A vascular stent and stent system

Abstract

The application provides a vascular stent and a stent system, and relates to the technical field of medical devices.The vascular stent can realize dynamic and continuous adjustment of the stent in the body, is favorable for improving the controllability of surgery, can realize quick and convenient recovery of the stent, and is favorable for reducing the difficulty of surgery.The vascular stent comprises a pushing assembly, a stent and a pulling assembly; at least a part of the stent extends in a spiral shape along the axial direction of the pushing assembly, and is sleeved on the pushing assembly; the distal end of the stent is fixed to the distal end of the pushing assembly; the proximal end of the stent is in sliding connection with the pushing assembly; the pulling assembly is connected to the proximal end of the stent; along the axial direction of the stent, the pulling assembly drives the proximal end of the stent to move towards the proximal end of the pushing assembly, and the outer diameter of the stent is reduced.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more particularly to a vascular stent and stent system. Background Technology

[0002] A vascular stent is a miniature medical device used to treat narrowing or blockage of blood vessels. It is typically implanted into the affected blood vessel site through interventional procedures, such as percutaneous coronary intervention (PCI). The functions of a vascular stent include dilating blood vessels, restoring blood flow, and preventing serious complications such as myocardial infarction, ischemic stroke, or limb necrosis. Utility Model Content

[0003] This application provides a vascular stent and stent system that enables dynamic and continuous adjustment of the stent within the body, which improves the controllability of the surgery and allows for rapid and convenient retrieval of the stent, thus reducing the difficulty of the surgery.

[0004] On one hand, this application provides a vascular stent, which includes: a pushing component, a stent, and a traction component; wherein at least a portion of the stent extends spirally along the axial direction of the pushing component and is sleeved on the pushing component, the distal end of the stent is fixed to the distal end of the pushing component, and the proximal end of the stent is slidably connected to the pushing component; the traction component is connected to the proximal end of the stent; along the axial direction of the stent, the traction component drives the proximal end of the stent to move closer to the proximal end of the pushing component, thereby reducing the outer diameter of the stent.

[0005] The vascular stent provided in this application extends helically along the axial direction of the delivery component, with the distal end of the stent fixedly connected to the delivery component and the proximal end slidably connected. When the stent needs to be inserted into the body, it can be stretched along the axial direction of the delivery component to contract, thereby reducing the radial dimension of the stent and facilitating its insertion through the delivery catheter. Furthermore, a traction component connected to the proximal end of the stent allows for precise and dynamic control of the continuous changes in the radial dimension and pitch of the stent after expansion, by pulling or releasing the traction component after it reaches the lesion site. For example, by pulling the handle, the outer diameter of the stent can be continuously varied between 1 mm (contracted state) and 12 mm (expanded state) to match the stent's vascular taper or bifurcation lesion (e.g., transitioning from a 4.0 mm main trunk to a 2.5 mm branch), thus improving the fit between the stent and the lesion site. Before stent release, the traction component can be controlled to reposition the stent multiple times, reducing the likelihood of stent rejection due to mispositioning. Furthermore, after the surgery, the stent can be retracted to its minimum size using a pulling and traction component, facilitating its rapid removal from the body and enabling the retrieval of the vascular stent. Therefore, the vascular stent described in this embodiment allows for dynamic and continuous adjustment of the stent within the body, improving surgical controllability and enabling rapid and convenient stent retrieval, thus reducing surgical difficulty.

[0006] In one possible implementation of this application, the support includes a first straight segment, a curved segment, and a second straight segment; the first straight segment is connected to the distal end of the curved segment, the second straight segment is connected to the proximal end of the curved segment, the first straight segment is fixedly connected to the pushing component, the second straight segment is slidably connected to the pushing component, and connected to the traction component; the curved segment is spiral-shaped and is sleeved on the pushing component.

[0007] In one possible implementation of this application, both the first straight segment and the second straight segment are spiral-shaped to match the push component, and both the spiral-shaped first straight segment and the second straight segment are fitted onto the push component; the pitch of the first straight segment and the pitch of the second straight segment are both smaller than the pitch of the curved segment.

[0008] In one possible implementation of this application, the bending segment includes a support segment and a deformable segment; the support segment is located at the distal end of the bending segment and is connected to a first straight segment; the deformable segment is located at the proximal end of the bending segment and is connected to a second straight segment; the pitch of the support segment is smaller than the pitch of the deformable segment.

[0009] In one possible implementation of this application, the outer diameter of the support segment is larger than the outer diameter of the deformation segment along the radial direction of the push component.

[0010] In one possible implementation of this application, the pitch of the bending segment gradually increases axially from the distal end to the proximal end of the bending segment; and / or, the pitch of the support segment is greater than or equal to 0.3 mm and less than or equal to 0.8 mm; and / or, the pitch of the bending segment is greater than or equal to 0.5 mm and less than or equal to 1.2 mm.

[0011] In one possible implementation of this application, the vascular stent further includes a limiting member disposed on the pushing assembly and located on the side of the second straight segment close to the first straight segment. The limiting member is used to restrict the first straight segment from moving axially toward the second straight segment.

[0012] In one possible implementation of this application, at least one of the first straight segment, the curved segment, and the second straight segment includes at least two braided filaments, which are spirally wound.

