A stent placement catheter

Abstract

The application provides a stent implantation catheter, and relates to the technical field of medical devices, which solves the problem of easy kinking of stent delivery and release. The application comprises an insertion tube and a distal tube coaxially butted in the axial direction. The inner circumferential surface of the distal tube is used to radially contact and extrude the outer circumferential surface of the stent, so as to stabilize the bearing of the stent by using the friction force between the distal tube and the stent, and prevent the stent from being unloaded during the delivery process. The proximal end of the distal tube is coaxially butted to the distal end of the insertion tube in a rotatable manner, so that the distal tube can rotate around the axis in the circumferential direction relative to the insertion tube under the action of external force. When the distal end of the stent extends out of the distal tube and is anchored on the wall of the human body cavity, the torque generated by the torsion difference between the distal end and the proximal end of the stent can be transmitted to the distal tube, so that the distal tube rotates to overcome the friction force between the distal tube and the insertion tube, thereby relieving or even eliminating the torsion difference between the distal end and the proximal end of the stent, and effectively preventing the stent from being kinked during the delivery process and the release process.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a stent placement catheter. Background Technology

[0002] The routine clinical delivery and deployment of endovascular stents (including intracranial, coronary, and peripheral stents) and other cavity stents all rely on catheter-based access. In related technologies, catheters used for stent delivery are mostly made of rigid or semi-rigid materials, with a single, integrated cavity design, and their tips are strictly coaxial. These catheters achieve stable support of the stent through the friction between their inner wall and the stent, preventing stent detachment during delivery and enabling axial pushing and retraction.

[0003] Because human blood vessels or other cavities have natural tortuosity, bifurcation, and rotation angles, complications such as stent kinking and poor opening can easily occur during the delivery and release of stents through catheters. Summary of the Invention

[0004] The purpose of this invention is to design a stent placement catheter to solve the problem of easy kinking during stent delivery and release.

[0005] This invention is achieved through the following technical solution: Some embodiments of the present invention provide a stent placement catheter, including an insertion tube and a distal tube; the insertion tube extends axially from a proximal end to a distal end; the distal tube extends axially from a proximal end to a distal end, and the inner circumferential surface of the lumen of the distal tube is used to radially contact and compress at least a portion of the axial segment of the outer circumferential surface of a stent placed therein. The proximal end of the distal tube is rotatably coaxially abutted against the distal end of the insertion tube, such that the distal tube can rotate circumferentially about an axis relative to the insertion tube under the action of an external force.

[0006] To further improve the present invention, the following configuration is adopted: the static friction between the distal tube and the support is greater than the static friction between the distal tube and the insertion tube.

[0007] To further improve the implementation of the present invention, the following configuration is adopted: at least a portion of the axial section of the distal tube is configured as a developing section.

[0008] To further improve the present invention, the following configuration is adopted: the proximal end of the distal tube and the distal end of the insertion tube are continuously engaged circumferentially to achieve rotatable coaxial docking.

[0009] To further improve the present invention, the following structure is specifically adopted: the overall stiffness of the engagement joint between the proximal end of the distal tube and the distal end of the insertion tube is greater than the stiffness of the axial segment of the distal tube located on the distal side of the engagement joint and the stiffness of the axial segment of the insertion tube located on the proximal side of the engagement joint.

[0010] To further improve the present invention, the following structure is specifically adopted: the stent placement catheter further includes at least one annulus coaxially disposed with the distal tube, all the annulus being axially positioned on the wall of the lumen of the distal tube and arranged sequentially along the axial direction of the distal tube; the annulus and the distal tube are circumferentially rotatable relative to each other about the axis; the inner circumferential surface of the annulus is flush with the inner circumferential surface of the lumen of the distal tube, for radially contacting and pressing the outer circumferential surface of the stent placed therein.

[0011] To further improve the implementation of the present invention, the following structure is adopted: the cavity wall of the distal tube is provided with a mounting groove, each of the rings is individually nested in a mounting groove, and a limiting protrusion is formed between two adjacent mounting grooves, the limiting protrusion maintaining the axial distance between two adjacent rings.

