Intravascular stent and stent system
By combining a spiral vascular stent with a traction component, dynamic and continuous adjustment of the stent within the body is achieved, solving the problems of poor surgical controllability and difficulty in retrieval in existing technologies, and improving the precision and ease of surgical operation.
Patent Information
- Application Number
- CN202511720457.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-01-20
AI Technical Summary
Existing vascular stents are difficult to dynamically and continuously adjust during interventional procedures, resulting in poor surgical controllability and difficulty in retrieval, thus increasing the complexity of the procedure.
A vascular stent was designed, which extends spirally along the axis of the pusher assembly, with the distal end fixed and the proximal end slidingly connected. It is equipped with a traction assembly, which enables continuous variation of the stent's radial dimension and pitch, and improves operational accuracy in conjunction with the imaging element.
It enables dynamic and continuous adjustment of the stent within the body, improving surgical controllability, simplifying the retrieval process, and reducing surgical difficulty.
Smart Images
Figure CN121360003A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of medical devices, in particular to a vascular stent and a stent system. BACKGROUND
[0002] The vascular stent is a kind of micro medical device for treating vascular stenosis or occlusion, which is usually implanted into the lesion site of blood vessel by interventional operation, such as percutaneous coronary intervention (PCI) operation. The functions of the vascular stent include expanding blood vessels, restoring blood flow, preventing serious complications such as myocardial infarction, ischemic stroke or limb necrosis, etc. SUMMARY
[0003] The present application provides a vascular stent and a stent system, which can realize dynamic and continuous adjustment of the stent in the body, improve the controllability of the operation, and realize quick and convenient recovery of the stent, thereby reducing the difficulty of the operation.
[0004] In one aspect, the present application provides a vascular stent, which comprises a pushing assembly, a stent and a pulling assembly; wherein 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, and the proximal end of the stent is slidingly connected to 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.
[0005] The blood vessel stent provided in the application is arranged on the pushing assembly in a helical manner along the axial direction of the pushing assembly, the distal end of the stent is fixedly connected with the pushing assembly, the proximal end of the stent is slidably connected with the pushing assembly, when the blood vessel stent needs to be introduced into the body, the stent can be stretched along the axial direction of the pushing assembly to make the stent shrink, so that the radial size of the stent can be reduced, thereby facilitating the introduction of the blood vessel stent into the body through the delivery catheter. The pulling assembly connected with the proximal end of the stent is arranged, after the blood vessel stent reaches the lesion site, the continuous change of the radial size and the helical pitch of the stent after expansion can be accurately and dynamically controlled by controlling the pulling and releasing of the pulling assembly, for example, the outer diameter of the stent is controlled to continuously change between 1mm (shrinkage state) and 12mm (expansion state) by pulling the handle, so that the stent matches the blood vessel taper or bifurcation lesion (such as transition from a 4.0mm main stem to a 2.5mm branch), thereby facilitating the improvement of the matching degree of the stent and the lesion site. Before the stent is released, the stent can be repositioned by controlling the pulling assembly multiple times, thereby reducing the occurrence of stent waste caused by positioning errors. At the same time, after the operation is completed, the stent can be shrunk to the minimum size by pulling the pulling assembly, thereby facilitating the rapid exit of the stent from the body, so that the blood vessel stent can be recycled. Therefore, the blood vessel stent provided in the application can realize the dynamic and continuous adjustment of the stent in the body, thereby facilitating the controllability of the operation, and the stent can be quickly and conveniently recycled, thereby facilitating the reduction of the operation difficulty.
[0006] In a possible implementation manner of the application, the stent comprises 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 with the pushing assembly, the second straight segment is slidably connected with the pushing assembly and connected with the pulling assembly; the curved segment is in a helical shape, and the curved segment is sleeved on the pushing assembly.
[0007] In a possible implementation manner of the application, the first straight segment and the second straight segment are both in a helical shape matched with the pushing assembly, and the helical first straight segment and the helical second straight segment are both sleeved on the pushing assembly; the helical pitch of the first straight segment and the helical pitch of the second straight segment are both smaller than the helical pitch of the curved segment.
[0008] In a possible implementation manner of the application, the curved segment comprises a support segment and a deformation segment; the support segment is located at the distal end of the curved segment and connected with the first straight segment; the deformation segment is located at the proximal end of the curved segment and connected with the second straight segment; the helical pitch of the support segment is smaller than the helical pitch of the deformation segment.
[0009] In a possible implementation manner of the application, along the radial direction of the pushing assembly, the outer diameter of the support segment is greater than the outer diameter of the deformation segment.
[0010] In a possible implementation of the present application, the pitch of the curved section gradually increases from the distal end of the curved section to the proximal end of the curved section in the axial direction; 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 curved section is greater than or equal to 0.5 mm and less than or equal to 1.2 mm.
[0011] In a possible implementation of the present application, the vascular stent further includes a limiting member, the limiting member is arranged on the pushing assembly and located on one side of the second linear section close to the first linear section, and the limiting member is configured to limit the movement of the first linear section to the second linear section in the axial direction.
[0012] In a possible implementation of the present application, at least one of the first linear section, the curved section and the second linear section includes at least two braided wires, and the at least two braided wires are spirally wound.
