Interventional stent and delivery system

Abstract

The application provides an intervention stent and a delivery system, a proximal end of an external iliac branch section is connected with a distal end of the main body section, a proximal end of an internal iliac branch section is connected with the proximal end of the external iliac branch section, the internal iliac branch section is wound along the circumference of the external iliac branch section in a contracted state, and the internal iliac branch section is movably connected with the external iliac branch section. By connecting the proximal end of the internal iliac branch section with the proximal end of the external iliac branch section, the entrance position of the internal iliac branch section can be located at the proximal end of the external iliac branch section, which is closer to the distal end region of the main body section, so that the internal iliac branch section does not need to extend downward from the middle of the main body section, but can be connected with the opening of the internal iliac artery through the connection with the proximal end of the external iliac branch section, thereby realizing the accurate alignment of the internal iliac branch section with the opening of the internal iliac artery even if the common iliac artery is short, and effectively reducing the minimum requirement of the length of the common iliac artery in the operation.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to interventional stents and delivery systems. Background Technology

[0002] An iliac artery aneurysm is a vascular lesion in which the wall of the iliac artery is locally weakened, resulting in permanent, localized dilation under the impact of blood flow. Currently, the main treatment for iliac artery aneurysms is endovascular repair. This procedure involves embolizing the internal iliac artery and extending a stent graft to the external iliac artery. However, embolizing the internal iliac artery can lead to a series of ischemic complications, including but not limited to sexual dysfunction, claudication of the hip or thigh, spinal cord ischemia, and colonic ischemia. Therefore, preserving or reconstructing the internal iliac artery while isolating the aneurysm is crucial for improving the patient's postoperative quality of life.

[0003] Iliac artery branch stents preserve blood flow to the internal iliac artery by adding additional branches to the stent body. However, existing iliac artery branch stents are primarily designed based on the vascular anatomy of Western populations. Compared to Western populations, Asian populations generally have shorter common iliac arteries. Therefore, existing stents typically have higher requirements for common iliac artery length (e.g., a common iliac artery length ≥55mm), resulting in poor anatomical adaptability in Asian populations and a clinical applicability rate of less than 25%. Summary of the Invention

[0004] Therefore, it is necessary to provide an interventional stent and delivery system to address the aforementioned technical problems.

[0005] This application provides an interventional stent, the interventional stent comprising:

[0006] The main body segment includes a first frame and a first covering body, the first covering body covering the first frame; the main body segment also has an anchoring part, and the anchoring part is located at the proximal end of the first frame;

[0007] The external iliac branch segment includes a second frame and a second covering body, the second covering body covering the second frame; the proximal end of the external iliac branch segment is connected to the distal end of the main body segment;

[0008] The internal iliac branch segment includes a third frame and a third covering body, the third covering body covering the third frame; the proximal end of the internal iliac branch segment is connected to the proximal end of the external iliac branch segment, wherein the internal iliac branch segment, in a contracted state, wraps circumferentially around the external iliac branch segment, and the distal end of the internal iliac branch segment is movably connected to the external iliac branch segment; the internal iliac branch segment also has a fixing part, the fixing part being connected to the third covering body; wherein the main body segment, the external iliac branch segment, and the internal iliac branch segment are configured as a cylindrical structure in their released states;

[0009] An anchoring portion is disposed at the near end of the main body segment; wherein, the first frame includes a plurality of wave rings, the anchoring portion is located at the trough of the wave ring at the near end of the first frame, and the anchoring portion is integrally formed with the first frame; or, the anchoring portion is located below the trough of the wave ring at the near end of the first frame, and the anchoring portion is connected to the first covering body.

[0010] In one embodiment, the main body segment is provided with a traction part; and / or,

[0011] The internal iliac branch segment is provided with a fixation part; and / or

[0012] The second frame includes a first unit frame segment, a second unit frame segment, and a transition frame segment. The first unit frame segment is connected to the first frame of the main body segment. The first unit frame segment is connected to the second unit frame segment through the transition frame segment. The radial support force of the first unit frame segment is greater than that of the second unit frame segment.

[0013] In one embodiment, the actuating portion is located at the proximal end of the main body segment; or,

[0014] The proximal end of the first frame is provided with a protrusion for constituting the traction part. The protrusion protrudes axially from the proximal end of the first frame and has a through hole; or,

[0015] The wave ring at the nearest end of the first frame includes a plurality of first curved rods and a plurality of second curved rods connected end to end; wherein, the dimension of the first curved rod along the axial direction of the first frame is greater than the dimension of the second curved rod along the axial direction of the first frame, and the near end of the first curved rod is configured to form the traction part.

[0016] In one embodiment, the anchoring portion includes at least a barb section; wherein the barb section is connected to the first covering body via a connecting section, or the barb section is directly connected to the first frame.

[0017] In one embodiment, the barb segment has an inclined angle relative to the connecting segment or relative to the first frame, and the angle of the inclined angle is 17°-23°; and / or,

[0018] The end of the barbed segment is configured as a rounded end; and / or,

[0019] The barbed section is configured as a rod-like element; and / or,

[0020] The number of the barbed segments is configured to be one or more; and / or,

[0021] The length of the barbed section is 2mm-3mm.

[0022] In one embodiment, the fixing portion is connected to the third covering body; and / or,

[0023] The fixing part is located inside the third covering body; and / or,

[0024] The fixing part is configured as a ring.

[0025] In one embodiment, the diameter of the fixing part in the released state is smaller than the diameter of the third frame in the released state.

