A vascular stent

Abstract

The present invention discloses a vascular stent, which is a self-expanding braided tube formed by cross-weaving a first component and a second component, or a self-expanding braided tube formed by cross-weaving a second component, wherein: the first component includes at least one first braided wire, the first braided wire including a first core wire and a sheath covering the first core wire; and the second component includes at least one first braided wire and at least one second braided wire. The vascular stent provided by the present invention can be visualized as a whole, and the boundaries of the vascular stent can be seen during surgery, allowing doctors to clearly determine whether the vascular stent is adherent to the wall and has high support strength.

Description

Technical Field

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

[0002] Intracranial aneurysms are abnormal bulges that occur in the walls of intracranial arteries. They are the leading cause of subarachnoid hemorrhage and the third most common cause of cerebrovascular accidents, after cerebral thrombosis and hypertensive cerebral hemorrhage. They can occur at any age, but are most common in women aged 40 to 60. The cause of intracranial aneurysms remains unclear. Most researchers believe that they are caused by localized congenital defects in the walls of intracranial arteries and increased intraluminal pressure. Hypertension, cerebral arteriosclerosis, and vasculitis are associated with the development and progression of aneurysms. Intracranial aneurysms commonly occur in the basilar arterial circle (Circle of Willis), with 80% occurring in the anterior half of the basilar arterial circle.

[0003] Currently, treatment for intracranial aneurysms primarily focuses on surgical clipping and intratumoral interventional embolization. Surgical clipping is invasive, has numerous side effects, and causes significant patient suffering. Studies have shown that 85% of narrow-necked aneurysms can be completely occluded, while only 15% of wide-necked aneurysms can be completely occluded. The greatest concern with endovascular treatment of complex and large aneurysms is the inability to achieve dense packing and aneurysm recurrence. The concept of using endovascular stents or stent-like methods to reshape the parent artery was first proposed in the late 1980s and began clinical application 15 years ago. Existing braided stents typically achieve only partial visualization through the use of radiopaque imaging dots spliced ​​onto the stent body or radiopaque hybrid braiding. In curved vessels, the pitch of the stent braid can affect stent adhesion, making it difficult to determine whether the stent is adherent to the wall using only a few imaging threads. In vessels with variable diameters, the pitch of the stent varies with vessel diameter, making it difficult for physicians to confidently determine whether the stent is fully occluded. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a vascular stent that can be visualized as a whole, so that the boundaries of the vascular stent can be seen during surgery, and the doctor can clearly judge whether the vascular stent is adhered to the wall, and has high supporting force.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is to provide a vascular stent, which is a self-expanding braided tube formed by cross-weaving a first component and a second component, or the vascular stent is a self-expanding braided tube formed by cross-weaving a second component, wherein: the first component includes at least one first braided wire, the first braided wire includes a first core wire and a sheath wrapped around the outside of the first core wire; and the second component includes at least one first braided wire and at least one second braided wire.

[0006] Preferably, the vascular stent is a self-expanding braided tube formed by spirally cross-braiding the first component and the second component.

[0007] Preferably, the vascular stent is a self-expanding braided tube formed by spirally cross-braiding the first component and the second component from both ends of the vascular stent in a clockwise and counterclockwise direction respectively.

[0008] Preferably, the sleeve is made of an elastic biomaterial, the first core wire is made of an opaque material, and the linear attenuation coefficient of the material of the first core wire is greater than the linear attenuation coefficient of the material of the sleeve.

[0009] Preferably, the radiopaque material is one of platinum, iridium, gold, silver and tantalum or an alloy thereof, and the elastic biomaterial is one or more of nickel titanium alloy, nitinol, stainless steel, cobalt chromium alloy and nickel cobalt alloy.

[0010] Preferably, the cross-sectional shape of the first braided wire is circular, square, elliptical or trapezoidal.

[0011] Preferably, the cross-sectional area of ​​the first core wire accounts for 10% to 40% of the total cross-sectional area of ​​the first braided wires.

[0012] Preferably, the second braided wire includes a second core wire and an opaque wire wound around the second core wire.

[0013] Preferably, among all materials constituting the first braided wires and the second braided wires, the linear attenuation coefficient of the material having the largest linear attenuation coefficient is no more than 25 times the linear attenuation coefficient of the material having the smallest linear attenuation coefficient.

[0014] Preferably, the linear attenuation coefficient of the non-transparent wire is no more than 25 times the linear attenuation coefficient of the first core wire.

[0015] Preferably, the cross-sectional shape of the second braided wire is circular, square, elliptical or trapezoidal.

