocks includes multiple fixing blocks 31, which can be selected as 2 to 5; the multiple fixing blocks 31 are evenly distributed in the circumferential direction on the inner wall of the bracket 3.

[0047] like Figure 3 As shown, the microscopic details of the catheter 1 and its internal structure are displayed. The guidewire 2, used for pushing the stent, is located in the center, with its tip 22 extending beyond the front end of the catheter 1. A variable-diameter section 23 is partially designed on the guidewire 2. This variable-diameter section 23 is the section where the rotor block 4 is fitted onto the guidewire 2. The two sides of the variable-diameter section 23 have slightly larger diameters, and the junction with the thinner section is a vertical step, thus restricting the sliding of the rotor block 4 along the guidewire 2. Figure 3 As shown, the portion inside the catheter is in the closed state of the stent 3 when it is not open. Two sets of fixing blocks are attached to the inner side of the proximal end of the stent 3, located on either side of the rotor block 4. The inner wall of the front section of the catheter 1 is designed with a rotating inner sleeve 5 nested within it. The catheter wall accommodates the rotating inner sleeve 5 parallel to the wall. The inner wall of the catheter has steps perpendicular to the lumen at both ends corresponding to the rotating inner sleeve 5. These steps restrict the axial sliding of the rotating inner sleeve 5 within the catheter 1. The inner diameter of the catheter wall excluding the rotating inner sleeve 5 is the same as that of the rotating inner sleeve 5, and the gap between the catheter 1 and the rotating inner sleeve 5 at the step is minimal, not affecting the sliding of the guidewire 2 and the stent 3 within the lumen.

[0048] like Figure 4 As shown, Figure 3 The cross-section at point F shows the catheter 1 and the guidewire 2 within the lumen. This position is near the rotating inner sleeve 5, and the stent 3 has also been advanced forward. Figure 5 As shown, Figure 3The cross-section at point G includes the catheter 1, the rotating inner sleeve 5, the stent 3, and the fixing blocks 31 attached to the proximal inner wall of the stent 3, as well as the guide wire 2. At this location, the rotating inner sleeve 5 is present, and the stent 3 is located within the lumen of the rotating inner sleeve 5 in a closed state. Under the constraint of the rotating inner sleeve 5, the fixing blocks 31 on the proximal inner wall of the stent 3 are tightly clustered around the guide wire 2. The fixing blocks 31 on both sides of the rotor block 4 can be in groups of 2 to 5, and these, along with the fixing blocks 31 attached to the proximal inner wall of the stent 3, can exert force on the rotor block 4 on the guide wire 2, causing the stent to move forward and backward. Figure 6 As shown, Figure 3 The cross-section at point H includes the conduit 1, the rotating inner sleeve 5, the support 3, the rotor block 4, and the tapered section of the guidewire 2. At this location, the conduit 1 contains the rotating inner sleeve 5, and the support 3 is in a closed state. The rotor block 4 on the guidewire 2 is located within this cross-section. The rotor block 4 can be cylindrical and can rotate around the tapered section of the guidewire 2, but the localized diameter change on this section of the guidewire restricts the rotor block 4 from sliding along the guidewire. Figure 7 As shown, Figure 3 The cross-section at point I includes the catheter 1, the rotating inner sleeve 5, the stent 3, and the guidewire 2; this cross-section contains the body of the stent 3. For example... Figure 8 As shown, Figure 3 The cross-section at point J includes catheter 1, stent 3 and guidewire 2; the cross-section includes the portion of catheter 1 near the orifice, and its thickness is consistent with the thickness of the catheter near the rotating inner cannula 5.

[0049] The working principle or process of this embodiment is as follows:

[0050] After the surgeon establishes the access pathway, the stent 3 is delivered and the catheter 1 is inserted into place. For catheters without pre-loaded stents, the stent 3 must first be pushed into the catheter 1 through the catheter tail end to the target area. For catheters containing pre-loaded stents, the stent 3 can be prepared for release after it has been pushed into the target area.

[0051] The guide wire 2 is pushed and pulled to adjust the front and rear positions of the bracket 3. The rotor block 4 on the front diameter-changing section 23 of the guide wire 2 moves forward and backward with the guide wire 2. The diameter change on the guide wire 2 restricts the axial sliding of the rotor block 4. When the guide wire 2 is pushed forward, the near-side diameter-changing step pushes the rotor block 4 forward, and when the guide wire 2 is pulled back, the far-side diameter-changing step pulls the rotor block 4 backward.

[0052] The stent 3 inside the lumen of catheter 1, constrained by the inner wall of the lumen, has two sets of fixing blocks attached to its proximal inner side that gather around the guidewire 2. When the guidewire 2 is pushed, the rotor block 4 acts on the fixing block 31, thereby driving the stent 3 to move forward and backward within the lumen of catheter 1. When the rotor block 4 cannot contact the fixing block 31, it cannot function on the stent 3. When the stent 3 is completely pushed out of the catheter 1, it opens under its own elasticity, the rotor block 4 disengages from the fixing block 31, and the guidewire 2 no longer functions on the stent 3.

