A stent

Abstract

The application relates to the technical field of medical devices, in particular to a stent, which comprises a main body structure, the main body structure comprises a plurality of annular structures and a plurality of connecting bridges, the annular structures are arranged in a rotationally symmetrical manner along the axial direction in a Z-shaped mode, the plurality of annular structures are connected to form the stent whole through the connecting bridges, and the lengths of the annular structures arranged in the Z-shaped mode are different. The annular structures are arranged in the rotationally symmetrical manner along the axial direction in the Z-shaped mode, the annular structures are connected to form the stent whole through the connecting bridges, the main body structure as a whole is deformed into a three-dimensional spiral type or an S-shaped mode, and the local part is not easy to stack, the problem that the stent cannot well adapt to the deformation of a blood vessel when the blood vessel is compressed and bent in the axial direction after the stent is implanted is solved, the stent and the blood vessel are synchronized in complex deformation (such as axial compression, bending and torsion), and therefore the mechanical stimulation to the blood vessel wall is reduced.

Description

Technical Field

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

[0002] Endovascular interventional surgery has advantages such as minimal trauma and rapid recovery. By releasing a stent into the blood vessel through interventional surgery, diseased blood vessels can be repaired and reconstructed.

[0003] Vascular stents are generally classified into two types: self-expanding and balloon-expandable. Balloon-expandable stents are typically made of materials such as cobalt-chromium alloys and stainless steel. They are usually pre-loaded onto a balloon catheter and delivered to the designated lesion site via interventional procedures. Then, balloon inflation expands the stent to its designed diameter, releasing it into the blood vessel. Self-expanding stents can expand and release themselves without a balloon. Typically, the stent is pre-loaded into a designated delivery sheath before implantation. After delivery to the lesion site via interventional procedures, the delivery sheath is removed, and the stent is released, providing support to the blood vessel wall.

[0004] Specifically, balloon dilation utilizes the plastic deformation of materials to achieve functional design, so the expanded stent is relatively rigid and lacks flexibility; at the same time, due to the inherent elastic properties of the stent material, the stent may also experience radial shrinkage after being expanded to the specified diameter.

[0005] For self-expanding stents, a Z-shaped pattern design is typically used. There are generally two types of axial arrangement for the Z-shaped structure: parallel arrangement and helical winding arrangement. The parallel arrangement design is usually flexible, but its bending compliance is generally poor, and the stent's axial compression performance is also poor. When the stent is axially compressed, it may stack, and in some areas, it may even bend. While the helical winding arrangement design has better bending compliance, when axial torsional deformation occurs, the stent deformation is acceptable when twisting in the direction of the helix, but when twisting against the direction of the helix, the stent may kink.

[0006] All of the above design deficiencies may cause the stent to irritate the blood vessel wall, or even eventually lead to stent breakage. Summary of the Invention

[0007] The main objective of this invention is to provide a stent that addresses the problem of poor deformation adaptability of existing stents under axial compression and bending after implantation in blood vessels.

[0008] To achieve the above objectives, the present invention provides a support frame, comprising a main structure, wherein the annular structure includes multiple Z-shaped units, and the multiple Z-shaped units are connected end to end to form an annulus. Adjacent annular structures are connected by a plurality of connecting bridges, and the widths of the annular structures when unfolded in plan are different.

[0009] Optionally, when several of the ring structures are arranged periodically along the axial direction, there is an angular difference in the circumferential direction between two adjacent ring structures.

[0010] Optionally, the Z-shaped unit includes a Z-peak and a Z-valley, one end of the connecting bridge is connected to the Z-peak, and the other end of the connecting bridge is connected to the Z-peak or Z-valley of an adjacent ring structure.

[0011] Optionally, the two ends of the main structure are connected by a first transition section and a second transition section.

[0012] Optionally, a first developing ring is connected to the side of the first transition section away from the annular structure, and a second developing ring is connected to the side of the second transition section away from the annular structure.

[0013] Optionally, both the first transition segment and the second transition segment include a hollow structure arranged longitudinally in a Z-shape, and the side away from the annular structure has the same length.

[0014] Optionally, when the connecting bridge connects a Z-peak and a Z-valley, the connecting bridge is straight; when the connecting bridge connects two Z-peaks, the connecting bridge is curved.

[0015] Optionally, the main structure is provided with a coating, and the coating material includes one or a combination of fluoropolymers, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fibers.

