Braided structure and medical stent

Abstract

The present application provides a kind of braided structure and medical stent, the braided structure includes: multiple mutually crossing braided thick wires and multiple filaments;The thick wire is overlapped at intersection along the first direction to form the first lap joint, the first direction is perpendicular to the extension direction of the thick wire;Multiple first lap joints along the top end of the first direction define braided top surface, multiple first lap joints along the bottom end of the first direction define braided bottom surface;The filament is overlapped with the thick wire, and the filament is located in the space defined by the braided top surface and the braided bottom surface.Such configuration, the filament is located in the space defined by the braided top surface and the braided bottom surface, so that the space utilization between the thick wires of braided structure increases;At the same time, the radial thickness of the whole braided structure is reduced, and different specifications of matching access instrument can be met.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a braided structure and a medical stent. Background Technology

[0002] Braided stents, as a type of medical stent, are widely used in medical fields such as neurointervention and lower extremity surgery. The braiding process of braided stents is simpler than that of cutting stents, and braided stents can achieve metal coverage rates that cutting stents cannot, thus having unique advantages in the treatment of aneurysms and plaque coverage.

[0003] Dense-mesh stents used in aneurysm treatment need to have a certain metal coverage rate, which can not only block the neck of the aneurysm but also improve the hemodynamics of the target vessel, reduce the impact of blood flow on the aneurysm wall, and have a certain radial support force, with good wall apposition performance. For in situ stenosis lesions, emphasis is placed on the coverage of the stent mesh on the vessel wall plaque to prevent thrombus escape to the distal end and cause poor prognosis. At the same time, the stent still has good flexibility at the tortuous part of the vessel and maintains wall apposition to avoid the formation of blood flow eddies. Meanwhile, strong radial support can resist a certain degree of elastic recoil of the vessel.

[0004] Increasing the metal coverage of the braided stent can improve some physical properties and meet the corresponding clinical needs. However, the problem that comes with this is that the release of harmful metal ions may cause inflammatory reactions. In addition, the increased area of ​​metal material in contact with blood can easily lead to risks such as protein denaturation and platelet aggregation, which increases the probability of postoperative thrombosis.

[0005] Aneurysms and stenosis diseases do not have single performance requirements for stents. They require stents to take into account a certain metal coverage, good flexibility and appropriate radial support, and other mechanical properties. Only the optimal combination of mechanical properties can achieve the best treatment effect.

[0006] In existing technologies, there are braided scaffolds that combine coarse and fine filaments. In these scaffolds, the fine filaments form a dense mesh layer for coverage, while the coarse filaments participate in the braiding structure to maintain its integrity and provide radial support. However, when both coarse and fine filaments are used in the scaffold weaving, it becomes extremely challenging whether the natural and compressed outer contour dimensions meet the specifications of the corresponding access devices. Summary of the Invention

[0007] The purpose of this invention is to provide a braided structure and a medical stent to solve the problem that the outer contour dimensions in the natural and compressed states of a medical stent made of a mixture of coarse and fine filaments cannot meet the specifications of the matching access devices.

[0008] To achieve the above objectives, the present invention provides a weaving structure comprising: multiple thick filaments interwoven with each other and multiple thin filaments;

[0009] The coarse filaments overlap at their intersections along a first direction to form a first overlap node, the first direction being perpendicular to the extension direction of the coarse filaments; a plurality of the first overlap nodes define a woven top surface along the top end of the first direction, and a plurality of the first overlap nodes define a woven bottom surface along the bottom end of the first direction.

[0010] The fine filaments intersect and overlap with the coarse filaments, and the fine filaments are located within the space defined by the top and bottom surfaces of the weave.

[0011] Optionally, the filaments are interwoven.

[0012] Optionally, a segment between two adjacent first overlapping nodes with opposite overlapping sequences of the thick filament is designated as a target segment, and the thin filament overlaps with the target segment to form a second overlapping node.

