Woven intravascular stent

Abstract

The invention belongs to the technical field of medical instruments, and relates to a woven intravascular stent which is of a tubular woven structure and comprises first woven filaments arranged in the first direction and second woven filaments arranged in the second direction. The first weaving filaments and the second weaving filaments are woven to form an upper and lower interwoven weaving structure, and are further woven to form a double-interwoven weaving structure and / or a three-interwoven weaving structure; interlacing points in the one-up and one-down interlacing weaving structure are marked as general interlacing points, and interlacing points in the double-interlacing weaving structure and the three-interlacing weaving structure are marked as special interlacing points; all the special interweaving points are arranged in a spiral line mode, and every two adjacent special interweaving points are spaced by at least three rows of interweaving points in the axial direction and spaced by at least one column of interweaving points in the circumferential direction. When the woven intravascular stent is axially compressed, the axial compression degree of the special interweaving points is smaller than the reduction distance of the interval of the common interweaving points, so that the stent forms a three-dimensional spiral form, fluid passing through a lumen generates spiral laminar flow, and the patency rate is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and relates to a braided vascular stent. Background Art

[0002] Lower extremity arteriosclerosis obliterans, especially lesions involving the femoropopliteal artery, is a serious vascular disease that often leads to intermittent claudication, rest pain, and even limb ischemia and necrosis, seriously affecting the patient's quality of life. For this disease, current treatments mainly include medication, exercise, endovascular treatment, and open surgery. Among them, endovascular treatment is often used as the preferred option because of its characteristics of less trauma, faster recovery, and fewer complications. In particular, endovascular treatment is recommended in cases where the quality of life is severely affected by intermittent claudication, medication and exercise therapy are ineffective, there are multiple underlying diseases, or open surgery is not suitable.

[0003] As an important tool for endovascular treatment, the femoral-popliteal artery stent has been widely used in clinical practice due to its significant effect of long-term lumen support. However, traditional stents cannot form a three-dimensional spiral shape when dealing with the three-dimensional spiral shape changes of the femoral-popliteal artery during daily activities such as walking, sitting, and squatting, which limits the natural deformation of the blood vessel, affects hemodynamics, and may cause damage to the blood vessel wall due to high stress concentration, thereby causing intimal thickening, lumen stenosis, and reduced blood perfusion, ultimately threatening limb health.

[0004] In addition, spiral laminar flow, as a natural physiological phenomenon of the blood circulation system, is essential for maintaining vascular health. It promotes the effective delivery of oxygen and nutrients, inhibits the accumulation of harmful substances, helps protect endothelial function, and prevents thrombosis and restenosis of arteriosclerosis. Therefore, it is particularly important to consider the restoration of spiral laminar flow in stent design.

[0005] In order to overcome the limitations of traditional stents, current femoropopliteal artery stents are usually prepared by laser cutting or weaving to produce a three-dimensional spiral structure stent that can conform to the physiological spiral morphology of the femoropopliteal artery.

[0006] Laser cutting refers to the use of laser cutting to shape hollow tubes. The stent structure design usually includes two parts, the annular support unit and the bridge ribs that axially connect the support units. When the longitudinal dimensions of the annular support unit change circumferentially around the annular element, or the axial bridge ribs are circumferentially offset from the previous bridge ribs, the axial shape of the stent will produce three-dimensional bending when the stent is subjected to an extrusion load in the axial direction, presenting a spiral shape. For example, the stent prepared in patent US11839558B2 is a straight tube type when not under force, and only becomes spiral when subjected to axial force. When the bridge rib structure is in a special shape in the axial direction, such as a spiral, it is expected to improve flexibility and guide the blood flow in the stent to flow in a spiral shape, thereby achieving the purpose of changing the blood flow state. For example, the stent prepared in patent CN106880429B contains laser-cut spiral bridge ribs. While improving flexibility, it also allows the prepared stent to guide the blood flow in the stent to flow in a spiral shape when it is not deformed by force.

[0007] However, the laser-cut stent is fixedly connected as a whole. When deformed by force, stress concentration will occur in the bending area of ​​the support unit and the junction between the bridge rib and the support unit, which has a high risk of fatigue fracture. In addition, the large number of sharp angles in the laser-cut stent structure will cause the "crocodile back" phenomenon when axially bent, that is, there are sharp protrusions on the surface of the stent, which stimulate the blood vessel wall, and then the vascular intimal hyperplasia occurs, causing restenosis in the stent. For example, patent application CN101065078B discloses a stent, the basic geometric shape of which is cut from a tube by laser, processed by electric discharge milling (EDM), chemical etching or other known methods. However, the non-planar curve in the patent is realized by relying on the fixed connection between the bridge rib and the support unit. However, the number and shape of this fixed connection affect the deformation capacity of the stent under biomechanics, and the stress concentration at this position makes it easy to cause fatigue fracture.

