Support

Abstract

The invention relates to the technical field of medical instruments, 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 Z-shaped mode in the axial direction in a rotational symmetry mode, the annular structures are connected through the connecting bridges to form a whole stent, and the lengths of the annular structures are different when the annular structures are arranged in the Z-shaped mode. The annular structures are arranged in the Z shape in the axial direction in the rotational symmetry mode, the annular structures are connected through the connecting bridges to form the whole stent, the whole main body structure is deformed in a similar three-dimensional spiral shape or an S shape, local stacking is not prone to occurring, and the problem that after the stent is implanted, the main body structure is prone to deformation is solved. The problem that the existing stent cannot well adapt to deformation of the blood vessel during axial compression and bending is solved, synchronization of complex deformation (such as axial compression, bending and torsion) of the stent and the blood vessel is achieved, and therefore mechanical stimulation to the blood vessel wall is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a bracket. Background Art

[0002] Intravascular interventional surgery has the advantages of less trauma and faster recovery. By releasing the stent into the blood vessels through interventional surgery, the diseased blood vessels can be repaired and reconstructed.

[0003] Vascular stents are generally divided into two types: self-expanding and balloon-expandable. Balloon-expandable stents are typically made of materials such as cobalt-chromium alloy and stainless steel. The stent is typically pre-pressed onto a balloon catheter and delivered to the designated lesion site through an interventional procedure. The balloon is then pressurized to expand the stent to its designed diameter and released into the vessel. Self-expanding stents can expand and release themselves without the use of a balloon. Prior to implantation, the stent is typically pressed into a designated delivery sheath. After the stent is delivered to the designated lesion site through an interventional procedure, the delivery sheath is removed, releasing the stent and providing support to the vessel wall.

[0004] Specifically, balloon expansion utilizes the plastic deformation of the material to achieve functional design, so the stent after expansion is relatively hard and has poor bending flexibility; at the same time, due to the inherent elastic properties of the stent material, the stent may also produce radial retraction after expanding to the specified diameter specification.

[0005] Self-expanding stents typically utilize a Z-shaped pattern design. There are generally two axial arrangements for this Z-shaped structure: a parallel arrangement and a spiral winding arrangement. Parallel arrangements typically allow for bending, but their bending compliance is generally poor, and the stent exhibits poor axial compression performance. When the stent is axially compressed, it may become stacked or even partially bent. While the spiral winding arrangement offers good bending compliance, it can also experience axial torsional deformation. While deformation along the spiral direction is acceptable, twisting against the spiral direction can lead to kinking.

[0006] The above design deficiencies may cause the stent to irritate the blood vessel wall and even eventually lead to stent rupture. Summary of the Invention

[0007] The main purpose of the present invention is to provide a stent, which aims to solve the problem that the existing stent has poor deformation adaptability during axial compression and bending after being implanted into a blood vessel.

[0008] To achieve the above object, the present invention provides a stent, comprising a main structure, wherein the annular structure comprises a plurality of Z-shaped units, and the plurality of Z-shaped units are connected end to end to form an annular structure, and adjacent annular structures are connected by a plurality of connecting bridges, and the width of the annular structure when unfolded is different.

[0009] Optionally, when a plurality of the annular structures are periodically arranged along the axial direction, there is an angle difference between the circumferential directions of two adjacent annular 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, two ends of the main structure are connected with a first transition section and a second transition section.

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

[0013] Optionally, the first transition section and the second transition section each include a hollow structure arranged longitudinally in a Z-shape, and the lengths of the sides away from the annular structure are the same.

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

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

[0016] Optionally, a drug eluting coating is provided on the main structure, and the drug eluting coating includes drug elution and drug coating, and the drug elution includes any one or combination of polylactic acid, polylactic acid derivatives, polylactic acid-glycolic acid, phosphorylcholine, polyvinylidene fluoride hexafluoropropylene copolymer, polyacrylate, and polybutyl methacrylate; the drug coating includes any one or combination of statins, rapamycin drugs, paclitaxel drugs or heparin drugs.