[0013] In a possible implementation of the present application, the vascular stent further includes a first developing member, and the first developing member is spirally arranged on the distal end of the pushing assembly and the first linear section.
[0014] In a possible implementation of the present application, the vascular stent further includes a second developing member, the second developing member is fixed to the pushing assembly, and the distal end of the stent is fixedly connected to the second developing member.
[0015] In a possible implementation of the present application, the vascular stent further includes a third developing member, the third developing member is slidably arranged on the pushing assembly, the proximal end of the stent is fixedly connected to the third developing member, and the pulling assembly is connected to the third developing member.
[0016] In a possible implementation of the present application, the pulling assembly includes a pulling wire and a handle, one end of the pulling wire is connected to the proximal end of the stent, the other end of the pulling wire is connected to the handle, the pushing assembly has a fixing structure matched with the pulling wire, the pulling wire is arranged in the fixing structure, and the fixing structure is configured to fix or release the pulling wire.
[0017] In a possible implementation of the present application, the vascular stent further includes a coating arranged on the surface of the stent, and the coating includes at least one of a drug coating and an anticoagulant coating.
[0018] In another aspect, the present application provides a stent system, which includes a delivery catheter and the vascular stent provided in any of the above aspects, and the delivery catheter is configured to be inserted into the body, and the delivery catheter has a delivery channel matched with the pushing assembly and the stent.
[0019] The stent system provided in the present application can realize the dynamic and continuous adjustment of the stent in the body, improve the controllability of the operation, and realize the rapid and convenient recovery of the stent, thereby reducing the difficulty of the operation.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 Structure diagram of a vascular stent provided in the present application Figure 1 ; Figure 2 Structure diagram of a vascular stent provided in the present application Figure 2 ; Figure 3 Structure diagram of a vascular stent provided in the present application
[0021] BRIEF DESCRIPTION OF DRAWINGS 1-push assembly; 11-push piece; 12-operating piece; 2-stent; 21-first straight section; 22-bent section; 221-support section; 222-deformation section; 23-second straight section; 24-first pitch; 25-second pitch; 3-pulling assembly; 31-pulling wire; 32-handle; 4-limiting piece; 5-first developing piece; 6-second developing piece; 7-third developing piece; Y-radial direction; Z-axial direction.
[0022] It should be noted that the above-mentioned "first" and "second" are only used to distinguish different schemes, and do not represent the priority of the schemes or the priority in the implementation process. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings, and the described embodiments should not be regarded as limitation of the present application. All other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0024] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood or implied to indicate or imply relative importance or implicitly indicate the number of indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.
[0025] In addition, in the embodiments of the present application, the orientation terms such as "up", "down", "left" and "right" are defined with respect to the orientation of the components shown in the drawings, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and can be changed accordingly according to the change of the orientation of the components placed in the drawings.
[0026] In the embodiments of the present application, unless specifically defined and limited otherwise, the term "connection" should be interpreted broadly, for example, "connection" can be fixed connection, or detachable connection, or integral; can be directly connected, or indirectly connected through an intermediate medium.
[0027] In the embodiments of the present application, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusions, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element.
[0028] In the embodiments of the present application, the words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present concepts in a concrete manner.
[0029] Vascular stents are mainly divided into bare mental stent (BMS), drug-eluting stent (DES), and bioresorbable vascular scaffold (BVS). BMS and DES are permanent implantation stents. Permanent metal may affect the natural vasomotion function of the blood vessel. Although the restenosis rate of DES is significantly reduced, the restenosis rate is 5%-10% (the restenosis rate within 6 months after BMS is as high as 15%-30%), but the polymer coating may delay endothelial healing, leading to a late thrombosis rate of about 0.5%-2%, and long-term (6-12 months) dual antiplatelet therapy (DAPT) is required. BVS is usually made of polylactic acid (PLA) or magnesium alloy, which gradually degrades into carbon dioxide and water within 2-3 years, temporarily supports the blood vessel, and is eventually completely absorbed, so that the blood vessel restores physiological function. Although BVS has no permanent foreign body retention, the blood vessel restores natural vasomotion after degradation, which can avoid the long-term side effects of metal stents, but the supporting force of BVS is weak, and the acute occlusion risk may occur due to shrinkage in the early stage of degradation, and the restenosis rate is high.
[0030] The embodiments of the present application provide a vascular stent, which can realize dynamic and continuous adjustment of the stent in the body, is conducive to improving the controllability of the operation, can realize rapid and convenient recovery of the stent, and is conducive to reducing the difficulty of the operation. Referring to Figure 1 , Figure 2and Figure 3 , Figure 1 Structure diagram of the vascular stent provided in the present application Figure 1 , Figure 2 Structure diagram of the vascular stent provided in the present application Figure 2 , Figure 3 Structure diagram of the vascular stent provided in the present application, the vascular stent provided in the embodiments of the present application will be described below in combination with the examples in the accompanying drawings.