[0013] Optionally, the diameter of the thick filament is M, the diameter of the thin filament is N, the length of the target segment along its own extension direction is L, and among the two adjacent first overlapping nodes, the first overlapping node where the thick filament containing the target segment is located below the thick filament that intersects it is the target first overlapping node, and the distance between the second overlapping node and the target first overlapping node is D.

[0014] If N+M If D / L > M, then the filament in the second overlapping node is located below the target segment;

[0015] If N+M If D / L≤M, then the filament in the second overlapping node is located above or below the target segment.

[0016] Optionally, the thick wire between two adjacent first overlapping nodes with the same overlapping sequence is a fixed segment;

[0017] When the thick filament in the fixed segment overlaps above the intersecting thick filament, the thin filament in the second overlapping node is located below the fixed segment;

[0018] When the thick filament in the fixed segment overlaps below the intersecting thick filament, the thin filament in the second overlapping node is located above or below the fixed segment.

[0019] Optional, 0.002 inch ≤ M ≤ 0.0095 inch.

[0020] Optional, 0.001 inch ≤ N ≤ 0.003 inch.

[0021] Optionally, the target segment includes an odd number of second overlapping nodes, all of which are evenly spaced on the target segment. The overlapping order of the second overlapping nodes in the middle is not limited, while the overlapping order of the second overlapping nodes on both sides is the same as the overlapping order of the first overlapping nodes adjacent to them.

[0022] Optionally, the target segment includes an even number of second overlapping nodes, all of which are evenly spaced on the target segment, and the overlapping order of the second overlapping nodes is the same as the overlapping order of the adjacent first overlapping nodes.

[0023] To achieve the above objectives, the present invention also provides a medical stent comprising a ring-shaped main body segment, the main body segment being formed by a woven structure as described above.

[0024] Optionally, the medical stent further includes an anticoagulation coating disposed on the outer periphery of the woven structure.

[0025] Optionally, the medical stent may further include auxiliary sections located on both sides of the main body section along its axial direction.

[0026] In summary, the braided structure and medical stent provided by this invention include: multiple interwoven coarse filaments and multiple fine filaments; the coarse filaments overlap at their intersections along a first direction to form first overlap nodes, the first direction being perpendicular to the extension direction of the coarse filaments; the plurality of first overlap nodes define a braided top surface along the top end of the first direction, and the plurality of first overlap nodes define a braided bottom surface along the bottom end of the first direction; the fine filaments intersect and overlap with the coarse filaments, and the fine filaments are located within the space defined by the braided top surface and the braided bottom surface. Compared with existing braided stents, it has the following advantages:

[0027] (1) The braided structure includes multiple interwoven coarse and fine filaments. The coarse filaments are used to enhance the radial support of the medical stent made of the braided structure, improve the opening performance of the stent tip and the overall wall adhesion performance; the fine filaments form a dense mesh layer to cover plaques or guide blood flow.

[0028] (2) Furthermore, the fine filaments are located within the space defined by the top and bottom surfaces of the braid, which maximizes the space utilization between the coarse filaments and minimizes the space ratio outside the coarse filament pressing structure. This reduces the volume of the medical stent in its natural and compressed states, enabling it to be adapted to smaller-sized access devices and improving the passability of the medical stent.

[0029] (3) Furthermore, when the filaments are located within the space defined by the top and bottom surfaces of the braid, the filaments with weaker mechanical strength are less likely to be scratched during the pushing and implantation process, thereby avoiding changes in the braiding pattern, maintaining the integrity and regularity of the scaffold, and also avoiding the possibility of the filaments affecting the pushing process.