[0016] Preferably, the non-transmissive wire is one of platinum, iridium, gold, silver and tantalum or an alloy thereof, and the second core wire is nickel-titanium alloy or the first braided wire.

[0017] Preferably, the axial distance L between two adjacent coils of the opaque wire wound around the second core wire is 1.0 to 1.5 times the diameter of the opaque wire.

[0018] Preferably, the number of the first braiding wires is 24 to 96, and the number of the second braiding wires is 2 to 6.

[0019] Preferably, the surfaces of the first braided wires and / or the second braided wires are sprayed or dipped with a drug coating, an anti-thrombotic coating and / or a hydrophilic coating.

[0020] Preferably, in the contracted state, the self-expanding braided tube has a first diameter, which is less than 0.74 mm; in the expanded state, the self-expanding braided tube has a second diameter, which is 1.5 mm to 7 mm, and the expansion force from the first diameter to the second diameter is not less than 0.01 N to 1 N.

[0021] Preferably, the cross-sectional diameter of the second braided wire is not greater than 90 μm, and the cross-sectional diameter of the first braided wire is not greater than 50 μm.

[0022] Preferably, in the contracted state, the first diameter of the self-expanding braided tube is less than 0.027 inches, wherein the cross-sectional diameter of the second braided wire is no greater than 80 μm, and the cross-sectional diameter of the first braided wire is no greater than 45 μm.

[0023] Preferably, in the contracted state, the first diameter of the self-expanding braided tube is less than 0.021 inches, wherein the cross-sectional diameter of the second braided wire is no more than 50 μm, and the cross-sectional diameter of the first braided wire is no more than 35 μm.

[0024] Preferably, in the contracted state, the diameter of the self-expanding braided tube is less than 0.019 inches, wherein the diameter of the second braiding wire is no greater than 30 μm, and the diameter of the first braiding wire is no greater than 30 μm.

[0025] Preferably, in the expanded state, the self-expanding braided tube includes a first end, a middle section and a second end in sequence, the middle section of the self-expanding braided tube has the same outer diameter, and the outer diameters of the first end and the second end of the self-expanding braided tube gradually increase from the middle section toward the port of the self-expanding braided tube.

[0026] Preferably, the axial length of the middle section is 2 mm to 60 mm, the axial lengths of the first end and the second end are both 0.5 to 3 mm, and the angle formed by the busbar constituting the first end or second end rotating body and the central axis direction of the self-expanding braided tube is 10° to 60°.

[0027] Preferably, the first end and the second end of the self-expanding braided tube are trumpet-shaped, truncated cone-shaped, or bevel-shaped, or the cross-sections of the first end and the second end are star-shaped.

[0028] Preferably, the self-expanding braided tube has an axial length of 2 to 70 mm, and the angles formed by the two cross-braided braided wires in the axial and circumferential directions are 100° to 140° and 40° to 80°, respectively.

[0029] Compared with the prior art, the present invention has the following beneficial effects: the vascular stent provided by the present invention is a self-expanding braided tube formed by cross-weaving a first braided wire composed of a composite of an opaque material and a shape memory alloy. The stent as a whole and each braided wire can be visualized, and has a shape memory effect and can self-expand to a predetermined size; the opaque core is visible under DSA angiography, and the boundary of the vascular stent can be clearly seen during surgery, so that the doctor can clearly judge whether the vascular stent is adhered to the wall; in particular, the addition of a second braided wire with stronger opacity has stronger visualization under X-rays than other braided wires, and is placed relative to each other in the circumferential direction. According to the distance between the two sides of the circumference, the opening diameter of the head end of the vascular stent and whether a fish mouth condition occurs can be judged. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the overall structure of the vascular stent in an embodiment of the present invention;

[0031] Figure 2 is a schematic cross-sectional view of a first braided yarn in an embodiment of the present invention;

[0032] Figure 3 Schematic cross-sectional view of the second braided wire in an embodiment of the present invention.

[0033] In the picture:

[0034] 1-combined braided wire, 11-first braided wire, 12-second braided wire, 111-first core wire, 112-sleeve,

[0035] 121 - second core wire, 122 - non-transmissive wire, 21 - middle section, 22 - first end, 23 - second end, 3 - mesh. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings and examples.

[0037] Figure 1 Schematic diagram of the overall structure of the vascular stent in an embodiment of the present invention; Figure 2 Schematic cross-sectional view of the first braided wire in an embodiment of the present invention.