[0013] In one possible implementation of this application, the vascular stent further includes a first imaging element, which is spirally sleeved on the distal end of the delivery assembly and the first straight segment.

[0014] In one possible implementation of this application, the vascular stent further includes a second imaging element, which is fixed to the push assembly, and the distal end of the stent is fixedly connected to the second imaging element.

[0015] In one possible implementation of this application, the vascular stent further includes a third imaging element, which is slidably sleeved on the pushing assembly, the proximal end of the stent is fixedly connected to the third imaging element, and the traction assembly is connected to the third imaging element.

[0016] In one possible implementation of this application, the traction assembly includes a traction line and a handle; one end of the traction line is connected to the proximal end of the support, and the other end of the traction line is connected to the handle; the pushing assembly has a fixing structure that matches the traction line, the traction line passes through the fixing structure, and the fixing structure is used to fix or release the traction line.

[0017] In one possible implementation of this application, the vascular stent further includes a coating disposed on the surface of the stent, the coating including at least one of the following: a drug coating and an anticoagulant coating.

[0018] On the other hand, this application provides a stent system comprising: a delivery catheter and a vascular stent provided by any of the above; wherein the delivery catheter is used for intra-body intervention; the delivery catheter has a delivery channel that is compatible with both the delivery component and the stent.

[0019] The stent system provided in this application, because it includes any of the vascular stents provided above, can achieve dynamic and continuous adjustment of the stent in the body, which is beneficial to improving the controllability of the operation and can also achieve rapid and convenient retrieval of the stent, which is beneficial to reducing the difficulty of the operation. Attached Figure Description

[0020] Figure 1 Schematic diagram of the vascular stent provided in this application Figure 1 ; Figure 2 Schematic diagram of the vascular stent provided in this application Figure 2 ; Figure 3 This is a schematic diagram of the structure of the vascular stent provided in this application.

[0021] Explanation of reference numerals in the attached figures: 1-Pushing component; 11-Pushing element; 12-Operating element; 2-Bracket; 21-First straight segment; 22-Bending segment; 221-Supporting segment; 222-Deformation segment; 23-Second straight segment; 24-First pitch; 25-Second pitch; 3-Tethering component; 31-Tethering line; 32-Handle; 4-Limiting element; 5-First developing element; 6-Second developing element; 7-Third developing element; Y-Radial; Z-Axial.

[0022] It should be noted that the terms "first" and "second" mentioned above are only used to distinguish between different options and do not represent the degree of superiority or inferiority of the options or their priority in the implementation process. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0025] Furthermore, in the embodiments of this application, directional terms such as "upper," "lower," "left," and "right" are defined relative to the positions in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0026] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0027] In embodiments of this application, 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. Without further limitation, 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.

[0028] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0029] Vascular stents are mainly classified into bare-metal stents (BMS), drug-eluting stents (DES), and bioresorbable vascular scaffolds (BVS). BMS and DES are permanent implantable stents. The permanent metal may affect the natural contraction and relaxation function of the blood vessel. Although the restenosis rate of DES is significantly lower, at 5%-10% (compared to 15%-30% within 6 months after BMS), the polymer coating may delay endothelial healing, leading to a late thrombosis rate of approximately 0.5%-2%, requiring long-term (6-12 months) dual antiplatelet therapy (DAPT). BVS is usually made of polylactic acid (PLA) or magnesium alloy, which gradually degrades into carbon dioxide and water within 2-3 years, temporarily supporting the blood vessel before being completely absorbed, restoring the vessel's physiological function. Although BVS leaves no permanent foreign body and the blood vessel recovers its natural contraction and relaxation after degradation, avoiding the long-term side effects of metal stents, BVS has weak support and may cause acute occlusion due to retraction in the early stages of degradation, with a high restenosis rate.

[0030] This application provides a vascular stent that allows for dynamic and continuous adjustment of the stent within the body, improving surgical controllability and enabling rapid and convenient stent retrieval, thus reducing surgical difficulty. (See also...) Figure 1 , Figure 2and Figure 3 , Figure 1 Schematic diagram of the vascular stent provided in this application Figure 1 , Figure 2 Schematic diagram of the vascular stent provided in this application Figure 2 , Figure 3 The following is a schematic diagram of the structure of the vascular stent provided in this application. The vascular stent provided in the embodiments of this application will be described below with reference to the examples in the accompanying drawings.

[0031] The vascular stent provided in this application includes: a pushing component 1, a stent 2, and a traction component 3; wherein, at least a portion of the stent 2 extends spirally along the axial direction Z of the pushing component 1 and is sleeved on the pushing component 1, the distal end of the stent 2 is fixed to the distal end of the pushing component 1, and the proximal end of the stent 2 is slidably connected to the pushing component 1; the traction component 3 is connected to the proximal end of the stent 2; along the axial direction Z of the stent 2, during the process of the traction component 3 moving relative to the pushing component 1 towards the proximal end of the pushing component 1, the traction component 3 drives the proximal end of the stent 2 to move towards the proximal end of the pushing component 1, and the outer diameter of the stent 2 decreases.