[0030] (4) Furthermore, the outer surface of the braided structure is provided with an anticoagulation coating, which can prevent the metal braided wires from coming into direct contact with blood, reduce the release of harmful metal ions, and reduce the formation of thrombi on the surface of medical stents made of braided structures. Attached Figure Description

[0031] Figure 1a This is a cross-sectional structural diagram of the braided structure provided in an embodiment of the present invention;

[0032] Figure 1b This is a cross-sectional schematic diagram of a braided structure in the prior art;

[0033] Figure 2a A schematic diagram of the radial thickness of the braided structure provided in an embodiment of the present invention;

[0034] Figure 2b This is a schematic diagram of the radial thickness of a braided structure in the prior art;

[0035] Figure 3 This is a schematic diagram of the braided structure provided in an embodiment of the present invention;

[0036] Figure 4 A cross-sectional view of the braided structure provided in an embodiment of the present invention;

[0037] Figure 5 A side view of the braided structure provided in an embodiment of the present invention;

[0038] Figure 6a A side view of a braided structure provided in an embodiment of the present invention;

[0039] Figure 6b A front view of a braided structure provided in an embodiment of the present invention;

[0040] Figure 6c This is a schematic diagram of a braided structure provided in an embodiment of the present invention;

[0041] Figure 7a A side view of another braided structure provided in an embodiment of the present invention;

[0042] Figure 7b A front view of another braided structure provided in an embodiment of the present invention;

[0043] Figure 7c A schematic diagram of another weaving structure provided in an embodiment of the present invention;

[0044] Figure 8 This is a schematic diagram of a medical stent provided in an embodiment of the present invention.

[0045] The labels in the accompanying drawings are explained as follows:

[0046] 1-Coarse filament; 2-Fine filament; 3-Target segment; 4-First overlapping node; 5-Second overlapping node; 6-Main segment; 7-Auxiliary segment. Detailed Implementation

[0047] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0048] As used herein, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature. “One end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, including not only endpoints. “Proximal end” generally represents the direction closer to the surgeon during surgery, and “distal end” generally represents the direction closer to the lesion during surgery. The terms “installed,” “connected,” and “joined” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral part; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components or an interaction between two components. Furthermore, as used in this specification, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element. It should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to the side of another element, unless otherwise explicitly stated. The terms "above," "below," "top," and "bottom" generally refer to relative positional relationships arranged according to the direction of gravity; the terms "vertical" or "vertical direction" generally refer to the direction of gravity, which is generally perpendicular to the ground; "horizontal" or "horizontal plane direction" generally refers to a direction parallel to the ground. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0049] The purpose of this invention is to provide a braided structure and a medical stent to solve the problem that the outer contour dimensions in the natural and compressed states of a medical stent made of a mixture of coarse and fine filaments cannot meet the specifications of the matching access devices.

[0050] The inventor discovered that, Figure 1b and Figure 2b In the schematic diagram of the existing braided structure shown, the fine filaments can be located above the top surface of the braid or below the bottom surface. This not only reduces the space utilization between the coarse filaments but also causes the fine filaments to cover the space outside the coarse filament pressing structure, resulting in an increase in the radial thickness of the braided structure, which cannot meet the needs of smaller access devices. Figure 2a and Figure 2bIn the illustrated example, the radial thickness of the braided structure is H, while the radial thickness of the braided structure in the prior art is S, satisfying H < S.