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

[0018] A stent proposed in an embodiment of the present invention is realized by arranging annular structures in a Z-shape in a rotationally symmetrical manner along the axial direction, and connecting the annular structures through connecting bridges to form an overall stent. Based on the above structure, when the stent as a whole undergoes compression deformation, each annular structure will produce a deformation trend similar to eccentric compression, that is, tilting to one side. At the same time, the periodic rotation arrangement of the annular structures makes the main structure as a whole present a three-dimensional spiral or S-shaped deformation, and it is not easy to stack locally. This solves the problem that the stent cannot adapt well to the deformation of the blood vessel during axial compression and bending after implantation, and realizes the synchronization of the stent and the complex deformation of the blood vessel (such as axial compression, bending and torsion), thereby reducing the mechanical stimulation to the blood vessel wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a two-dimensional plane of the entire stent of the present invention;

[0020] Figure 2 Schematic diagram of the Z-shaped characteristics 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 entire stent of the present invention based on two dimensions;

[0022] Figure 4 Schematic diagram of the periodic axial rotation arrangement of the annular structure of the present invention;

[0023] Figure 5 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 Schematic diagram of the connection bridge of the present invention connected in a Z-peak-Z-valley form;

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

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

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

[0029] Figure 11 The deformation and strain distribution diagrams of the axial compression finite element analysis of the bridge connected in a mixed Z-peak-Z-valley and Z-peak-Z-peak form;

[0030] Figure 12The deformation and strain distribution diagram of the axial compression finite element analysis of the connection bridge in the Z-peak-Z-peak form;

[0031] Figure 13 The deformation and strain distribution diagram of the finite element analysis of the axial compression of the main structure with ring structures arranged in parallel with equal lengths.

[0032] Reference numerals:

[0033] 1-main structure, 2-annular structure, 3-first transition section, 4-second transition section, 5-connecting bridge, 6-first developing ring, 7-second developing ring.

[0034] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Example 1:

[0040] Please refer to the attached Figure 1 To the attached Figure 13 In this embodiment, a stent is provided, comprising a main structure 1, the annular structure 2 comprising a plurality of Z-shaped units, and the plurality of Z-shaped units are connected end to end to form a ring, adjacent annular structures 2 are connected by a plurality of connecting bridges 5, and the width of the annular structure 2 when unfolded in a plane is different.

[0041] It should be noted that, clinically, after stents are implanted in blood vessels, they deform due to limb movement, respiration, and muscle movement. Clinical research by Smouse et al. shows that, particularly in the peripheral femoral and popliteal arteries, limb movements are large, so different limb movements significantly affect vascular deformation. When the leg bends, the blood vessels are first stretched and then axially compressed, resulting in bending deformation. However, after stents are implanted in blood vessels, they are not easily axially compressed, which alters the mechanical properties of the vessels. Localized vascular stacking and knotting are prone to occur during limb movement, potentially leading to a series of complications such as restenosis within the stent, scratches on the vessel wall, and even perforations. Stents are also prone to fracture in these situations, potentially requiring secondary surgical intervention. Delayed treatment can even lead to serious adverse events such as amputation.

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

[0043] Those skilled in the art will appreciate that, in the existing field of stent medical device technology, stents and other structures are relatively mature, their basic shape is fixed to a rod-like structure, and significant pioneering improvements are difficult to achieve. Therefore, technical personnel generally have questions about the maturity of stent structures. Under the premise of this problem, technical personnel find it difficult to consider other possibilities, which hinders the further improvement and development of this characteristic stent structure. On this basis, the applicant proposes that by using a Z-shaped axial arrangement and different lengths during the arrangement, not only is bending compliance improved, but also the deformation characteristic of eccentric compression of the stent during axial compression is enabled. Combined with the periodic arrangement of the annular stent rings composed of the Z-shaped pattern, the stent exhibits a deformation trend similar to a three-dimensional spiral or S-shaped deformation during axial compression. This allows the stent deformation to be coordinated with the deformation of the blood vessel, achieving a design similar to that of patent CN101065078B that guides blood flow and reduces stent fracture, without the problems that may exist during compression and release. This has outstanding substantive features and significant progress, and at the same time, to a certain extent overcomes the technical prejudice that it is difficult to make significant improvements in the field of stent structures.