[0016] Optionally, the main structure is provided with a drug elution coating, which includes drug elution and drug coating. The drug elution includes any one or combination of polylactic acid, polylactic acid derivatives, polylactic-co-hydroxyacetic acid, choline phosphate, polyvinylidene fluoride hexafluoropropylene copolymer, polyacrylate, and polybutyl methacrylate. The drug coating includes any one or combination of statins, rapamycin, paclitaxel, or heparin.

[0017] Optionally, the material of the first developing ring or the second developing ring includes one or a combination of gold, platinum, platinum-iridium alloy, and platinum-tungsten alloy.

[0018] The stent proposed in this invention is achieved by arranging the annular structures in a Z-shape along the axial direction in a rotationally symmetrical manner, and connecting the annular structures with connecting bridges to form the entire stent. Based on the above structure, when the entire stent undergoes compression deformation, each annular structure will produce a deformation trend similar to eccentric compression, that is, tilt to one side. At the same time, the periodic rotational arrangement of the annular structures makes the main structure as a whole exhibit a three-dimensional spiral or S-shaped deformation, and local stacking is not easy. This solves the problem that the stent cannot adapt well to the deformation of blood vessels under axial compression and bending after implantation, and realizes the synchronization of the stent with the complex deformation of blood vessels (such as axial compression, bending and torsion), thereby reducing mechanical stimulation to the blood vessel wall. Attached Figure Description

[0019] Figure 1 This is a two-dimensional planar schematic diagram of the entire support structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the Z-shaped features and length structure of the ring structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the three-dimensional structure of the support frame of the present invention, which is based on a two-dimensional implementation.

[0022] Figure 4 This is a schematic diagram of the periodic axial rotation arrangement of the annular structure of the present invention;

[0023] Figure 5 This is a schematic diagram of the main structure formed by the periodic axial rotation arrangement of the annular structure of the present invention;

[0024] Figure 6 This is a schematic diagram of the connection structure of the second transition section of the present invention;

[0025] Figure 7 This is a schematic diagram of the connecting bridge of the present invention connected in a Z-peak-Z-valley pattern;

[0026] Figure 8 This is a schematic diagram of the connecting bridge of the present invention connected in a Z-peak-Z-peak form;

[0027] Figure 9 This is a schematic diagram of the shape of the main structure of the present invention after bending;

[0028] Figure 10 The diagram shows the morphology and strain distribution of the main structure of the present invention after finite element analysis of bending.

[0029] Figure 11 Deformation and strain distribution diagrams of axial compression finite element analysis for connecting bridges in a mixed form of Z-peak-Z-valley and Z-peak-Z-peak;

[0030] Figure 12Deformation and strain distribution diagrams for axial compression finite element analysis of the connecting bridge in the form of Z-peak-Z-peak connection;

[0031] Figure 13 The deformation and strain distribution diagrams are obtained from the axial compression finite element analysis of the main structure of the ring structure with parallel structures of equal length.

[0032] Figure label:

[0033] 1-Main structure, 2-Ring structure, 3-First transition section, 4-Second transition section, 5-Connecting bridge, 6-First developing ring, 7-Second developing ring.

[0034] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0037] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] Example 1:

[0040] Please refer to the attached document as well. Figure 1 To be continued Figure 13 In this embodiment, a support is provided, including a main structure 1, and an annular structure 2 comprising multiple Z-shaped units connected end-to-end to form an annulus. Adjacent annular structures 2 are connected by several connecting bridges 5. The widths of the annular structures 2 when unfolded in plan are different.

[0041] It is important to note that, clinically, after stent implantation, the blood vessel deforms due to limb movements, respiration, and muscle activity. Clinical studies by Smouse et al. show that, particularly in the peripheral femoral and popliteal arteries, where limb movements are significant, different limb movements can have a substantial impact on vascular deformation. When the leg is bent, the blood vessel is first stretched and then axially compressed, resulting in bending deformation. However, after stent implantation, because the stent is not easily axially compressed, the mechanical properties of the blood vessel are altered. During limb movement, the blood vessel is prone to stacking and knotting in certain areas, potentially leading to in-stent restenosis, vessel wall abrasion, or even perforation, among other complications. The stent is also more prone to breakage in such situations, necessitating secondary surgical intervention. Delayed treatment can even lead to serious adverse events such as amputation.

[0042] It should also be noted that, taking Chinese patent application number CN101065078B as an example, it provides a stent for a fluid catheter inserted into a human or animal body. Combining geometric design and heat treatment qualitative process, the stent is designed as a three-dimensional spiral structure. Clinical results have shown that, due to its unique three-dimensional spiral design, the stent is easy to deform under axial compression, so the restenosis rate and stent breakage rate are relatively low. However, the disadvantage of this solution is that the length of the stent changes when it is pressed into the delivery sheath, and the three-dimensional spiral structure will axially shorten during release, thus causing inaccurate release.