[0051] Based on the above research, the present invention provides a weaving structure, comprising: multiple interwoven coarse filaments 1 and multiple fine filaments 2; the coarse filaments 1 overlap at their intersections along a first direction to form a first overlap node 4, the first direction being perpendicular to the extension direction of the coarse filaments 1. Specifically, in any one first overlap node 4, the first direction is perpendicular to the extension directions of the two coarse filaments 1 forming the first overlap node 4; the plurality of first overlap nodes 4 define a weaving top surface along the top end of the first direction, and the plurality of first overlap nodes 4 define a weaving bottom surface along the bottom end of the first direction; the fine filaments 2 intersect and overlap with the coarse filaments 1, and the fine filaments 2 are located within the space defined by the weaving top surface and the weaving bottom surface. In some embodiments, multiple filaments 2 can be interwoven to form a mesh structure; in other embodiments, the multiple filaments 2 do not interweave but are arranged in parallel; in still other embodiments, the multiple filaments 2 intersect, but all the same filament 2 are located in the same direction as the intersecting filaments 2, for example, one filament 2 is located above or below all the intersecting filaments 2, that is, the multiple filaments 2 intersect but do not form a woven structure. It should be noted that in Figure 1a and Figure 2a In the illustrated example, the top surface is a weaving surface formed by the intersection of thick filaments 1 at the top along the first direction, and the bottom surface is a weaving surface formed by the intersection of thick filaments 1 at the bottom along the first direction. The top and bottom surfaces can be planar, curved, or irregular surfaces with concavity and convexity. The first direction is the radial direction of the thick filaments 1 at the first overlapping node 4. In other embodiments, the top and bottom surfaces may change due to the influence of placement position and angle. Those skilled in the art will understand that the top surface is the weaving surface at the top along the first direction among all the weaving surfaces formed by thick filaments 1 in the current position state; the bottom surface is the weaving surface at the bottom along the first direction among all the weaving surfaces formed by thick filaments 1 in the current position state. At the same time, the first direction can also be other reasonable directions. Those skilled in the art can configure the top surface, bottom surface, and first direction according to the actual situation, and the present invention is not limited thereto. Furthermore, it should be noted that multiple coarse filaments 1 and multiple fine filaments 2 refer to the presence of multiple ends of coarse filaments 1 and fine filaments 2 on the cross-section of the braided structure. This can be achieved by simultaneously weaving multiple coarse filaments 1 and multiple fine filaments 2, or by having a back-knitting structure to form multiple ends on the cross-section. In extreme cases, the braided structure of the present invention can be formed by back-knitting a single coarse filament 1 and a single fine filament 2.

[0052] Taking a braided stent used in blood vessels as an example, this type of stent is typically tubular in shape, with a circular cross-section. In this shape, the top and bottom braided surfaces are curved. Ideally, the top and bottom braided surfaces are cylindrical throughout the stent structure, with the top braided surface located on the outer surface and the bottom braided surface on the inner surface. The diameter of the cylinder formed by the top braided surface is larger than the diameter of the cylinder formed by the bottom braided surface. However, due to limitations in manufacturing processes, a perfectly regular braided structure is usually not achievable, resulting in irregularities such as unevenness on the top and bottom braided surfaces. Furthermore, in a tubular stent structure with a circular cross-section, the first direction is parallel to the radial direction of the stent. Of course, this invention does not limit the structure in which the braided structure is located. The braided structure of this invention can be used for tubular structures, as well as planar, spherical, ellipsoidal, cylindrical, and other structures.

[0053] This configuration, with its braided structure comprising multiple interwoven coarse filaments 1 and multiple interwoven fine filaments 2, enhances the radial support of the medical stent made of the braided structure, improving the stent's tip opening performance and overall wall apposition performance. The dense mesh layer formed by the fine filaments 2 covers plaque, reducing the probability of plaque escaping from stenotic sites to distal vessels and causing embolism. It also guides blood flow. In aneurysm disease, after implantation into the affected diseased artery, it alters the hemodynamics within the aneurysm, alleviating... The thrombus slowly forms within the aneurysm, allowing the intimal epithelium to climb onto the surface of the medical stent, thereby repairing the diseased vessel and inducing vascular remodeling to repair the diseased parent artery. Furthermore, the fine filament 2 is located within the space defined by the top and bottom surfaces of the braid, maximizing the space utilization between the thicker filaments 1 and minimizing the space occupied by the fine filament 2 outside the pressure structure of the thicker filaments 1. This reduces the volume of the medical stent in both its natural and compressed states, allowing it to accommodate smaller access devices and improving its permeability. Simultaneously, when the fine filament 2 is located within the space defined by the top and bottom surfaces of the braid, its weaker mechanical strength makes it less prone to abrasion during delivery and implantation, thus preventing changes in the braid pattern, maintaining the integrity and regularity of the stent, and avoiding the possibility of the fine filament 2 interfering with delivery.