[0026] In one embodiment, the fixing part is formed into a ring by winding braided wire, wherein the braided wire is wound several times on a tool with a groove, and each time the braided wire is wound, it passes through the groove and is intertwined with the previous one or more turns.

[0027] In one embodiment, the diameter of the first unit frame segment in the released state is smaller than the diameter of the second unit frame segment in the released state; and / or,

[0028] The wire diameter of the first unit frame segment is 0.013 inches to 0.018 inches; and / or,

[0029] The second unit frame segment is configured as a spiral structure constructed from filaments.

[0030] This application provides a delivery system including the interventional stent.

[0031] The aforementioned interventional stent and delivery system connect the proximal end of the internal iliac branch segment to the proximal end of the external iliac branch segment, allowing the entrance of the internal iliac branch segment to be located proximal to the external iliac branch segment, closer to the distal region of the main segment. This eliminates the need for the internal iliac branch segment to extend downwards from the middle of the main segment; instead, it can connect with the opening of the internal iliac artery through the connection with the proximal end of the external iliac branch segment. Thus, even with a short common iliac artery, precise alignment between the internal iliac branch segment and the opening of the internal iliac artery can still be achieved, effectively reducing the minimum requirement for the length of the common iliac artery during surgery.

[0032] Meanwhile, because the internal iliac branch is spirally wound around the external iliac branch in a contracted state, the interventional stent can transition from the external iliac branch to the opening of the internal iliac artery with a gentler arc, even when the length of the common iliac artery is limited. This allows the distal opening of the internal iliac branch to be precisely aligned with the opening of the internal iliac artery, thus enabling more patients with short common iliac arteries to undergo endovascular repair surgery with preservation of the internal iliac artery. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an interventional stent provided in one embodiment of this application.

[0034] Figure 2 This is a schematic diagram of the structure of the traction part provided in one embodiment of this application.

[0035] Figure 3 This is a schematic diagram of the structure of the traction part provided in another embodiment of this application.

[0036] Figure 4 This is a schematic diagram of the arrangement of the anchoring part provided in one embodiment of this application.

[0037] Figure 5 This is a schematic diagram of the arrangement of the anchoring part provided for another embodiment of this application.

[0038] Figure 6 This is a schematic diagram of the structure of an anchoring part provided in one embodiment of this application.

[0039] Figure 7 This is a schematic diagram of the structure of the anchoring part provided in another embodiment of this application.

[0040] Figure 8 This is a schematic diagram of the winding method of the fixing part provided in one embodiment of this application.

[0041] Figure 9 This is a schematic diagram of establishing a pre-embedded guide wire passage according to one embodiment of this application.

[0042] Figure 10 This is a schematic diagram of the release body segment and the external iliac branch segment provided in one embodiment of this application.

[0043] Figure 11 This is a schematic diagram of a long sheath crossing a mountain from the opposite side, according to one embodiment of this application.

[0044] Figure 12 This is a schematic diagram of a superselective internal iliac artery provided in one embodiment of this application.

[0045] Figure 13 This is a schematic diagram of an embodiment of the present application of an exchangeable rigid guidewire.

[0046] Figure 14 This is a schematic diagram illustrating the implantation and release of an internal iliac stent according to one embodiment of this application.

[0047] Icon labels:

[0048] 10. Interventional stent; 20. Pre-embedded guidewire; 30. Dilator; 40. Long sheath; 50. Single-curved catheter; 60. Soft guidewire; 70. Rigid guidewire; 80. Internal iliac stent;

[0049] 100. Main body segment; 200. External iliac branch segment; 300. Internal iliac branch segment; 400. Traction part; 500. Anchoring part; 600. Fixation part;

[0050] 110. First frame; 120. First membrane body;

[0051] 210. Second frame; 220. Second membrane structure; 211. First unit frame section; 212. Second unit frame section; 213. Transition frame section;

[0052] 310. Third frame; 320. Third covering body;

[0053] 410. Protrusion; 411. Through hole; 420. Wave ring; 421. First bent rod; 422. Second bent rod;

[0054] 510. Connecting section; 520. Barbed section;

[0055] 610, tooling; 620, groove; 630, braided yarn. Detailed Implementation

[0056] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0057] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "several" appears, "several" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In this application, unless otherwise expressly specified and limited, the terms "connected," "linked," "fixed," etc., shall be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] To more clearly describe the structure of the interventional stent and delivery system, the terms "proximal" and "distal" are defined herein as referring to the end of the interventional stent closer to the heart and the end farther from the heart, respectively. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0060] This application discloses a delivery system, which includes an interventional stent 10. (See also...) Figures 1 to 8 As shown, the interventional stent 10 may include a main body segment 100, an external iliac branch segment 200, and an internal iliac branch segment 300. The main body segment 100, the external iliac branch segment 200, and the internal iliac branch segment 300 are integrally formed and constructed as shown in the figure. Figure 1 The diagram shows a Y-shaped forked structure. It should be noted that, in cases like... Figure 1 In the partitions of the stent 10 shown, the proximal end of the external iliac branch segment 200 is located at the same position as the distal end of the main segment 100. The proximal end of the internal iliac branch segment 300 is located at the same position as the proximal end of the external iliac branch segment 200, thus constructing a structure as shown below. Figure 1 The diagram shows a Y-shaped bifurcation structure. Furthermore, the internal iliac branch segment 300, in a contracted state, wraps around the circumference of the external iliac branch segment 200, allowing the distal end of the internal iliac branch segment 300 to remain connected to or separate from the external iliac branch segment 200 under controllable conditions.