[0044] Based on the above problems, the applicant provides a stent, which is achieved by arranging the annular structure 2 in a Z-shape in a rotationally symmetrical manner along the axial direction, and connecting the annular structure 2 through a connecting bridge 5 to form a stent as a whole. Based on the above structure, when the stent as a whole undergoes compression deformation, each annular structure 2 will produce a deformation trend similar to eccentric compression, that is, tilting to one side. At the same time, the periodic rotation arrangement of the annular structure 2 makes the main structure 1 as a whole present a three-dimensional spiral or S-shaped deformation, and it is not easy to stack locally, so it can be coordinated with the deformation of the blood vessel, while reducing 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, which presents a shape similar to "one end is big and the other end is small" in three dimensions. Figure 2 For example, assume that the rod length at the Z peak of a certain annular structure 2 is shorter, and the rod length at the Z valley is longer. Since the annular structures 2 in this embodiment are arranged periodically in the axial direction, the characteristics of the Z peak and the Z valley are relative. Therefore, the side of the annular structure 2 close to the second transition section 4 is convex as the Z peak and concave as the Z valley. When axial pressure is applied, the long rod area bends first due to its higher flexibility, while the short rod area resists deformation due to its higher rigidity, causing the annular structure 2 to tilt toward the long rod side (Z valley direction) as a whole. The direction of this tilt is determined by the rod length distribution, and the tilt direction of each annular structure 2 may be different due to differences in rod length.

[0046] In this embodiment, the Z-peak-Z-valley straight connecting bridge 5 limits the relative displacement of adjacent annular structures 2 through rigid connection to prevent local excessive bending; the Z-peak-Z-peak curved connecting bridge 5 allows a larger bending radius through flexible design to promote the continuity of spiral deformation. Figure 11 In the stent, the hybrid bridge 5 combines two connection methods, ensuring both local stability and overall compliance. During compression, the bridge 5 absorbs some stress through deformation and, through different connection methods, guides the tilt of the annular structure 2, ensuring a continuous and coordinated deformation path. This mechanism enables the stent to synchronize with the complex deformation of the vessel (such as axial compression, bending, and torsion), thereby reducing mechanical irritation to the vessel wall.

[0047] The stent involved in this embodiment may have different diameter characteristics in different application scenarios. For example, during entry delivery, the stent is radially pressed into the delivery sheath and has a smaller diameter. After entering the target lesion location of the blood vessel, the delivery sheath can be removed, and the stent has a larger diameter after expansion. The material of the stent is usually a superelastic material, such as superelastic metal materials such as nickel-titanium alloy, and other implantable polymer materials with superelastic characteristics. The present invention does not impose any specific material restrictions on the stent.

[0048] Example 2:

[0049] As an optional embodiment, when a plurality of the annular structures 2 are periodically arranged along the axial direction, there is an angle difference between two adjacent annular structures 2 in the circumferential direction.

[0050] In this embodiment, adjacent annular structures 2 are gradually offset in the circumferential direction by the value of θ due to the existence of the angle difference θ. For example, when θ = 60°, after the first annular structure 2 is fixed, the second annular structure 2 is rotated 60° clockwise or counterclockwise in the circumferential direction based on the first annular structure 2. The third annular structure 2 is rotated in the same direction by the corresponding angle difference θ. This periodic change in the tilt direction causes the overall structure to form a continuous three-dimensional spiral or S-shaped deformation path when compressed, such as Figure 4 、 Figure 5 As shown, rather than the traditional design of single direction stacking.

[0051] It should be noted that, as Figure 13As shown, it is a deformation and strain distribution diagram of the finite element analysis of the axial compression of the stent structure in the prior art with equal lengths arranged in parallel. During axial compression, all the annular structures 2 tilt in the same direction, resulting in structural stacking or even local bending. In contrast, in this embodiment, the tilt directions of adjacent annular structures 2 are different by periodically rotating the angle difference θ. For example, when θ=60°, every six annular structures 2 complete a 360° rotation cycle, and the tilt directions are evenly distributed in three-dimensional space, avoiding stress concentration. In addition, the spiral or S-shaped deformation path increases the deformation space of the stent. The tilt directions of each annular structure 2 are distributed along the spiral trajectory and are staggered with each other, reducing the contact probability between adjacent structures. For example, in spiral deformation, the tilt direction of each annular structure 2 forms an angle complementary to that of the adjacent structure, so that the compressive force is evenly distributed to the entire stent rather than a local area.

[0052] It should also be noted that the unequal rod lengths 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. The longer connecting bridge 5 can bend more significantly when compressed, while the shorter connecting bridge 5 provides support. This length difference further limits the possibility of adjacent structures fitting together. In addition, the radian design of the curved connecting bridge 5 allows the annular structure 2 to form a "wave-like" deformation when tilted, further increasing the gap between the structures. These designs work together to make the stent form a spring-like spiral shape when compressed (with no local stacking, and the deformation of the blood vessel is coordinated, thereby significantly reducing the risk of stent fracture and vascular damage.