[0043] Those skilled in the art will understand that in the existing field of stent medical device technology, stent structures are relatively mature, with their basic shape fixed as a rod-like structure, making significant pioneering improvements difficult. Therefore, the maturity of stent structures is a common concern among those skilled in the art. This precondition limits their ability to consider other possibilities, hindering further improvement and development of this characteristic structure. Based on this, the applicant proposes a Z-shaped axial arrangement with varying lengths, which not only provides better bending flexibility but also allows the stent to undergo eccentric compression deformation during axial compression. Combined with the periodic arrangement of the Z-shaped ring stent rings, the stent exhibits a three-dimensional spiral or S-shaped deformation trend during axial compression. This allows the stent deformation to coordinate with vascular deformation, achieving a design similar to that in patent CN101065078B, guiding blood flow and reducing stent breakage. Furthermore, it avoids potential problems during gripping and release, demonstrating outstanding substantive features and significant progress. Simultaneously, it overcomes, to some extent, the technical bias that significant improvements in stent structures are difficult to achieve.

[0044] Based on the above-mentioned problems, the applicant provides a stent that is achieved by arranging the annular structures 2 in a Z-shape along the axial direction in a rotationally symmetrical manner, and connecting the annular structures 2 through the connecting bridge 5 to form the entire stent. Based on the above structure, when the entire stent undergoes compression deformation, each annular structure 2 will produce a deformation trend similar to eccentric compression, that is, tilt to one side. At the same time, the periodic rotational arrangement of the annular structures 2 makes the main structure 1 as a whole exhibit a three-dimensional spiral or S-shaped deformation, and it is not easy to stack locally. Therefore, it can be coordinated with the deformation of blood vessels and reduce the risk of stent breakage.

[0045] In this embodiment, the length difference of the Z-shaped arrangement is the direct cause of the eccentric compression, presenting a shape similar to "one end larger than the other" in three dimensions. Figure 2 For example, suppose that the rods at the Z-peak of a certain annular structure 2 are shorter and the rods at the Z-valley are longer. Since the annular structures 2 in this embodiment are arranged periodically in the axial direction, the characteristics of the Z-peak and Z-valley are relative. Therefore, the side of the annular structure 2 closer to the second transition segment 4 presents a convex Z-peak and a concave Z-valley. When axial pressure is applied, the longer rod area bends first due to its higher flexibility, while the shorter rod area resists deformation due to its higher stiffness. This causes the annular structure 2 to tilt towards the longer rod side (Z-valley direction). This tilt direction is determined by the rod length distribution, and the tilt direction of each annular structure 2 may be different due to the difference in rod length.

[0046] In this embodiment, the Z-peak-Z-valley straight connecting bridge 5 restricts the relative displacement of adjacent annular structures 2 through rigid connection, preventing excessive local bending; while the Z-peak-Z-peak curved connecting bridge 5 allows for a larger bending radius through flexible design, promoting the continuity of helical deformation. Figure 11 In this design, the hybrid connecting bridge 5 combines two connection methods, ensuring both local stability and improved overall compliance. During compression, the connecting bridge 5 absorbs some stress through deformation and guides the tilting direction of the annular structure 2 through different connection methods, ensuring the continuity and coordination of the deformation path. This mechanism allows the stent to synchronize with the complex deformations of blood vessels (such as axial compression, bending, and torsion), thereby reducing mechanical stimulation to the vessel wall.

[0047] The stent involved in this embodiment may have different diameter characteristics in different application scenarios. For example, during access delivery, the stent is radially pressed into the delivery sheath and has a smaller diameter. After entering the target lesion location in the blood vessel, the delivery sheath can be removed, at which time the stent has a larger diameter after expansion. The stent material is usually a superelastic material, such as a superelastic metal material like nickel-titanium alloy, as well as other implantable polymer materials with superelastic characteristics. In this invention, no specific material is limited for the stent.

[0048] Example 2:

[0049] As an optional implementation, when several of the ring structures 2 are arranged periodically along the axial direction, there is an angular difference in the circumferential direction between two adjacent ring structures 2.

[0050] In this embodiment, due to the angle difference θ, adjacent annular structures 2 gradually shift in the circumferential direction according to the value of θ. For example, when θ = 60°, after the first annular structure 2 is fixed, the second annular structure 2 rotates 60° clockwise or counterclockwise in the circumferential direction with the first annular structure 2 as a reference, and the third annular structure 2 follows the same rotation in the same direction according to the corresponding angle difference θ. This periodically changing tilt direction causes the overall structure to form a continuous three-dimensional spiral or S-shaped deformation path during compression, such as... Figure 4 , Figure 5 As shown, it is not stacked in a single direction as in traditional designs.