[0061] like Figure 1As shown, the main body segment 100 of the interventional stent 10 refers to the main part of the interventional stent 10. After the interventional stent 10 is delivered to the target location and released, the main body segment 100 supports the common iliac artery to isolate the aneurysm cavity. In the released state, the main body segment 100 has a cylindrical structure, with its proximal end closer to the heart and its distal end further away from the heart. The external iliac branch segment 200 is a branch structure connected to the main body segment 100 and extending distally (i.e., away from the heart), used to connect with the external iliac artery to maintain blood supply to the lower limbs. The proximal end (closer to the heart) of the external iliac branch segment 200 is connected to the distal end (away from the heart) of the main body segment 100.

[0062] Continue reading Figure 1 As shown, the internal iliac branch segment 300 is another branch structure connected to the external iliac branch segment 200. Specifically, the proximal end (the end closer to the heart) of the internal iliac branch segment 300 is in the same position as the proximal end (the end closer to the heart) of the external iliac branch segment 200, so that the entrance position of the internal iliac branch segment 300 corresponds axially to the proximal position of the external iliac branch segment 200. The internal iliac branch segment 300 can emerge from the proximal end of the external iliac branch segment 200 and extend towards the internal iliac artery.

[0063] The interventional stent 10 has a contracted state and a released state; therefore, the main body segment 100, the external iliac branch segment 200, and the internal iliac branch segment 300 also have contracted and released states. In the contracted state, the internal iliac branch segment 300 is wound around the circumference of the external iliac branch segment 200, which differs from the structure in traditional branch stents where the internal iliac branch segment 300 extends in a straight or near-straight line. In this application, the internal iliac branch segment 300, in the contracted state (i.e., when the interventional stent 10 is compressed within the delivery system), is spirally wound around the circumference of the external iliac branch segment 200; that is, the internal iliac branch segment 300 wraps around the outer periphery of the external iliac branch segment 200 like a spiral. This spiral winding shape allows the internal iliac branch segment 300 to be arranged more compactly in the contracted state, which is beneficial for reducing the overall diameter of the delivery system.

[0064] Therefore, after the stent 10 is deployed at the target location, the internal iliac branch segment 300 can unfold from its constricted state to its deployed state. Its spiral shape surrounding the external iliac branch segment 200 allows it to transition more smoothly from the external iliac branch segment 200 to the opening of the internal iliac artery, avoiding stent kinking or twisting due to sharp bends over a short distance. Simultaneously, the spiral shape better conforms to the natural anatomical course of the internal iliac artery, minimizing interference with blood flow and contributing to maintaining a favorable hemodynamic environment.

[0065] The distal end of the internal iliac branch segment 300 and the external iliac branch segment 200 can be kept connected or separated under controllable conditions, forming a controllable movable connection state. For example, the distal end of the internal iliac branch segment 300 and the external iliac branch segment 200 can be connected by a suture. When subjected to a predetermined force, the suture can move flexibly relative to each other within a preset range of motion, thereby achieving controllable relative separation between the two. However, this separation will not result in complete relative detachment, but will always maintain the connection.

[0066] The position where the distal end of the internal iliac branch segment 300 is movably connected to the external iliac branch segment 200 can be designed according to requirements. For example, in one embodiment, the distal end of the internal iliac branch segment 300 is movably connected to the proximal region of the external iliac branch segment 200. When the interventional stent 10 is in a compressed state in the delivery system, the internal iliac branch segment 300 is constrained within the delivery system and wound circumferentially along the external iliac branch segment 200. When the interventional stent 10 is released at the target location, the internal iliac branch segment 300 gradually unfolds. Based on the movably connected design, it can undergo small positional adjustments relative to the external iliac branch segment 200 until its distal end is precisely aligned and flush with the opening of the internal iliac artery.

[0067] The aforementioned interventional stent 10 connects the proximal end of the internal iliac branch segment 300 to the proximal end of the external iliac branch segment 200, allowing the entrance of the internal iliac branch segment 300 to be located at the proximal end of the external iliac branch segment 200, closer to the distal region of the main segment 100. Therefore, the internal iliac branch segment 300 does not need to extend downward from the middle of the main segment 100, but can achieve docking with the opening of the internal iliac artery through the connection with the proximal end of the external iliac branch segment 200. Thus, even when the common iliac artery is short, precise alignment between the internal iliac branch segment 300 and the opening of the internal iliac artery can still be achieved, effectively reducing the minimum requirement for the length of the common iliac artery during surgery. Meanwhile, because the internal iliac branch segment 300 spirals around the external iliac branch segment 200 in a contracted state, the interventional stent 10 can transition from the external iliac branch segment 200 to the opening of the internal iliac artery with a gentler arc, even when the length of the common iliac artery is limited. This allows the distal opening of the internal iliac branch segment 300 to be precisely aligned with the opening of the internal iliac artery, thus enabling more patients with short common iliac arteries to receive endovascular repair treatment with preservation of the internal iliac artery.

[0068] In one embodiment, the distal end of the internal iliac branch segment 300 and the external iliac branch segment 200 can be controlled to remain connected or separated from each other, forming a controllable active connection state. For example, the distal end of the internal iliac branch segment 300 and the external iliac branch segment 200 can be sutured and fixed by one or more sutures. The sutures can provide a temporary connection between the two and allow the distal end of the internal iliac branch segment 300 to undergo a slight displacement relative to the external iliac branch segment 200 after being subjected to force.