[0031] The vascular stent provided in the embodiments of the present application comprises a pushing assembly 1, a stent 2 and a pulling assembly 3; at least a part of the stent 2 extends in a helical shape along the axial direction Z of the pushing assembly 1, and is sleeved on the pushing assembly 1, the distal end of the stent 2 is fixed to the distal end of the pushing assembly 1, and the proximal end of the stent 2 is in sliding connection with the pushing assembly 1; the pulling assembly 3 is connected to the proximal end of the stent 2; in the process of moving the pulling assembly 3 relative to the pushing assembly 1 towards the proximal end of the pushing assembly 1 along the axial direction Z of the stent 2, the pulling assembly 3 drives the proximal end of the stent 2 to move towards the proximal end of the pushing assembly 1, and the outer diameter of the stent 2 decreases.
[0032] In the embodiments of the present application, the pushing assembly 1 can provide support and installation basis for the stent 2, the pulling assembly 3 and the like, and the vascular stent can be introduced into the body through the pushing assembly 1 along the delivery catheter. For example, the pushing assembly 1 can be configured to have a structure comprising a pushing member 11 and an operating member 12, the pushing member 11 can be configured in an elongated strip shape, for example, the pushing member 11 can be configured as a filament with a diameter of about 1 mm, the length of the pushing member 11 can be 50 cm to 200 cm, and the length of the pushing member 11 can be selected according to the specific application scenario of the vascular stent, and the embodiments of the present application do not limit the length of the pushing member 11. The pushing member 11 can be made of a metal material or a high polymer composite material. The operating member 12 can be provided at the proximal end of the pushing member 11, and the operating member 12 can be configured in a columnar or blocky structure that is convenient for holding by hand. The proximal end of the pushing member 11 and the operating member 12 can be fixedly connected by bonding, welding, insertion or the like, and the operator can hold the vascular stent through the operating member 12.
[0033] It should be noted that the distal end and the proximal end described in the present application are both in the extension direction of the axial direction Z of the pushing assembly 1, the distal end is the end of the pushing assembly 1 away from the operator, that is, the distal end is the end that enters the body first or is closest to the body, and the proximal end is the end of the pushing assembly 1 closest to the operator, that is, the proximal end is the end that enters the body last or is farthest from the body. For example, as shown in Figure 1 , the distal end is the upper end of the pushing assembly 1 in Figure 1 , and the proximal end is the lower end of the pushing assembly 1 in Figure 1 .
[0034] In the embodiments of the present application, the stent 2 can support blood vessels and the like to achieve the purpose of expanding blood vessels. The stent 2 can be provided in a spiral shape, that is, the stent 2 continuously extends along the axial direction Z of the pushing assembly 1 and continuously surrounds the pushing assembly 1 along the radial direction Y of the pushing assembly 1. 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 and platinum-tungsten alloy, so that the stent 2 has good elasticity and rigidity.
[0035] For example, the distal end of the stent 2 can be fixed to the distal end of the pushing member 11 by welding, bonding, clamping or the like. The proximal end of the stent 2 can be provided in a circular ring shape matched with the pushing rod, so that the proximal end of the stent 2 is slidably sleeved on the pushing rod; or a sliding groove matched with the proximal end of the stent 2 can be provided on the pushing member 11, and the proximal end of the stent 2 is slidably arranged in the sliding groove, so that the proximal end of the stent 2 is slidably connected with the pushing member 11. In this way, the proximal end of the stent 2 can move relative to the pushing assembly 1 along the axial direction Z.
[0036] In the embodiments of the present application, the stent 2 can be provided with a pulling assembly 3, and the operator can drive the proximal end of the stent 2 to move relative to the pushing assembly 1 along the axial direction Z through the pulling assembly 3.
[0037] For example, the pulling assembly 3 can be provided in a structure including a pulling wire 31 and a handle 32. One end of the pulling wire 31 is connected with the proximal end of the stent 2, and the other end of the pulling wire 31 is connected with the handle 32. The pushing assembly 1 has a fixing structure (not shown in the figure) matched with the pulling wire 31, and the pulling wire 31 is arranged in the fixing structure, and the fixing structure is used for fixing or releasing the pulling wire 31.
[0038] For another example, the pulling wire 31 can be made of metal filaments or filaments made of high polymer composite materials. The pulling wire 31 can be arranged in parallel with the pushing member 11, or the pushing member 11 can be provided in a structure having a cavity, so that the pulling wire 31 is arranged in the pushing member 11. The distal end of the pulling wire 31 can be fixedly connected with the proximal end of the stent 2 by welding, bonding, clamping or the like. The handle 32 can be fixed to the proximal end of the pulling wire 31, or the handle 32 can be fixed to the proximal end of the pushing member 11 or the proximal end of the operating member 12. The handle 32 can also not be fixed to the pushing member 11 and the operating member 12. A fixing structure matched with the pulling wire 31 can be provided on the operating member 12, for example, a threading hole matched with the pulling wire 31 can be provided on the operating member 12, and a knob is arranged on the operating member 12. The knob is threadedly connected with the operating member 12, and the hole wall of the threading hole can be brought close to or away from each other by rotating the knob, so that the pulling wire 31 is clamped and fixed in the threading hole, or the pulling wire 31 can freely move in the threading hole.