[0038] See Figure 1 and Figure 2The vascular stent provided in this embodiment is a self-expanding braided tube formed by cross-braiding a first component and a second component, or the vascular stent is a self-expanding braided tube formed entirely by cross-braiding the second component. In a preferred embodiment, the vascular stent is a self-expanding braided tube formed by spirally cross-braiding the first component and the second component. Furthermore, the vascular stent is a self-expanding braided tube formed by spirally cross-braiding the first component and the second component from both ends of the vascular stent in a clockwise and counterclockwise direction, respectively. The first component includes at least one first braided wire 11, the first braided wire 11 including a first core wire 111 and a sheath 112 covering the first core wire 111. The first core wire 111 is made of an opaque material, such as platinum, iridium, gold, silver, tantalum, or alloys thereof. The sheath 112 is made of an elastic biomaterial, such as one or more of nickel-titanium alloy, nitinol, stainless steel, cobalt-chromium alloy, or nickel-cobalt alloy. The linear attenuation coefficient of the material of the first core wire 111 is higher than the linear attenuation coefficient of the sheath 112, and the first core wire 111 has a stronger opacity. The cross-section of the first braided wire 11 can be circular, square, elliptical or trapezoidal, etc. Preferably, the cross-section of the first braided wire 11 is circular; the cross-sectional area of ​​the first core wire 111 accounts for 10% to 40% of the total cross-sectional area of ​​the first braided wire 11; preferably, the cross-sectional area of ​​the first core wire 111 accounts for 30% of the total cross-sectional area of ​​the first braided wire 11.

[0039] See Figure 3 , the second component includes at least one of the first braided wires 11 and at least one second braided wire 12. The second braided wire 12 includes a second core wire 121 and an opaque wire 122 wound on the second core wire 121. The opaque wire 122 can be made of opaque materials such as platinum, iridium, gold, silver, tantalum and their alloys. The material of the second core wire 121 is preferably nickel-titanium alloy or the second core wire 121 is the first braided wire 11. Furthermore, each second braided wire 12 is combined with a first braided wire 11 to form a combined braided wire 1 and then spirally cross-braided with the first component. The linear attenuation coefficient of the opaque wire 122 is greater than the linear attenuation coefficient of the second core wire 121. Each material has a linear attenuation coefficient / linear absorption coefficient μ l (linear absorption coefficient), linear attenuation coefficient μ l From the mass attenuation coefficient μ mThe linear attenuation coefficient is obtained by multiplying the linear attenuation coefficient by the density ρ of the material itself. The higher the linear attenuation coefficient, the stronger the opacity. Preferably, among all the materials comprising the first braided wire 11 and the second braided wire 12, the linear attenuation coefficient of the material with the largest linear attenuation coefficient does not exceed 25 times the linear attenuation coefficient of the material with the smallest linear attenuation coefficient. Furthermore, the linear attenuation coefficient of the non-transparent wire 122 does not exceed 25 times the linear attenuation coefficient of the first core wire 111.

[0040] The cross section of the second braided wire 12 can be circular, square, elliptical or trapezoidal, etc. Preferably, the cross section of the second braided wire 12 is circular; see Figure 3 Preferably, the axial distance L between two adjacent effective coils of the non-transparent wire 122 wound around the second core wire is 1.0 to 1.5 times the diameter of the non-transparent wire 122. More preferably, the axial distance L between two adjacent effective coils of the non-transparent wire 122 is 1.0 to 1.2 times the diameter of the non-transparent wire 122.

[0041] Furthermore, the number of second braided wires 12 constituting the self-expanding braided tube is less than the number of first braided wires 11. The number of first braided wires 11 is preferably 24 to 96, and the number of second braided wires 12 is preferably 2 to 6. More preferably, the number of first braided wires 11 is 44 to 62, and the number of second braided wires 12 is 2 to 4. Preferably, when the self-expanding braided tube is in an expanded state, the first braided wires 11 and the second braided wires 12 are evenly distributed in the circumferential direction.

[0042] Furthermore, the surfaces of the first braided wire 11 and the second braided wire 12 can be sprayed or leached with a drug coating, an anti-thrombotic coating and / or a hydrophilic coating as needed, so that the vascular stent has better use and performance.

[0043] In the contracted state, the self-expanding braided tube has a first diameter, and in the expanded state, the self-expanding braided tube has a second diameter. The self-expanding braided tube can be transported to the lesion site by a delivery catheter in the first diameter state and expanded to the second diameter, wherein the first diameter is less than 0.74 mm and can be delivered through a catheter with an inner diameter of 0.029 inches or less, and the second diameter can be expanded to 1.5 mm to 7 mm. Because the first braided wire and the second braided wire both contain elastic material, the expansion force of the self-expanding braided tube from the first diameter to the second diameter ranges from 0.01 N to 1 N, and the deployed vascular stent has a high support force. Therefore, the vascular stent provided in this embodiment, because each braided wire constituting the stent contains an opaque material and an elastic material, the vascular stent as a whole and each braided wire can be visualized, and has a shape memory effect, and can self-expand to a predetermined size; the first core wire 111 made of the opaque material is visible under DSA angiography (angiography), and the boundary of the vascular stent can be clearly seen during surgery, allowing the doctor to clearly determine whether the vascular stent is adherent to the wall.

