Iliac vein stent

Abstract

The utility model discloses an iliac vein stent which comprises a plurality of weaving wires, each weaving wire comprises a main body part, a first weaving part and a second weaving part which are integrated, the main body parts extend in the axial direction, and the first weaving parts and the second weaving parts are connected at the two ends, relative to the axial direction, of the main body parts respectively; the first weaving part and the second weaving part extend oppositely until the end parts, far away from the main body part, of the first weaving part and the second weaving part are connected to form a connecting point; wherein all the connecting points are sequentially arranged in the axial direction. According to the iliac vein stent, the connecting points are sequentially arranged in the axial direction, so that the whole stent has good structural integrity, and the wall attaching performance and the supporting capacity of the whole iliac vein stent are improved.

Description

Technical Field

[0001] This utility model relates to the field of interventional medical devices, and in particular to an iliac vein stent. Background Technology

[0002] Iliac vein stenosis can be divided into three stages based on its progression: asymptomatic, venous insufficiency, and deep vein thrombosis (DVT) of the lower extremities. The asymptomatic and venous insufficiency stages are termed non-thrombotic iliac vein lesions, while the DVT stage evolves into thrombotic iliac vein lesions. These are different stages in the progression of iliac vein stenosis. Iliac vein stenting is an effective treatment for iliac vein compression or stenosis.

[0003] Existing iliac vein stents are mainly divided into braided stents and laser-engraved stents. Among them, braided stents are further divided into open-loop braided stents and closed-loop braided stents. Closed-loop braided stents are made of multi-strand alloy wires braided together, with closed loops at both ends. Compared with open-loop braided iliac vein stents, they have much better compliance, and at the same time, they avoid the stent breakage problem caused by the poor flexibility of laser-engraved stents.

[0004] However, existing closed-loop braided scaffolds have problems such as insufficient wall adhesion and support performance, which can lead to easy shrinkage and collapse. Utility Model Content

[0005] An embodiment of this utility model provides an iliac vein stent, which improves the wall adhesion performance and support capacity of the iliac vein stent by sequentially arranging the connection points of the closed-loop braided wires along the axial direction of the iliac vein stent.

[0006] To solve the above-mentioned technical problems, the embodiments of this utility model disclose the following technical solutions:

[0007] An iliac vein stent is provided, the iliac vein stent extending axially, wherein one end of the iliac vein stent about the axial direction is a proximal end and the other end is a distal end, the iliac vein stent comprising:

[0008] Multiple braided filaments, each braided filament comprising an integral body portion, a first braided portion, and a second braided portion, the body portion extending along the axial direction, the first braided portion and the second braided portion being connected at opposite ends of the body portion about the axial direction; the first braided portion and the second braided portion extending toward each other until their ends away from the body portion are connected to form a connection point;

[0009] All the connection points are arranged sequentially along the axial direction.

[0010] In addition to one or more of the features disclosed above, or alternatively, the iliac vein stent further includes a central segment disposed at a central location between the proximal end and the distal end, with the connection point disposed close to the central segment.

[0011] In addition to one or more of the features disclosed above, or as an alternative, the first woven portion has a first end face at the end away from the main body portion, and the second woven fabric has a second end face at the end away from the main body portion, with the first end face and the second end face being parallel to each other.

[0012] In addition to one or more of the features disclosed above, or as an alternative, the first braid and the second braid are welded together via the first end face and the second end face.

[0013] In addition to one or more of the features disclosed above, or as an alternative, the main body, the first braided portion, and the second braided portion extend spirally along the axial direction, with the spiral direction of the first braided portion and the second braided portion being opposite to the spiral direction of the main body.

[0014] In addition to one or more of the features disclosed above, or as an alternative, the main body, the first braided portion, and the second braided portion are woven to form a plurality of mesh openings, the mesh openings including a first mesh opening and a second mesh opening, the first mesh opening being disposed at the proximal end of the iliac vein stent, the second mesh opening being disposed at the distal end of the iliac vein stent, and the diameter of the first mesh opening being smaller than the diameter of the second mesh opening.

[0015] In addition to one or more of the features disclosed above, or as an alternative, the first mesh is quadrilateral in shape, and the acute angle of the first mesh is ∠M, wherein 75°≤∠M≤80°;

[0016] The second mesh is quadrilateral in shape, and the acute angle of the second mesh is ∠N, where 88°≤∠N≤90°.

[0017] In addition to one or more of the features disclosed above, or alternatively, the iliac vein stent includes a proximal segment, a variable-diameter segment, and a distal segment arranged sequentially along the axial direction; the diameters of the proximal segment and the distal segment are uniform, and the radial cross-section of the variable-diameter segment gradually decreases along the axial direction.