[0039] As shown in Figure 2 Fig. 1, before the stent is implanted in the body, the handle 32 can be pulled to drive the pull wire 31 to move along the axial direction Z of the push assembly 1 to the proximal end of the push assembly 1, so as to stretch the stent 2 along the axial direction Z, expand the stent 2 along the radial direction Y to the push member 11, and finally make the stent 2 tightly wrap around the push member 11 with the largest pitch, so as to reduce the outer diameter of the stent 2 to the minimum. As shown in Figure 1 Fig. 2, after the stent is implanted in the lesion site of the body through the delivery catheter, the pull wire 31 can be released by operating the operating member 12, at this time, the stent 2 is contracted along the axial direction Z and expanded along the radial direction Y under the action of its own elasticity to restore to the spiral shape with the larger outer diameter, so as to expand the lesion part of the blood vessel. After the operation is completed, the stent 2 is stretched to tightly wrap around the push member 11 by pulling the handle 32 and the pull wire 31, so that the stent 2 is separated from the blood vessel, and the stent is withdrawn from the body.
[0040] The stent provided by the embodiment of the present application can be stretched along the axial direction Z of the push assembly 1 to contract the stent 2, so as to reduce the radial dimension Y of the stent 2, thereby facilitating the stent to be implanted in the body through the delivery catheter. The pull assembly 3 connected with the proximal end of the stent 2 is provided, after the stent reaches the lesion site, the continuous and dynamic control of the radial dimension Y and the pitch of the stent 2 after expansion can be realized by controlling the pull assembly 3 to be pulled or released, for example, the outer diameter of the stent 2 is controlled to continuously change between 1 mm (in the contracted state) and 12 mm (in the expanded state) by pulling the handle 32, so that the stent 2 matches the blood vessel taper or bifurcation lesion (for example, from 4.0 mm main stem to 2.5 mm branch), thereby facilitating to improve the matching degree of the stent 2 and the lesion site. Before the stent 2 is released, the stent 2 can be contracted and repositioned for multiple times by controlling the pull assembly 3, which is beneficial to reduce the situation that the stent 2 is abandoned due to positioning error. After the operation is completed, the stent 2 can be contracted to the minimum by pulling the pull assembly 3, so as to quickly withdraw the stent 2 from the body, thereby realizing the recyclability of the stent. Therefore, the stent provided by the embodiment of the present application can realize the dynamic and continuous adjustment of the stent 2 in the body, which is beneficial to improve the controllability of the operation, and can realize the quick and convenient recycling of the stent 2, which is beneficial to reduce the difficulty of the operation.
[0041] In some possible embodiments of the present application, as shown in Figure 1 andFigure 3 As shown, the stent 2 comprises a first straight section 21, a curved section 22 and a second straight section 23; the first straight section 21 is connected to the distal end of the curved section 22, the second straight section 23 is connected to the proximal end of the curved section 22, the first straight section 21 is fixedly connected with the pushing assembly 1, the second straight section 23 is slidably connected with the pushing assembly 1 and is connected with the pulling assembly 3; the curved section 22 is in a spiral shape, and the curved section 22 is sleeved on the pushing assembly 1.
[0042] In the embodiments of the present application, the stent 2 can be provided in a structure comprising a first straight section 21, a curved section 22 and a second straight section 23, so as to connect the stent 2 with the pushing member 11 through the first straight section 21 and the second straight section 23, and to realize the contraction and expansion of the stent 2 through the curved section 22.
[0043] For example, the first straight section 21 can be provided at the distal end of the curved section 22, and the second straight section 23 can be provided at the proximal end of the curved section 22; the first straight section 21, the curved section 22 and the second straight section 23 can be integrally formed, that is, the first straight section 21, the curved section 22 and the second straight section 23 are processed and formed by one or more complete braided wires. The first straight section 21, the curved section 22 and the second straight section 23 can also be separately manufactured, and then sequentially fixedly connected through welding, bonding or the like.
[0044] For another example, the first straight section 21 and the second straight section 23 can both be provided in a sheet shape matched with the pushing member 11, so as to wrap the first straight section 21 and the second straight section 23 on the pushing member 11 along the circumferential direction of the pushing member 11, such as wrapping one circle, or half a circle, one third of a circle or the like. The first straight section 21 can be fixedly connected with the pushing member 11 through welding, bonding or the like, so as to fixedly connect the distal end of the stent 2 with the pushing member 11. The second straight section 23 is not fixed with the pushing member 11, so that the second straight section 23 can slide relative to the pushing member 11.
[0045] For another example, the curved section 22 can be provided in a spiral shape, that is, the curved section 22 extends along the axial direction Z in a spiral shape, and the pushing member 11 can be arranged through the curved section 22, so that the curved section 22 is sleeved on the pushing member 11. The curved section 22 can be provided in different lengths according to the application scene of the vascular stent, for example, the curved section 22 can be provided in a length of 9mm to 100mm. It should be noted that the length of the curved section 22 described herein refers to the length of the stent 2 measured in a natural stretched state without external force.
[0046] The stent provided by the embodiment of the present application is provided with a structure including a first straight section 21, a curved section 22 and a second straight section 23, so that the stent 2 is fixedly connected with the pushing assembly 1 through the first straight section 21, and the stent 2 is slidingly connected with the pushing assembly 1 along the axial direction Z through the second straight section 23. The curved section 22 is provided in a spiral shape, so that the stent 2 can be contracted or expanded along the radial direction Y through the curved section 22, and the stent 2 is convenient for interventional operation and recovery operation.