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

[0054] In terms of performance in different angle difference ranges:

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

[0056] For 45°, each 360° spiral period 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 larger than the 30° design; during compression, the annular structure 2 gradually tilts at an angle difference of 45°, forming a medium-frequency spiral deformation. The hybrid design of the connecting bridge 5 (a combination of straight lines and curves) can effectively balance rigidity and flexibility at this angle; the moderate pitch retains a certain degree of flexibility and provides better radial support through a slightly larger annular spacing. It is suitable for scenarios that require both opening vascular stenosis and adapting to deformation, such as blood vessels with moderate curvature (such as the iliac artery) or lesions that require both radial support and flexibility.

[0057] For 60°, each 360° spiral cycle contains 6 annular structures 2, with a large pitch, a clear spiral path and ample deformation space. The annular structure 2 is tilted at a 60° angle difference, forming a clear three-dimensional spiral or S-shaped deformation. The curved design of the connecting bridge 5 (Z peak-Z peak connection) performs better at this angle. Due to its moderate pitch and deformation space, it can adapt to the axial compression and bending of the blood vessel without sacrificing support due to excessive flexibility. It is an optimal design for peripheral blood vessels (such as the superficial femoral artery). In addition, its preparation process is mature, and the design of 6 annular structures 2 / cycle is easy to control during laser engraving and heat treatment, suitable for large-scale production, and can be widely used in peripheral arterial diseases (such as superficial femoral artery stenosis) and occasions requiring long-term implantation.

[0058] For 90°, each 360° spiral cycle contains four annular structures 2, with a larger pitch and a more open spiral path. The spacing between the annular structures 2 is significantly increased. 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) can enhance local rigidity at this angle. The open spiral structure reduces the proportion of flexible connecting bridge 5, thereby improving overall rigidity. It is suitable for blood vessels that require strong support for calcification or severe stenosis. Such as calcified lesions, aortoiliac arteries, and other areas that require high radial support force, or interventional procedures where the delivery sheath diameter is limited.

[0059] For 120°, each 360° spiral period contains 3 annular structures 2, the pitch is further increased, and the spiral path is close to a semi-symmetrical form (one repeating unit every 120°). During compression, the annular structure 2 tilts at an angle difference of 120°, forming a wide spiral deformation. The hybrid design of the connecting bridge 5 (alternating straight lines and curves) can optimize the anti-kink performance at this angle. The semi-symmetrical spiral structure deforms more evenly in the forward / reverse torsional direction, avoiding the kinking risk of a unidirectional spiral design (such as the defect of the Cordis SMART Flex stent). The wide pitch design is suitable for larger diameter blood vessels (such as the abdominal aorta) to avoid poor adhesion to the blood vessel wall due to too dense a spiral. It is also suitable for large diameter blood vessels (such as abdominal aortic aneurysms) or complex lesions that require anti-torsion.

[0060] For 180°, each 360° spiral period contains only two annular structures 2, and the annular structures 2 are arranged in a completely symmetrical manner (adjacent structures are rotated 180°), forming an "S-shaped" alternating deformation path. During compression, adjacent annular structures 2 tilt in opposite directions, forming alternating S-shaped deformations. The connecting bridge 5 is mainly straight and provides rigid support. The symmetrical arrangement reduces the complexity of laser engraving, and the heat treatment shaping is easier to control, which is suitable for rapid mass production. The S-shaped alternating deformation path avoids stacking in a single direction while maintaining high axial stability. It has a simple structure and high material utilization, making it suitable for clinical applications with limited budgets. It is suitable for straight blood vessel segments (such as the carotid artery) or lesions with low flexibility requirements that require economical solutions.

[0061] In this embodiment, the number of vertices of the annular structure 2 when arranged in a zigzag shape is one of 6, 8, 10, 12, 14, and 16. Accordingly, by varying the number of vertices of the annular structure 2 when arranged in a zigzag shape, the problem of balancing the flexibility, support, and conformability of the stent under different vascular conditions, as well as the problem of balancing processing difficulty and manufacturing cost, is resolved. This ensures the stent's good adaptability in various vascular environments, ensuring the stent's flexibility to adapt to complex vascular deformation, reducing mechanical stimulation to the vascular wall and the occurrence of complications, while also ensuring the stent's support to maintain vascular patency. Furthermore, the stent's conformability to the vascular wall is optimized, improving the therapeutic effect. Furthermore, a balance is achieved between processing difficulty and manufacturing cost, making the stent easier to manufacture while ensuring performance, facilitating large-scale application.