[0044] The mesh 3 formed by the spiral cross-weaving of the first braided wire 11 of the self-expanding braided tube and the combined braided wire 1 is preferably 0.1mm to 1mm in axial dimension; preferably, the axial dimension is 0.1mm to 0.5mm. The mesh size can be controlled by the number of braided wires and the braiding angle. Preferably, the axial length of the self-expanding braided tube is 2 to 70mm, and the angles formed by the two groups of cross-woven braided wires in the axial and circumferential directions are 100° to 140° and 40° to 80°, respectively. In some embodiments, the angles formed by the two groups of cross-woven braided wires in the axial and circumferential directions are 110° to 130° and 50° to 70°, respectively.

[0045] The metal coverage of the self-expanding braided tube is 20% to 40%, preferably 25% to 35%. The metal coverage refers to the percentage of the surface area of ​​the metal wire forming the self-expanding braided tube to the entire surface area of ​​the self-expanding braided tube.

[0046] In the expanded state, the self-expanding braided tube includes a first end 22, a middle section 21, and a second end 23 in sequence. The middle section 21 of the self-expanding braided tube has the same outer diameter. The outer diameters of the first end 22 and the second end 23 of the self-expanding braided tube gradually increase from the middle section 21 to the end of the self-expanding braided tube. That is, the outer diameter d2 of the first end 22 and the second end 23 is larger than the diameter d1 of the middle section 21. The first end 22 and the second end 23 can be as follows: Figure 1The trumpet shape shown is, but not limited to, a trumpet shape. It may also be a truncated cone shape, a slope shape, or the cross section of the first end 22 and the second end 23 may be star-shaped. The present invention does not impose any special restrictions on this. The axial length of the first end 22 and the second end 23 is preferably 0.5 to 3 mm, and the busbar constituting the rotating body of the first end 22 or the second end 23 forms an angle of 10 to 60° with the central axis direction of the self-expanding braided tube. Preferably, the busbar constituting the rotating body of the first end 22 and the second end 23 forms an angle α of 30 to 60° with the central axis direction of the self-expanding braided tube. Preferably, the busbar constituting the rotating body of the first end 22 and the second end 23 forms an angle α of 30 to 45° with the central axis direction of the self-expanding braided tube.

[0047] When in use, the self-expanding braid can be compressed to a first diameter and, in one embodiment, delivered to the location of the aneurysm through a 0.029-inch catheter, wherein the cross-sectional diameter of the second braided wire 12 is no greater than 90 μm and the cross-sectional diameter of the first braided wire 11 is no greater than 50 μm.

[0048] In another embodiment, the self-expandable braided tube can be delivered to the location of the aneurysm through a 0.027-inch catheter, i.e., the diameter of the self-expandable braided tube in the compressed state is less than 0.027 inches, wherein the diameter of the second braided wire 12 is no more than 80 μm, and the diameter of the first braided wire 11 is no more than 45 μm.

[0049] In other embodiments, the self-expandable braided tube can be delivered to the location of the aneurysm through a 0.021-inch catheter, i.e., the diameter of the self-expandable braided tube in the compressed state is less than 0.021 inches, wherein the diameter of the second braided wire 12 is no greater than 50 μm, and the diameter of the first braided wire 11 is no greater than 35 μm.

[0050] In other embodiments, the self-expandable braided tube can be delivered to the location of the aneurysm through a 0.017-inch catheter, i.e., the diameter of the self-expandable braided tube in the compressed state is less than 0.017 inches, wherein the diameter of the second braided wire 12 is no greater than 30 μm, and the diameter of the first braided wire 11 is no greater than 30 μm.

[0051] Example 1

[0052] See Figure 1 、 Figure 2 and Figure 3The vascular stent provided in this embodiment is a self-expanding braided tube formed by spirally cross-braiding a first component and a second component. The first component is a first braided wire 11, and the second component is a combined braided wire 1 formed by combining the first braided wire 11 and the second braided wire 12. The first braided wire 11 includes a first core wire 111 and a sleeve 112 wrapped around the first core wire 111. The first core wire 111 is made of platinum; the sleeve 112 is made of nickel-titanium alloy. The second braided wire 12 includes a second core wire 121 and an opaque wire 122 wrapped around the second core wire 121. The opaque wire 122 is platinum, and the second core wire 121 is nickel-titanium alloy. The linear attenuation coefficient of the first core wire 111 in the first braided wire 11 is 5148cm -1 , the linear attenuation coefficient of the casing 112 is 258cm -1 The linear attenuation coefficient of the non-transparent wire 122 in the second braided wire 12 is 5148cm -1 The linear attenuation coefficient of the second core wire 121 is 258cm -1 Among the four materials that make up the self-expanding braided tube, the ratio of the maximum linear attenuation coefficient to the minimum linear attenuation coefficient is approximately 20.