[0047] In some possible embodiments of the present application, the first straight section 21 and the second straight section 23 are both provided in a spiral shape matched with the pushing assembly 1, and the first straight section 21 and the second straight section 23 are both sleeved on the pushing assembly 1; the pitch of the first straight section 21 and the pitch of the second straight section 23 are both smaller than the pitch of the curved section 22.
[0048] In the embodiment of the present application, the first straight section 21 and the second straight section 23 can both be provided in a spiral shape, so that the first straight section 21 and the second straight section 23 are both sleeved on the pushing member 11. For example, the first straight section 21 and the second straight section 23 can be wound in a spiral shape according to the outer diameter of the pushing member 11.
[0049] For example, two adjacent turns in the spiral-shaped first straight section 21 can abut along the axial direction Z, that is, the pitch of the first straight section 21 can be the diameter of the braided wire of the first straight section 21. Two adjacent turns in the spiral-shaped second straight section 23 can also abut along the axial direction Z, that is, the pitch of the second straight section 23 can be the diameter of the braided wire of the second straight section 23. The pitch of the first straight section 21 and the pitch of the second straight section 23 can also be other values. The spiral-shaped first straight section 21 can be sleeved on the pushing member 11, and the first straight section 21 can be fixedly connected with the pushing member 11 by welding, bonding or the like. The inner diameter of the spiral-shaped second straight section 23 can be greater than the outer diameter of the pushing member 11, so that the second straight section 23 is sleeved on the pushing member 11, and the second straight section 23 is in clearance fit with the pushing member 11.
[0050] For another example, the pitch of the curved section 22 can be set to be much greater than the pitch of the first straight section 21 and much greater than the pitch of the second straight section 23. The pitch of the curved section 22 can be set according to the specific use scene of the stent 2. It should be noted that the pitch of the first straight section 21, the pitch of the second straight section 23 and the pitch of the curved section 22 described herein all refer to the length measured when the stent 2 is in a natural extension state without external force.
[0051] In another example, the first straight section 21 and the second straight section 23 can be both provided in a straight line type, that is, the first straight section 21 can be provided in a straight strip shape parallel to the pushing member 11, and the second straight section 23 can also be provided in a straight strip shape parallel to the pushing member 11, so that the first straight section 21 can be attached and fixed to the pushing member 11 along the axial direction Z, and the second straight section 23 can be attached and slidably arranged to the pushing member 11 along the axial direction Z.
[0052] The blood vessel stent provided by the embodiments of the present application can be sleeved on the pushing assembly 1, which is beneficial to improving the reliability of the fixed connection of the first straight section 21 and the pushing assembly 1, and improving the stability of the sliding connection of the second straight section 23 and the pushing assembly 1, so as to reduce the risk of the proximal end of the stent 2 being stuck with the pushing assembly 1, and improve the smoothness of the sliding of the proximal end of the stent 2 relative to the pushing assembly 1.
[0053] In some possible embodiments of the present application, as shown in Figure 3 The support section 221 is located at the distal end of the curved section 22 and connected with the first straight section 21, and the deformation section 222 is located at the proximal end of the curved section 22 and connected with the second straight section 23. The pitch of the support section 221 is smaller than the pitch of the deformation section 222.
[0054] In the embodiments of the present application, the curved section 22 can be provided in a structure including the support section 221 and the deformation section 222, that is, the curved section 22 is provided in two parts with different pitches, so that the support section 221 is located at the distal end of the curved section 22, and the deformation section 222 is located at the proximal end of the curved section 22.
[0055] For example, the first pitch 24 of the support section 221 can 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 deformation section 222 can be greater than or equal to 0.5 mm and less than or equal to 1.2 mm. For example, the pitch of the support section 221 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm, and the pitch of the deformation section 222 can be 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. In this way, the pitch of the support section 221 is selected to be smaller than the pitch of the deformation section 222.
[0056] In another example, along the axial direction Z of the pushing assembly 1, the pitch of the curved section 22 gradually increases from the distal end of the curved section 22 to the proximal end of the curved section 22. In the case where the pitch of the support section 221 is smaller than the pitch of the deformation section 222, the pitch of the entire curved section 22 can also gradually change, that is, from the support section 221 to the deformation section 222, the pitch between two adjacent turns of the support section 221 gradually increases, and the pitch between two adjacent turns of the deformation section 222 also gradually increases. For example, the pitch in the support section 221 gradually increases from 0.3 mm to 0.7 mm, and the pitch in the deformation section 222 gradually increases from 0.8 mm to 1.2 mm.
[0057] In this way, the distance between the turns of the stent 2 and the diameter of the primary turns (the turn farthest from the distal end of the curved section 22 and the turn closest to the proximal end of the curved section 22) of the stent 2 can be adjusted according to the specific application scenario to change the radial support force of the stent 2. The smaller the pitch of the stent 2 or the larger the diameter of the primary turns, the larger the stress area of the blood vessel, and the stronger the anti-extrusion capacity of the stent 2 can withstand, thereby increasing the radial support force of the stent 2; the larger the pitch of the stent 2 or the smaller the diameter of the primary turns, the smaller the stress area of the blood vessel, and the weaker the anti-extrusion capacity of the stent 2 can withstand, thereby reducing the radial support force of the stent 2.