[0012] The present invention has the following advantages and beneficial effects: In this invention, the distal end of the stent placement catheter can constrain the stent through radial contact compression on the inner circumferential surface of its lumen, thereby utilizing the frictional force between the distal end and the stent to stably support the stent and prevent stent detachment during delivery. Because the insertion tube and distal end of the stent placement catheter are rotatably coaxially connected in the axial direction, the distal end can rotate circumferentially relative to the insertion tube. Thus, when the distal end of the stent extends out of the distal end and anchors against the wall of the body cavity, the torque generated by the torsional difference between the proximal and distal ends of the stent can be transmitted to the distal end, causing it to overcome the frictional force between itself and the insertion tube and rotate. This alleviates or even eliminates the torsional difference between the proximal and distal ends of the stent, effectively preventing stent kinking during delivery and release. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the stent placement catheter in some embodiments of this application, in which the distal end of the stent has extended out of the catheter and unfolded. Figure 2This is a schematic diagram of the distal end of the stent placement catheter in some embodiments of this application. Figure 1 ; Figure 3 This is a schematic diagram of the interior of the stent placement catheter in some embodiments of this application. Figure 1 The red-filled area in the figure represents the axial segment where the developing section of the distal tube is located; Figure 4 This is a schematic diagram of the distal end of the stent placement catheter in some embodiments of this application. Figure 2 ; Figure 5 This is a schematic diagram of the interior of the stent placement catheter in some embodiments of this application. Figure 2 ; Figure 6 This is a schematic diagram of the use of the stent placement catheter in some embodiments of this application. Figure 1 ; Figure 7 This is a schematic diagram of the connection structure between the distal tube and the insertion tube in some embodiments of this application; Figure 8 This is a schematic diagram of the use of the stent placement catheter in some embodiments of this application. Figure 2 ; Figure 9 This is a schematic diagram of the connection between the annulus and the distal tube in some embodiments of this application.

[0015] The diagram is marked as follows: 100. Stent placement catheter; 110. Insertion tube; 111. First axial ring; 112. First annular buckle; 113. First annular groove; 114. T-slot; 120. Distal tube; 121. Second axial ring; 122. Second annular buckle; 123. Second annular groove; 124. Developing section; 125. Mounting groove; 126. Limiting protrusion ring; 127. T-shaped buckle; 130. Circular ring; 200. Bracket. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be noted that, unless otherwise stated, "multiple" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0018] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0019] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0020] In the various embodiments of this application, "near end" and "far end" refer to the distance of each component from the user in the usage environment. The end closer to the user is designated as the "near end", and the end farther from the user is designated as the "far end".

[0021] Existing catheters used for stent delivery and control all feature a single-lumen design as their core structure, with the distal and proximal ends of the catheter strictly coaxial. The catheters are mostly made of rigid or semi-rigid materials.

[0022] The inventors discovered in production practice that existing catheters are one-piece designs and lack axial rotation adjustment capabilities, only enabling axial pushing and retraction. This easily leads to stent kinking. The core mechanism is as follows: During stent advancement within the catheter lumen, sufficient friction between the stent and the catheter inner wall is required to prevent stent dislodgement. However, when the distal end of the stent rotates due to resistance from vascular tortuosity or bifurcation, the catheter tip cannot follow the rotation, and the proximal end of the stent cannot rotate synchronously due to the frictional force of the catheter inner wall. This results in an imbalance of forces at both ends of the stent, ultimately causing twisting and kinking in the middle segment, obstructing the patency of the stent lumen, and affecting the normal release and apposition of the stent. Furthermore, different types of stents exhibit different kinking characteristics. Braided stents are prone to "coiling" during testing, while cut-type and self-expanding stents, due to their structural characteristics, are more likely to experience distal rotation and proximal fixation in tortuous vessel segments, thus leading to kinking.

[0023] This application discloses a stent placement catheter 100, the distal end of which has the ability to rotate based on the torque applied to the stent 200, so that the stent 200 can be untwisted and prevent kinking.