[0008] The braiding method is usually a vascular stent forming method based on wire materials and interweaving and winding along the length of the stent. This method generally uses two-way wires, interweaving up and down, and spirally winding along the length of the stent. When the stent is deformed by force, slippage and bending of the wires occur between the braided stent wires. Between the interweaving points, the wires will be subject to friction and bending deformation forces caused by pressure between the wires. Since each braided wire is of uniform thickness, has no weak nodes, and its length runs through the entire stent tube, stress can be transmitted along the length when it occurs and disperse the stress, so that the stress can be more evenly distributed on the stent, and the risk of fracture is lower than that of laser-cut stents. The stent has good axial flexibility, a smooth surface and is not easy to bend. In terms of structural design, the literature (Shape-Setting of Self-Expanding Nickel-Titanium Laser-Cut and Wire-Braided Stents to Introduce a Helical Ridge, Cardiovascular Engineering and Technology, (2024).) has disclosed the introduction of a concave spiral ridge on the basis of a circular lumen. After braiding, the cylindrical braided tube is placed in a special mold for heat setting to form a stent structure with an axially embedded three-dimensional spiral. However, the concave ridge of the stent cannot support the narrow lumen, causing the tube wall to prolapse (the cross section of the stent is concave into the lumen at the concave ridge, the radius of the stent tube at the concave part is small, the extrusion and support of the tube wall are small, and the tube wall prolapses under a small support force), reducing the patency rate.

[0009] Currently commonly used braided stents include Suprea and InnoSpring. When axial compression is performed on these two stents, the stents have a cylindrical tubular structure and will not cause flow interference to the passing fluid. A three-dimensional spiral will only appear when twisted.

[0010] Therefore, it is of great significance to study a braided vascular stent to solve the above problems. Summary of the invention

[0011] The purpose of the present invention is to solve the problems existing in the prior art and provide a braided blood vessel stent.

[0012] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0013] A braided vascular stent is a tubular braided structure, comprising more than 6 first braided wires arranged along a first direction and more than 6 second braided wires arranged along a second direction; the number of the braided wires is 12+2x, where x is 0 or a positive integer;

[0014] The first braided wire and the second braided wire are braided to form an upper-lower interlaced braided structure, and further braided to form a double interlaced braided structure and / or a triple interlaced braided structure;

[0015] The one-up-and-one-down interlaced braiding structure means that a first braided wire and a second braided wire are interlaced only once;

[0016] The double interlaced braided structure means that a first braided wire and a second braided wire are interlaced twice;

[0017] The three-interlaced braided structure means that a first braided wire and a second braided wire are interlaced three times;

[0018] The interweaving points in the one-up-and-one-down interweaving braiding structure are recorded as general interweaving points, and the interweaving points in the double interweaving braiding structure and the triple interweaving braiding structure are recorded as special interweaving points;

[0019] All the special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by at least three rows of interweaving points in the axial direction and at least one column of interweaving points in the circumferential direction.

[0020] As the preferred technical solution:

[0021] In the braided vascular stent as described above, the number of the first braided wires and the number of the second braided wires are the same.

[0022] In the braided vascular stent as described above, the angle between the helix and the axial direction is the helix angle, and the helix angle ranges from 5° to 60°. The same stent may have a helix angle greater than or equal to 1, and the helix angle may be changed gradually or segmentally.

[0023] In the braided vascular stent as described above, the angle between the first braided wire and the second braided wire interweaving one above and one below is in the range of 60° to 160°, and the braiding angle between the first braided wire and the second braided wire interweaving one above and one below (the angle between the braided wire and the axis of the braided vascular stent is the braiding angle) is in the range of 30° to 80°. The same stent can have more than or equal to one braiding angle, and the braiding angle change mode is gradual or segmental change.

[0024] In the braided vascular stent as described above, the material of the braided wire can be degradable or non-degradable metal, polymer or a mixed combination thereof, such as nickel-titanium alloy, cobalt-chromium alloy, medical stainless steel, tantalum metal, nickel-titanium alloy containing tantalum or platinum core, degradable magnesium and its alloys, degradable zinc and its alloys, degradable iron and its alloys, polycaprolactone (PCL), polylactic acid (PLA) or polydioxanone (PPDO).

[0025] In the braided vascular stent as described above, the cross-sectional shape of each braided wire is circular, square, elliptical or trapezoidal.

[0026] In the braided vascular stent as described above, the distance between the farthest two points in the cross section of each braided wire is 20 to 500 μm.

[0027] The braided vascular stent as described above has an outer diameter of 3 to 8 mm (when the cross-section of each braided wire is square, elliptical or trapezoidal, the outer diameter is the maximum outer diameter of the braided vascular stent) and a length of 50 to 300 mm.