[0032] In this embodiment, the pushing component 1 provides support and a mounting base for the stent 2, traction component 3, etc., and allows the vascular stent to be inserted into the body along the delivery catheter via the pushing component 1. For example, the pushing component 1 can be configured as a structure including a pushing element 11 and an operating element 12. The pushing element 11 can be configured as a long and thin strip, such as a thin wire with a diameter of about 1 mm. The length of the pushing element 11 can be 50 cm to 200 cm, and the length of the pushing element 11 can be selected according to the specific application scenario of the vascular stent. This embodiment does not limit the length of the pushing element 11. The pushing element 11 can be made of metal or polymer composite material. The operating element 12 can be set at the proximal end of the pushing element 11, and the operating element 12 can be configured as a columnar, block-shaped, or other structure that is easy to hold. The proximal end of the pushing element 11 and the operating element 12 can be fixedly connected by means of bonding, welding, insertion, etc., and the operator can hold the vascular stent through the operating element 12.

[0033] It should be noted that the terms "distal end" and "proximal end" as described in this application refer to the extension direction along the Z-axis of the pushing component 1. The distal end is the end of the pushing component 1 furthest from the surgeon, meaning it is the end that first enters or approaches the body. The proximal end is the end of the pushing component 1 closest to the surgeon, meaning it is the end that last enters or moves away from the body. For example, as... Figure 1 As shown, the far end is Figure 1 The upper and near ends of push component 1 are... Figure 1 The lower end of push component 1.

[0034] In this embodiment, the stent 2 can support blood vessels to achieve the purpose of dilating them. The stent 2 can be configured as a spiral, meaning that the stent 2 extends continuously along the axial direction Z of the pushing component 1 and continuously surrounds the pushing component 1 along the radial direction Y. The outer diameter of the stent 2 can be set according to the specific application scenario of the vascular stent. The stent 2 can be made of metal materials such as stainless steel or platinum-tungsten alloy to give the stent 2 good elasticity and rigidity.

[0035] For example, the distal end of the bracket 2 can be fixed to the distal end of the pushing component 1, and the proximal end of the bracket 2 can be slidably disposed on the pushing component 1. For instance, the distal end of the bracket 2 can be fixed to the distal end of the pushing component 11 by welding, bonding, snap-fitting, or other methods. The proximal end of the bracket 2 can be set as an annular shape that matches the pushing rod, thereby slidably fitting the proximal end of the bracket 2 onto the pushing rod; or, a groove matching the proximal end of the bracket 2 can be provided on the pushing component 11, and the proximal end of the bracket 2 can be slidably disposed in the groove, thereby slidably connecting the proximal end of the bracket 2 to the pushing component 11. In this way, the proximal end of the bracket 2 can move relative to the pushing component 1 along the Z-axis.

[0036] In this embodiment, a traction component 3 can be provided on the stent 2, and the surgeon can use the traction component 3 to drive the proximal end of the stent 2 to move relative to the pushing component 1 along the Z-axis.

[0037] For example, the traction assembly 3 can be configured to include a traction line 31 and a handle 32; one end of the traction line 31 is connected to the proximal end of the bracket 2, and the other end of the traction line 31 is connected to the handle 32; the push assembly 1 has a fixing structure (not shown in the figure) that matches the traction line 31, the traction line 31 passes through the fixing structure, and the fixing structure is used to fix or release the traction line 31.

[0038] In another example, the pull wire 31 can be made of thin metal wire or polymer composite material. The pull wire 31 can be arranged parallel to the pusher 11, or the pusher 11 can be configured with a cavity structure to allow the pull wire 31 to pass through it. The distal end of the pull wire 31 can be fixedly connected to the proximal end of the support 2 by welding, bonding, snap-fitting, or other methods. The handle 32 can be fixed to the proximal end of the pull wire 31, or to the proximal end of the pusher 11 or the operating member 12. Alternatively, the handle 32 may not be fixed to the pusher 11 or the operating member 12. A fixing structure matching the pull wire 31 can be provided on the operating component 12. For example, a threading hole matching the pull wire 31 can be provided on the operating component 12, and a knob can be provided on the operating component 12. The knob and the operating component 12 are connected by a thread. By rotating the knob, the hole wall of the threading hole can be moved closer or further away from each other, thereby clamping and fixing the pull wire 31 in the threading hole, or allowing the pull wire 31 to move freely in the threading hole.

[0039] Thus, as Figure 2 As shown, before inserting the vascular stent provided in this embodiment into the body, the traction wire 31 can be moved along the axial direction Z of the pushing component 1 towards the proximal end of the pushing component 1 by pulling the handle 32. This stretches the helical stent 2 with a larger outer diameter along the axial direction Z, causing the stent 2 to extend along the pushing member 11 and move in the radial direction Y towards the pushing member 11. Ultimately, the stent 2 is tightly wound around the pushing member 11 with the maximum pitch, thereby reducing the outer diameter of the stent 2 to a minimum. Figure 1 As shown, after the vascular stent is inserted into the lesion site through the delivery catheter, the traction wire 31 can be released by operating the manipulator 12. At this time, the stent 2 contracts along the axial direction Z under its own elastic force and expands along the radial direction Y to return to a spiral shape with a larger outer diameter, thereby opening up the blood vessel in the lesion area. After the operation is completed, the stent 2 is stretched to be tightly wrapped around the pusher 11 by pulling the handle 32 and the traction wire 31, so that the stent 2 is separated from the blood vessel and the vascular stent can be withdrawn from the body.