[0051] It should be noted that, as shown in the attached document... Figure 13The diagram shows the deformation and strain distribution of a support structure in the prior art under axial compression finite element analysis with parallel structures of equal length. Under axial compression, all the annular structures 2 tilt in the same direction, leading to structural stacking and even local bending. In contrast, this embodiment uses a periodic rotation angle difference θ to make the tilting directions of adjacent annular structures 2 different. For example, when θ = 60°, every six annular structures 2 complete a 360° rotation cycle, and the tilting directions are evenly distributed in three-dimensional space, avoiding stress concentration. Furthermore, the spiral or S-shaped deformation path increases the deformation space of the support. The tilting directions of each annular structure 2 are distributed along the spiral trajectory and are staggered, reducing the probability of contact between adjacent structures. For example, in spiral deformation, the tilting direction of each annular structure 2 forms an angle complementary with the adjacent structure, so that the compressive force is evenly distributed throughout the support rather than in a local area.

[0052] It should also be noted that the unequal lengths of the struts in the Z-shaped arrangement inevitably lead to different spacing between adjacent annular structures 2, and the length of the connecting bridge 5 also varies accordingly. Longer connecting bridges 5 can bend more significantly during compression, while shorter connecting bridges 5 provide support. This length difference further limits the possibility of close fit between adjacent structures. Furthermore, the curved design of the connecting bridge 5 allows the annular structure 2 to form a "wave-like" deformation when tilted, further increasing the gaps between structures. These design features work together to allow the stent to form a spring-like spiral shape during compression (without local stacking, coordinating vascular deformation, thus significantly reducing the risk of stent breakage and vascular injury).

[0053] In this embodiment, the angle difference θ ranges from 30° to 180°. The angle difference θ is one of 30°, 45°, 60°, 90°, 120°, and 180°.

[0054] Performance across different angular differences:

[0055] For a 30° helical cycle, each complete 360° spiral cycle contains 12 ring structures 2, forming a tight helical arrangement. The angle difference between ring structures 2 is small, the arrangement is dense, and the overall helical path pitch is small. During axial compression, the tilt direction of each ring structure 2 gradually shifts at 30°, forming a high-frequency three-dimensional helical deformation. Due to the small angle difference between adjacent structures, the deformation path is continuous and the changes are subtle. The dense helical arrangement allows the stent to produce small and continuous deformations during bending and axial compression, adapting to the complex dynamic deformation of blood vessels (such as the high-frequency bending of the superficial femoral artery). In addition, the high-density characteristics of the helical path disperse torsional stress and avoid local kinking when twisting in the opposite helical direction; it is suitable for peripheral blood vessels that require extremely high flexibility (such as the proximal end of the superficial femoral artery to the popliteal artery) or for cases where the blood vessels at the lesion site have high tortuosity.

[0056] For 45°, each 360° spiral cycle contains 8 annular structures 2 (360°÷45°=8). The pitch of the spiral path is moderate, and the spacing between the annular structures 2 is slightly greater than 30°. During compression, the annular structures 2 gradually tilt at a 45° angle difference, forming a medium-frequency spiral deformation. The hybrid design of the connecting bridge 5 (combining straight lines and curves) can effectively balance rigidity and flexibility at this angle. The moderate pitch retains a certain degree of compliance while providing better radial support through the slightly larger annular spacing. It is suitable for scenarios that need to both open vascular stenosis and adapt to deformation, such as vessels with moderate curvature (such as the iliac artery) or lesions that need to emphasize both radial support and compliance.

[0057] For a 60° helical cycle, each 360° spiral cycle contains six annular structures 2. The pitch is relatively large, the helical path is clear, and there is ample deformation space. The annular structures 2 are tilted at a 60° angle difference, forming a distinct three-dimensional spiral or S-shaped deformation. The curved design (Z-peak to Z-peak connection) of the connecting bridge 5 performs best at this angle. Due to its moderate pitch and deformation space, it can adapt to the axial compression and bending of blood vessels without sacrificing support due to excessive flexibility, making it a preferred design for peripheral blood vessels (such as the superficial femoral artery). Furthermore, its manufacturing process is mature; the design of six annular structures 2 / cycle is easy to control during laser engraving and heat treatment, suitable for large-scale production, and widely applicable to peripheral arterial diseases (such as superficial femoral artery stenosis) and applications requiring long-term implantation.