[0054] Please refer to Figure 3 A segment of the thick filament 1 between two adjacent first overlapping nodes 4 with opposite overlapping sequences is designated as target segment 3. The thin filament 2 overlaps with the target segment 3 to form a second overlapping node 5. It should be noted that the target segment 3 is the segment located between two first overlapping nodes 4 with opposite overlapping sequences, but this does not mean that all adjacent first overlapping nodes 4 have opposite overlapping sequences. Figure 3In the illustrated embodiment, the overlapping order of all adjacent first overlapping nodes is reversed; however, in other embodiments, adjacent first overlapping nodes 4 may have the same overlapping order. The thick filament 1 between adjacent first overlapping nodes 4 with the same overlapping order is called a fixed segment. When the thick filament 1 containing the fixed segment is above the thick filament 1 intersecting with it, the thin filament 2 can only be located below the fixed segment; when the thick filament 1 containing the fixed segment is below the thick filament 1 intersecting with it, the thin filament 2 can be located above or below the fixed segment. Furthermore, it should be noted that the overlapping order refers to the relative positional relationship of the two overlapping wires. Taking the overlapping of thick wire 1 and thin wire 2 as an example, the overlapping order of thick wire 1 can be below or above thin wire 2. The overlapping order between thick wires 1 can be based on the target segment 2 or the fixed segment. The thick wire 1 containing the target segment 2 or the fixed segment can be above or below the thick wire 1 it intersects with. Figure 3 In the example shown, the connections between coarse filament 1, between coarse filament 1 and fine filament 2, and between fine filament 2 are all one-press-one-weave structures (e.g., Figures 4 to 5 As shown), if the same thick filament 1 overlaps another thick filament 1 at a certain first overlap node 4, then it overlaps another thick filament 1 at an adjacent first overlap node 4. As those skilled in the art will understand, in some embodiments, the weaving structure of the filaments is different, and the overlapping order of two adjacent first overlap nodes 4 can also be the same. Those skilled in the art can configure the overlapping order of the first overlap nodes 4 according to the weaving structure, and the present invention is not limited to this.

[0055] Furthermore, the diameter of the thick filament 1 is M, the diameter of the thin filament 2 is N, the length of the target segment 3 along its own extension direction is L, and among the two adjacent first overlapping nodes 4, the first overlapping node 4 where the target segment 3 is located is below the thick filament 1 that intersects it is the target first overlapping node, and the distance between the second overlapping node 5 and the target first overlapping node is D; if N+M If D / L > M, then the filament 2 in the second overlapping node 5 is located below the target segment 3; if N+M If D / L≤M, then the filament 2 in the second overlapping node 5 is located above or below the target segment 3. It should be noted that... Figure 3 For example, thick wire 1 overlaps with another thick wire 1 at the first overlap node A, meaning the first overlap node A is the target first overlap node. If the second overlap node 5 satisfies N+M... If D / L > M, then the thinner filament 2 overlaps under the thicker filament 1 at that point; if the second overlap node 5 satisfies N+M If D / L ≤ M, then the thinner filament 2 can overlap either above or below the thicker filament 1. Of course, in other embodiments, the method for determining the overlap order can be other reasonable methods, and those skilled in the art can configure it according to actual conditions; this invention is not limited in this regard. As an optional embodiment, 0.002 inch ≤ M ≤ 0.0095 inch; 0.001 inch ≤ N ≤ 0.003 inch. In other embodiments, the diameters of the thicker filament 1 and the thinner filament 2 can also be other reasonable values, and those skilled in the art can flexibly configure the diameters of the thicker filament 1 and the thinner filament 2 according to actual conditions.