[0018] In addition to one or more of the features disclosed above, or alternatively, the diameter of the proximal segment is φ1, wherein 10mm≤φ1≤40mm;

[0019] The diameter of the iliac vein stent in the distal segment is φ2, wherein 2mm≤φ2≤4mm.

[0020] In addition to one or more of the features disclosed above, or alternatively, the iliac vein stent has an axial length of L1, wherein 14mm≤L1≤70mm;

[0021] The length of the variable diameter section in the axial direction is L2, where 2mm≤L2≤10mm.

[0022] One of the above technical solutions has the following advantages or beneficial effects: This application, by sequentially arranging the connection points of the closed-loop braided wires along the axial direction of the iliac vein stent, ensures better overall structural integrity of the stent, improves its overall wall-adherence performance and support capacity, prevents scratching of the inner wall of the sheath when the stent is loaded, reduces friction between the stent and the sheath during stent release, and improves stent release performance. This application, by placing all the connection points of the braided wires in the central segment of the iliac vein stent, ensures good flexibility in the central segment while not affecting the support capacity of the proximal and distal ends of the iliac vein stent, conforming to the physiological and anatomical characteristics of the iliac vein. Attached Figure Description

[0023] The technical solution and other beneficial effects of this utility model will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0024] Figure 1 This is a side view of an iliac vein stent provided according to an embodiment of the present utility model;

[0025] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0026] Figure 3 This is a schematic diagram of the structure of the first mesh near the proximal end of an iliac vein stent according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the second mesh near the distal end of an iliac vein stent according to an embodiment of the present invention;

[0028] In the diagram: 1. Braided yarn; 100. Proximal section; 200. Distal section; 300. Center section; 400. Variable diameter section; 101. Proximal end; 11. First mesh; 102. Distal end; 201. Second mesh; 10. Main body; 20. First braided section; 30. Second braided section; 40. Connection point. Detailed Implementation

[0029] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are merely for explaining the present utility model and are not intended to limit the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" 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, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] Combination Figure 1 and Figure 2 As shown, Figure 1A side view of an iliac vein stent according to an embodiment of the present invention is shown. Figure 2 It shows Figure 1 The enlarged structural diagram at point A shows an embodiment of the iliac vein stent provided in this application. The stent includes multiple closed-loop braided filaments 1, which are woven into a mesh-like structure. The iliac vein stent extends along the axial direction X. One end of the iliac vein stent with respect to the axial direction X is the proximal end 101, and the other end is the distal end 102. The center position between the proximal end 101 and the distal end 102 is the central segment 300. The braided filament 1 has a filamentous structure, including a main body 10, a first braided portion 20, and a second braided portion 30. The main body 10, the first braided portion 20, and the second braided portion 30 are an integral structure. The main body 10 extends spirally along the X-axis. The first braided portion 20 and the second braided portion 30 are connected to the two ends of the main body 10 about the X-axis. After the first braided portion 20 and the main body 10 are wound at the proximal end 101, the first braided portion 20 extends spirally along the X-axis. After the second braided portion 30 and the main body 10 are wound at the distal end 102, the second braided portion 30 extends spirally in the opposite direction of the X-axis. That is, the first braided portion 20 and the second braided portion 30 extend towards each other until they are connected to form a connection point 40, making the braided filament 1 a closed loop structure. It should be noted that in the X-axis direction, the spiral direction of the main body 10 is opposite to that of the first braided portion 20 and the second braided portion 30. Multiple braided filaments 1 are interwoven, and the main body 10 of adjacent braided filaments 1 with the opposite spiral direction of the first braided portion 20 and / or the second braided portion 30 form several mesh-like structures, thereby forming a network-like iliac vein stent.

[0034] Among them, the connection points 40 of all the braided wires 1 are sequentially arranged on the iliac vein stent along the axial direction X. The regular arrangement of the connection points 40 gives the iliac vein stent good structural integrity as a whole, thereby improving the overall support performance and wall adhesion performance of the iliac vein stent.