[0053] The cross section of the second braided wire 12 is circular; see Figure 3 The axial distance L between two adjacent effective coils of the non-transparent wire 122 in the second braided wire 12 is 1.2 times the wire diameter of the non-transparent wire 122 .

[0054] The first braided wires 11 have a diameter of 45 μm, and the second braided wires 12 have a diameter of 85 μm. They can be compressed to a first diameter of 0.029 inches for delivery. There are 44 first braided wires 11 and 4 second braided wires 12. When the self-expanding braided tube is expanded, the first and second braided wires 11, 12 are evenly distributed circumferentially. The surfaces of the first and second braided wires 11, 12 are sprayed with a drug coating.

[0055] In the expanded state, the self-expanding braided tube includes a first end 22, a middle section 21, and a second end 23 in sequence. The middle section 21 of the self-expanding braided tube has the same outer diameter. The outer diameters of the first end 22 and the second end 23 of the self-expanding braided tube gradually increase from the middle section 21 to the end of the self-expanding braided tube. That is, the outer diameter d2 of the first end 22 and the second end 23 is larger than the diameter d1 of the middle section 21. The first end 22 and the second end 23 are as follows: Figure 1 The first end 22 and the second end 23 have an axial length of 0.5 mm. The angle α between the first end 22 and the second end 23 and the central axis of the self-expanding braided tube is 30°.

[0056] Example 2

[0057] See Figure 1 、 Figure 2 and Figure 3 The vascular stent provided in this embodiment is a self-expanding braided tube formed by spirally cross-braiding a first component and a second component. The first component is a first braided wire 11, and the second component is a combined braided wire 1 formed by combining the first braided wire 11 and the second braided wire 12. The first braided wire 11 includes a first core wire 111 and a sleeve 112 wrapped around the first core wire 111. The first core wire 111 is made of platinum; the sleeve 112 is made of cobalt-chromium alloy. The second braided wire 12 includes a second core wire 121 and an opaque wire 122 wrapped around the second core wire 121. The opaque wire 122 is platinum, and the second core wire 121 is the first braided wire 11. The linear attenuation coefficient of the first core wire 111 in the first braided wire 11 is 5148cm -1 , the linear attenuation coefficient of the casing 112 is 379cm -1 The linear attenuation coefficient of the non-transparent wire 122 in the second braided wire 12 is 5148cm -1 The linear attenuation coefficient of the second core wire 121 is 952cm -1 Among the four materials that make up the self-expanding braided tube, the ratio of the maximum linear attenuation coefficient to the minimum linear attenuation coefficient is approximately 14.

[0058] The cross section of the second braided wire 12 is circular; see Figure 3 The axial distance L between two adjacent effective coils of the non-transparent wire 122 in the second braided wire 12 is 1.1 times the wire diameter of the non-transparent wire 122 .

[0059] The first braided wires 11 have a diameter of 40 μm, and the second braided wires 12 have a diameter of 75 μm. They can be compressed to a first diameter of 0.027 inches for delivery. There are 46 first braided wires 11 and 2 second braided wires 12. When the self-expanding braided tube is expanded, the first and second braided wires 11, 12 are evenly distributed along the circumference.

[0060] The surfaces of the first braided wire 11 and the second braided wire 12 are sprayed with an anti-thrombotic coating, so that the vascular stent has better anti-thrombotic performance.

[0061] In the expanded state, the self-expanding braided tube includes a first end 22, a middle section 21, and a second end 23 in sequence. The middle section 21 of the self-expanding braided tube has the same outer diameter. The outer diameters of the first end 22 and the second end 23 of the self-expanding braided tube gradually increase from the middle section 21 to the end of the self-expanding braided tube. That is, the outer diameter d2 of the first end 22 and the second end 23 is larger than the diameter d1 of the middle section 21. The first end 22 and the second end 23 are as follows: Figure 1The first end 22 and the second end 23 have an axial length of 0.5 mm. The angle α between the first end 22 and the second end 23 and the central axis of the self-expanding braided tube is 45°.