[0024] The following is in conjunction with the appendix Figures 1-9 The stent placement catheter 100 provided in this application will be described in detail through specific embodiments and application scenarios.

[0025] Embodiments of this application disclose a stent placement catheter 100, such as Figures 1-6 As shown, the stent placement catheter 100 extends axially from the proximal end to the distal end, and has an axially penetrating lumen inside. The stent placement catheter 100 includes a distal tube 120 disposed at the distal end and an insertion tube 110 coaxially connected to the proximal end of the distal tube 120. In this embodiment, the insertion tube 110 and the distal tube 120 are separate components, and both the insertion tube 110 and the distal tube 120 are straight tubes extending axially from the proximal end to the distal end. The insertion tube 110 and the distal tube 120 are straight tubes made of rigid or semi-rigid materials. The stent placement catheter 100 after the insertion tube 110 and the distal tube 120 are coaxially connected has a certain degree of flexibility and can adapt to the bending path of human cavities, such as blood vessels, to a certain extent, so as to have good bending performance.

[0026] like Figure 6 and Figure 8 As shown, the inner circumferential surface of the lumen of the distal tube 120 is used to radially contact and compress at least a portion of the axial section of the outer circumferential surface of the bracket 200 inserted therein, so as to constrain the bracket 200 and use the friction between the distal tube 120 and the bracket 200 to stabilize and support the bracket 200, and prevent the bracket 200 from being deloaded during transportation.

[0027] like Figure 2 , Figure 6 and Figure 7 As shown, the stent placement catheter 100 allows the proximal end of the distal tube 120 to be rotatably coaxially connected with the distal end of the insertion tube 110, so that the distal tube 120 can rotate circumferentially relative to the insertion tube 110 around the axis under the action of external force.

[0028] The frictional force between the rotatable connection between the distal tube 120 and the insertion tube 110 is small, allowing the distal tube 120 to easily rotate axially relative to the insertion tube 110 under the drive of the torsion stent 200, thus enabling the stent 200 to eventually untwist. The frictional force between the distal tube 120 and the insertion tube 110 can be controlled between 0.0001N and 0.02N. For example, the static frictional force between the distal tube 120 of the stent placement catheter 100 and the stent 200 is set to be greater than the static frictional force between the distal tube 120 and the insertion tube 110, allowing the stent 200 to drive the distal tube 120 to rotate circumferentially.

[0029] In this embodiment, the insertion tube 110 and the distal tube 120 of the stent placement catheter 100 are rotatably coaxially connected in the axial direction, allowing the distal tube 120 to rotate circumferentially relative to the insertion tube 110. Thus, when the distal end of the stent 200 extends out of the distal tube 120 and is anchored to the wall of the body cavity, the torque generated by the torsional difference between the proximal and distal ends of the stent 200 can be transmitted to the distal tube 120, causing the distal tube 120 to overcome the frictional force between itself and the insertion tube 110 and rotate. This alleviates or even eliminates the torsional difference between the proximal and distal ends of the stent 200, effectively preventing the stent 200 from twisting during delivery and release.

[0030] In one application scenario, the stent placement catheter 100 is advanced along the guidewire into a tortuous diseased blood vessel, and the stent 200 is pushed to the target site. The distal end of the stent 200 is as follows... Figure 1 , Figure 6 and Figure 8 As shown, the distal end of the stent placement catheter 100 is first withdrawn from the lumen of the distal tube 120, unfolding and anchoring to the inner wall of the blood vessel. As the stent placement catheter 100 continues to withdraw and release the remaining stent 200, the bending of the blood vessel pulls on the distal end of the stent 200, generating a circumferential torsional moment. Because the proximal end of the stent 200 is constrained by the inner circumferential surface of the distal tube 120, the torsional force acts directly on the distal tube 120. After overcoming the minor friction with the insertion catheter 110, the distal tube 120 follows the proximal end of the stent 200 in circumferential rotation, releasing the torsional stress in real time. This alleviates or even eliminates the torsional difference between the proximal and distal ends of the stent 200, preventing mid-segment kinking or curling throughout the process. After the stent 200 is completely released, the stent placement catheter 100 is withdrawn entirely from the blood vessel.