[0028] The braided vascular stent described above, when subjected to axial compression, will become a spiral shape, the pitch of the spiral is 14 to 33 mm, 1.05

[0029] Principle of the invention:

[0030] When the braided vascular stent of the present invention is subjected to axial compression, the interwoven braided structure of the stent body causes the interwoven wires to slip and rotate perpendicular to the axial direction, such as Figure 2 As shown, the distance h between axially adjacent interlacing points decreases and the braiding angle increases. The structure of the special interlacing points limits the slippage and rotation between the interlaced wires. When the stent is axially compressed, the wires that make up the special interlacing points are bent by force. Under the action of material stiffness, the degree of axial compression of the special interlacing points is less than the reduced distance of the general interlacing point spacing. The axial morphology of the stent follows the three-dimensional spiral morphology of the non-planar curve that is the same as the arrangement morphology of the special interlacing points, thereby inducing spiral laminar flow in the fluid passing through the lumen. The braided vascular stent of the prior art is a cylindrical tubular structure, and all the general interlacing points are in the structure. When the stent is axially compressed, the interlaced wires are subjected to the same force, and the distance h between all axially adjacent interlacing points decreases by the same amount, so the stent remains a cylindrical tubular structure after axial compression. This cylindrical tube structure will not cause flow interference to the passing fluid.

[0031] Beneficial effects:

[0032] (1) When the braided vascular stent of the present invention is subjected to axial compression, the slippage and rotation between the interwoven wires are limited by the special interweaving point structure. Under the action of material stiffness, the axial compression degree of the special interweaving points is less than the reduced distance of the general interweaving point spacing. The axial shape of the stent follows the three-dimensional spiral shape of the non-planar curve that is the same as the arrangement shape of the special interweaving points, thereby inducing the fluid passing through the lumen to generate spiral laminar flow, so that the patency rate is higher;

[0033] (2) The present invention adopts a weaving method to prepare a vascular stent, thereby avoiding the risks of using a laser to cut the stent. In addition, the stent woven by the weaving method has good axial flexibility, a smooth surface and is not easy to bend. BRIEF DESCRIPTION OF THE DRAWINGS ​

[0034] Figure 1 A schematic diagram of the braiding direction and braiding angle of the braided vascular stent of the present invention;

[0035] Figure 2 Schematic diagram of the distance h between axially adjacent interlacing points on the braided vascular stent of the present invention;

[0036] Figure 3 It is a data curve diagram of the three-point bending test of the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2;

[0037] Figure 4 The actual pictures are of the bending shapes of the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 when the presser foot is lowered by 8.08 mm;

[0038] Figure 5 The actual deformation diagram of the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 when subjected to a torsion test after being axially compressed by 25%;

[0039] Figure 6 The data curve diagram of the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 when subjected to a torsion test after being axially compressed by 25%;

[0040] Figure 7 Schematic diagrams of the side expansion of the present invention respectively arranged by three kinds of special interlacing points and general interlacing points and a schematic diagram of the side expansion of the arrangement of only general interlacing points; in the figure, a is a schematic diagram of the arrangement of special interlacing points in Example 1 and Example 4, b is a schematic diagram of the arrangement of special interlacing points in Example 2 and Example 5, c is a schematic diagram of the arrangement of special interlacing points in Example 3 and Example 6, and d is a schematic diagram of the arrangement of general interlacing points in Comparative Example 1 and Comparative Example 2;

[0041] Figure 8 The physical pictures of the distribution of special interlacing points and general interlacing points on the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 under an optical microscope;

[0042] Fig. 9 This is a schematic diagram of the three-dimensional spiral shape of the braided vascular stent of the present invention when it is axially compressed;

[0043] Fig.10 Schematic diagram of the three-dimensional curvature of the braided vascular stent of the present invention; in the figure, P is the pitch of the helical line on the helical braided vascular stent;

[0044] Fig.11 The actual pictures are of the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 when the axial compression is 25%;

[0045] Fig.12 The actual picture shows that the braided vascular stents prepared in Examples 1 to 6 of the present invention and Comparative Examples 1 to 2 are axially compressed by 25% and blood flow is observed at a flow rate of 1280 ml / min using simulated blood with a viscosity of 35 mPa·s, and spiral laminar flow is generated in the stent. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0047] Example 1

[0048] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0049] The angle between the first braided wire and the second braided wire interlaced one above and one below is 111.22°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 55.61°;

[0050] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0051] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0052] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0053] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by three rows of interweaving points in the axial direction and one column of interweaving points in the circumferential direction;

[0054] The angle between the helix and the axial direction is the helix angle, which is 26°;

[0055] The pitch P of the helix is ​​39.59 mm;

[0056] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0057] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 29.69 mm, and the S / D is 1.23.