[0069] In one embodiment, the main body segment 100, the external iliac branch segment 200, and the internal iliac branch segment 300 are configured in a cylindrical structure upon release. This cylindrical structure means that after the stent 10 is fully released and deployed, each of its main body segment 100, external iliac branch segment 200, and internal iliac branch segment 300 has a complete annular cross-section. The cylindrical structure ensures that the stent 10 can support the vessel wall and form a blood flow channel. During the manufacturing process of the stent 10, its main body segment 100, external iliac branch segment 200, and internal iliac branch segment 300 can be composed of a metal frame and a covering body, respectively. The metal frame provides radial support, and the covering body provides blood isolation. After the stent 10 is released, the cylindrical structure ensures that blood can only flow inside the stent 10 and will not come into contact with the aneurysm wall, thereby achieving the purpose of isolating the aneurysm.

[0070] Continue reading Figure 1 As shown, the main body segment 100 includes a first frame 110 and a first covering body 120, with the first covering body 120 covering the first frame 110. The first frame 110 is the metal skeleton of the main body segment 100, providing radial support to maintain vascular patency. The first covering body 120 is a membrane-like structure covering the first frame 110, used to form a closed blood channel, isolating blood flow from contact with the aneurysm wall. The first covering body 120 may completely cover the inner and outer surfaces of the first frame 110, or it may only cover the outer or inner surface of the first frame 110. The first covering body 120 and the first frame 110 can be fixed together by sutures or by heat fusion, which is not limited here.

[0071] The external iliac branch segment 200 includes a second frame 210 and a second covering body 220, with the second covering body 220 covering the second frame 210. The second frame 210 is the metal skeleton of the external iliac branch segment 200, and the second covering body 220 covers the second frame 210, forming a continuous blood channel together with the first covering body 120. The second covering body 220 may completely cover the inner and outer surfaces of the second frame 210, or it may only cover the outer or inner surface of the second frame 210. The second covering body 220 and the second frame 210 can be fixed together by sutures or by heat fusion, which is not limited here.

[0072] The internal iliac branch segment 300 includes a third frame 310 and a third covering body 320, with the third covering body 320 covering the third frame 310. The third frame 310 is the metal skeleton of the internal iliac branch segment 300, and the third covering body 320 covers the third frame 310. The third covering body 320 may completely cover the inner and outer surfaces of the third frame 310, or it may only cover the outer or inner surface of the third frame 310. The third covering body 320 and the third frame 310 can be fixed together by sutures or by heat fusion, which is not limited here.

[0073] It should be noted that the first frame 110, the second frame 210, and the third frame 310 can be made of the same or different metallic materials. For example, the first frame 110, the second frame 210, and the third frame 310 can all be made of nickel-titanium shape memory alloy, utilizing its superelasticity and shape memory effect to allow the interventional stent 10 to be compressed in the delivery system and automatically return to its predetermined shape after release. In other embodiments, biocompatible metallic materials such as stainless steel and cobalt-chromium alloys can also be used, and this is not limited here.

[0074] Similarly, the first coating 120, the second coating 220, and the third coating 320 can also be made of the same or different polymer materials. For example, the first coating 120, the second coating 220, and the third coating 320 can be made of any one of polyester, polytetrafluoroethylene, or expanded polytetrafluoroethylene, which have good biocompatibility and antithrombotic properties.

[0075] Continue reading Figures 1 to 5 As shown, the main body segment 100 is provided with a traction part 400. The traction part 400 can be located at the proximal end of the main body segment 100 or other suitable positions, which are not limited here. The traction part 400 can be used to enable the proximal end of the interventional stent 10 to be released in stages under the control of the delivery system during the release process of the interventional stent 10. Specifically, the traction part 400 can be pre-coordinated with the release control structure of the delivery system so that even after most of the interventional stent 10 has been released, the proximal end of the main body segment 100 can still be constrained by the traction part 400, maintaining a state that is not fully opened.

[0076] Once the position of the interventional stent 10 is confirmed to be correct, the traction unit 400 can be released by manipulating the delivery system, causing the proximal end of the main body segment 100 to finally open and conform to the vessel wall. Due to the design of the traction unit 400, the interventional stent 10 can still move axially after partial release, thus allowing for fine-tuning of the stent 10's position during the procedure.

[0077] See Figure 2As shown, a protrusion 410 is provided at the proximal end of the first frame 110. The protrusion 410 protrudes axially from the nearest end of the first frame 110 and has a through hole 411. The protrusion 410 can be a sheet-like or rod-like structure extending outward from the proximal edge of the first frame 110 along the axial direction (i.e., the length direction of the interventional stent 10), protruding from the end face of the nearest end of the first frame 110. The through hole 411 on the protrusion 410 can be used for the passage of the traction line (such as suture or wire) of the delivery system. When the interventional stent 10 is loaded into the delivery system, the traction line can pass through the through hole 411 in advance, restraining the protrusion 410 and the proximal end of the main body segment 100 connected thereto in a partially released state.

[0078] When the pull line is removed or cut, the protrusion 410 can be released, and the proximal end of the main body 100 opens. The protrusion 410 and the first frame 110 can be integrally formed, for example, by laser cutting a metal tube. In other embodiments, the protrusion 410 can also be manufactured separately and then fixed to the first frame 110 by welding or sewing. The number of protrusions 410 can be 2 to 6, preferably 3, evenly spaced circumferentially.

[0079] See Figure 3 As shown, the first frame 110 includes a plurality of wave rings 420. The wave ring 420 located at the closest end of the first frame 110 includes a plurality of first curved rods 421 and a plurality of second curved rods 422 connected end to end. The dimension of the first curved rod 421 along the axial direction of the first frame 110 is larger than the dimension of the second curved rod 422 along the axial direction of the first frame 110. The proximal end of the first curved rod 421 can be configured to form a traction part 400.