[0053] It should be noted that in traditional methods and devices, when the stent 3 is not fully released, the front part gradually opens, and the landing part of the stent 3 adheres to the inner wall of the blood vessel. Due to the tortuosity of the blood vessel and the inability to release the internal torsional tension of the system, torsional tension accumulates between the front and rear parts of the stent 3. This torsional tension cannot be relieved, thus affecting the opening of the stent. During the release of the stent 3, the rear part cannot rotate freely to relieve the internal torsional tension of the stent. The main reason is that the rear part of the stent cannot rotate synchronously with the front part of the stent 3. The resistance comes from the friction between the stent 3 and the delivery system, i.e., the delivery and release catheter, including two parts: the stent 3 and the inner wall of the catheter 1, and the guidewire 2, with the former being the main force. In this embodiment, the rotor block 4 is not fixedly welded to the guidewire 2, but is sleeved on the guidewire 2. It is cylindrical and can rotate freely around the guidewire 2. The contact points between it and the guidewire 2 and the fixing block 31 are limited, so the friction is minimal. Once the rotor block 4 is subjected to torque, it will rotate and be dislodged, acting similarly to a bearing. When the stent 3 is not opened, the friction between it and the inner wall of the catheter 1 is the main force affecting the free rotation of the stent 3. After the self-expanding stent is manufactured and compressed into the catheter 1, its own outward expansion elasticity acts on the inner wall of the catheter 1. Due to the large radial force and large contact area, the friction is large. In addition, the tortuosity of the blood vessel causes local bending of the catheter 1 and the stent 3, which further increases the resistance to the rotation of the stent 3 in the catheter 1. As a result, the stent 3 cannot rotate completely at the same arc when it is released, resulting in the accumulation of torsional tension, which affects the opening of the stent. In this embodiment, the front part of the catheter wall is designed with two layers. The inner layer is a movable layer that is embedded in the outer layer but can rotate freely along the axial direction. The elastic pressure of the stent 3 itself acts on the inner wall of the rotating inner sleeve 5 that restricts its opening. When there is torsional tension inside the stent 3, the front part is already attached to the blood vessel wall and fixed. The tail part of the stent 3 can rotate together with the rotating inner sleeve 5 to relieve the torsional tension inside the stent, so the stent 3 is easy to open.

[0054] Example 2:

[0055] This embodiment provides an interventional surgical instrument that employs a self-unloading torsion tension device during the release of a cerebral vascular stent as described in Embodiment 1. It is understood that the interventional surgical instrument includes not only the catheter 1, guidewire 2, and stent 3 as described in Embodiment 1, but also other auxiliary devices. One type of interventional surgical instrument is the one operated by the surgeon as described in Embodiment 1, while the other type of interventional surgical instrument can be an interventional surgical instrument that uses a robot to operate the catheter and guidewire.

[0056] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A self-releasing torsional tension device during the release of a cerebral vascular stent, characterized in that, Includes a catheter and a guidewire fitted inside the catheter; The catheter is rotatably equipped with a rotating inner sleeve, which is located at the distal end of the catheter. An installation groove is provided on the inner wall of the catheter, and the rotating inner sleeve is rotatably positioned within this groove. The inner diameter of the rotating inner sleeve is equal to that of the catheter, and it contacts the outer wall of the stent to be intervened in. The guidewire is rotatably equipped with a rotor block, which is a circular tube with a connecting hole in the center. The guidewire has a variable diameter section with a smaller diameter than other parts. The rotor block is fitted onto the variable diameter section through the connecting hole. The two sides of the variable diameter section have slightly larger diameters, and the connection with the smaller diameter section is a vertical step-like shape, restricting the rotor block from sliding along the guidewire. Two sets of fixing blocks are spaced apart on the inner wall of the stent, and the rotor block is engaged between these two sets of fixing blocks. The rotor block is also engaged with the inner wall of the stent to be intervened in. When torsional tension occurs during stent deployment in the cerebral blood vessels, the stent can rotate around the catheter and guidewire under the action of the rotating inner sleeve and the rotor block, achieving self-relieving of torsional tension during stent deployment.

2. The self-unloading torsion tension device during the release of the cerebral vascular stent as described in claim 1, characterized in that, The inner diameter of the connecting hole is larger than the diameter of the variable diameter section of the guide wire, but smaller than the diameter of other parts of the guide wire.

3. The self-unloading torsion tension device during the release of the cerebral vascular stent as described in claim 1, characterized in that, Two sets of fixing blocks are set at one end of the support near the operating end of the catheter.

4. The self-unloading torsion tension device during the release of the cerebral vascular stent as described in claim 1, characterized in that, Each set of fixing blocks includes multiple fixing blocks, which are evenly distributed circumferentially on the inner wall of the bracket.

5. An interventional surgical instrument, characterized in that, The device employs a self-unloading torsion tension device during the release of a cerebral vascular stent as described in any one of claims 1-4.

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