[0062] Example 3:

[0063] As an optional embodiment, refer to the attached Figure 7 、 Figure 8 , the Z-shaped unit includes a Z peak and a Z valley, one end of the connecting bridge 5 is connected to the Z peak, and the other end of the connecting bridge 5 is connected to the Z peak or Z valley of the adjacent annular structure 2. The connecting bridge 5 can be a Z-shaped pattern Z-peak-Z peak connection of two adjacent circular structures, or it can be connected from the Z peak of the Z-shaped pattern on one side of the annular structure 2 to the Z valley of the Z-shaped pattern on the adjacent circular ring structure 2, or it can be a combination of the above two types. The shape of the connecting bridge 5 can be linear or S-shaped. Preferably, the connecting bridge 5 is designed to be S-shaped with a Z-peak-Z peak connection; since the lengths of the Z-shaped pattern rods on the circular ring structure are different, the spacing between adjacent circular rings is different, so the lengths of the connecting bridges 5 are 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 is connected to the Z peak and the Z valley, the connecting bridge 5 is a straight line.

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

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

[0067] It should also be noted that the performance of the bracket is improved by optimizing the design of the connecting bridge 5. The solution is to connect the two ends of the connecting bridge 5 to the Z peak and Z valley of the adjacent annular structure 2, or two Z peaks, or a combination of the above. The former uses a straight connecting bridge 5 to limit displacement and prevent local excessive bending, and the latter uses a curved connecting bridge 5 to allow a larger bending radius 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 flexibility are solved. The straight connecting bridge 5 is highly rigid and can effectively limit the relative displacement of adjacent annular structures 2, prevent local excessive bending, and ensure local stability; the curved connecting bridge 5 is flexible and allows greater bending, making the bracket more flexible as a whole. During axial compression, the connecting bridge 5 absorbs stress through deformation, guides the tilt direction of the annular structure 2, ensures continuous and coordinated deformation path, avoids stress concentration, and reduces the risk of bracket fracture.

[0069] Furthermore, during compression, the hybrid bridges 5 combine the advantages of both linear and curved bridges, ensuring local stability while enhancing overall compliance. This allows the stent to synchronize with the complex deformation of the vessel, reducing mechanical irritation to the vessel wall. The variable number of bridges 5 also provides a more flexible design, allowing stent performance to be optimized based on specific needs.

[0070] Example 4:

[0071] As an optional embodiment, refer to the attached Figure 2 The two ends of the main structure 1 are connected with a first transition section 3 and a second transition section 4.

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

[0073] In this embodiment, the first transition section 3 and the second transition section 4 both include a hollow structure arranged longitudinally in a Z-shape, and the lengths of the sides away from the annular structure 2 are the same.

[0074] Based on the above structure, by connecting the first transition section 3 and the second transition section 4 at both ends of the stent main structure 1, and connecting a developing ring on the side away from the annular structure 2, and making the transition section have a specific structure and length, the visibility and stability of the stent at both ends during the surgical operation are solved; the developing ring is made of high-density material, which can enhance the imaging effect of the stent at both ends under X-ray, making it easier for doctors to accurately judge the position of the stent and improve surgical accuracy. The structural design of the transition section makes the two ends of the stent fit more closely to the blood vessel wall, reducing gaps and blood impact, and reducing 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 of the transition section and the developing 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 embodiment, a coating is provided on the main structure 1, and the coating material includes one or a combination of fluoropolymer, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fiber.

[0077] In this embodiment, a coating is provided on the main structure 1 of the stent, and the coating material includes one or a combination of fluoropolymers, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fiber, thereby solving the problem of the stent irritating the blood vessel wall in certain special circumstances, as well as the problems of the stent's sealing and prevention of blood leakage. The provision of the coating makes the contact between the stent and the blood vessel wall smoother, reduces the mechanical stimulation of the stent on the blood vessel wall, and reduces the risk of damage to the blood vessel wall. At the same time, the selection of the coating material also takes into account biocompatibility and durability, ensuring the long-term stability of the stent in the body.