[0080] First, it needs to be clarified that the first frame 110 can be composed of several wavering rings 420 arranged axially. These wavering rings 420 can be directly connected or indirectly connected through the first covering body 120. Each wavering ring 420 can be formed by several curved rods arranged end-to-end around it circumferentially. At this point, the wavering ring 420 located at the closest end (i.e., the end of the first frame 110 closest to the heart) has several curved rods that, depending on their size, can be divided into several first curved rods 421 and several second curved rods 422. The first curved rods 421 have a larger axial dimension, forming relatively higher peaks, while the second curved rods 422 have a smaller axial dimension, forming relatively lower peaks. This can create a wavering ring as follows: Figure 3 The wave peaks shown are arranged in an alternating pattern of high and low. The proximal end of the first curved rod 421, due to its higher wave peak, can be configured to form the driving part 400.

[0081] At this time, the traction line of the delivery system can simultaneously pass through the rings or holes of the proximal crests of multiple higher first curved rods 421. When the traction line is released, the proximal ends of the first curved rods 421 are released, and the proximal end of the main body section 100 can be fully opened. In this embodiment, the traction part 400 and the first frame 110 are an integrated structure, so no additional setting is required, which simplifies the manufacturing process. The number of first curved rods 421 can be 2 to 6, preferably 3, and they are evenly spaced along the circumference. The proximal ends of the first curved rods 421 can be wrapped by the first covering body 120 to prevent deformation or detachment from the first covering body 120 during the process of pulling the interventional stent 10 into the delivery system.

[0082] Continue reading Figures 4 to 7 As shown, the main body segment 100 is provided with an anchoring portion 500. In clinical applications, the interventional stent 10 of this application is typically used in conjunction with an abdominal aortic stent to treat abdominal aortic aneurysms complicated with common iliac artery aneurysms. Therefore, the anchoring portion 500 serves to increase the pull-out force between the interventional stent 10 and the matched abdominal aortic stent, preventing detachment at the splice joint under long-term blood flow impact, thereby avoiding type III endoleak due to splice separation.

[0083] The anchoring portion 500 may be located at the proximal end of the main body segment 100 or other suitable locations, without limitation herein. For example, since the interventional stent 10 of this application is used in conjunction with an abdominal aortic stent, the function of the anchoring portion 500 is to anchor the matched abdominal aortic stent, and the overlapping area between the two is located in the proximal region of the main body segment 100. Therefore, the anchoring portion 500 can be positioned at the proximal end of the main body segment 100 so that the anchoring portion 500 can be located within the overlapping area with the matched abdominal aortic stent to achieve the anchoring function.

[0084] In one embodiment, the first frame 110 may include a plurality of wave rings 420, in which case the anchoring portion 500 may be located at or below the trough of the nearest wave ring 420 of the first frame 110. It should be noted that the wave ring 420 is a wave-shaped annular structure formed by a plurality of curved rods arranged circumferentially, with its convex portion axially towards the proximal end called a wave crest and its concave portion axially towards the distal end called a wave trough. In this case, the anchoring portion 500 can be positioned at the wave trough, which facilitates effective anchoring with the matched abdominal main stent. After the stent is released, the matched abdominal main stent is located inside the main body segment 100 of the interventional stent 10 of this application, and the frames of the two overlap. The anchoring portion 500 can extend from the wave trough, anchoring the frame of the abdominal main stent and achieving locking.

[0085] The anchoring part 500 can be connected to the main body section 100 in various ways, for example, in... Figure 4In one embodiment shown, the anchoring part 500 can be sewn to the first covering body 120 by a suture thread and is located below the trough of the corrugated ring 420 at the nearest end of the first frame 110. In this case, the anchoring part 500 can be in no direct contact with the first frame 110. In this embodiment, since the anchoring part 500 is connected to the first covering body 120, it has a certain degree of freedom of movement, which can better adapt to the shape of its frame and achieve reliable anchoring.

[0086] In such Figure 5 In another embodiment shown, the anchoring portion 500 can also be integrally formed with the first frame 110. For example, by laser cutting a metal tube, the anchoring portion 500 can be integrally cut from the trough position while forming the corrugated ring 420 of the first frame 110. The connection between the integrally formed anchoring portion 500 and the first frame 110 is more robust, and there will be no anchoring failure due to seam breakage. At the same time, integral forming reduces the number of parts and assembly steps, thus reducing manufacturing costs.

[0087] The anchoring part 500 can be in the form of a barbed structure, capable of hooking onto the frame of the matched main support, serving a mechanical locking function. There can be multiple anchoring parts 500, preferably at least three, which can be evenly distributed circumferentially to ensure uniform force distribution. For example, see... Figure 6 As shown, the anchoring portion 500 may include a connecting section 510 and a barb section 520. In this case, the anchoring portion 500 can be sewn to the first covering body 120 by a suture, and the connecting section 510 may also have holes for the suture to pass through. Or, for example, see [reference needed]. Figure 7 As shown, the anchoring part 500 may also consist only of the barb section 520. In this case, the barb section 520 is directly integrally formed with the first frame 110.

[0088] In such Figure 6 In one embodiment, the barb segment 520 may have an inclined angle relative to the connecting segment 510, and the angle of the inclined angle is 17°-23°, for example, 17°, 18°, 19°, 20°, 21°, 22°, 23°. Similarly, in other embodiments... Figure 7 In the embodiment shown, the barb segment 520 may also have the same tilt angle relative to the first frame 110, and the tilt angle is 17°-23°.