[0031] According to some optional embodiments, the axial length of the lumen of the distal tube 120 of the stent placement catheter 100 can be designed as needed to accommodate stents 200 with different axial lengths. The axial length of the distal tube 120 is controlled between 3mm and 25mm, for example, 3mm, 10mm, or 20mm.

[0032] In some embodiments, the axial length of the lumen of the distal tube 120 is less than or equal to the axial length of the stent 200. For example, the axial length of the distal tube 120 is equal to the axial length of the stent 200 to be inserted, such that the distal tube 120 can radially contact and compress the entire axial segment of the stent 200. For example, the axial length of the distal tube 120 is less than the axial length of the stent 200 to be inserted, such that the distal tube 120 can only radially compress a portion of the axial segment of the stent 200.

[0033] According to some optional embodiments, at least a portion of the axial section of the distal tube 120 is configured as a radiopaque portion 124. Exemplarily, the radiopaque portion 124 is formed on the inner or outer circumferential surface of the distal tube 120 by coating with a radiopaque coating. Exemplarily, the radiopaque portion 124 is formed in the tube wall of the distal tube 120 by mixing a high-density radiopaque substance into the material during manufacturing. With the radiopaque portion 124 provided on the distal tube 120, the position of the distal end of the stent placement catheter 100 can be observed in real time during surgery, facilitating precise control of the stent 200 release process by the surgeon.

[0034] In some embodiments, the axial length of the developing section 124 is 0.8 mm to 1.2 mm, for example, 1 mm.

[0035] In some embodiments, in order to better visualize the position of the distal tube 120 of the catheter 100 by imaging, the imaging portion 124 is disposed on the distal tube 120 near its distal end face. Preferably, the axial distance between the distal end of the imaging portion 124 and the distal end face of the distal tube 120 is set to 0.6-1.2 mm, with 1 mm being optimal.

[0036] According to some optional embodiments, such as Figure 3 , Figure 6 and Figure 7 As shown, in this embodiment, the stent placement catheter 100 rotatably connects the proximal end of the distal tube 120 and the distal end of the insertion tube 110 via a snap-fit ​​structure. Specifically, the proximal end of the distal tube 120 and the distal end of the insertion tube 110 are continuously snapped together circumferentially to achieve coaxial connection, so that the snap-fit ​​connection between the distal tube 120 and the insertion tube 110 has a certain degree of sealing while being able to rotate relative to each other around the axis.

[0037] In some embodiments, the proximal end of the distal tube 120 and the distal end of the insertion tube 110 are made more rigid than their respective other parts, thus having higher stiffness. For example, the material of the proximal end of the distal tube 120 and the distal end of the insertion tube 110 is made of a harder material than other parts, or a harder short tube is embedded in the tube wall of the proximal end of the distal tube 120 and the distal end of the insertion tube 110, so that the interlocking part of the proximal end of the distal tube 120 and the distal end of the insertion tube 110 can form an axial rigid joint. The overall stiffness of this axial rigid joint is greater than the stiffness of the axial segment of the distal tube 120 located on the distal side of the interlocking part, and also greater than the stiffness of the axial segment of the insertion tube 110 located on the proximal side of the interlocking part. An axial hard joint is formed at the engagement point between the proximal end of the distal tube 120 and the distal end of the insertion tube 110. This can better maintain the connection stability of the engagement point and prevent the engagement point from disengaging when the distal tube 120 and the insertion tube 110 adapt to bending within the human body cavity.