[0035] It should be noted that in the prior art, the connection points 40 of closed-loop braided iliac vein stents are usually irregularly arranged or all connection points 40 are located at the proximal end 101 or distal end 102 of the iliac vein stent. On the one hand, closed-loop braided iliac vein stents with irregularly arranged connection points 40 may experience uncontrollable retraction or even collapse during implantation. The iliac vein stent of this application has good structural integrity, avoiding problems such as retraction and collapse, and further improving the support performance and wall apposition performance of the iliac vein stent. On the other hand, closed-loop braided iliac vein stents with all connection points 40 located at the proximal end 101 or distal end 102 inevitably have sharp edges or burrs at the connection points 40 due to the limitations of existing processes. During implantation, connection points 40 with sharp edges or burrs are very likely to scratch the wall of the sheath on which the stent is installed or even the inner wall of the iliac vein. Furthermore, the support performance and wall apposition performance of the iliac vein stent at the proximal end 101 or distal end 102 of the connection points 40 are greatly affected and the performance deteriorates. The iliac vein stent of this application has a blunt surface formed by the main body 10 and the first braided part 20 and the second braided part 30 wound around the proximal end 101 or the distal end 102, which avoids the above situation and further improves the support performance and wall adhesion performance of the iliac vein stent.

[0036] Furthermore, all the connection points 40 of the braided wires 1 are located near the central segment 300, which is situated between the proximal end 101 and the distal end 102. This ensures that the iliac vein stent has good flexibility at the central segment 300 without affecting the support capacity of the proximal end 101 and the distal end 102. Veins are characterized by poor elasticity, weak self-support, and a tendency to collapse after dilation. The iliac vein, especially in its central position, is characterized by the absence of external pressure and its physiological curvature. The iliac vein stent of this application has good support capacity at its distal end 102 and proximal end 101, enabling the stent to be stably anchored within the vessel. The flexible central segment 300 is adapted to the shape of the iliac vein in its central position, conforming to the physiological and anatomical characteristics of the iliac vein and resulting in a high long-term patency rate.

[0037] Furthermore, the end face of the first braided portion 20 furthest from the main body 10 is designated as the first end face, and the end face of the second braided portion 30 furthest from the main body 10 is designated as the second end face. The first braided portion 20 and the second braided portion 30 are connected face-to-face through the first end face and the second end face to form a connection point 40, thereby forming a closed-loop structure of the braided filaments 1. The first end face and the second end face are parallel, and the first braided portion 20 and the second braided portion 30 are welded together by welding with a connecting tube. This connection method ensures that the connection point 40 between the first braided portion 20 and the second braided portion 30 has a good connection effect, giving the braided filaments 1 better structural integrity, thereby improving the overall wall adhesion performance and support capacity of the iliac vein stent. Moreover, the surface of the connection point 40 is smooth, preventing the iliac vein stent from scratching the inner wall of the sheath when loaded in the sheath, reducing the friction between the iliac vein stent and the sheath body during stent release, and improving the stent release performance.

[0038] Combination Figure 1 , Figure 3 , Figure 4 As shown, Figure 3 and Figure 4 The diagram illustrates the mesh structure of an iliac vein stent according to an embodiment of the present invention. The iliac vein stent includes a proximal segment 100, a variable-diameter segment 400, and a distal segment 200 arranged sequentially in the axial X direction. The proximal segment 100 is positioned near the proximal end 101, and the distal segment 200 is positioned near the distal end 102. The mesh formed by the braided wires 1 includes a first mesh 11 in the proximal segment 100 and a second mesh 201 in the distal end 200. The braided wires 1 have different braiding densities in the proximal segment 100 and the distal segment 200 of the iliac vein stent, such that the mesh density of the first mesh 11 in the proximal segment 100 is greater than the mesh density of the second mesh 201 in the distal segment 200, and the diameter of the first mesh 11 is smaller than that of the second mesh 201. Because the iliac vein stent is easily subjected to unidirectional external pressure at the proximal end 101, while the distal end 102 is not subjected to external pressure, and runs closely along the pelvis with physiological curvature, the supporting force of the proximal segment 100 with the first mesh 11 having a large mesh density and small diameter is greater than that of the distal segment 200 with the second mesh 201 having a small mesh density and large diameter. This enhances the supporting performance of the proximal segment 100 of the iliac vein stent, effectively supporting the compressed part of the iliac vein. The distal segment 200 of the iliac vein has better wall apposition performance, which allows endothelial cells to quickly cover the stent, reducing the stimulation and inflammatory damage of the stent to the vascular wall.

[0039] Specifically, the first mesh 11 and the second mesh 201 are quadrilaterals formed by the interlacing of braided wires 1. The shape of the first mesh 11 is approximately rhomboid, and the acute angle of the first mesh 11 is ∠M, where 75°≤∠M≤80°; the second mesh 201 is approximately square, and the acute angle of the second mesh 201 is ∠N, where 88°≤∠N≤90°.