[0040] The vascular stent provided in this embodiment extends the stent 2 along the Z-axis of the pushing component 1 in a spiral manner, with the distal end of the stent 2 fixedly connected to the pushing component 1 and the proximal end of the stent 2 slidably connected to the pushing component 1. When the vascular stent needs to be inserted into the body, the stent 2 can be stretched along the Z-axis of the pushing component 1 to shrink the stent 2, thereby reducing the radial Y-dimensional dimension of the stent 2, which facilitates the insertion of the vascular stent into the body through the delivery catheter. Furthermore, a traction component 3 connected to the proximal end of the stent 2 is provided. After the vascular stent reaches the lesion site, the radial Y-dimensional dimension and pitch of the stent 2 after expansion can be precisely and dynamically controlled by pulling or releasing the traction component 3. For example, by pulling the handle 32, the outer diameter of the stent 2 can be continuously changed between 1 mm (contracted state) and 12 mm (expanded state) to match the vascular taper or bifurcation lesion (such as transitioning from a 4.0 mm main trunk to a 2.5 mm branch), thereby improving the matching degree between the stent 2 and the lesion site. Before stent 2 is released, it can be repositioned multiple times by controlling the traction component 3, which helps reduce the occurrence of stent 2 being discarded due to positioning errors. Simultaneously, after the surgery, the stent 2 can be retracted to its minimum size by pulling the traction component 3, facilitating its rapid removal from the body and enabling the vascular stent to be retrieved. Therefore, the vascular stent described in this embodiment allows for dynamic and continuous adjustment of stent 2 within the body, improving surgical controllability and enabling rapid and convenient retrieval of stent 2, thus reducing surgical difficulty.

[0041] In some possible embodiments of this application, such as Figure 1 and Figure 3 As shown, the support 2 includes a first straight segment 21, a curved segment 22, and a second straight segment 23; the first straight segment 21 is connected to the distal end of the curved segment 22, and the second straight segment 23 is connected to the proximal end of the curved segment 22. The first straight segment 21 is fixedly connected to the pushing component 1, and the second straight segment 23 is slidably connected to the pushing component 1 and connected to the traction component 3; the curved segment 22 is spiral-shaped and is sleeved on the pushing component 1.

[0042] In this embodiment, the support 2 can be configured to include a first straight segment 21, a curved segment 22, and a second straight segment 23, so that the support 2 can be connected to the pusher 11 through the first straight segment 21 and the second straight segment 23, and the contraction and expansion of the support 2 can be achieved through the curved segment 22.

[0043] For example, a first straight segment 21 can be provided at the distal end of the curved segment 22, and a second straight segment 23 can be provided at the proximal end of the curved segment 22. The first straight segment 21, the curved segment 22, and the second straight segment 23 can be integrally formed, that is, the first straight segment 21, the curved segment 22, and the second straight segment 23 can be processed from one or more complete braided filaments. The first straight segment 21, the curved segment 22, and the second straight segment 23 can also be manufactured separately, and then the first straight segment 21, the curved segment 22, and the second straight segment 23 can be sequentially fixed and connected by welding, bonding, or other methods.

[0044] In another example, both the first straight segment 21 and the second straight segment 23 can be configured as sheet-like shapes that match the pusher 11, so that the first straight segment 21 and the second straight segment 23 respectively cover the pusher 11 circumferentially, such as covering a full circle, or covering half a circle, one-third of a circle, etc. The first straight segment 21 can be fixedly connected to the pusher 11 by welding, bonding, etc., so as to fix the distal end of the bracket 2 to the pusher 11. The second straight segment 23 is not fixed to the pusher 11, so that the second straight segment 23 can slide relative to the pusher 11.

[0045] In another example, the curved segment 22 can be configured as a spiral, meaning that the curved segment 22 extends spirally along the Z-axis. The pusher 11 can be inserted through the curved segment 22, so that the curved segment 22 is fitted onto the pusher 11. The curved segment 22 can be configured with different lengths depending on the application scenario of the vascular stent; for example, the curved segment 22 can be configured with a length of 9mm to 100mm. It should be noted that the length of the curved segment 22 described here refers to the length measured when the stent 2 is in its natural extended state without external force.

[0046] The vascular stent provided in this embodiment has a structure including a first straight segment 21, a curved segment 22, and a second straight segment 23. This facilitates the fixed connection of the stent 2 to the pushing component 1 via the first straight segment 21 and the slidable connection of the stent 2 to the pushing component 1 along the axial direction Z via the second straight segment 23. Furthermore, the curved segment 22 is spiral-shaped, allowing the stent 2 to contract or expand radially Y via the curved segment 22, facilitating interventional and retrieval operations of the stent 2.

[0047] In some possible embodiments of this application, the first straight segment 21 and the second straight segment 23 are both spiral-shaped and matched with the push component 1. The spiral first straight segment 21 and the second straight segment 23 are both sleeved on the push component 1. The pitch of the first straight segment 21 and the pitch of the second straight segment 23 are both smaller than the pitch of the curved segment 22.