[0058] The method for preparing the braided vascular stent comprises the following steps:

[0059] (1) Preparation of raw materials;

[0060] Material of braided wire: nickel-titanium alloy;

[0061] The cross-sectional shape of the braided wire is circular, and the distance between the two farthest points in the cross section (i.e. the diameter of the braided wire) is 150 μm;

[0062] (2) Braided vascular stent;

[0063] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0064] (2.2) According to Figure 7 (a) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the braiding direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this way in a cycle, and at the same time, when weaving the fourth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 3 rows of interweaving points in the axial direction and 1 column of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the braiding reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket is braided when it is woven to a length of 16 cm.

[0065] Example 2

[0066] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0067] The angle between the first braided wire and the second braided wire interlaced one above and one below is 111.22°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 55.61°;

[0068] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0069] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0070] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0071] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 6 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0072] The angle between the helix and the axial direction is the helix angle, which is 26°;

[0073] The pitch P of the helix is ​​39.59 mm;

[0074] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0075] The braided vascular stent will become a spiral shape when axially compressed by 25%, with a spiral pitch of 29.69 mm and an S / D of 1.19.

[0076] The method for preparing the braided vascular stent comprises the following steps:

[0077] (1) Preparation of raw materials;

[0078] Material of braided wire: nickel-titanium alloy;

[0079] The cross-sectional shape of the braided wire is circular, and the distance between the farthest two points in the cross section is 150 μm;

[0080] (2) Braided vascular stent;

[0081] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0082] (2.2) According to Figure 7 (b) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the braiding direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 6 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the braiding reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the braiding reaches a length of 16 cm.

[0083] Comparative Example 1

[0084] A braided vascular stent, which is basically the same as the second embodiment, except that: the first braided wire and the second braided wire are woven to form only an upper and lower interwoven braided structure, and do not have a double interwoven braided structure;

[0085] The braided vascular stent had no helical morphology when the axial compression was 25%.

[0086] The method for preparing the braided vascular stent as described above is basically the same as that in Example 2, except that: in step (2.2), Figure 7 When weaving the braided structure shown in (d), two adjacent braided wires will only be interwoven up and down once to form a general interweaving point, and no special interweaving point will be formed.

[0087] By comparing Comparative Example 1 with Example 2, it can be seen that the braided vascular stent prepared in Comparative Example 1 has no spiral shape after being compressed. This is because when the braided vascular stent prepared in Comparative Example 1 is axially compressed, the interwoven wires are subjected to the same force, and the distance h between all axially adjacent interwoven points decreases in the same range. Fig.11 It can be seen from the figure of comparative example 1 that the braided vascular stent is still a cylindrical tubular structure after axial compression. Fig.12 As can be seen from the figure of comparative example 1, the blood morphology test proves that the cylindrical tubular structure after axial compression will not cause flow interference to the passing fluid, and therefore will not generate a spiral laminar flow that is beneficial to the patency of the lumen.

[0088] Example 3

[0089] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0090] The angle between the first braided wire and the second braided wire interlaced one above and one below is 111.22°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 55.61°;

[0091] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0092] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0093] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0094] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0095] The angle between the helix and the axial direction is the helix angle, which is 36.19°;

[0096] The pitch P of the helix is ​​26.39 mm;

[0097] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0098] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 19.79 mm, and the S / D is 1.09.

[0099] The method for preparing the braided vascular stent comprises the following steps:

[0100] (1) Preparation of raw materials;

[0101] Material of braided wire: nickel-titanium alloy;

[0102] The cross-sectional shape of the braided wire is circular, and the distance between the farthest two points in the cross section is 150 μm;

[0103] (2) Braided vascular stent;

[0104] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0105] (2.2) According to Figure 7 (c) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the weaving direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the weaving reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the weaving reaches a length of 16 cm.

[0106] Example 4

[0107] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0108] The angle between the first braided wire and the second braided wire interlaced one above and one below is 121.14°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 60.57°;

[0109] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0110] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0111] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0112] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by three rows of interweaving points in the axial direction and one column of interweaving points in the circumferential direction;

[0113] The angle between the helix and the axial direction is the helix angle, which is 30.61°;

[0114] The pitch P of the helix is ​​32.64 mm;

[0115] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0116] The braided vascular stent will become a spiral shape when axially compressed by 25%, with a spiral pitch of 24.48 mm and an S / D of 1.18.