[0040] Reference Figure 1 As shown, the iliac vein stent includes a proximal segment 100, a variable-diameter segment 400, and a distal segment 200 sequentially arranged in the axial X direction. The diameter of the proximal segment 100 of the iliac vein stent is larger than the diameter of the distal segment 200. The radial cross-section of the variable-diameter segment 400 of the iliac vein stent gradually decreases in the axial X direction. Based on the physiological and anatomical characteristics of the iliac vein, the diameter of the common iliac vein is larger than that of the external iliac vein. The iliac vein stent with the variable-diameter segment 400 of this application better meets vascular requirements, and the large diameter of the proximal end 101 of the iliac vein stent allows the stent to be better anchored at the opening of the common iliac vein.

[0041] Specifically, the diameter of the proximal segment 100 is φ1, where 10mm ≤ φ1 ≤ 40mm. The diameter of the distal segment 200 is φ2, where 2mm ≤ φ2 ≤ 4mm. The length of the iliac vein stent in the axial X direction is L1, where 14mm ≤ L1 ≤ 70mm. The length of the variable-diameter segment 400 in the axial X direction is L2, where 2mm ≤ L2 ≤ 10mm.

[0042] In this embodiment, the central segment 300 of the iliac vein stent is located on the distal segment 200 of the umbilical vein stent, and all connection points 40 are located on the distal segment 200. In other embodiments, the central segment 300 of the iliac vein stent is located on the proximal segment 100 or the variable-diameter segment 400, and the connection points 40 are located on either the proximal segment 100 or the variable-diameter segment 400. It should be noted that the connection points 40 are located at the central segment 300 of the entire iliac vein stent, rather than at a specific location on the distal segment 200, the variable-diameter segment 400, or the proximal segment 100. The connection points 40 can be located at any one or more of these locations, and no specific limitation is made here.

[0043] Furthermore, the outer surface of the braided filament 1 is coated with a heparin coating, which gives the stent of this application better biocompatibility, reduces the incidence of subacute thrombosis, and reduces bleeding complications caused by the extensive use of anticoagulants.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An iliac vein stent, characterized in that, The iliac vein stent extends along an axial direction (X), with one end of the iliac vein stent about the axial direction (X) being a proximal end and the other end being a distal end. The iliac vein stent includes: Multiple braided filaments, each braided filament comprising an integral body portion, a first braided portion, and a second braided portion, the body portion extending along the axial direction (X), the first braided portion and the second braided portion respectively connecting at both ends of the body portion about the axial direction (X); the first braided portion and the second braided portion extending toward each other until their ends away from the body portion are connected to form a connection point; All of the connection points are arranged sequentially along the axial (X) direction.

2. The iliac vein stent as described in claim 1, characterized in that, The iliac vein stent also includes a central segment located at the center between the proximal end and the distal end, with the connection point located close to the central segment.

3. The iliac vein stent as described in claim 1 or 2, characterized in that, The first braided portion has a first end face at the end away from the main body, and the second braided portion has a second end face at the end away from the main body, with the first end face and the second end face being parallel.

4. The iliac vein stent as described in claim 3, characterized in that, The first braided portion and the second braided portion are welded together via the first end face and the second end face.

5. The iliac vein stent as described in claim 1 or 2, characterized in that, The main body, the first braided portion, and the second braided portion extend spirally along the axial direction (X), and the spiral direction of the first braided portion and the second braided portion is opposite to that of the main body.

6. The iliac vein stent as described in claim 5, characterized in that, The main body, the first braided part, and the second braided part are woven together to form a plurality of mesh holes. The mesh holes include a first mesh hole and a second mesh hole. The first mesh hole is located near the proximal end of the iliac vein stent, and the second mesh hole is located near the distal end of the iliac vein stent. The diameter of the first mesh hole is smaller than the diameter of the second mesh hole.

7. The iliac vein stent as described in claim 6, characterized in that, The first mesh is quadrilateral in shape, and the acute angle of the first mesh is ∠M, wherein 75°≤∠M≤80°; The second mesh is quadrilateral in shape, and the acute angle of the second mesh is ∠N, where 88°≤∠N≤90°.

8. The iliac vein stent as described in claim 1, characterized in that, The iliac vein stent includes a proximal segment, a variable-diameter segment, and a distal segment arranged sequentially along the axial (X) direction; the diameters of the proximal segment and the distal segment are uniform, and the radial cross-section of the variable-diameter segment gradually decreases along the axial (X) direction.

9. The iliac vein stent as described in claim 8, characterized in that, The diameter of the proximal segment is φ1, wherein 10mm≤φ1≤40mm; the diameter of the distal segment of the iliac vein stent is φ2, wherein 2mm≤φ2≤4mm.

10. The iliac vein stent as described in claim 8, characterized in that, The length of the iliac vein stent in the axial (X) direction is L1, wherein 14mm≤L1≤70mm; the length of the variable diameter section in the axial (X) direction is L2, wherein 2mm≤L2≤10mm.

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