[0048] In this embodiment, both the first straight segment 21 and the second straight segment 23 can be configured as spirals so that both the first straight segment 21 and the second straight segment 23 are fitted onto the pusher 11. For example, the first straight segment 21 and the second straight segment 23 can be wound into spirals according to the outer diameter of the pusher 11.

[0049] For example, adjacent turns of the first helical straight segment 21 can abut along the axial direction Z, meaning the pitch of the first straight segment 21 can be the diameter of the braided yarn of the first straight segment 21. Similarly, adjacent turns of the second helical straight segment 23 can abut along the axial direction Z, meaning the pitch of the second straight segment 23 can be the diameter of the braided yarn of the second straight segment 23. The pitches of the first straight segment 21 and the second straight segment 23 can also be other values. The first helical straight segment 21 can be fitted onto the pusher 11, and the first straight segment 21 and the pusher 11 can be fixedly connected by welding, bonding, or other methods. The inner diameter of the second helical straight segment 23 can be larger than the outer diameter of the pusher 11, thereby fitting the second straight segment 23 onto the pusher 11 with a clearance fit.

[0050] In another example, the pitch of the curved segment 22 can be set to be much larger than the pitch of the first straight segment 21 and also much larger than the pitch of the second straight segment 23. The pitch of the curved segment 22 can be set according to the specific application scenario of the bracket 2. It should be noted that the pitch of the first straight segment 21, the pitch of the second straight segment 23, and the pitch of the curved segment 22 described here all refer to the length measured when the bracket 2 is in its natural extension without external force.

[0051] In another example, both the first straight segment 21 and the second straight segment 23 can be set as straight lines. That is, the first straight segment 21 can be a straight strip parallel to the pusher 11, and the second straight segment 23 can also be a straight strip parallel to the pusher 11. In this way, the first straight segment 21 and the pusher 11 can be attached and fixed along the Z-axis, and the second straight segment 23 and the pusher 11 can be attached and slidably set along the Z-axis.

[0052] The vascular stent provided in this application embodiment, by setting both the first straight segment 21 and the second straight segment 23 as a spiral shape matching the pushing component 1, can have both the first straight segment 21 and the second straight segment 23 fitted onto the pushing component 1. This is beneficial to improving the reliability of the fixed connection between the first straight segment 21 and the pushing component 1, and can also improve the stability of the sliding connection between the second straight segment 23 and the pushing component 1. This can reduce the risk of the proximal end of the stent 2 getting stuck with the pushing component 1, and is beneficial to improving the smoothness of the sliding of the proximal end of the stent 2 relative to the pushing component 1.

[0053] In some possible embodiments of this application, such as Figure 3 As shown, the bending section 22 includes a support section 221 and a deformation section 222; the support section 221 is located at the far end of the bending section 22 and is connected to the first straight section 21; the deformation section 222 is located at the near end of the bending section 22 and is connected to the second straight section 23; the pitch of the support section 221 is smaller than the pitch of the deformation section 222.

[0054] In this embodiment, the bending segment 22 can be configured as a structure including a support segment 221 and a deformation segment 222, that is, the bending segment 22 can be configured as two parts with different pitches, so that the support segment 221 is located at the far end of the bending segment 22 and the deformation segment 222 is located at the near end of the bending segment 22.

[0055] For example, the support section 221 can be configured with a smaller pitch, while the deformable section 222 can be configured with a larger pitch, so that the pitch of the support section 221 is smaller than the pitch of the deformable section 222. For instance, the first pitch 24 of the support section 221 can be set to be greater than or equal to 0.3 mm and less than or equal to 0.8 mm, and the second pitch 25 of the deformable section 222 can be set to be greater than or equal to 0.5 mm and less than or equal to 1.2 mm. Alternatively, the pitch of the support section 221 can be set to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm, and the pitch of the deformable section 222 can be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. The pitch of the support section 221 is chosen to be smaller than the pitch of the deformable section 222.

[0056] In another example, along the axial direction Z of the push assembly 1, the pitch of the bending segment 22 gradually increases from the distal end to the proximal end of the bending segment 22. While making the pitch of the support segment 221 smaller than the pitch of the deformed segment 222, the pitch of the entire bending segment 22 can also be gradually varied. That is, from the support segment 221 to the deformed segment 222, the pitch between two adjacent rings in the support segment 221 gradually increases, and the pitch between two adjacent rings in the deformed segment 222 also gradually increases. For example, the pitch in the support segment 221 gradually increases from 0.3 mm to 0.7 mm, and the pitch in the deformed segment 222 gradually increases from 0.8 mm to 1.2 mm.

[0057] In this way, the spacing between the coils of stent 2 and the diameter of the first-order coils (the most distal coil and the closest coil of the curved segment 22) can be adjusted according to the specific application scenario to change the radial support force of stent 2. A smaller pitch or a larger diameter of the first-order coil results in a larger stress-bearing area in the blood vessel, strengthening the stent 2's resistance to compression and thus increasing its radial support force. Conversely, a larger pitch or a smaller diameter of the first-order coil results in a smaller stress-bearing area in the blood vessel, weakening the stent 2's resistance to compression and thus reducing its radial support force.