[0117] The method for preparing the braided vascular stent comprises the following steps:

[0118] (1) Preparation of raw materials;

[0119] Material of braided wire: nickel-titanium alloy;

[0120] The cross-sectional shape of the braided wire is circular, and the distance between the farthest two points in the cross section is 150 μm;

[0121] (2) Braided vascular stent;

[0122] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0123] (2.2) According to Figure 7(a) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the braiding direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this way in a cycle, and at the same time, when weaving the fourth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 3 rows of interweaving points in the axial direction and 1 column of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the braiding reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket is braided when it is woven to a length of 16 cm.

[0124] Example 5

[0125] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0126] The angle between the first braided wire and the second braided wire interlaced one above and one below is 121.14°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 60.57°;

[0127] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0128] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0129] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0130] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 6 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0131] The angle between the helix and the axial direction is the helix angle, which is 30.61°;

[0132] The pitch P of the helix is ​​32.64 mm;

[0133] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0134] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 24.48 mm, and the S / D is 1.12.

[0135] The method for preparing the braided vascular stent comprises the following steps:

[0136] (1) Preparation of raw materials;

[0137] Material of braided wire: nickel-titanium alloy;

[0138] The cross-sectional shape of the braided wire is circular, and the distance between the farthest two points in the cross section is 150 μm;

[0139] (2) Braided vascular stent;

[0140] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0141] (2.2) According to Figure 7 (b) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the braiding direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 6 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the braiding reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the braiding reaches a length of 16 cm.

[0142] Comparative Example 2

[0143] A braided vascular stent, which is basically the same as the fifth embodiment, except that: the first braided wire and the second braided wire are woven to form only an upper and lower interwoven braided structure, and do not have a double interwoven braided structure;

[0144] The braided vascular stent had no helical morphology when the axial compression was 25%.

[0145] The method for preparing the braided vascular stent as described above is basically the same as that in Example 5, except that: in step (2.2), Figure 7 When weaving the braided structure shown in (d), two adjacent braided wires will only be interwoven up and down once to form a general interweaving point, and no special interweaving point will be formed.

[0146] By comparing Comparative Example 2 with Example 5, it can be seen that the braided vascular stent prepared in Comparative Example 2 has no spiral shape after being compressed. This is because when the braided vascular stent prepared in Comparative Example 2 is axially compressed, the interwoven wires are subjected to the same force, and the distance h between all axially adjacent interwoven points decreases in the same range. Fig.11 It can be seen from the figure of comparative example 2 that the braided vascular stent is still a cylindrical tubular structure after axial compression. Fig.12 As can be seen from the figure of comparative example 2, the fluid experiment proves that the cylindrical tubular structure after axial compression will not cause flow interference to the passing fluid, and therefore will not generate a spiral laminar flow that is beneficial to the patency of the lumen.

[0147] Example 6

[0148] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0149] The angle between the first braided wire and the second braided wire interlaced one above and one below is 121.14°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 60.57°;

[0150] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0151] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0152] The double interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced twice, and the interlaced point is recorded as a special interlaced point;

[0153] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0154] The angle between the helix and the axial direction is the helix angle, which is 41.79°;

[0155] The pitch P of the helix is ​​18.80 mm;

[0156] The outer diameter of the braided vascular stent is 6.6 mm and the length is 160 mm;

[0157] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 14.10 mm, and the S / D is 1.06.

[0158] The method for preparing the braided vascular stent comprises the following steps:

[0159] (1) Preparation of raw materials;

[0160] Material of braided wire: nickel-titanium alloy;

[0161] The cross-sectional shape of the braided wire is circular, and the distance between the farthest two points in the cross section is 150 μm;

[0162] (2) Braided vascular stent;

[0163] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0164] (2.2) According to Figure 7 (c) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the weaving direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the weaving reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the weaving reaches a length of 16 cm.

[0165] Example 7

[0166] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0167] The angle between the first braided wire and the second braided wire interlaced one above and one below is 98.2°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 49.1°;

[0168] The first braided wire and the second braided wire are braided to form an up-down interlaced braided structure and a three-interlaced braided structure;

[0169] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0170] The three-interlaced braided structure means that a first braided yarn and a second braided yarn are interlaced three times, and the interlaced point is recorded as a special interlaced point;

[0171] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0172] The angle between the helix and the axial direction is the helix angle, which is 30.1°;

[0173] The pitch P of the helix is ​​32.64 mm;

[0174] The outer diameter of the braided vascular stent is 6.4 mm and the length is 160 mm;

[0175] The braided vascular stent will become a spiral shape when axially compressed by 25%, with a spiral pitch of 24.48 mm and an S / D of 1.41.

[0176] The method for preparing the braided vascular stent comprises the following steps:

[0177] (1) Preparation of raw materials;

[0178] Material of braided wire: nickel-titanium alloy;

[0179] The cross-sectional shape of the braided wire is circular, and the distance between the two farthest points in the cross section is 100 μm;

[0180] (2) Braided vascular stent;

[0181] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0182] (2.2) According to Figure 7 (c) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the weaving direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down three times at one interweaving point to form the first special interweaving point, and then form the next special interweaving point at a position separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction, and then continue to weave according to this spacing rule until the weaving reaches a length of 15 cm, and interweave up and down three times at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the weaving reaches a length of 16 cm.