[0058] In another example, along the radial direction Y of the pushing assembly 1, the outer diameter of the support section 221 is larger than the outer diameter of the deformation section 222. The support section 221 can be configured as a relatively thick structure, and the deformation section 222 can be configured as a relatively thin structure, so that the outer diameter of the support section 221 is larger than the outer diameter of the deformation section 222, and the entire curved section 22 is approximately conical. For example, along the direction from the support section 221 to the deformation section 222, the outer diameter of the support section 221 can gradually decrease, and the outer diameter of the deformation section 222 can gradually decrease.
[0059] The stent provided by the embodiments of the present application can make the pitch of the curved section 22 increase from the distal end to the proximal end, so that the curved section 22 can form a better mechanical gradient to adapt to the natural mechanical distribution of the blood vessel. In addition, the support section 221 with a smaller pitch can provide a stronger radial support force, which is beneficial to effectively expand the lesion site, and the deformation section 222 with a larger pitch can reduce the local rigidity of the proximal end of the curved section 22 (the elastic modulus is 20% to 40% smaller than that of the distal end of the curved section 22), so that the proximal end of the curved section 22 is more easily bent and deformed, which is beneficial to adapt the curved section 22 to the physiological bending of the blood vessel.
[0060] In some possible embodiments of the present application, as Figure 1As shown, the vascular stent further comprises a limiting piece 4, which is arranged on the pushing assembly 1 and located on one side of the second straight segment 23 close to the first straight segment 21. The limiting piece 4 is used to limit the movement of the first straight segment 21 along the axial direction Z to the second straight segment 23.
[0061] In the embodiments of the present application, the limiting piece 4 can be arranged on the pushing assembly 1 to limit the movement range of the proximal end of the stent 2 on the pushing assembly 1 through the limiting piece 4.
[0062] For example, the limiting piece 4 can be an injection molded piece or a metal piece. The limiting piece 4 can be fixed on the pushing member 11 at a position close to the proximal end of the curved segment 22, and the limiting piece 4 is located on one side of the second straight segment 23 close to the first straight segment 21. The outer diameter of the limiting piece 4 can be greater than the inner diameter of the first straight segment 21 and less than the inner diameter of the deformed segment 222. In this way, during the expansion of the stent 2 under the action of its own elastic force to move the first straight segment 21 towards the distal end of the pushing member 11, until the first straight segment 21 abuts against the limiting piece 4, the proximal end of the stent 2 can be limited to a unique and determined position.
[0063] The vascular stent provided by the embodiments of the present application can limit the position of the first straight segment 21 moving towards the distal end along the axial direction Z through the limiting piece 4 arranged on the pushing assembly 1 corresponding to the first straight segment 21, so that the stent 2 can stop at an accurate position during expansion, which is beneficial to improve the accuracy and stability of the shape of the stent 2 after expansion.
[0064] In some possible embodiments of the present application, at least one of the first straight segment 21, the curved segment 22 and the second straight segment 23 comprises at least two braided wires, and the at least two braided wires are spirally wound.
[0065] In the embodiments of the present application, the stent 2 can be entirely arranged as a structure wound by a plurality of braided wires, or one or two of the first straight segment 21, the curved segment 22 and the second straight segment 23 of the stent 2 can be arranged as a structure wound by a plurality of braided wires.
[0066] For example, the three braided wires can be uniformly distributed at an angle of 120° in the circumferential direction, and the three braided wires are twisted to be spirally wound with each other, so as to form a thicker blank. The blank is processed to form the stent 2 comprising the first straight segment 21, the curved segment 22 and the second straight segment 23.
[0067] Another example, the three strands of braided wires of the first straight segment 21 and the three strands of braided wires of the second straight segment 23 can be formed into a cylinder shape matching the pusher 11, the three strands of braided wires of the first straight segment 21 can be sleeved on the pusher 11, and the three strands of braided wires of the second straight segment 23 can be sleeved on the pusher 11.
[0068] The blood vessel stent provided by the embodiment of the present application can disperse the load of each part of the stent 2 through the multiple strands of braided wires, which is beneficial to reduce the local stress of the stent 2. For example, the first straight segment 21, the curved segment 22 and the second straight segment 23 are all provided as three strands of uniformly distributed braided wires, which can not only make the structure of each part of the stent 2 more stable (the structural symmetry coefficient can reach 0.987), but also improve the flexibility of each part of the stent 2, so that each part of the stent 2 is more easily bent, thereby the stent 2 can adapt to the direction of the blood vessel; and the stent 2 can also expand more uniformly through the contact of multiple points to reduce the deformation of the stent 2.
[0069] Compared with the related art, most of the conventional stents adopt a closed unit or a rhombic grid structure (such as a laser-cut metal tube), the connection points of each closed unit are fixed, and local stress concentration is easy to occur when the conventional stent is bent, which limits the flexibility of the stent 2 (folding marks are easy to occur when the bending radius is greater than or equal to 15 mm). The stent 2 provided by the embodiment of the present application adopts an open spiral braided mesh structure (the diameter of the braided wire can be 0.06 mm to 0.1 mm), which can form a continuous elastic body similar to a spring, so that the stent 2 can freely deform along the bending direction of the blood vessel, and the stent 2 can still adhere to the wall in the blood vessel with a bending radius less than or equal to 5 mm (the conventional stent cannot adhere to the wall when the bending radius of the blood vessel is less than or equal to 10 mm), the spiral structure allows the stent 2 to twist in the axial direction Z (the maximum twisting angle is ± 30°) with the blood vessel, which can reduce the distortion of the blood vessel caused by excessive rigidity of the stent 2.