[0078] Secondly, the coating can effectively prevent excessive deposition of cells and proteins in the blood on the stent surface, reducing the risk of thrombosis. The diversity and combination of coating materials allow the stent to be customized according to different clinical needs, such as using silicone in areas requiring greater flexibility and using fluoropolymers in areas requiring greater corrosion resistance. This material flexibility provides more possibilities for stent design, allowing it to better adapt to the vascular conditions and lesion types of different patients. Finally, the coating can also enhance the radial support force of the stent to a certain extent, improving the overall performance of the stent, allowing it to more effectively maintain blood vessel patency after implantation and reduce the occurrence of restenosis.

[0079] Example 6:

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

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

[0082] In addition, these materials have good biocompatibility, which can reduce the body's rejection of stents and improve the safety and reliability of stents. Secondly, they have high hardness and strength, which can maintain good shape and stability during stent implantation, ensuring that the stent can accurately reach the target position and effectively support the blood vessel. Thirdly, the development effect of these materials can remain stable at different angles and conditions, providing doctors with more comprehensive and accurate stent position information, helping to improve the success rate of surgery and treatment effectiveness. Finally, the diversity and combination of materials also provide more flexibility in the design and manufacture of stents, which can be optimized and adjusted according to different clinical needs and patient conditions to meet personalized medical requirements.

[0083] Example 7:

[0084] As an optional embodiment, the preparation process of the stent of the present invention includes the following steps:

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

[0086] Step 2: Based on the designed bracket structure, a Z-shaped pattern is processed on the hollow tube using laser engraving technology. During the engraving process, the power, frequency and scanning speed of the laser are precisely controlled to ensure the dimensional accuracy and quality of the pattern.

[0087] Step 3: heat-treating the laser-engraved stent to eliminate internal stress generated during the processing and to impart good elasticity and shape memory properties to the stent;

[0088] Step 4: Pickling is performed to remove the oxide layer and impurities that may be generated on the surface of the stent during the laser engraving and heat treatment process;

[0089] Step 5: further improving the surface finish and corrosion resistance of the stent by electrolytic polishing;

[0090] Step 6: As needed, according to different pathological characteristics, a drug eluting coating is provided on the main structure 1, and its functions include but are not limited to inhibiting vascular wall proliferation, vascular inflammation, etc.

[0091] In this embodiment, the main structure is provided with a drug-eluting coating, which includes a drug eluting agent, a drug coating, and the drug eluting agent includes any one or a combination of polylactic acid, a polylactic acid derivative, polylactic acid-glycolic acid, phosphorylcholine, polyvinylidene fluoride hexafluoropropylene copolymer, polyacrylate, and polybutyl methacrylate; the drug coating includes any one or a combination of statins, rapamycins, paclitaxels, or heparins. Specifically, after stent implantation, excessive smooth muscle cell proliferation may lead to restenosis of the blood vessels, and the drug-eluting coating can effectively inhibit this proliferation, maintaining blood vessel patency. By inhibiting smooth muscle cell proliferation and reducing inflammatory responses, the risk of thrombosis is also reduced.

[0092] As attached Figures 9 to 13 , it can be seen that the stent has a good shape when bent, and there is no folding at the bent part. Good bending flexibility can prevent the stent from irritating the blood vessel wall. In order to more clearly demonstrate the bending flexibility of the stent in this technical solution, a model was established using the finite element analysis method (FEM), and the material parameters of the superelastic nickel-titanium alloy tube were used to simulate the deformation of the stent bending. The deformation characteristics and strain cloud map distribution after bending are shown in the figure. Figure 10 As shown, it can be seen Figure 9 and Figure 10 The deformation of the two at the bending part is very similar, and the results are consistent, which shows that the stent has excellent bending flexibility and that the finite element modeling is reasonable.

[0093] Furthermore, in order to more clearly demonstrate the unique axial compression performance of the stent in this technical solution, the above finite element analysis method (FEM) was used to establish a model, and the deformation simulation of the stent during axial compression was performed. The deformation morphology and strain distribution cloud diagram of the stent during axial compression were also given, as shown in FIG. Figure 11 , Figure 12 As shown. Among them, Figure 11 The connecting bridge 5 of the middle structure is designed as Figure 7 and Figure 8 A hybrid, Figure 12 The connecting bridge 5 of the middle structure is similar Figure 8 It can be seen that under the two different connecting bridges 5, the stent produces deformation characteristics similar to three-dimensional spiral or S-shaped deformation when axially compressed, which is consistent with the deformation characteristics described in the technical solution. It also shows that the different connecting bridge 5 design schemes proposed in the technical solution are feasible.