[0183] Example 8

[0184] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0185] The angle between the first braided wire and the second braided wire interlaced one above and one below is 98.2°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 49.1°;

[0186] The first braided wire and the second braided wire are braided to form an up-down interlaced braided structure, a double interlaced braided structure and a triple interlaced braided structure;

[0187] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0188] The double interlaced braided structure means that a first braided wire and a second braided wire are interlaced twice, and the triple interlaced braided structure means that a first braided wire and a second braided wire are interlaced three times. The interlacing points in the double interlaced braided structure and the triple interlaced braided structure are recorded as special interlacing points;

[0189] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by 4 rows of interweaving points in the axial direction and 2 columns of interweaving points in the circumferential direction;

[0190] The angle between the helix and the axial direction is the helix angle, which is 30.1°;

[0191] The pitch P of the helix is ​​32.64 mm;

[0192] The outer diameter of the braided vascular stent is 6.4 mm and the length is 160 mm;

[0193] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 24.48 mm, and the S / D is 1.35.

[0194] The method for preparing the braided vascular stent comprises the following steps:

[0195] (1) Preparation of raw materials;

[0196] Material of braided wire: nickel-titanium alloy;

[0197] The cross-sectional shape of the braided wire is circular, and the distance between the two farthest points in the cross section is 100 μm;

[0198] (2) Braided vascular stent;

[0199] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0200] (2.2) According to Figure 7 (c) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interwoven point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the weaving direction once to form a general interwoven point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interwoven point in this cycle, and at the same time, when weaving the fifth circle, interweave up and down three times at one interwoven point to form the first special interwoven point, and then interweave up and down twice at a position separated by 4 rows of interwoven points in the axial direction and 2 columns of interwoven points in the circumferential direction to form the next special interwoven point, and then continue to weave according to this spacing rule with the weaving rule of special interwoven points of "interweaving up and down three times-interweaving up and down twice", until when the weaving is 15 cm long, it is interwoven up and down twice at one interwoven point to form the last special interwoven point, so that all special interwoven points are arranged in a spiral line, and the bracket weaving is completed when the weaving is 16 cm long.

[0201] Example 9

[0202] A braided vascular stent is a tubular braided structure, comprising 8 first braided wires arranged along a first direction and 8 second braided wires arranged along a second direction;

[0203] The angle between the first braided wire and the second braided wire interlaced one above and one below is 111.22°, and the braiding angle between the first braided wire and the second braided wire interlaced one above and one below is 55.61°;

[0204] The first braided wire and the second braided wire are braided to form an up-and-down interlaced braided structure and a double interlaced braided structure;

[0205] The one-up-and-one-down interlaced braiding structure means that a first braided yarn and a second braided yarn are interlaced only once, and the interlacing point is recorded as a general interlacing point;

[0206] The double interlaced braided structure means that a first braided wire and a second braided wire are interlaced twice, and the interlacing points in the double interlaced braided structure are recorded as special interlacing points;

[0207] All special interweaving points are arranged in a spiral line, and two adjacent special interweaving points are separated by three rows of interweaving points in the axial direction and one column of interweaving points in the circumferential direction;

[0208] The angle between the helix line and the axial direction is the helix angle, which is 25.8°;

[0209] The pitch P of the helix is ​​39.59 mm;

[0210] The outer diameter of the braided vascular stent is 6.4 mm and the length is 160 mm;

[0211] The braided vascular stent will become a spiral shape when axially compressed by 25%, the pitch of the spiral is 32.90 mm, and the S / D is 1.50.

[0212] The method for preparing the braided vascular stent comprises the following steps:

[0213] (1) Preparation of raw materials;

[0214] Material of braided wire: nickel-titanium alloy;

[0215] The cross-sectional shape of the braided wire is circular, and the distance between the two farthest points in the cross section is 100 μm;

[0216] (2) Braided vascular stent;

[0217] (2.1) 8 first braided wires arranged along the first direction and 8 second braided wires arranged along the second direction are evenly spaced in the circumferential direction in the order of 1 first braided wire-1 second braided wire-1 first braided wire on a stainless steel mandrel with an outer diameter of 6 mm;

[0218] (2.2) According to Figure 7 (c) is woven, when weaving the first circle, two adjacent braided wires are interwoven up and down once to form a general interweaving point, with the first direction interwoven wire on the top and the second direction interwoven wire on the bottom; when weaving the second circle, continue to interweave up and down with an adjacent wire along the weaving direction once to form a general interweaving point, with the first direction interwoven wire on the bottom and the second direction interwoven wire on the top, and weave the general interweaving point in this way in a cycle, and at the same time, when weaving the fourth circle, interweave up and down twice at one interweaving point to form the first special interweaving point, and then interweave up and down twice at a position separated by 3 rows of interweaving points in the axial direction and 1 column of interweaving points in the circumferential direction to form the next special interweaving point, and then continue to weave according to this spacing rule until the weaving reaches a length of 15 cm, and interweave up and down twice at one interweaving point to form the last special interweaving point, so that all special interweaving points are arranged in a spiral line, and the bracket weaving is completed when the weaving reaches a length of 16 cm.