[0070] In some possible embodiments of the present application, as shown in Figure 1 The blood vessel stent further includes a first developing member 5, a second developing member 6 and a third developing member 7. The first developing member 5 is sleeved on the distal end of the push assembly 1 and the first straight segment 21 in a spiral shape. The second developing member 6 is fixed to the push assembly 1, and the distal end of the stent 2 is fixedly connected with the second developing member 6. The third developing member 7 is sleeved on the push assembly 1 in a sliding manner, the proximal end of the stent 2 is fixedly connected with the third developing member 7, and the pulling assembly 3 is connected with the third developing member 7.
[0071] In the embodiments of the present application, the developing member can be arranged in the vascular stent, and the developing member can be made of X-ray opaque material, such as platinum-tungsten alloy, platinum-iridium alloy, stainless steel, and the like.
[0072] For example, the first developing member 5 can be made of platinum-tungsten alloy filament, and the platinum-tungsten alloy filament can be wound on the distal head of the pushing member 11 to form a helix, and the first developing member 5 can be wound on the first straight section 21, that is, the first developing member 5 is wound on the first straight section 21 and the distal head of the pushing member 11 in parallel. For example, the pitch of the first developing member 5 can be equal to the diameter of the first developing member 5, that is, each turn of the first developing member 5 is closely arranged on the pushing member 11. The first developing member 5 can be fixedly connected to the pushing member 11 by bonding, welding, or the like. In this way, the first developing member 5 can be in the form of a soft spring that is easy to deform, and when the vascular stent is pushed out of the delivery catheter, the risk of damage to the blood vessel caused by the head of the pushing member 11 directly pressing against the blood vessel wall (the head of the pushing member 11 can be bent and deformed) due to improper operation can be reduced, and the passability of the vascular stent can be improved.
[0073] For another example, the second developing member 6 can be arranged at the distal end of the stent 2, for example, the second developing member 6 can be arranged in the form of a ring matched with the pushing member 11, the ring-shaped second developing member 6 can be arranged on the pushing member 11 adjacent to the first developing member 5, and the second developing member 6 can be fixed to the pushing member 11 by welding, bonding, or the like. Each strand of the first straight section 21 can be fixed to the second developing member 6 by welding, bonding, or the like to fix the first straight section 21 on the pushing member 11.
[0074] For another example, the third developing member 7 can be arranged at the proximal end of the stent 2, for example, the third developing member 7 can be arranged in the form of a ring matched with the pushing member 11, and the ring-shaped third developing member 7 can be arranged on the pushing member 11 in a clearance fit. The ring-shaped third developing member 7 can be arranged on the pushing member 11, and the third developing member 7 can be fixed to the pulling member by welding, bonding, or the like. Each strand of the second straight section 23 can be fixed to the third developing member 7 by welding, bonding, or the like to slide the second straight section 23 on the pushing member 11 through the third developing member 7.
[0075] The blood vessel stent provided by the embodiments of the present application can realize the cooperative positioning of three developing points through the first developing element 5, the second developing element 6 and the third developing element 7 after the blood vessel stent is introduced into the body, so that the three developing points can be positioned in the three-dimensional space, and then the blood vessel stent can be calibrated in three dimensions (the error can be less than 0.5 mm) in the operation. Meanwhile, when the stent 2 is contracted or expanded, the specific form of the stent 2 can be determined according to the distance change between the second developing element 6 and the third developing element 7, for example, the pitch change of the stent 2 can reflect the form of the stent 2 (for example, the increase of 1 mm in the pitch can correspond to the decrease of 15% in the outer diameter), so as to assist the operator to judge the apposition effect of the stent 2.
[0076] In some possible embodiments of the present application, the blood vessel stent further comprises a coating, which is arranged on the surface of the stent 2, and the coating comprises at least one of a drug coating and an anticoagulant coating.
[0077] In the embodiments of the present application, the coating can be coated on the surface of the stent 2, such as the drug coating, the anticoagulant coating and the like on the surface of the curved section 22.
[0078] For example, the drug coating (such as rapamycin) can be coated on the surface of the curved section 22, and the drug coating can be released by passive diffusion. The stent 2 can also realize the triggered drug stripping, for example, when the stent 2 is stretched along the axial direction Z, the drug coating can be released, so as to accelerate the separation of the drug residue. The anticoagulant coating, such as heparin coating, choline phosphate coating, polyvinylpyrrolidone (PVP) coating and the like, can also be coated on the surface of the curved section 22.
[0079] For another example, the perfusion channel can be arranged on the side wall of the pushing member 11, such as the perfusion channel with an inner diameter of 0.1 mm to 0.3 mm arranged on the side wall of the pushing member 11, which can extend to the injection port on the operating member 12, so as to synchronize the perfusion of the antithrombotic drug to the lesion site through the pushing member 11 when the stent 2 is released.