[0089] The angled inclination allows the barbed segment 520 to extend into the interior of the interventional stent 10 to hook onto the abdominal main stent located inside the interventional stent 10. This angle ensures that the barbed segment 520 can effectively hook onto the frame of the abdominal main stent, while preventing the barbed segment 520 from puncturing the membrane of the abdominal main stent due to an excessively large angle, and avoiding hook failure due to an excessively small angle.

[0090] like Figure 6 As shown, the connecting segment 510 can be configured as a U-shaped structure, and two barbed segments 520 can be configured, with the two barbed segments 520 connected to both ends of the U-shaped structure. In the example... Figure 6 Or such as Figure 7 In the embodiments shown, the barb segments 520 can all be configured as rod-shaped members, such as elongated strips or bars, and the cross-section of the rod-shaped members can be circular, elliptical, or rectangular. Moreover, the ends of the barb segments 520 can be configured as rounded ends, for example, the ends of the barb segments 520 (i.e., the farthest ends) are processed into smooth shapes such as spherical, hemispherical, or arc-shaped.

[0091] The purpose of the rounded end design is that after the matched abdominal stent is released inside the main body segment 100, the end of the barbed segment 520 will come into contact with the lining of the abdominal stent. If the end is sharp, it may repeatedly rub against the lining of the abdominal stent under the continuous impact of blood flow, eventually leading to lining damage and type IV endoleak. The rounded end can significantly reduce the risk of lining abrasion and improve long-term safety. In terms of manufacturing process, the rounded end can be achieved by welding the end of the metal wire into a ball shape, or by retaining the rounded corners during laser cutting.

[0092] The number of barbed segments 520 is configured to be one or more, for example... Figure 6 As shown in the diagram, the addition of multiple barbed segments 520 increases the contact points and hooking force with the abdominal stent, further enhancing pull-out resistance. The length of the barbed segments 520 can be set to 2mm-3mm, for example, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, and 3mm. If the length is too short, the hooking may not be secure, making it easy to dislodge under the impact of blood flow. If the length is too long, bulges may form in the overlapping area between the barbed segments 520 and the abdominal stent, resulting in poor adhesion between the stent and the vessel wall, which could lead to type III endoleak.

[0093] See Figure 1 As shown, the internal iliac branch segment 300 may also be provided with a fixation part 600. The fixation part 600 can be used to fix the matched internal iliac stent 80. During the operation, after the distal end of the internal iliac branch segment 300 is aligned with the opening of the internal iliac artery, the internal iliac stent 80 needs to be implanted into the actual internal iliac artery using a traversing technique. The proximal end of the internal iliac stent 80 needs to be abutted with the internal iliac branch segment 300 of the interventional stent 10. Therefore, the function of the fixation part 600 is to increase the pull-out force between the internal iliac branch segment 300 and the matched internal iliac stent 80, preventing the splice between the two from detaching in the long term, which could lead to endoleak.

[0094] In one embodiment, the fixing part 600 can be connected to the third membrane body 320. For example, the fixing part 600 can be sewn to the inner or outer surface of the third membrane body 320 by sutures, or it can be fused to the third membrane body 320 by heat fusion. Since the fixing part 600 is located in the internal iliac branch segment 300, it needs to form a stable connection with the third membrane body 320 to ensure that it does not shift or fall off during long-term use.

[0095] Furthermore, the fixation portion 600 can be primarily located inside the third laparoscopic graft 320, i.e., within the lumen enclosed by the third laparoscopic graft 320. After the matched internal iliac stent 80 is implanted and released, the proximal end of the internal iliac stent 80 extends from the distal end of the internal iliac branch segment 300 and is located inside the third laparoscopic graft 320. The fixation portion 600, located inside the third laparoscopic graft 320, can directly contact the outer wall of the internal iliac stent 80, applying radial restraint force to it.

[0096] The fixation part 600 can be configured as a ring, that is, a generally circular or nearly circular structure. The ring surrounds the inner wall of the third cover body 320, which allows the fixation part 600 to apply a uniform restraint force to the circumference of the internal iliac stent 80, without causing excessively high or low local pressure.

[0097] In one embodiment, the diameter of the fixing part 600 in the released state can be designed to be smaller than the diameter of the third frame 310 in the released state. When the internal iliac stent 80 is released into the internal iliac branch segment 300, the frame of the internal iliac stent 80 will be stuck by the fixing part 600 and needs to overcome a certain resistance to pass through. Therefore, the pull-out force between the two can be effectively increased, and the internal iliac stent 80 can be effectively prevented from coming out of the internal iliac branch segment 300.

[0098] The fixing part 600 can be formed into a ring shape by winding the braided yarn 630. (See also...) Figure 8 As shown, the braided wire 630 is wound several times around the tooling 610 with grooves 620, and each time the braided wire 630 is wound, it passes through the grooves 620 and intertwines with the previous one or more turns. Specifically, during the winding process, after each turn, the braided wire 630 can pass through the grooves 620 provided on the mold, allowing the current turn of the braided wire 630 to cross or intertwine with the previous one or more turns. After being braided in this way, the end of the braided wire 630 can be fixed by the adjacent turns during the winding process, making it less likely to come out and preventing the end from puncturing blood vessels. The turns are tightly connected, and during the subsequent deployment of the iliac stent 80 and post-balloon dilation, the turns will not loosen or separate due to radial expansion force, thus ensuring the restraint function of the fixation part 600 during long-term use.

[0099] The diameter of the braided wire 630 can be set from 0.002 inches to 0.006 inches, such as 0.002 inches, 0.003 inches, 0.004 inches, 0.005 inches, and 0.006 inches. The number of winding turns can be 4, 5, 6, or other numbers. The material of the braided wire 630 can be nickel-titanium wire or stainless steel wire.