[0058] In another example, along the radial direction Y of the pushing component 1, the outer diameter of the support segment 221 is larger than the outer diameter of the deformable segment 222. The support segment 221 can be configured as a thicker structure, while the deformable segment 222 can be configured as a thinner structure, thus making the outer diameter of the support segment 221 larger than that of the deformable segment 222, and making the bending segment 22 approximately conical overall. For example, along the direction from the support segment 221 to the deformable segment 222, the outer diameter of the support segment 221 can be gradually reduced, and the outer diameter of the deformable segment 222 can also be gradually reduced.

[0059] The vascular stent provided in this embodiment allows the pitch of the bending segment 222 to increase from distal to proximal because the pitch of the support segment 221 is smaller than that of the deformable segment 222. This creates a better mechanical gradient in the bending segment 22 to adapt to the natural mechanical distribution of the blood vessel. Furthermore, the smaller pitch of the support segment 221 provides stronger radial support, which is beneficial for effective expansion of the lesion site. The larger pitch of the deformable segment 222 reduces the local stiffness of the proximal end of the bending segment 22 (the elastic modulus is 20% to 40% smaller than that of the distal end of the bending segment 22), making it easier for the proximal end of the bending segment 22 to bend and deform, thus facilitating the adaptation of the bending segment 22 to the physiological curvature of the blood vessel.

[0060] In some possible embodiments of this application, such as Figure 1As shown, the vascular stent also includes a limiting member 4, which is disposed on the pushing component 1 and located on the side of the second straight segment 23 close to the first straight segment 21. The limiting member 4 is used to restrict the first straight segment 21 from moving along the Z-axis to the second straight segment 23.

[0061] In this embodiment of the application, a limiting member 4 can be provided on the pushing component 1 to limit the range of motion of the proximal end of the support 2 on the pushing component 1.

[0062] For example, the limiting member 4 can be disposed on the surface of the pusher 11. For instance, the limiting member 4 can be an injection-molded part or a metal part. The limiting member 4 can be fixed on the pusher 11 near the proximal end of the bent segment 22, and positioned on the side of the second straight segment 23 near the first straight segment 21. The outer diameter of the limiting member 4 can be larger than the inner diameter of the first straight segment 21 and smaller than the inner diameter of the deformable segment 222. Thus, as the support 2 expands under its own elastic force, causing the first straight segment 21 to move towards the distal end of the pusher 11, until the first straight segment 21 abuts against the limiting member 4, the proximal end of the support 2 can be uniquely and definitively positioned.

[0063] The vascular stent provided in this application embodiment has a limiting member 4 corresponding to the first straight segment 21 on the pushing component 1. The limiting member 4 can restrict the position of the first straight segment 21 moving towards the distal end along the axial Z direction, so that the stent 2 can stop at the accurate position when it expands, which is beneficial to improving the accuracy and stability of the shape of the stent 2 after expansion.

[0064] In some possible embodiments of this application, at least one of the first straight segment 21, the curved segment 22, and the second straight segment 23 includes at least two braided filaments, which are spirally wound.

[0065] In this embodiment of the application, the bracket 2 can be configured as a structure made of multiple strands of braided filaments, or one or both of the first straight segment 21, the curved segment 22, and the second straight segment 23 in the bracket 2 can be configured as a structure made of multiple strands of braided filaments.

[0066] For example, the first straight segment 21, the curved segment 22, and the second straight segment 23 can all be configured as structures formed by three strands of braided filaments wound together. For instance, the three strands of braided filaments can be evenly distributed at 120° in the circumferential direction and twisted so that the three strands of braided filaments are spirally intertwined to form a relatively thick blank. The blank is then processed to form a support 2 including the first straight segment 21, the curved segment 22, and the second straight segment 23.

[0067] In another example, the three-strand braided yarns of the first straight segment 21 and the three-strand braided yarns of the second straight segment 23 can both be formed into a cylindrical shape that matches the pusher 11. Then the three-strand braided yarns of the first straight segment 21 can be sleeved on the pusher 11, and the three-strand braided yarns of the second straight segment 23 can be sleeved on the pusher 11.

[0068] The vascular stent provided in this embodiment includes at least two braided strands in at least one of the first straight segment 21, the curved segment 22, and the second straight segment 23. These braided strands can distribute the load across the various parts of the stent 2, thus reducing local stress. For example, by setting the first straight segment 21, the curved segment 22, and the second straight segment 23 as uniformly distributed three-strand wound braided strands, the structure of each part of the stent 2 can be made more stable (the structural symmetry coefficient can reach 0.987), and the flexibility of each part of the stent 2 can be improved, making it easier to bend and adapt to the direction of the blood vessel. Furthermore, the stent 2 can expand more uniformly during expansion through multi-point contact, reducing deformation.

[0069] Compared to related technologies, most traditional stents use closed units or diamond-shaped mesh structures (such as laser-cut metal tubes). The connection points of each closed unit are fixed, which easily leads to local stress concentration when the traditional stent is bent, resulting in limited flexibility of the stent 2 (creases easily appear when the bending radius is ≥15mm). However, the stent 2 provided in this application uses an open spiral braided mesh structure (the diameter of the braided filaments can be 0.06mm to 0.1mm), which can make the stent 2 form a continuous elastic body similar to a spring. This allows the stent 2 to deform freely along the bending direction of the blood vessel. In blood vessels with a bending radius of less than or equal to 5mm, the stent 2 can still maintain wall adhesion (traditional stents show poor wall adhesion when the bending radius of the blood vessel is less than or equal to 10mm). The spiral structure allows the stent 2 to undergo axial Z-twist with the vascular pulsation (maximum twist angle ±30°), which can reduce vascular torsion caused by excessive rigidity of the stent 2.