[0094] for Figure 13As a comparison, a stent model with parallel arrangement of equal-length rods was established through the above finite element analysis method (FEM), and the deformation simulation of the stent during axial compression was performed. The deformation morphology and strain distribution cloud diagram of the stent during axial compression were given. It can be seen that when the structure is axially compressed, the stent rings all deform in a single axial direction and tend to stack together. This also illustrates the advantages of the technical solution in this patent.

[0095] In order to better illustrate the advantages of the technical solution of this patent, the above embodiments are given. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. The stent of the present 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, inguinal artery, aortoiliac artery, subclavian artery, carotid artery, mesenteric or renal artery, etc. When coated, it can also be used to treat aneurysms and arterial dissections, such as in the iliac artery area.

[0096] Finally, compared to existing technologies, patent CN101065078B provides a self-expanding stent with a three-dimensional helical structure that can guide blood flow. The slight three-dimensional helical design also reduces the stent fracture rate. However, the three-dimensional helical structure can be difficult to manipulate during stent compression and surgical release, and the manufacturing tooling is more complex. Patents CN103784222B and US8333799B2 both use helical windings for self-expanding stents. These two technical solutions are similar. The helical windings provide good flexibility, but the stents exhibit directional deformation when twisted, making them prone to kinking when twisted in the opposite direction of the helix. Most other patents use a longitudinally parallel arrangement, and therefore 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 morphological comparison of vascular deformation before and after stent implantation under the same movement. This illustrates the insufficient application of existing stents, especially their inability to adapt well to vascular deformation during limb bending, resulting in high stent rupture rates and high restenosis rates in clinical practice.

[0098] Compared with the above content, in the technical solution of the present invention, the rod length of each annular stent ring Z-shaped pattern is different. After being periodically rotated and extended along the axial direction, the stent has good bending flexibility; secondly, and also another core point in the technical solution, the rod lengths of the Z-shaped pattern are different, which can make the stent have eccentric compression deformation characteristics during axial compression. In addition, the annular stent ring composed of the Z-shaped pattern is periodically arranged. Therefore, during axial compression, the stent will show a deformation trend similar to a three-dimensional spiral or S-shaped, which makes the deformation of the stent coordinated with the deformation of the blood vessel, achieving a design similar to that of patent CN101065078B to guide blood flow and reduce stent fracture, but will not cause problems that may exist during compression and release, as well as the challenges of complex tooling preparation.

[0099] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A bracket, characterized in that: It comprises a main body structure, wherein the annular structure comprises a plurality of Z-shaped units, and the plurality of Z-shaped units are connected end to end to form an annular shape, and adjacent annular structures are connected by a plurality of connecting bridges, and the widths of the annular structures when unfolded in plane are different.

2. A bracket according to claim 1, characterized in that: When the annular structures are arranged periodically along the axial direction, there is an angle difference between the circumferential directions of two adjacent annular structures.

3. A bracket according to claim 1, characterized in that: 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.

4. The bracket according to claim 1, wherein: The two ends of the main structure are connected with a first transition section and a second transition section.

5. A bracket according to claim 4, characterized in that: A first developing ring is connected to a side of the first transition section away from the annular structure, and a second developing ring is connected to a side of the second transition section away from the annular structure.

6. A bracket according to claim 4 or 5, characterized in that: The first transition section and the second transition section both include a hollow structure arranged longitudinally in a Z-shape, and the lengths of the sides away from the annular structure are the same.

7. The bracket according to claim 3, wherein: When the connecting bridge is connected to the Z peak and the Z valley, the connecting bridge is a straight line; when the connecting bridge is connected to two Z peaks, the connecting bridge is a curved line.

8. The bracket according to claim 1, wherein: The main structure is provided with a coating, and the coating material includes one or a combination of fluoropolymer, polytetrafluoroethylene, silicone, urethane, polyethylene, and aramid fiber.

9. The bracket according to claim 1, wherein: A drug eluting coating is provided on the main structure.

10. The bracket according to claim 5, wherein: The material of the first developing ring or the second developing ring includes one of gold, platinum, platinum-iridium alloy, platinum-tungsten alloy or a combination thereof.

Images