[0062] Example 3

[0063] See Figure 1 、 Figure 2 and Figure 3 The vascular stent provided in this embodiment is a self-expanding braided tube formed by spirally cross-braiding a first component and a second component. The first component is a first braided wire 11, and the second component is a combined braided wire 1 formed by combining the first braided wire 11 and the second braided wire 12. The first braided wire 11 includes a first core wire 111 and a sleeve 112 wrapped around the first core wire 111. The first core wire 111 is made of tantalum; the sleeve 112 is made of cobalt-chromium alloy. The second braided wire 12 includes a second core wire 121 and an opaque wire 122 wrapped around the second core wire 121. The opaque wire 122 is made of tantalum, and the second core wire 121 is the first braided wire 11. The linear attenuation coefficient of the first core wire 111 in the first braided wire is 1671cm -1 , the linear attenuation coefficient of the casing material 112 is 379cm -1 The linear attenuation coefficient of the non-transparent wire 122 in the second braided wire is 1671cm -1 The linear attenuation coefficient of the second core wire 121 is 952cm -1 Among the four materials that make up the self-expanding braided tube, the ratio of the material with the largest linear attenuation coefficient to the smallest linear attenuation coefficient is approximately 4.4.

[0064] The cross section of the second braided wire 12 is circular; see Figure 3 The axial distance L between two adjacent effective coils of the opaque wire 122 in the second braided wire 12 is 1.0 times the wire diameter of the opaque wire 122 .

[0065] The first braided wire 11 has a wire diameter of 35 μm, and the second braided wire 12 has a wire diameter of 50 μm, which can be compressed to a first diameter of 0.021 inches for transportation.

[0066] The number of the first braided wires 11 is 60, and the number of the second braided wires 12 is 4. When the self-expanding braided tube is in an expanded state, the first braided wires 11 and the second braided wires 12 are evenly distributed in the circumferential direction.

[0067] The surfaces of the first braided wires 11 and the second braided wires 12 are leached with a hydrophilic coating.

[0068] In the expanded state, the self-expanding braided tube includes a first end 22, a middle section 21, and a second end 23 in sequence. The middle section 21 of the self-expanding braided tube has the same outer diameter. The outer diameters of the first end 22 and the second end 23 of the self-expanding braided tube gradually increase from the middle section 21 to the end of the self-expanding braided tube. That is, the outer diameter d2 of the first end 22 and the second end 23 is larger than the diameter d1 of the middle section 21. The first end 22 and the second end 23 can be as follows: Figure 1 The first end 22 and the second end 23 have an axial length of 1.0 mm. The angle α between the first end 22 and the second end 23 and the central axis of the self-expanding braided tube is 60°.

[0069] Example 4

[0070] See Figure 1 、 Figure 2 and Figure 3 The vascular stent provided in this embodiment is a self-expanding braided tube formed by spirally cross-braiding a first component and a second component. The first component is a first braided wire 11, and the second component is a combined braided wire 1 formed by combining the first braided wire 11 and the second braided wire 12. The first braided wire 11 includes a first core wire 111 and a sleeve 112 wrapped around the first core wire 111. The first core wire 111 is made of gold; the sleeve 112 is made of cobalt-chromium alloy. The second braided wire 12 includes a second core wire 121 and an opaque wire 122 wrapped around the second core wire 121. The opaque wire 122 is made of tantalum. The second core wire 121 is the first braided wire 11. The linear attenuation coefficient of the first core wire 111 in the first braided wire is 3864cm -1 , the linear attenuation coefficient of the casing material 112 is 379cm -1 The linear attenuation coefficient of the non-transparent wire 122 in the second braided wire is 1671cm -1 The linear attenuation coefficient of the second core wire 121 is 952cm -1 Among the four materials that make up the self-expanding braided tube, the ratio of the maximum linear attenuation coefficient to the minimum linear attenuation coefficient is approximately 10.2.

[0071] The cross section of the second braided wire 12 is circular; see Figure 3 The axial distance L between two adjacent effective coils of the non-transparent wire 122 in the second braided wire 12 is 1.5 times the wire diameter of the non-transparent wire 122 .

[0072] Furthermore, the first braided wire 11 has a wire diameter of 25 μm, and the second braided wire 12 has a wire diameter of 25 μm. They can be compressed to a first diameter and then delivered to the location of the aneurysm by a 0.017-inch catheter.

[0073] The number of the first braided wires 11 is 62, and the number of the second braided wires 12 is 2. When the self-expanding braided tube is in an expanded state, the first braided wires 11 and the second braided wires 12 are evenly distributed in the circumferential direction.

[0074] Furthermore, the surfaces of the first braided wires 11 and the second braided wires 12 are coated with a drug.