[0070] In some possible embodiments of this application, such as Figure 1 As shown, the vascular stent also includes a first imaging element 5, a second imaging element 6, and a third imaging element 7. The first imaging element 5 is spirally sleeved on the distal end of the pushing assembly 1 and the first straight segment 21. The second imaging element 6 is fixed to the pushing assembly 1, and the distal end of the stent 2 is fixedly connected to the second imaging element 6. The third imaging element 7 is slidably sleeved on the pushing assembly 1, and the proximal end of the stent 2 is fixedly connected to the third imaging element 7. The traction assembly 3 is connected to the third imaging element 7.

[0071] In this embodiment, a radiopaque element can be placed in the vascular stent. The radiopaque element can be made of a material that is not transparent to X-rays, such as a platinum-tungsten alloy, a platinum-iridium alloy, or stainless steel.

[0072] For example, a first imaging element 5 can be provided at the distal end of the push assembly 1. The first imaging element 5 can be made of a platinum-tungsten alloy filament, which can be wound around the distal head of the push assembly 11 to make the first imaging element 5 spiral. The first imaging element 5 can also be wound around a first straight segment 21, meaning the first imaging element 5 is simultaneously wound around the parallel and fitted first straight segment 21 and the distal head of the push assembly 11. For example, the pitch of the first imaging element 5 can be equal to its diameter, meaning each turn of the first imaging element 5 is tightly wound around the push assembly 11. The first imaging element 5 can be fixedly connected to the push assembly 11 by bonding, welding, or other methods. This allows the first imaging element 5 to be in the form of a flexible, easily deformable spring, reducing the risk of damage to the blood vessel caused by the head of the push assembly 11 directly hitting the vessel wall due to misoperation (the head of the push assembly 11 can bend and deform) when the vascular stent is inserted through the delivery catheter, and improving the permeability of the vascular stent.

[0073] In another example, a second developing element 6 can be provided at the distal end of the support 2. For instance, the second developing element 6 can be configured as a ring that matches the pusher 11. The ring-shaped second developing element 6 can be fitted onto the pusher 11 at a position adjacent to the first developing element 5, and the second developing element 6 can be fixed to the pusher 11 by welding, bonding, or other methods. Each strand of braided yarn in the first straight segment 21 can be fixed to the second developing element 6 by welding, bonding, or other methods to fix the first straight segment 21 to the pusher 11.

[0074] In another example, a third developing element 7 can be provided at the proximal end of the support 2. For instance, the third developing element 7 can be configured as an annular shape that matches the pusher 11, with the annular third developing element 7 having a clearance fit with the pusher 11. The annular third developing element 7 can be sleeved on the pusher 11 and fixed to the pulling member by welding, bonding, or other methods. Each strand of braided wire in the second straight segment 23 can be fixed to the third developing element 7 by welding, bonding, or other methods, so that the second straight segment 23 can be slidably sleeved on the pusher 11 via the third developing element 7.

[0075] The vascular stent provided in this embodiment has a second imaging element 6 and a third imaging element 7 respectively at both ends of the stent 2, and a first imaging element 5 at the distal end of the pushing component 1. After the vascular stent is inserted into the body, the three imaging points can be coordinated and positioned through the first imaging element 5, the second imaging element 6, and the third imaging element 7. This allows for the positioning of the three imaging points in three-dimensional space, enabling three-dimensional calibration of the vascular stent during the procedure (with an error of less than 0.5 mm). Simultaneously, when the stent 2 contracts or expands, the specific shape of the stent 2 can be determined based on the change in distance between the second imaging element 6 and the third imaging element 7. For example, the change in the pitch of the stent 2 can reflect its shape (e.g., an increase of 1 mm in the pitch corresponds to a 15% reduction in the outer diameter), thus assisting the surgeon in judging the stent 2's wall apposition effect.

[0076] In some possible embodiments of this application, the vascular stent further includes a coating disposed on the surface of the stent 2, the coating including at least one of the following: a drug coating and an anticoagulant coating.

[0077] In this embodiment, a coating can be applied to the surface of the stent 2, such as a drug coating or an anticoagulant coating on the surface of the curved section 22.

[0078] For example, a drug coating (such as rapamycin) can be applied to the surface of the curved segment 22, and the drug coating can be released through passive diffusion. The stent 2 can also achieve triggered drug dislodgement, for example, by releasing the drug coating when the stent 2 is stretched along the Z-axis, thereby accelerating the removal of drug residues. An anticoagulant coating, such as a heparin coating, a phosphocholine coating, or a polyvinylpyrrolidone (PVP) coating, can also be applied to the surface of the curved segment 22.