[0219] The braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were cut into samples of 50 mm in length, and then subjected to a three-point bending test and an axial compression torsion test to simulate the mechanical properties of the braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 under the degree of physiological deformation of the proximal end of the PA (i.e., popliteal artery), and a blood flow morphology test was performed to verify the performance of the braided vascular stent in guiding spiral laminar flow. The test results are as follows:

[0220] Three-point bending test: At an ambient temperature of 37°C ± 2°C, using a 5N mechanical sensor, the braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were placed horizontally and centrally on two pillars of the lower clamp with a spacing of 4 cm on a universal strength testing machine, and then the upper clamp foot was lowered to bend the braided blood vessel, and the lowering was performed to 8.08 mm and 12.26 mm to achieve the average and maximum bending degrees (138° and 117°) of the popliteal artery (PA) when the knees were bent and squatted. The bending shapes of the braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 when the upper clamp foot was lowered by 8.08 mm are shown in FIG. Figure 4 As shown, the data from the beginning of the decline to the time when it drops to 12.26mm is as follows Figure 3 As shown, from Figure 3 , Figure 4 It can be seen that the bending strength of the braided vascular stents of Examples 1 to 6 is affected by the braiding density, the number of special interlacing points and the helix angle, and as the braiding density increases (the braiding angle increases), the bending strength of the stent decreases. When the braiding angle is 55.61°, the fewer the special interlacing points, the smaller the bending strength, and the smaller the helix angle, the greater the bending strength; when the braiding angle is 60.57°, there is no significant difference in the bending strength between Examples 1 to 6 and Comparative Examples 1 to 2, indicating that the number of special interlacing points and the helix angle do not affect the bending strength of the stent.

[0221] Axial compression torsion test: At an ambient temperature of 37°C ± 2°C, a 20N mechanical sensor was used to axially compress the braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 by 25% on a torsion tester. Then, the two ends of the braided vascular stent were clamped with a chuck, one end was fixed, and the other end was twisted clockwise and counterclockwise at a speed of 360° / h. When the stent was twisted to 26° / cm (i.e., the PA average torsion angle), the stent morphology was photographed and recorded. The morphology and torsion test data are shown in FIG. Figure 5 , Figure 6As shown, it can be seen from the figure that for Comparative Examples 1 to 2 without special interweaving points, the torque decreases with the increase of weaving density; the torsional performance of the braided vascular stents of Examples 1 to 6 is related to the weaving density, torsional direction, the number of special interweaving points and the size of the helix angle. When twisting in the same direction as the helix (i.e. clockwise twisting), the smaller the helix angle, the lower the weaving density, and the greater the torque; at a braiding angle of 55.61°, the fewer special interweaving points, the smaller the torque; at a braiding angle of 60.57°, there is no significant difference in the torque between the braided vascular stents of Examples 1 to 6 and the braided vascular stents of Comparative Examples 1 to 2, and the number of special interweaving points and the size of the helix angle will not affect the torsional performance of the stent. When twisting in the opposite direction to the helix (i.e. counterclockwise twisting): at a braiding angle of 55.61°, the density of special interweaving points has no obvious effect on the torque, and the larger the helix angle, the smaller the torque; at a braiding angle of 60.57°, the greater the density of special interweaving points, the greater the torque, and the greater the helix angle, the smaller the torque.