[0075] In the expanded state, the self-expanding braided tube includes a first end 22, a middle section 21, and a second end 23 in sequence. The middle section 21 of the self-expanding braided tube has the same outer diameter. The outer diameters of the first end 22 and the second end 23 of the self-expanding braided tube gradually increase from the middle section 21 to the end of the self-expanding braided tube. That is, the outer diameter d2 of the first end 22 and the second end 23 is larger than the diameter d1 of the middle section 21. The first end 22 and the second end 23 are as follows: Figure 1 The first end 22 and the second end 23 have an axial length of 2 mm, and an angle α between the first end 22 and the second end 23 and the central axis of the self-expanding braided tube is 35°.

[0076] Comparative Example

[0077] Vascular stent product A provided by a foreign medical device manufacturer is made of 36 MP35N (a nickel-cobalt-chromium-molybdenum alloy) and 12 platinum wires. The braided wire diameter is 30μm, and the density of the MP35N material is 8.41g / cm 3 , platinum is 21.45g / cm 3 At a wavelength of 0.07107 nm, the mass absorption coefficient of MP35N material is approximately 35 to 45 cm 2 / g, the mass absorption coefficient of platinum is 200~240cm 2 / g. If the first braiding wire 11 in Example 2 is used for spiral braiding, the diameter of the first braiding wire 11 is 40 μm and the density is 13.6 g / cm 3 , the mass absorption coefficient is 60~70cm 2 / g. The calculation formula of intensity attenuation is: I=I0e -μt (where t is the thickness of the material, which is the diameter of the braided wire in this case). When a beam of light with an intensity of I0 is irradiated onto a uniform material with a thickness of t, the intensity of the X-ray is attenuated by I after passing through the material. The smaller the I value, the greater the attenuation of the material to the radiation, and the better the imaging performance. Therefore, I = I0e for MP35N in vascular stent product A. -1.01 , I=I0e of platinum -14.2 , I=I0e of the first braided wire 11 in Example 2 -3.5. It can be seen that the development effect of the first braided wire 11 in Example 2 is stronger than that of the MP35N braided wire, but slightly worse than that of the platinum wire. Therefore, if the vascular stent provided in Example 2 is only composed of the first braided wire, although the overall development effect is stronger than that of the existing product, the development effect is not significantly better than that of the existing technology. After adding the second braided wire, the second core wire 121 of the second braided wire 12 has a diameter of 35μm and a density of 6.45g / cm 3 , the mass absorption coefficient is 30~40cm 2 / g; the density of the non-transparent wire 122 of the second braided wire 12 is 21.45 g / cm 3 , mass absorption coefficient is 200~240cm 2 / g, I of the second braided yarn 12 = I0e -24.24 The second braided wire 12 has significantly better visualization than the platinum wire used in stent product A. Therefore, the stent provided in Example 2 has better visualization than stent product A. Furthermore, the second braided wire 12 has stronger visualization under X-rays than the other braided wires. The second braided wire 12 is positioned circumferentially relative to each other, and the distance between the two sides of the circumference determines the open diameter of the stent end, thereby determining whether a fish-mouth condition exists.

[0078] Therefore, the vascular stent provided by the present invention has at least the following advantages:

[0079] 1. Each braided wire that makes up the stent contains both radiopaque and elastic materials. The stent as a whole and each wire are radiopaque and exhibit a shape memory effect, allowing it to self-expand to a predetermined size.

[0080] 2. The stent body is woven from an outer sheath made of elastic material and an inner first braided core made of radiopaque material. The elastic material accounts for a large proportion, providing self-expansion and strong support. The radiopaque core is visible under DSA angiography, allowing the stent boundary to be clearly seen during surgery, allowing the doctor to clearly determine whether the stent is adherent to the wall.

[0081] 3. The added second braided wire is made of a more opaque material. Under X-rays, the second braided wire is more visible than other braided wires. It is placed relative to each other in the circumferential direction. The distance between the two sides of the circumference can determine the opening diameter of the stent head end and judge whether there is a fish mouth.

[0082] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A vascular stent, characterized in that: The vascular stent is a self-expanding braided tube formed by spirally cross-braiding the first component and the second component from both ends of the vascular stent in a clockwise and counterclockwise direction, respectively. Alternatively, the vascular stent is a self-expanding braided tube formed by cross-braiding the second component, wherein: The first component includes at least one first braided wire, the first braided wire includes a first core wire and a sleeve covering the first core wire, the sleeve is made of an elastic biomaterial, the first core wire is made of an opaque material, and the linear attenuation coefficient of the material of the first core wire is greater than the linear attenuation coefficient of the material of the sleeve; and The second component includes at least one first braided wire and at least one second braided wire, the second braided wire includes a second core wire and an opaque wire wrapped around the second core wire, the second core wire is a nickel-titanium alloy or the first braided wire, and when the self-expanding braided tube is in an expanded state, the first braided wire and the second braided wire are evenly distributed in the circumferential direction.