[0038] According to some optional embodiments, such as Figure 3 and Figure 6 As shown, the stent insertion catheter 100 uses a ring-shaped snap-fit ​​structure at the engagement point to coaxially and circumferentially rotatably connect the proximal end of the distal tube 120 to the distal end of the insertion tube 110. Specifically, the distal end face of the insertion tube 110 is provided with a first axial ring 111 extending axially at one end. The first axial ring 111 is circumferentially closed. The inner circumferential surface of the distal end of the first axial ring 111 is provided with a radially protruding first annular buckle 112, and the inner circumferential surface of the proximal end of the first axial ring 111 is provided with a radially concave first annular groove 113. Correspondingly, the proximal end face of the distal tube 120 is provided with a second axial ring 121 extending axially at one end. The second axial ring 121 is circumferentially closed. The outer circumferential surface of the proximal end of the second axial ring 121 is provided with a radially protruding second annular buckle 122, and the outer circumferential surface of the distal end of the second axial ring 121 is provided with a radially concave second annular groove 123. The first annular buckle 112 radially engages with the second annular groove 123 in the full circumferential direction to rotatably engage with the second axial ring 121. Simultaneously, the second annular buckle 122 radially engages with the first annular groove 113 in the full circumferential direction to rotatably engage with the first axial ring 111. The distal end of the insertion tube 110 and the proximal end of the distal tube 120 are engaged by the first annular buckle 112 and the second annular buckle 122, allowing the distal tube 120 to rotate coaxially with respect to the insertion tube 110.

[0039] In some embodiments, such as Figure 6As shown, the width of the second annular groove 123 is slightly larger than the width of the first annular groove 113, and the axial length of the first annular buckle 112 is slightly larger than that of the second annular buckle 122. This results in a wider engagement contact area at the proximal end of the distal tube 120 compared to the distal end of the insertion tube 110, improving the anti-dislodgement capability of the distal tube 120. Conversely, a narrower engagement contact area at the distal end of the insertion tube 110 helps maintain better flexibility, giving the distal end of the stent placement catheter 100 better anti-dislodgement capability and flexibility, reducing the risk of injury to body cavities.

[0040] In some embodiments, in order to give the distal tube 120 a small rotational resistance, there is a small radial and / or axial fit gap between the first annular buckle 112 and the second annular groove 123; there is a small radial and / or axial fit gap between the second annular buckle 122 and the first annular groove 113.

[0041] According to some optional embodiments, such as Figure 7 As shown, the stent insertion catheter 100 uses a ring-shaped snap-fit ​​structure at the engagement point to coaxially and circumferentially rotatably connect the proximal end of the distal tube 120 to the distal end of the insertion tube 110. Specifically, the distal end face of the insertion tube 110 is provided with an axially concave T-shaped groove 114, which is circumferentially closed. Correspondingly, the proximal end face of the distal tube 120 is provided with an axially extending T-shaped buckle 127 with a T-shaped cross-section, which is circumferentially closed into a ring. The proximal end of the distal tube 120 is rotatably engaged by axially inserting the T-shaped buckle 127 into the T-shaped groove 114 on the distal end face of the insertion tube 110.

[0042] According to some optional embodiments, such as Figure 4 , Figure 5 , Figure 8 and Figure 9 As shown, the stent placement catheter 100 also includes at least one annulus 130 coaxially disposed with respect to the distal tube 120. In this embodiment, all annulus 130 are axially positioned on the wall of the lumen of the distal tube 120 and are arranged sequentially at intervals along the axial direction of the distal tube 120. At the same time, the annulus 130 and the distal tube 120 can rotate relative to each other around the axis.

[0043] like Figure 6 As shown, the inner circumferential surface of the annulus 130 is flush with the inner circumferential surface of the lumen of the distal tube 120, for radial contact and compression of the outer circumferential surface of the bracket 200 inserted therein, so as to constrain the bracket 200.

[0044] The ring 130 is a structural component made of polymer, metal or inorganic non-metallic materials, such as nickel-titanium ultrathin tubing or ePTFE extrusion ring.

[0045] The number of rings 130 is typically between 50 and 500. The axial length occupied by all rings 130 is determined based on the axial length of the bracket 200 to be constrained. (Reference) Figure 8 The axial distance between each ring 130 and the distal end face of the distal tube 120 is less than the axial length of the support 200. This allows the ring 130 to contact and compress the outer circumferential surface of the support 200 after it has been pushed out of the lumen of the distal tube 120 at the distal end of the support 200. This enables the ring 130 to alleviate the torsional difference of the support 200, rather than simply to contact the outer circumferential surface of the support 200 when the lumen of the distal tube 120 has not been pushed out.