[0100] Continue reading Figure 1 As shown, the second frame 210 may include a first unit frame segment 211, a second unit frame segment 212, and a transition frame segment 213. The first unit frame segment 211 is connected to the first frame 110 of the main body segment 100, and the first unit frame segment 211 is connected to the second unit frame segment 212 through the transition frame segment 213. The radial support force of the first unit frame segment 211 is greater than that of the second unit frame segment 212. Since the first unit frame segment 211 is located proximally to the external iliac branch, this area is simultaneously subjected to lateral compression forces from the internal iliac branch segment 300 after release and recoil forces from the vessel wall, making it prone to compression deformation. Therefore, by giving the first unit frame segment 211 a greater radial support force, it is possible to ensure that the proximal end of the external iliac branch remains patent in a complex mechanical environment. The second unit frame segment 212 is located distal to the external iliac artery, where the vessel has greater curvature and requires better flexibility to adapt to the natural curvature of the vessel and limb movement. Therefore, the second unit frame segment 212 does not require the same radial support force as the first unit frame segment 211, but rather requires better flexibility.

[0101] In one embodiment, the diameter of the first unit segment 211 in the released state is smaller than the diameter of the second unit segment 212 in the released state. This gradual diameter change matches the anatomical shape of the external iliac artery in the human body, which gradually thickens from proximal to distal. At the same time, the smaller diameter of the first unit segment 211 can form a relatively smaller cross-sectional area at the proximal end of the external iliac branch, which is beneficial for smooth connection with the blood flow channel at the distal end of the main segment 100, reducing turbulence and energy loss.

[0102] The wire diameter of the first unit segment 211 is 0.013 inches to 0.018 inches, for example, 0.013 inches, 0.014 inches, 0.015 inches, 0.016 inches, 0.017 inches, or 0.018 inches. The second unit segment 212 can be configured as a spiral structure constructed of filaments. When the distal end of the external iliac branch segment 200 extends into the external iliac artery, the external iliac artery bends and twists with the movement of the lower limb. The spiral structure can conform to this deformation without causing local stress concentration or kinking.

[0103] An exemplary method of using the interventional stent provided in this application embodiment is as follows:

[0104] First, such as Figure 9As shown, a pre-embedded guidewire 20 and other vascular access can be established through puncture of the patient's contralateral femoral artery using standard vascular interventional techniques. Specifically, a pre-embedded guidewire 20 can be inserted into the affected side's common iliac artery via the contralateral external iliac artery and common iliac artery, crossing the bifurcation of the abdominal aorta, serving as a track for subsequent instrument delivery. The distal end of the pre-embedded guidewire 20 can be positioned in the distal segment of the affected side's common iliac artery or the proximal segment of the external iliac artery, providing a stable guiding path for the subsequent delivery system.

[0105] Continue as Figure 10 As shown, after pre-dilation of the puncture pathway using dilator 30, the delivery system loaded with interventional stent 10 can be inserted along the pre-embedded guide wire 20 into the aneurysm location of the affected common iliac artery. Under fluoroscopic visualization, the position of interventional stent 10 is adjusted using the imaging markers on the delivery system so that the distal outlet of the internal iliac branch segment 300 of interventional stent 10 is substantially flush with the opening of the patient's own internal iliac artery in the axial direction.

[0106] After confirming the location, the stent is released. This is primarily achieved by retracting the outer sheath of the delivery system, first releasing the distal end of the main segment 100 and the external iliac branch segment 200, while simultaneously unfolding the internal iliac branch segment 300 from its contracted state to its released state. At this point, because the internal iliac branch segment 300 is spirally wound around the external iliac branch segment 200 in its contracted state, it can gradually unwind from its spiral shape during unfolding, while still maintaining its spiral shape around the external iliac branch segment 200, transitioning with a gentle arc from the external iliac branch segment 200 towards the internal iliac artery. During this stage, the proximal end of the main segment 100 remains restrained by the traction part 400 and is not released temporarily.

[0107] like Figure 11 As shown, the post-release control mechanism of the delivery system releases one of the post-release control lines, causing the proximal end of the main body segment 100 to open slightly, creating a gap between the proximal end of the main body segment 100 and the vessel wall, allowing the guidewire and catheter to pass through. At this time, because the proximal end of the main body segment 100 is still partially constrained by the traction part 400, the interventional stent 10 still has good torsional control and adjustability in the axial direction.

[0108] At this point, the long sheath 40 can be used to perform a "mountain-crossing" operation from the opposite side. The long sheath 40 is inserted into the proximal region of the common iliac artery on the affected side via the contralateral vascular access, crossing the bifurcation of the abdominal aorta. The distal end of the long sheath 40 crosses the bifurcation of the abdominal aorta, establishing a stable channel for subsequent superselective procedures.

[0109] like Figure 12As shown, the axial position and angle of the interventional stent 10 can be finely adjusted via a rotation and push-pull delivery system to ensure precise alignment of the distal end of the internal iliac branch segment 300 with the opening of the internal iliac artery. Then, a single-curved catheter 50 is inserted through the long sheath 40, and the distal end of the single-curved catheter 50 is passed through the gap between the proximal end of the main body segment 100 and the vessel wall, precisely superselectively entering the affected side's internal iliac artery. After successful superselection, it is confirmed that the distal end of the single-curved catheter 50 is at the appropriate depth within the internal iliac artery.