[0056] Please refer to Figures 6a to 6c In an optional embodiment, the target segment 3 includes an odd number of second overlapping nodes 5. All second overlapping nodes 5 are evenly spaced on the target segment 3. The overlapping order of the middle second overlapping nodes 5 is not limited, while the overlapping order of the second overlapping nodes 5 on both sides is the same as the overlapping order of their adjacent first overlapping nodes 4 (the same overlapping order applies to the target segment 3; the same overlapping order means that the thick filament 1 of the target segment 3 is simultaneously located above or below the intersecting filament). Figure 6c For example, a thick filament 1 overlaps with another thick filament 1 at the first overlap node A1, and overlaps with another thick filament 1 below at the adjacent first overlap node A2. Then, at the second overlap node 5 near the first overlap node A1, the thick filament 1 overlaps with the thin filament 2. At the second overlap node 5 near the first overlap node A2, the thick filament 1 overlaps with the thin filament 2. At the second overlap node 5 located in the middle, the thick filament 1 can overlap with the thin filament 2 or it can overlap with the thin filament 2. In some other embodiments, the overlapping order of the second overlap node 5 is different due to the influence of the weaving structure, and the present invention is not limited to this.

[0057] For further information, please refer to the following: Figures 6a to 6c The target segment 3 includes n second overlapping nodes 5, where n1 second overlapping nodes 5 are close to the first overlapping node A1, n2 second overlapping nodes 5 are close to the first overlapping node A2, and one second overlapping node 5 is located in the middle position between the first overlapping node A1 and the first overlapping node A2, thus satisfying n = n1 + n2 + 1. In other embodiments, the number of second overlapping nodes 5 can also be calculated by other reasonable relationships, and the present invention is not limited to this.

[0058] Furthermore, the diameter of the coarse filament 1 is M, the diameter of the fine filament 2 is N, the length of the target segment 3 along its own extension direction is L, the target segment 3 includes an odd number of second overlapping nodes 5, the overlapping order of the second overlapping nodes 5 located in the middle is not limited, and the second overlapping node 5 and the target first overlapping node 4 ( Figure 6c The distance between A2 and M+N+M is D; If D / L > 2M, then the overlapping sequence of the second overlapping node 5 is such that filament 2 is located below the target segment 3; if M+N+M If D / L≤2M, then the overlapping order of the second overlapping node 5 is not limited. Figure 6c For example, thick wire 1 overlaps with another thick wire 1 at the first overlap node A1, and overlaps with another thick wire 1 below at the adjacent first overlap node A2. First overlap segment A2 is the target first overlap node. Then, if M+N+M is satisfied... D / L > 2M, the aforementioned coarse filament 1 overlaps with the fine filament 2 at the second overlapping node 5; if M+N+M is satisfied... For a diameter (D / L) of ≤2M, the overlapping order of the coarse filament 1 at the second overlapping node 5 within the target segment 3 is not limited; it can overlap above or below the fine filament 2. Of course, in other embodiments, the method for determining the overlapping order can also be other reasonable methods, and those skilled in the art can configure it according to the actual situation; this invention is not limited in this regard.

[0059] Please refer to Figures 7a to 7c The target segment 3 includes an even number of second overlapping nodes 5, all of which are evenly spaced on the target segment 3, and the overlapping order of the second overlapping nodes 5 is the same as the overlapping order of their adjacent first overlapping nodes 4. Figure 7c For example, thick filament 1 overlaps under another thick filament 1 at the first overlap node A3, and overlaps above another thick filament 1 at the adjacent first overlap node A4. Then, at the second overlap node 5 near the first overlap node A3, the aforementioned thick filament 1 overlaps under the thin filament 2, and at the second overlap node 5 near the first overlap node A4, the aforementioned thick filament 1 overlaps above the thin filament 2. In other embodiments, the overlap order of the second overlap node 5 is different due to the influence of the weaving structure, and the present invention is not limited to this.

[0060] For further information, please refer to the following: Figures 7a to 7c The target segment 3 includes n second overlapping nodes 5, wherein n3 second overlapping nodes 5 are close to the first overlapping node A3, and n4 second overlapping nodes 5 are close to the first overlapping node A4, thus satisfying n = n3 + n4. In other embodiments, the number of second overlapping nodes 5 can also be calculated by other reasonable relationships, and the present invention is not limited to this.