[0058] For a 90° helical cycle, each 360° spiral period contains four annular structures 2. The larger pitch and more open spiral path significantly increase the spacing between the annular structures 2. During compression, the annular structures 2 tilt at a 90° angle difference, forming a looser spiral deformation. The linear design of the connecting bridge 5 (Z-peak-Z-valley connection) enhances local rigidity at this angle. The open spiral structure reduces the proportion of flexible connecting bridges 5, resulting in increased overall rigidity, making it suitable for vessels requiring strong support for calcification or severe stenosis, such as calcified lesions, the aorta and iliac arteries requiring high radial support, or interventional procedures with limited delivery sheath diameter.

[0059] For a 120° helical cycle, each 360° helical period contains three annular structures 2, with a further increased pitch, resulting in a nearly semi-symmetrical helical path (one repeating unit every 120°). During compression, the annular structures 2 tilt at a 120° angle difference, creating a wide-amplitude helical deformation. The hybrid design of the connecting bridge 5 (alternating straight and curved lines) optimizes anti-kinking performance at this angle. The semi-symmetrical helical structure deforms more uniformly in both clockwise and counter-clockwise torsion directions, avoiding the kinking risk of unidirectional helical designs (such as the defects of the Cordis SMART Flex stent). The wide-pitch design is suitable for larger diameter vessels (such as the abdominal aorta), avoiding poor adhesion to the vessel wall due to excessively dense helices, and is also suitable for large-diameter vessels (such as abdominal aortic aneurysms) or complex lesions requiring anti-torsion.

[0060] For a 180° spiral cycle, each 360° spiral cycle contains only two annular structures 2, arranged symmetrically (adjacent structures rotate 180°), forming an alternating "S-shaped" deformation path. During compression, adjacent annular structures 2 tilt in opposite directions, forming alternating S-shaped deformations. The connecting bridge 5 is predominantly linear, providing rigid support. The symmetrical arrangement reduces the complexity of laser engraving, makes heat treatment and shaping easier to control, and is suitable for rapid mass production. The alternating S-shaped deformation path avoids stacking in a single direction while maintaining high axial stability. The structure is simple, with high material utilization, making it suitable for clinical applications with limited budgets. It is suitable for straight vessel segments (such as the carotid artery) or lesions requiring less flexibility and an economical solution.

[0061] In this embodiment, the number of vertices of the annular structure 2 arranged in a Z-shape is one of 6, 8, 10, 12, 14, or 16. Correspondingly, by changing the number of vertices of the annular structure 2 arranged in a Z-shape, the problem of balancing the flexibility, support, and fit of the stent under different vascular conditions, as well as the problem of balancing processing difficulty and manufacturing cost, is solved. This achieves good adaptability of the stent in various vascular environments, ensuring the stent's flexibility to adapt to complex vascular deformation, reducing mechanical stimulation to the vascular wall, and reducing the occurrence of complications. It also ensures the stent's support to maintain vascular patency, while optimizing the fit between the stent and the vascular wall, improving the therapeutic effect. In addition, it balances processing difficulty and manufacturing cost, making the stent easier to manufacture while ensuring performance, which is conducive to large-scale application.

[0062] Example 3:

[0063] As an optional implementation method, refer to the appendix. Figure 7 , Figure 8 The Z-shaped unit includes Z-peaks and Z-valleys. One end of the connecting bridge 5 is connected to a Z-peak, and the other end of the connecting bridge 5 is connected to a Z-peak or Z-valley of an adjacent annular structure 2. The connecting bridge 5 can be a Z-peak-Z-peak connection between two adjacent circular structures, or it can be a Z-peak of a Z-shaped pattern on one side of the annular structure 2 connected to a Z-valley of a Z-shaped pattern on an adjacent circular structure 2, or it can be a combination of the above two types. The shape of the connecting bridge 5 can be straight or S-shaped. Preferably, the connecting bridge 5 is designed as an S-shaped connection of Z-peaks. Since the Z-shaped pattern rods on the annular structure are of different lengths, the spacing between adjacent annular structures is different, so the length of the connecting bridge 5 is also different. The number of connecting bridges 5 will be adjusted according to the number of vertices of the Z-shaped structure.

[0064] In this embodiment, when the connecting bridge 5 connects the Z-peak and the Z-valley, the connecting bridge 5 is a straight line.

[0065] In this embodiment, when the connecting bridge 5 connects two Z-peaks, the connecting bridge 5 is curved.

[0066] In this embodiment, the number of connecting bridges 5 is one of 3, 4, 5, or 6.