2. The vascular stent according to claim 1, wherein: The radiopaque material is one of platinum, iridium, gold, silver and tantalum or an alloy thereof, and the elastic biomaterial is one or more of nickel titanium alloy, nitinol, stainless steel, cobalt chromium alloy and nickel cobalt alloy.

3. The vascular stent according to claim 1, wherein: The cross-sectional shape of the first braided wire is circular, square, elliptical or trapezoidal.

4. The vascular stent according to claim 3, wherein: The cross-sectional area of ​​the first core wire accounts for 10% to 40% of the total cross-sectional area of ​​the first braided wire.

5. The vascular stent according to claim 1, wherein: Among all materials constituting the first braided wire and the second braided wire, the linear attenuation coefficient of the material with the largest linear attenuation coefficient is not more than 25 times the linear attenuation coefficient of the material with the smallest linear attenuation coefficient.

6. The vascular stent according to claim 5, characterized in that: The linear attenuation coefficient of the non-transparent wire is no more than 25 times the linear attenuation coefficient of the first core wire.

7. The vascular stent according to claim 1, wherein: The cross-sectional shape of the second braided wire is circular, square, elliptical or trapezoidal.

8. The vascular stent according to claim 1, wherein: The non-transparent wire is one of platinum, iridium, gold, silver and tantalum or an alloy thereof.

9. The vascular stent according to claim 1, wherein: An axial distance L between two adjacent coils of the non-transparent wire wound around the second core wire is 1.0 to 1.5 times the diameter of the non-transparent wire.

10. The vascular stent according to claim 1, wherein: The number of the first braiding wires is 24 to 96, and the number of the second braiding wires is 2 to 6.

11. The vascular stent according to claim 1, wherein: The surfaces of the first braided wires and / or the second braided wires are sprayed or leached with a drug coating, an anti-thrombotic coating and / or a hydrophilic coating.

12. The vascular stent according to claim 1, wherein: In a contracted state, the self-expanding braided tube has a first diameter, which is less than 0.74 mm; in an expanded state, the self-expanding braided tube has a second diameter, which is 1.5 mm to 7 mm.

13. The vascular stent according to claim 12, wherein: The expansion force of the self-expanding braided tube from the first diameter to the second diameter ranges from 0.01N to 1N.

14. The vascular stent according to claim 12, wherein: The cross-sectional diameter of the first braided wire is not greater than 50 μm, and the cross-sectional diameter of the second braided wire is not greater than 90 μm.

15. The vascular stent according to claim 14, wherein: In the contracted state, the first diameter of the self-expanding braided tube is less than 0.027 inches, wherein the cross-sectional diameter of the second braiding wire is no greater than 80 μm, and the cross-sectional diameter of the first braiding wire is no greater than 45 μm.

16. The vascular stent according to claim 14, wherein: In the contracted state, the first diameter of the self-expanding braided tube is less than 0.021 inches, wherein the cross-sectional diameter of the second braiding wire is no greater than 50 μm, and the cross-sectional diameter of the first braiding wire is no greater than 35 μm.

17. The vascular stent according to claim 14, wherein: In the collapsed state, the self-expanding braided tube has a diameter of less than 0.019 inches, wherein the diameter of the second braiding wire is no greater than 30 μm, and the diameter of the first braiding wire is no greater than 30 μm.

18. The vascular stent according to claim 1, wherein: In the expanded state, the self-expanding braided tube includes a first end, a middle section and a second end in sequence. The middle section of the self-expanding braided tube has the same outer diameter, and the outer diameters of the first end and the second end of the self-expanding braided tube gradually increase from the middle section toward the port of the self-expanding braided tube.

19. The vascular stent according to claim 18, wherein: The axial length of the middle section is 2mm~60mm, the axial lengths of the first end and the second end are both 0.5~3mm, and the angle formed by the busbar constituting the first end or the second end rotating body and the central axis direction of the self-expanding braided tube is 10°~60°.

20. The vascular stent according to claim 18, wherein: The first end and the second end of the self-expanding braided tube are in a trumpet shape, a truncated cone shape, a bevel shape, or the cross-sections of the first end and the second end are in a star shape.

21. The vascular stent according to claim 1, wherein: The self-expanding braided tube has an axial length of 2-70 mm, and the angles formed by the two groups of cross-braided braided wires in the axial and circumferential directions are 100°-140° and 40°-80°, respectively.

Images