[0061] Furthermore, the diameter of the coarse filament 1 is M, the diameter of the fine filament 2 is N, the length of the target segment 3 along its own extending direction is L, and the target segment 3 includes an even number of second overlapping nodes 5, the second overlapping nodes 5 and the target first overlapping node (in Figure 7c The distance between the first overlapping node of the target (A3) and the target (N+M) is D; If D / L > M, then the overlapping order of the second overlapping node 5 is that the filament 2 is located below the target segment 3; if N+M If D / L≤M, then the overlapping order of the second overlapping node 5 is not limited. Figure 7c For example, thick wire 1 overlaps with another thick wire 1 at the first overlap node A3, and overlaps with another thick wire 1 at the adjacent first overlap node A4. The target first overlap node is A3. If N+M is satisfied... D, / L>M, the aforementioned coarse filament 1 overlaps with the fine filament 2 at the second overlapping node 5; if N+M is satisfied... When D / L≤M, the overlapping order of the coarse filament 1 at the second overlapping node 5 within the target segment 3 is not limited; it can overlap above or below the fine filament 2. Of course, in other embodiments, the method for determining the overlapping order can also be other reasonable methods, and those skilled in the art can configure it according to the actual situation; this invention is not limited in this respect.

[0062] Please refer to Figure 8 The present invention also provides a medical stent, comprising a ring-shaped main body segment 6, which is formed by a braided structure as described above. Further, the medical stent also includes auxiliary segments 7 located on both axial sides of the main body segment 6. For example, the auxiliary segments 7 can be a double-layer structure: the inner layer is woven with fine filaments 2, and the outer layer with coarse filaments 1; or the inner layer is woven with coarse filaments 1, and the outer layer with fine filaments 2. The double-layer structure of the auxiliary segments 7 can improve the radial support force at both ends of the stent, preventing displacement after implantation. Simultaneously, when the inner layer of the auxiliary segments 7 is woven with fine filaments 2 and the outer layer with coarse filaments 1, it can prevent the exposure of the fine filaments 2 at the tip during stent insertion, reducing the difficulty of insertion. Optionally, in some embodiments, the medical stent may be entirely formed by a braided structure; optionally, in some embodiments, a portion of the main body segment 6 of the medical stent is formed by the braided structure as described above, while the braided structure of other portions is not limited; optionally, in some embodiments, both ends of the medical stent are formed by the braided structure as described above, while the braided structure of the middle portion is not limited; those skilled in the art can configure it according to actual conditions, and the present invention is not limited thereto.

[0063] In a preferred embodiment, the medical stent further includes an anticoagulant coating disposed on the outer periphery of the braided structure. This configuration, with the anticoagulant coating on the outer surface of the braided structure, prevents direct contact between the metal braids and blood, reduces the release of harmful metal ions, and decreases the formation of thrombi on the surface of the medical stent made of the braided structure, further improving the safety and practicality of the medical stent. Optionally, the anticoagulant coating can be a coating of natural anticoagulants such as heparin to inhibit the formation of prothrombin kinase; the anticoagulant coating can also be a polymer coating such as phosphorycholine biocompatible polymer (PC) or a biomimetic coating to reduce the probability of thrombus formation caused by protein aggregation. Those skilled in the art can configure the anticoagulant coating according to the specific application of the medical stent, and this invention is not limited thereto.

[0064] In summary, in the braided structure and medical stent provided in the embodiments of the present invention, the braided structure includes: multiple interwoven coarse filaments and multiple fine filaments; the coarse filaments overlap at their intersections along a first direction to form a first overlap node, the first direction being perpendicular to the extension direction of the coarse filaments; the multiple first overlap nodes define a braided top surface along the top end of the first direction, and the multiple first overlap nodes define a braided bottom surface along the bottom end of the first direction; the fine filaments intersect and overlap with the coarse filaments, and the fine filaments are located within the space defined by the braided top surface and the braided bottom surface.