[0046] To minimize surface friction in the cylindrical ring 130, its outer circumferential surface can be polished to create a polished surface; alternatively, a hydrophilic or hydrophobic coating can be applied to the inner circumferential surface of the ring 130. To accommodate the general dimensional requirements of catheters used for vascular stent placement, the ring width of the ring 130 is 0.02 mm–0.08 mm. The axial distance between adjacent rings 130 is 0.01 mm–0.02 mm.

[0047] To minimize the rotational resistance between the annulus 130 and the distal tube 120, such as Figure 9 As shown, there is a small axial fit clearance between the ring 130 and the mounting groove 125. Simultaneously, there is a small radial fit clearance between the ring 130 and the mounting groove 125. The radial fit clearance can be 0.002mm-0.01mm.

[0048] In this embodiment, each ring 130 in the stent placement catheter 100 can rotate independently circumferentially relative to the distal tube 120. This allows the stent placement catheter 100 to achieve a large-angle rotation of the distal tube 120 by utilizing the relative rotation between the distal tube 120 and the insertion tube 110. The rings 130 can also achieve a small-angle adaptive rotation of the proximal part of the stent 200. This better ensures that the stent 200 fits tightly against the human body cavity without generating additional torsion during delivery and release, making it particularly suitable for long stents with a large axial length.

[0049] According to some optional embodiments, the cavity wall of the distal tube 120 is provided with mounting grooves 125, the number of which is the same as the number of annular rings 130, with each annular ring 130 nested individually within a mounting groove 125. A limiting protrusion 126 formed between two adjacent mounting grooves 125 is used to axially limit the annular rings 130, so as to maintain the axial distance between two adjacent annular rings 130 and prevent the annular rings 130 from moving axially.

[0050] According to some alternative embodiments, in order to securely mount the ring 130 within the mounting groove 125, the ring 130 and the mounting groove 125 are magnetically attracted to each other in the radial direction. For example, the ring 130 is configured as a magnetic structural component, and the cavity wall of the distal tube 120 is ferromagnetic at the location of the mounting groove 125, so that the ring 130 is securely attracted to the mounting groove 125 by magnetic force.

[0051] Current catheter technology only establishes a pathway through its lumen to deliver the stent to the lesion site, but it cannot solve the problem of stent kinking and lumen loss that can occur when the stent passes through tortuous blood vessels.

[0052] The distal end of the stent placement catheter 100, employing a distal tube 120 that can rotate circumferentially relative to the insertion tube 110, can reduce the incidence of stent kinking while delivering the stent 200 to the lesion site. Whether the torsion occurs during the delivery system's transit through tortuous vessels or as the stent 200 gradually opens from the distal tortuous vessel, the distal tube 120 and / or the annulus 130 of the stent placement catheter 100 can adapt to the torsion direction of the proximal end of the stent 200, thereby unwinding the proximal end of the stent 200, preventing further torsion, maintaining the patency of the internal lumen of the stent 200, and thus improving surgical efficiency and first-time success rate. It also reduces the need for repeated retrieval and resetting actions to handle stent kinking, effectively reducing the risk of stent dislodgement and deformation, thereby improving the success rate of stent implantation and treatment safety. It can effectively avoid the need for post-stent remedial procedures, such as preventing balloon dilation and surgical stent removal after severe stent kinking, reducing postoperative complications caused by the original remedial surgery, and reducing the risk of vascular intimal tearing, bleeding, and stent retention.

[0053] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0054] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A stent placement catheter, characterized in that: include: An insertion tube (110) extends axially from the proximal end to the distal end; The distal tube (120) extends axially from the proximal end to the distal end, and the inner circumferential surface of the lumen of the distal tube (120) is used to radially contact at least a portion of the axial segment of the outer circumferential surface of the support (200) inserted therein. The proximal end of the distal tube (120) is rotatably coaxially connected to the distal end of the insertion tube (110), so that the distal tube (120) can rotate circumferentially around the axis relative to the insertion tube (110) under the action of external force.