[0110] like Figure 13 As shown, after the single-curved catheter 50 successfully superselectively enters the internal iliac artery, a soft guidewire 60 (e.g., a loach guidewire) can be advanced into the distal end of the internal iliac artery through the lumen of the single-curved catheter 50. After confirming that the soft guidewire 60 is properly positioned, the single-curved catheter 50 is withdrawn, and then the soft guidewire 60 is replaced with a rigid guidewire 70 with higher rigidity. The distal end of the rigid guidewire 70 forms a stable support anchor in the distal end of the internal iliac artery, and its proximal end extends out of the body, providing a stable guide track for subsequent delivery of the internal iliac stent.

[0111] like Figure 14 As shown, the internal iliac stent 80 is delivered into the internal iliac artery along the rigid guidewire 70. The internal iliac stent 80 is accurately positioned at the predetermined release site in the internal iliac artery, such that the proximal end of the internal iliac stent 80 extends into the internal iliac branch segment 300 of the interventional stent 10. The internal iliac stent 80 is then released, allowing it to fully expand and adhere to the wall of the internal iliac artery, thus forming a connection between the internal iliac branch segment 300 and the internal iliac stent 80.

[0112] Once the position and blood flow of the internal iliac stent 80 are confirmed to be good, the post-release control mechanism of the delivery system can be operated to release all remaining traction wires, allowing the proximal end of the main body segment 100 to fully open and adhere to the vessel wall. At this point, the main body segment 100 of the interventional stent 10 is fully released, the external iliac branch segment 200 is connected to the external iliac artery, and the internal iliac branch segment 300 is connected to the internal iliac artery through the internal iliac stent 80, completing the preservation and reconstruction of the internal iliac artery. Finally, the rigid guidewire 70, long sheath 40, delivery system, and pre-embedded guidewire 20 are withdrawn.

[0113] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0114] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An interventional stent, characterized in that, The interventional stent includes: The main body segment includes a first frame and a first covering body, the first covering body covering the first frame; the main body segment also has an anchoring part, and the anchoring part is located at the proximal end of the first frame; The external iliac branch segment includes a second frame and a second covering body, the second covering body covering the second frame; the proximal end of the external iliac branch segment is connected to the distal end of the main body segment; The internal iliac branch segment includes a third frame and a third covering body, the third covering body covering the third frame; the proximal end of the internal iliac branch segment is connected to the proximal end of the external iliac branch segment, wherein the internal iliac branch segment, in a contracted state, wraps circumferentially around the external iliac branch segment, and the distal end of the internal iliac branch segment is movably connected to the external iliac branch segment; the internal iliac branch segment also has a fixing part, the fixing part being connected to the third covering body; wherein the main body segment, the external iliac branch segment, and the internal iliac branch segment are configured as a cylindrical structure in their released states; An anchoring portion is disposed at the near end of the main body segment; wherein, the first frame includes a plurality of wave rings, the anchoring portion is located at the trough of the wave ring at the near end of the first frame, and the anchoring portion is integrally formed with the first frame; or, the anchoring portion is located below the trough of the wave ring at the near end of the first frame, and the anchoring portion is connected to the first covering body.

2. The interventional stent according to claim 1, characterized in that, The main body segment is provided with a traction part; and / or, The internal iliac branch segment is provided with a fixation part; and / or The second frame includes a first unit frame segment, a second unit frame segment, and a transition frame segment. The first unit frame segment is connected to the first frame of the main body segment. The first unit frame segment is connected to the second unit frame segment through the transition frame segment. The radial support force of the first unit frame segment is greater than that of the second unit frame segment.

3. The interventional stent according to claim 2, characterized in that, The actuating part is located at the proximal end of the main body segment; or, The proximal end of the first frame is provided with a protrusion for constituting the traction part. The protrusion protrudes axially from the proximal end of the first frame and has a through hole; or, The wave ring at the nearest end of the first frame includes a plurality of first curved rods and a plurality of second curved rods connected end to end; wherein, the dimension of the first curved rod along the axial direction of the first frame is greater than the dimension of the second curved rod along the axial direction of the first frame, and the near end of the first curved rod is configured to form the traction part.

4. The interventional stent according to claim 2, characterized in that, The anchoring part includes at least a barb section; wherein the barb section is connected to the first covering body through a connecting section, or the barb section is directly connected to the first frame.

5. The interventional stent according to claim 4, characterized in that, The barbed segment has an inclined angle relative to the connecting segment or relative to the first frame, and the angle of the inclined angle is 17°-23°; and / or, The end of the barbed segment is configured as a rounded end; and / or, The barbed section is configured as a rod-like element; and / or, The number of the barbed segments is configured to be one or more; and / or, The length of the barbed section is 2mm-3mm.

6. The interventional stent according to claim 2, characterized in that, The fixing part is connected to the third covering body; and / or, The fixing part is located inside the third covering body; and / or, The fixing part is configured as a ring.

7. The interventional stent according to claim 6, characterized in that, The diameter of the fixed part in the released state is smaller than the diameter of the third frame in the released state.

8. The interventional stent according to claim 6, characterized in that, The fixing part is formed into a ring by winding braided wire, wherein the braided wire is wound several times on a tool with a groove, and each time the braided wire is wound, it passes through the groove and is intertwined with the previous one or more turns.

9. The interventional stent according to claim 3, characterized in that, The diameter of the first unit frame segment in the released state is smaller than the diameter of the second unit frame segment in the released state; and / or, The wire diameter of the first unit frame segment is 0.013 inches to 0.018 inches; and / or, The second unit frame segment is configured as a spiral structure constructed from filaments.

10. A conveying system, characterized in that, The delivery system includes an interventional stent as described in any one of claims 1-9.

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