[0080] The blood vessel stent provided by the embodiments of the present application can deliver the drug coating, the anticoagulant coating and the like to the lesion site through the stent 2 due to the arrangement of the drug coating and / or the anticoagulant coating on the stent 2. And the release of the drug in the coating can be triggered by the contraction and expansion of the stent 2, which is conducive to the control of the release of the drug.
[0081] In addition, the application further provides a stent system, which comprises a delivery catheter and the vascular stent provided by any one of the above embodiments; wherein the delivery catheter is used for interventional operation in vivo; and the delivery catheter has a delivery channel matched with the push assembly 1 and the stent 2.
[0082] In the application, the delivery catheter can be used for interventional operation in vivo. For example, the delivery catheter can be provided as a tubular structure having a delivery channel, and the inner diameter of the delivery channel is greater than the outer diameter of the vascular stent (the stent 2 is in a contracted state). In this way, the delivery catheter can be introduced into the body through a guide wire, the guide wire is then withdrawn from the body, and then the vascular stent is introduced into the body along the delivery channel until the distal end of the stent 2 reaches the lesion site, and finally the proximal end of the stent 2 is released, so that the stent 2 is expanded under the action of its own elasticity to fully support the lesion site.
[0083] The stent system provided by the application can realize dynamic and continuous adjustment of the stent 2 in vivo, which is beneficial to improve the controllability of the operation, and can also realize quick and convenient recovery of the stent 2, which is beneficial to reduce the difficulty of the operation.
[0084] The above is only an embodiment of the application, and is not used to limit the protection scope of the application. Any modification, equivalent replacement and improvement made within the spirit and scope of the application shall be included in the protection scope of the application.
Claims
1. A vascular stent, characterized by, The blood vessel stent comprises: a pushing assembly; a stent, at least a part of the stent extends spirally along an axial direction of the pushing assembly, and the stent is sleeved on the pushing assembly, a distal end of the stent is fixed to a distal end of the pushing assembly, and a proximal end of the stent is in sliding connection with the pushing assembly; a pulling assembly, the pulling assembly is connected to the proximal end of the stent, and the pulling assembly drives the proximal end of the stent to move towards the proximal end of the pushing assembly along the axial direction, and the outer diameter of the stent decreases.
2. The vascular stent of claim 1, wherein, The stent comprises a first straight segment, a curved segment and a second straight segment, the first straight segment is connected to a distal end of the curved segment, the second straight segment is connected to a proximal end of the curved segment, the first straight segment is fixedly connected to the pushing assembly, the second straight segment is in sliding connection with the pushing assembly and is connected to the pulling assembly, and the curved segment is spirally sleeved on the pushing assembly.
3. The vascular stent of claim 2, wherein, The curved segment comprises a support segment and a deformation segment, the support segment is located at the distal end of the curved segment and is connected to the first straight segment, and the deformation segment is located at the proximal end of the curved segment and is connected to the second straight segment, and the pitch of the support segment is smaller than the pitch of the deformation segment.
4. The vascular stent of claim 3, wherein, Along a radial direction of the pushing assembly, the outer diameter of the support segment is greater than the outer diameter of the deformation segment.
5. The vascular stent of claim 3, wherein, Along the axial direction, the pitch of the curved segment gradually increases from the distal end of the curved segment to the proximal end of the curved 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 curved segment is greater than or equal to 0.5 mm and less than or equal to 1.2 mm.
6. The vascular stent of claim 2, wherein, The blood vessel stent further comprises a limiting piece, the limiting piece is arranged on the pushing assembly and is located on a side of the second straight segment close to the first straight segment, and the limiting piece is used to limit the movement of the first straight segment towards the second straight segment along the axial direction.
7. The vascular stent defined in any one of Claims 2-6, wherein, At least one of the first straight segment, the curved segment and the second straight segment comprises at least two braided wires, and the at least two braided wires are spirally wound.
8. The vascular stent according to any one of claims 2 to 6, wherein The blood vessel stent further comprises a first developing piece, the first developing piece is spirally sleeved on the distal end of the pushing assembly and the first straight segment. And / or, the blood vessel stent further comprises a second developing piece, the second developing piece is fixed to the pushing assembly, and the distal end of the stent is fixedly connected to the second developing piece. And / or, the blood vessel stent further comprises a third developing piece, the third developing piece is sleeved on the pushing assembly in a sliding manner, the proximal end of the stent is fixedly connected to the third developing piece, and the pulling assembly is connected to the third developing piece.
9. The vascular stent according to any one of claims 1 to 6, wherein The pulling assembly comprises a pulling wire and a handle, one end of the pulling wire is connected to the proximal end of the stent, the other end of the pulling wire is connected to the handle, the pushing assembly has a fixing structure matched with the pulling wire, the pulling wire is arranged in the fixing structure, and the fixing structure is used to fix or release the pulling wire.
10. The vascular stent defined in any one of Claims 1-6, wherein, The blood vessel stent further comprises a coating, the coating is arranged on the surface of the stent, and the coating comprises at least one of a drug coating and an anticoagulant coating.
11. A stent system characterized by, The blood vessel stent comprises: A delivery catheter for use in an interventional procedure; The stent of any one of claims 1 to 10, the delivery catheter having a delivery channel that fits both the push assembly and the stent.