2. The stent placement catheter according to claim 1, characterized in that: The axial length of the lumen of the distal tube (120) is 3mm-25mm; And / or, the axial length of the lumen of the distal tube (120) is less than or equal to the axial length of the support (200); And / or, the static friction between the distal tube (120) and the support (200) is greater than the static friction between the distal tube (120) and the insertion tube (110).

3. The stent placement catheter according to claim 1, characterized in that: At least a portion of the axial section of the distal tube (120) is configured as a developing section (124).

4. The stent placement catheter according to claim 3, characterized in that: The axial length of the developing section (124) is 0.8mm-1.2mm; And / or, the axial distance between the distal end of the developing section (124) and the distal end face of the distal tube (120) is 0.6mm-1.2mm.

5. A stent placement catheter according to claim 1, characterized in that: The proximal end of the distal tube (120) and the distal end of the insertion tube (110) are continuously engaged circumferentially to be rotatably coaxially connected.

6. The stent placement catheter according to claim 5, characterized in that: The overall stiffness of the mating joint between the proximal end of the distal tube (120) and the distal end of the insertion tube (110) is greater than the stiffness of the axial segment of the distal tube (120) located on the distal side of the mating joint and the stiffness of the axial segment of the insertion tube (110) located on the proximal side of the mating joint.

7. A stent placement catheter according to claim 6, characterized in that: The distal end of the insertion tube (110) is provided with a circumferentially closed first axial ring (111), the inner circumferential surface of the distal end of the first axial ring (111) is provided with a radially protruding first annular buckle (112), and the inner circumferential surface of the proximal end of the first axial ring (111) is provided with a radially concave first annular groove (113). The proximal end face of the distal tube (120) is provided with a circumferentially closed second axial ring (121), the outer circumferential surface of the proximal end of the second axial ring (121) is provided with a radially protruding second annular buckle (122), and the outer circumferential surface of the distal end of the second axial ring (121) is provided with a radially concave second annular groove (123). The first annular buckle (112) is fastened into the second annular groove (123) so as to be rotatably engaged with the second axial ring (121); The second annular buckle (122) is inserted into the first annular groove (113) to be rotatably engaged with the first axial ring (111).

8. A stent placement catheter according to claim 7, characterized in that: The width of the second annular groove (123) is greater than the width of the first annular groove (113).

9. A stent placement catheter according to any one of claims 1-8, characterized in that: It also includes at least one annulus (130) coaxially disposed with the distal tube (120), all of the annulus (130) being axially positioned on the cavity wall of the distal tube (120) and arranged sequentially along the axial direction of the distal tube (120); the annulus (130) and the distal tube (120) are circumferentially rotatable relative to each other about the axis; The inner circumferential surface of the ring (130) is flush with the inner circumferential surface of the lumen of the distal tube (120) for radial contact with and compression of the outer circumferential surface of the support (200) inserted therein.

10. A stent placement catheter according to claim 9, characterized in that: The cavity wall of the distal tube (120) is provided with an installation groove (125), and each ring (130) is individually nested in one of the installation grooves (125). A limiting protrusion (126) is formed between two adjacent installation grooves (125), and the limiting protrusion (126) maintains the axial distance between two adjacent rings (130). And / or, the ring width of the ring (130) is 0.02mm-0.08mm; And / or, the axial distance between two adjacent rings (130) is 0.01mm-0.02mm; And / or, the number of rings (130) is set to 50-500; And / or, the outer peripheral surface of the ring (130) is set as a polished surface; And / or, the inner circumferential surface of the ring (130) is provided with a hydrophilic coating or a hydrophobic coating; And / or, the ring (130) is magnetically attracted to the mounting groove (125) in the radial direction; And / or, there is an axial fit clearance between the ring (130) and the mounting groove (125); And / or, there is a radial fit clearance between the ring (130) and the mounting groove (125), the radial fit clearance being 0.002mm-0.01mm; And / or, the ring (130) is a structural component made of polymer, metal or inorganic non-metallic material; And / or, the axial distance between the annulus (130) and the distal end face of the distal tube (120) is less than the axial length of the bracket (200).

Images