[0222] Blood flow morphology test: First, the braided vascular stents prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were placed in a transparent heat shrink tube before heat shrinkage, and then the transparent heat shrink tube was heated after axial compression by 25% to fix the shape of the braided vascular stent (the fixed braided vascular stent was as shown in FIG. Fig.11 As shown, the braided vascular stents prepared in Examples 1 to 6 formed an axial spiral shape, while the braided vascular stents prepared in Comparative Examples 1 to 2 formed a straight tubular shape). Then, transparent artificial synthetic blood at 37°C±2°C was pumped into one end of the transparent heat shrinkable tube through a peristaltic pump, and the waste liquid was discharged from the other end. At the same time, after the transparent artificial synthetic blood filled the transparent heat shrinkable tube, red artificial synthetic blood was sent into the transparent heat shrinkable tube by a syringe at a distance of 20 cm from the stent upstream of the blood flow to fill the 2 cm long transparent heat shrinkable tube. Then, the shape of blood flow (red artificial synthetic blood) flowing through the braided vascular stent was observed at a flow rate of 1280 ml / min, as shown in FIG. Fig.12 As shown in the figure, it can be seen that the braided vascular stents prepared in Examples 1 to 6 will produce a spiral laminar flow when artificial synthetic blood flows through them, especially the spiral laminar flow of the braided vascular stents prepared in Examples 1, 2, 3, 4, and 5 is more obvious, while the blood flow of the braided vascular stents prepared in Comparative Examples 1 to 2 is a laminar flow without helicity;

[0223] The transparent artificial blood and red artificial blood used in the above blood flow morphology test are configured according to GB19083-2010 standard, and the configuration ratio is as follows:

[0224] Transparent artificial blood: 4.5 g sodium carboxymethyl cellulose, 0.04 g polyoxyethylene (20) sorbitan monolaurate, 2.4 g sodium chloride (analytical grade), 2.4 g potassium dihydrogen phosphate (KH 2 PO 4)1.2g, disodium hydrogen phosphate (Na 2 HPO 4 )4.3g, dilute to 1L with deionized water;

[0225] Red artificial blood: 4.5 g sodium carboxymethyl cellulose, 0.04 g polyoxyethylene (20) sorbitan monolaurate, 2.4 g sodium chloride (analytical grade), 2 g amaranth red dye, 2 g potassium dihydrogen phosphate (KH 2 PO 4 )1.2g, disodium hydrogen phosphate (Na 2 HPO 4 )4.3g, dilute to 1L with deionized water.

[0226] It can be seen from the above tests, especially by comparing Example 2 with Comparative Example 1, and Example 5 with Comparative Example 2, that the braided vascular stent prepared by the present invention has excellent performance in guiding spiral laminar flow while not affecting the bending performance and torsional performance, and can better improve the patency rate of the stent.

Claims

1. A braided vascular stent, characterized in that: It is a tubular braided structure, including more than 6 first braided wires arranged in the first direction and more than 6 second braided wires arranged in the second direction; The first braided wires and the second braided wires are braided to form an over-under interlaced braided structure, and further, a double interlaced braided structure and / or a triple interlaced braided structure are also formed; The over-under interlaced braided structure means that one first braided wire and one second braided wire are interlaced only once; The double interlaced braided structure means that one first braided wire and one second braided wire are interlaced twice; The triple interlaced braided structure means that one first braided wire and one second braided wire are interlaced three times; The interlacing points in the over-under interlaced braided structure are denoted as general interlacing points, and the interlacing points in the double interlaced braided structure and the triple interlaced braided structure are denoted as special interlacing points; All special interlacing points are arranged in a spiral, and the adjacent two special interlacing points are separated by at least 3 rows of interlacing points axially and at least 1 column of interlacing points circumferentially.

2. A braided vascular stent according to claim 1, characterized in that: The number of the first braided wires is the same as that of the second braided wires.

3. The braided vascular stent according to claim 1, characterized in that: The angle between the spiral and the axial direction is the spiral angle, and the range of the spiral angle is 5° to 60°.

4. The braided vascular stent according to claim 1, characterized in that: The range of the angle between the first braided wire and the second braided wire in the over-under interlacing is 60° to 160°, and the range of the braiding angle between the first braided wire and the second braided wire in the over-under interlacing is 30° to 80°.

5. The braided vascular stent according to claim 1, characterized in that: The material of the braided wire is nitinol, cobalt-chromium alloy, medical stainless steel, tantalum metal, nitinol with a tantalum or platinum core, degradable magnesium and its alloys, degradable zinc and its alloys, degradable iron and its alloys, polycaprolactone, polylactic acid or poly-p-dioxanone.

6. The braided vascular stent according to claim 1, characterized in that: The cross-sectional shape of each braided wire is circular, square, oval or trapezoidal.

7. The braided vascular stent according to claim 6, characterized in that: The distance between the two farthest points in the cross-section of each braided wire is 20 to 500 μm.

8. The braided vascular stent according to claim 1, characterized in that: The outer diameter of the braided vascular stent is 3 to 8 mm, and the length is 50 to 300 mm.

9. The braided vascular stent according to claim 1, characterized in that: When the braided vascular stent is axially compressed, it will become a spiral shape, and the pitch of the spiral is 14 to 33 mm, 1.05 < S / D ≤ 1.50, where S is the maximum distance along the radial direction in the longitudinal section of the braided vascular stent in the spiral shape, and D is the outer diameter of the braided vascular stent in the spiral shape.

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