[0065] This configuration involves a braided structure comprising multiple interwoven coarse filaments and multiple interwoven fine filaments. The coarse filaments enhance the radial support of the medical stent made from the braided structure, improving the opening performance of the stent tip and its overall apposition performance. The dense mesh layer formed by the fine filaments covers plaques or guides blood flow. Furthermore, the fine filaments are located within the space defined by the top and bottom surfaces of the braid, maximizing the space utilization between the coarse filaments and minimizing the space occupied by the fine filaments outside the coarse filament pressure structure. This reduces the volume of the medical stent made from the braided structure in both its natural and compressed states. This design allows for the adaptation to smaller-sized access devices, improving the permeability of medical stents. Furthermore, when the filaments are located within the space defined by the top and bottom surfaces of the braid, the weaker filaments are less prone to abrasion during delivery and implantation, thus preventing changes in the braid pattern, maintaining the integrity and regularity of the stent, and avoiding the possibility of filaments affecting delivery. Additionally, the outer surface of the braid structure is coated with an anticoagulant coating, which prevents direct contact between the metal braids and blood, reduces the release of harmful metal ions, and decreases the formation of thrombi on the surface of medical stents made of the braid structure.

[0066] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A braided structure, characterized in that, include: Multiple thick filaments and multiple thin filaments interwoven with each other; The coarse filaments overlap at their intersections along a first direction to form a first overlap node, the first direction being perpendicular to the extension direction of the coarse filaments; a plurality of the first overlap nodes define a woven top surface along the top end of the first direction, and a plurality of the first overlap nodes define a woven bottom surface along the bottom end of the first direction. The fine filaments intersect and overlap with the coarse filaments, and the fine filaments are located within the space defined by the top surface and the bottom surface of the weave; A segment between two adjacent first overlapping nodes with opposite overlapping sequences of the thick filament is a target segment. The thin filament overlaps with the target segment to form a second overlapping node. The diameter of the thick filament is M, the diameter of the thin filament is N, and the length of the target segment along its own extension direction is L. Among the two adjacent first overlapping nodes, the first overlapping node where the thick filament containing the target segment is located below the thick filament that intersects it is the target first overlapping node. The distance between the second overlapping node and the target first overlapping node is D. If N+M If D / L > M, then the filament in the second overlapping node is located below the target segment; If N+M If D / L≤M, then the filament in the second overlapping node is located above or below the target segment.

2. The braided structure as described in claim 1, characterized in that, The filaments are interwoven with each other.

3. The braided structure as described in claim 1, characterized in that, The thick filament between two adjacent first overlapping nodes with the same overlapping sequence is a fixed segment, and the thin filament overlaps with the fixed segment to form a second overlapping node; When the thick filament in the fixed segment overlaps above the intersecting thick filament, the thin filament in the second overlapping node is located below the fixed segment; When the thick filament in the fixed segment overlaps below the intersecting thick filament, the thin filament in the second overlapping node is located above or below the fixed segment.

4. The braided structure as described in claim 1, characterized in that, 0.002 inch ≤ M ≤ 0.0095 inch.

5. The braided structure as described in claim 1, characterized in that, 0.001 inch ≤ N ≤ 0.003 inch.

6. The braided structure as described in claim 1, characterized in that, The target segment includes an odd number of second overlapping nodes. All the second overlapping nodes are evenly spaced on the target segment. The overlapping order of the second overlapping nodes in the middle is not limited, and the overlapping order of the second overlapping nodes on both sides is the same as the overlapping order of the first overlapping nodes that are close to them.

7. The braided structure as described in claim 1, characterized in that, The target segment includes an even number of second overlapping nodes, all of which are evenly spaced on the target segment, and the overlapping order of the second overlapping nodes is the same as the overlapping order of the adjacent first overlapping nodes.

8. A medical stent, characterized in that, It includes a ring-shaped main body segment, which is formed by a woven structure as described in any one of claims 1 to 7.

9. The medical stent as described in claim 8, characterized in that, The medical stent also includes an anticoagulation coating, which is disposed on the outer periphery of the woven structure.

10. The medical stent as described in claim 8, characterized in that, The medical stent also includes auxiliary sections located on both sides of the main body section along its axial direction.

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