[0067] It should also be noted that by optimizing the design of the connecting bridge 5, the performance of the support is improved. The solution is to connect the two ends of the connecting bridge 5 to the Z-peak and Z-valley of the adjacent ring structure 2, or two Z-peaks, or a combination thereof. The former uses a straight connecting bridge 5 to limit displacement and prevent excessive bending in some areas, while the latter uses a curved connecting bridge 5 to allow for a larger bending arc and promote continuous spiral deformation. The number of connecting bridges 5 can also be selected as 3, 4, 5, or 6.

[0068] Based on the above solution, the problems of local stability and overall compliance are solved. The straight connecting bridge 5 is rigid and can effectively limit the relative displacement of adjacent ring structures 2, prevent excessive local bending, and ensure local stability. The curved connecting bridge 5 is flexible and allows for greater bending, making the support more compliant as a whole. When axially compressed, the connecting bridge 5 absorbs stress through deformation, guides the tilting direction of the ring structure 2, ensures continuous and coordinated deformation path, avoids stress concentration, and reduces the risk of support fracture.

[0069] Furthermore, during compression, the hybrid connector 5 combines the advantages of both linear and curved connectors 5, ensuring local stability while improving overall flexibility. This allows the stent to adapt to the complex deformation of the blood vessel, reducing mechanical stimulation to the vessel wall. The varying number of connectors 5 also provides more flexible design options, enabling optimization of stent performance based on specific needs.

[0070] Example 4:

[0071] As an optional implementation method, refer to the appendix. Figure 2 The main structure 1 is connected to a first transition section 3 and a second transition section 4 at both ends.

[0072] In this embodiment, the first transition segment 3 is connected to the side away from the annular structure 2 by a first developing ring 6, and the second transition segment 4 is connected to the side away from the annular structure 2 by a second developing ring 7.

[0073] In this embodiment, both the first transition segment 3 and the second transition segment 4 include a hollow structure arranged longitudinally in a Z-shape, and the side away from the annular structure 2 has the same length.

[0074] Based on the above structure, by connecting the first transition segment 3 and the second transition segment 4 at both ends of the main stent structure 1, and connecting a contrast ring on the side away from the annular structure 2, and by giving the transition segments a specific structure and length, the problems of stent visibility and end-point stability during surgical operations are solved. The contrast ring is made of high-density material, which enhances the contrast effect of the stent ends under X-rays, making it easier for doctors to accurately determine the stent position and improve surgical precision. The structural design of the transition segments allows the stent ends to fit more closely to the blood vessel wall, reducing gaps and blood impact, and lowering the risk of thrombosis. At the same time, its length is consistent with the main structure 1, maintaining the overall coordination and stability of the stent. In addition, the material selection for the transition segments and the contrast ring must take into account both biocompatibility and mechanical properties to ensure the long-term stability of the stent in the body.

[0075] Example 5:

[0076] As an optional implementation, the main structure 1 is provided with a coating, and the coating material includes one or a combination of fluoropolymers, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fibers.

[0077] In this embodiment, by providing a membrane on the main stent structure 1, and the membrane material including one or a combination of fluoropolymers, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fibers, the problems of stent irritation to the blood vessel wall under certain special circumstances, as well as the problems of stent sealing and prevention of blood leakage, are solved. The membrane makes the contact between the stent and the blood vessel wall smoother, reduces the mechanical stimulation of the blood vessel wall by the stent, and reduces the risk of damage to the blood vessel wall. At the same time, the selection of membrane material also takes into account biocompatibility and durability, ensuring the long-term stability of the stent in the body.

[0078] Secondly, the lining effectively prevents excessive deposition of blood cells and proteins on the stent surface, reducing the risk of thrombosis. The diversity and combination of lining materials allow for stent customization to meet different clinical needs; for example, silicone can be used in areas requiring greater flexibility, while fluoropolymers can be used in areas requiring greater corrosion resistance. This material flexibility provides more possibilities for stent design, enabling better adaptation to different patients' vascular conditions and lesion types. Finally, the lining can also enhance the radial support of the stent to some extent, improving its overall performance and allowing it to more effectively maintain vascular patency after implantation, reducing restenosis.

[0079] Example 6:

[0080] As an optional implementation, the material of the first developing ring 6 or the second developing ring 7 includes one or a combination of gold, platinum, platinum-iridium alloy, and platinum-tungsten alloy.