[0079] Another example is that an infusion channel can be provided on the side wall of the pusher 11, such as an infusion channel with an inner diameter of 0.1 mm to 0.3 mm on the side wall of the pusher 11. This infusion channel can extend to the injection port on the operating member 12, so that antithrombotic drugs can be infused into the lesion site simultaneously through the pusher 11 when the stent 2 is released.

[0080] The vascular stent provided in this application embodiment has a drug coating and / or anticoagulant coating on the stent 2, which facilitates the delivery of the drug coating and anticoagulant coating to the lesion site through the stent 2. Furthermore, the release of the drug in the coating can be triggered by the contraction and expansion of the stent 2, which is beneficial for controlling the release of the drug.

[0081] In addition, this application embodiment also provides a stent system, which includes: a delivery catheter and a vascular stent provided in any of the above embodiments; wherein, the delivery catheter is used for intra-body intervention; the delivery catheter has a delivery channel that matches both the delivery component 1 and the stent 2.

[0082] In this embodiment, the delivery catheter can be inserted into the body. For example, the delivery catheter can be configured as a tubular structure with a delivery channel, the inner diameter of which is larger than the outer diameter of the vascular stent (stent 2 in a contracted state). In this way, the delivery catheter can be inserted into the body through a guidewire, the guidewire can be withdrawn from the body, and then the vascular stent can be inserted into the body along the delivery channel until the distal end of stent 2 reaches the lesion site. Finally, the proximal end of stent 2 is released, allowing stent 2 to expand under its own elasticity and fully support the lesion site.

[0083] The stent system provided in this application includes the vascular stent provided in any of the above embodiments. Therefore, it can realize the dynamic and continuous adjustment of the stent 2 in the body, which is beneficial to improve the controllability of the operation. It can also realize the rapid and convenient retrieval of the stent 2, which is beneficial to reduce the difficulty of the operation.

[0084] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A vascular stent, characterized in that, include: Push component; A support, at least a portion of which extends spirally along the axial direction of the push assembly and is sleeved on the push assembly, wherein the distal end of the support is fixed to the distal end of the push assembly and the proximal end of the support is slidably connected to the push assembly. A traction assembly is connected to the proximal end of the support; along the axial direction, the traction assembly drives the proximal end of the support to move closer to the proximal end of the push assembly, thereby reducing the outer diameter of the support.

2. The vascular stent according to claim 1, characterized in that, The support includes a first straight segment, a curved segment, and a second straight segment; the first straight segment is connected to the distal end of the curved segment, and the second straight segment is connected to the proximal end of the curved segment. The first straight segment is fixedly connected to the pushing component, and the second straight segment is slidably connected to the pushing component and connected to the traction component; the curved segment is spiral-shaped and is sleeved on the pushing component.

3. The vascular stent according to claim 2, characterized in that, The curved section includes a supporting section and a deformable section; the supporting section is located at the distal end of the curved section and is connected to the first straight section; the deformable section is located at the proximal end of the curved section and is connected to the second straight section; the pitch of the supporting section is smaller than the pitch of the deformable section.

4. The vascular stent according to claim 3, characterized in that, Along the radial direction of the pushing component, the outer diameter of the support segment is larger than the outer diameter of the deformable segment.

5. The vascular stent according to claim 3, characterized in that, Along the axial direction, from the distal end of the curved section to the proximal end of the curved section, the pitch of the curved section gradually increases; And / or, the pitch of the support section is greater than or equal to 0.3 mm and less than or equal to 0.8 mm; And / or, the pitch of the bent section is greater than or equal to 0.5 mm and less than or equal to 1.2 mm.

6. The vascular stent according to claim 2, characterized in that, The vascular stent further includes a limiting member disposed on the pushing component and located on the side of the second straight segment close to the first straight segment. The limiting member is used to restrict the first straight segment from moving along the axial direction toward the second straight segment.

7. The vascular stent according to any one of claims 2 to 6, characterized in that, At least one of the first straight segment, the curved segment, and the second straight segment comprises at least two braided filaments, which are spirally wound.

8. The vascular stent according to any one of claims 2 to 6, characterized in that, The vascular stent further includes a first imaging element, which is spirally sleeved on the distal end of the push assembly and the first straight segment. And / or, the vascular stent further includes a second imaging element, the second imaging element being fixed to the push assembly, and the distal end of the stent being fixedly connected to the second imaging element; And / or, the vascular stent further includes a third imaging element, which is slidably sleeved on the pushing assembly, the proximal end of the stent is fixedly connected to the third imaging element, and the traction assembly is connected to the third imaging element.

9. The vascular stent according to any one of claims 1 to 6, characterized in that, The traction assembly includes a traction line and a handle; one end of the traction line is connected to the proximal end of the bracket, and the other end of the traction line is connected to the handle; the pushing assembly has a fixing structure that matches the traction line, the traction line passes through the fixing structure, and the fixing structure is used to fix or release the traction line.

10. The vascular stent according to any one of claims 1 to 6, characterized in that, The vascular stent further includes a coating disposed on the surface of the stent, the coating comprising at least one of the following: a drug coating and an anticoagulant coating.

11. A support system, characterized in that, include: A delivery catheter for use in intraoperative intervention; The vascular stent according to any one of claims 1 to 10, wherein the delivery catheter has a delivery channel that matches both the delivery component and the stent.

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