[0081] In this embodiment, by setting the material of the first imaging ring 6 or the second imaging ring 7 to one or a combination of gold, platinum, platinum-iridium alloy, and platinum-tungsten alloy, the problem of accurately determining the position of the stent during stent implantation and the problem of poor imaging effect of existing stents leading to difficulties in surgical operation are solved. These materials have high density and atomic number, and can produce obvious imaging effect under imaging equipment such as X-rays, enabling doctors to clearly observe the position and shape of the stent in the blood vessel, thereby performing surgical operation more accurately and reducing surgical risks and complications.

[0082] Furthermore, these materials exhibit excellent biocompatibility, reducing the body's rejection response to the stent and improving its safety and reliability. Secondly, their high rigidity and strength allow them to maintain good shape and stability during stent implantation, ensuring the stent accurately reaches its target location and effectively supports the blood vessel. Thirdly, the imaging effects of these materials remain stable under different angles and conditions, providing physicians with more comprehensive and accurate stent placement information, contributing to improved surgical success rates and treatment outcomes. Finally, the diversity and combination of these materials also provide greater flexibility in stent design and manufacturing, allowing for optimization and adjustment based on different clinical needs and patient conditions to meet personalized medical requirements.

[0083] Example 7:

[0084] As an optional implementation, the fabrication process of the stent in this invention includes the following steps:

[0085] Step 1: Select a suitable scaffold material, such as a super-elastic metal material like nickel-titanium alloy, or other implantable polymer materials with super-elastic characteristics;

[0086] Step 2: Based on the designed support structure, use laser engraving technology to process Z-shaped patterns on the hollow tube. During the engraving process, precisely control the laser power, frequency and scanning speed to ensure the dimensional accuracy and quality of the pattern.

[0087] Step 3: Heat-treat the laser-engraved bracket to eliminate internal stress generated during processing and to give the bracket good elasticity and shape memory properties.

[0088] Step 4: In order to remove the oxide layer and impurities that may be generated on the surface of the bracket during laser engraving and heat treatment, acid pickling is performed;

[0089] Step 5: Further improve the surface finish and corrosion resistance of the support by electropolishing;

[0090] Step 6: As needed, depending on the different lesion characteristics, the main structure 1 is provided with a drug elution coating, the function of which includes, but is not limited to, inhibiting vascular wall proliferation, vascular inflammation, etc.

[0091] In this embodiment, the main structure is provided with a drug-eluting coating. The drug-eluting coating includes drug elution and drug coating. The drug elution includes any one or a combination of polylactic acid, polylactic acid derivatives, polylactic-co-glycolic acid, phosphocholine, polyvinylidene fluoride hexafluoropropylene copolymer, polyacrylate, and polybutyl methacrylate. The drug coating includes any one or a combination of statins, rapamycin, paclitaxel, or heparin. Specifically, after stent implantation, excessive proliferation of smooth muscle cells may lead to restenosis of the blood vessel, while the drug-eluting coating can effectively inhibit this proliferation and maintain vascular patency. By inhibiting smooth muscle cell proliferation and reducing inflammatory response, it also reduces the risk of thrombosis.

[0092] As attached Figures 9 to 13 As can be seen, the stent maintains a good shape when bent, without any kinking at the bend. Good bending flexibility prevents the stent from irritating the blood vessel wall. To more clearly demonstrate the bending flexibility of the stent in this technical solution, a model was established using the finite element method (FEM), and the material parameters of the hyperelastic nickel-titanium alloy tube were used to simulate the deformation of the stent during bending. The deformation characteristics and strain contour distribution after bending are shown below. Figure 10 As shown, it can be seen Figure 9 and Figure 10 The deformations of the two at the bending points are very similar, and the results are in good agreement, which indicates that the support has excellent bending compliance and that the finite element modeling is reasonable.

[0093] Furthermore, to clearly demonstrate the unique axial compression performance of the support in this technical solution, a model was established using the finite element analysis (FEM) method described above. Deformation simulation of the support under axial compression was performed, and the deformation morphology and strain distribution cloud diagram under axial compression are presented, as shown below. Figure 11 , Figure 12 As shown. Among them, Figure 11 The connecting bridge 5 in the middle structure is designed as Figure 7 and Figure 8 The hybrid type Figure 12 The connecting bridge 5 in the middle structure is similar Figure 8 The S-shape is shown in the figure. It can be seen that under both different connecting bridges 5, the support produces a similar three-dimensional spiral or S-shaped deformation feature when axially compressed, which is consistent with the deformation feature described in the technical solution. This also shows that the different connecting bridge 5 design schemes proposed in the technical solution are feasible.

[0094] for Figure 13In contrast, a support model with parallel rods of equal length was established using the finite element analysis (FEM) method described above. The deformation of the support under axial compression was simulated, and the deformation morphology and strain distribution cloud map of the support under axial compression were given. It can be seen that when the structure is axially compressed, the support rings all deform in a single axial direction and tend to stack together, which also illustrates the advantages of the technical solution in this patent.

[0095] To better illustrate the advantages of this patented technical solution, the above embodiments are provided. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. The stent of this invention can be used in any artery, vein, bile duct, or other blood vessel, such as the ureter or urethra. The stent can be used to treat arterial stenosis, such as the coronary artery, superficial femoral artery, inferior inguinal artery, aorta-iliac artery, subclavian artery, carotid artery, mesentery, or renal artery. When covered with a lining, it can also be used to treat aneurysms and arterial dissections, such as in the iliac artery region.

[0096] Finally, compared to existing technologies, patent CN101065078B provides a self-expanding stent with a three-dimensional helical structure, which can guide blood flow. The slight three-dimensional helical design also results in a lower fracture rate. However, the three-dimensional helical structure may be difficult to handle during stent compression and surgical release, and the preparation tooling is more complex. Patents CN103784222B and US8333799B2 are both self-expanding stents with helical windings. These two technologies are similar; the helical windings give the stent good flexibility. However, the stent's torsion is directional, and the deformation is uniform. When torsion is reversed, the stent is prone to kinking. Most other patents use longitudinally parallel arrangement technologies, therefore, they cannot effectively achieve deformation under axial compression.

[0097] The paper (Smouse, H. Bob, Alexander Nikanorov, and Danielle LaFlash. "Biomechanical forces in the femoropopliteal arterial segment." Endovasc Today 4.6 (2005): 60-6.) describes the mechanical deformation characteristics of human blood vessels during different limb movements, including a comparison of vascular deformation morphology before and after stent implantation under the same movement. This demonstrates the inadequacy of existing stents, especially their inability to adapt well to vascular deformation during limb bending, leading to high stent breakage and restenosis rates in clinical practice.

[0098] Compared to the above, in the technical solution of this invention, the length of the rods in each of the Z-shaped patterns on the annular stent rings is different. After being periodically rotated and extended along the axial direction, the stent has better bending flexibility. Secondly, and this is another core point of the technical solution, the unequal rod lengths of the Z-shaped patterns allow the stent to undergo eccentric compression deformation during axial compression. In addition, the annular stent rings composed of these Z-shaped patterns are periodically arranged. Therefore, during axial compression, the stent will exhibit a deformation trend similar to a three-dimensional spiral or S-shape. This allows the stent deformation to be coordinated with the deformation of the blood vessel, achieving a design similar to that in patent CN101065078B, which guides blood flow and reduces stent breakage. However, it avoids the problems that may exist during gripping and release, as well as the challenges of complex tooling preparation.

[0099] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A support, characterized in that, The system includes a main structure, which comprises several ring structures and several connecting bridges. Each ring structure includes multiple Z-shaped units, which are connected end to end to form a ring. Adjacent ring structures are connected by several connecting bridges. The ring structures have different widths when unfolded in a plane. When several of the aforementioned ring structures are arranged periodically along the axial direction, there is an angular difference in the circumferential direction between two adjacent ring structures, and the spacing between two adjacent ring structures is different, so that the overall structure forms a continuous three-dimensional spiral or S-shaped deformation path when compressed, and the angular difference ranges from 30° to 180°. The Z-shaped unit includes a Z-peak and a Z-valley. One end of the connecting bridge is connected to the Z-peak, and the other end of the connecting bridge is connected to the Z-peak or Z-valley of the adjacent ring structure. The main structure is connected at both ends by a first transition section and a second transition section; The first transition section is connected to a first developing ring on the side away from the annular structure, and the second transition section is connected to a second developing ring on the side away from the annular structure. Both the first transition segment and the second transition segment include a hollow structure arranged longitudinally in a Z-shape, and the side away from the annular structure has the same length.

2. The stent as described in claim 1, characterized in that, When the connecting bridge connects the Z-peak and the Z-valley, the connecting bridge is straight; when the connecting bridge connects two Z-peaks, the connecting bridge is curved.

3. The stent as described in claim 1, characterized in that, The main structure is provided with a coating material, which includes one or a combination of fluoropolymers, silicone, urethane, polyethylene, and aramid fibers.

4. A stent as described in claim 1, characterized in that, The main structure is provided with a drug elution coating.

5. A stent as described in claim 1, characterized in that, The material of the first or second developing ring includes one or a combination of gold, platinum, platinum-iridium alloy, and platinum-tungsten alloy.

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