Intravascular stent and manufacturing method thereof

Abstract

The embodiment of the invention discloses an intravascular stent and a manufacturing method thereof, and the manufacturing method of the intravascular stent comprises the steps that a to-be-machined stent is provided, the to-be-machined stent has an axial direction, and the to-be-machined stent comprises a plurality of ribs extending in the axial direction; at least part of the ribs are subjected to directional machining, so that the radial sizes of at least part of the ribs are changed in the axial direction, and the intravascular stent is obtained; wherein the radial size and / or radial force of the part of the intravascular stent subjected to directional machining are / is changed compared with the stent to be machined. According to the invention, the radial size or radial force of different areas of the intravascular stent can be accurately adjusted, the natural transition requirement of the diameter of the blood vessel can be met, and the adaptability of the product can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vascular stents, and in particular to a vascular stent and a manufacturing method thereof. Background Art

[0002] As an important implantable medical device, vascular stents play different roles depending on the implantation site, such as restoring vascular patency, alleviating vascular stenosis, maintaining vascular structural stability, and optimizing hemodynamics. Vascular stents achieve anchoring and support functions within blood vessels through uniform radial force. In order to improve the anchoring performance of stents within blood vessels, medical device manufacturers usually solve this problem by increasing the size of the ribs to increase the radial support force.

[0003] However, this method is difficult to achieve a good transition when the diameter of the blood vessel changes from wide to narrow, which may lead to the problem of mismatched support force. In the narrow part of the blood vessel, excessive support force may cause blood vessel damage and rupture; while in the wider part, insufficient support force may easily cause the stent to shift and break. In addition, when the individual vascular morphology of the patient's blood vessels does not match the existing vascular stents, it is usually difficult to complete a large-scale structural design adjustment at a low cost, which limits the flexibility and personalized adaptability of the stent to a certain extent. Summary of the invention

[0004] The embodiments of the present invention provide a vascular stent and a method for manufacturing the same, so as to accurately adjust the radial size or radial force of different regions of the vascular stent, meet the natural transition requirements of the blood vessel diameter, and improve the adaptability of the product.

[0005] In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0006] In one aspect, a method for manufacturing a vascular stent is provided, comprising:

[0007] Providing a support to be processed, wherein the support to be processed has an axial direction and comprises a plurality of ribs extending along the axial direction;

[0008] Directingly processing at least part of the ribs so that the radial dimensions of at least part of the ribs vary in the axial direction, so as to obtain a blood vessel stent;

[0009] Wherein, the radial size and / or radial force of the part of the vascular stent that has completed the directional processing is changed compared with the stent to be processed.

[0010] In addition to or as an alternative to one or more of the features disclosed above, the method of pricing at least a portion of the ribs comprises:

[0011] Material is removed from a portion of the ribs, or material is added to a portion of the ribs.

[0012] In addition to or as an alternative to one or more of the features disclosed above, the method for removing material from at least a portion of the ribs includes: performing at least one of a sandblasting process, a polishing process, or a pickling process on a portion of the ribs to reduce the radial dimension of the portion of the ribs.

[0013] In addition to or as an alternative to one or more of the features disclosed above, the parameters of the sandblasting process include: particle type, particle size s, sandblasting gas pressure p and rotation speed n;

[0014] The particle types include at least one of aluminum oxide or glass beads, 5 μm≤s≤100 μm, 0.01 MPa≤p≤1 MPa, and 5 rpm≤n≤120 rpm.

[0015] In addition to or as an alternative to one or more features disclosed above, the radial dimensions of the rib include thickness and width, the thickness variation value of the rib is △T, and the width variation value of the rib is △W, wherein 0.05mm≤|△T|≤0.5mm, 0.1mm≤|△W|≤1mm.

[0016] In addition to or as an alternative to one or more of the features disclosed above, the radial dimensions of at least part of the ribs may vary in the axial direction in a form including: a stepped distribution or a gradual distribution.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the stent to be processed includes: a cut-type stent or a woven-type stent.

[0018] In addition to or as an alternative to one or more of the features disclosed above, the material of the vascular stent includes at least one of stainless steel, titanium-nickel alloy or cobalt-chromium alloy.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the invention further comprises:

[0020] After the step of orienting at least part of the ribs is completed, the vascular stent is passivated.

[0021] On the other hand, a vascular stent is further disclosed. In addition to or instead of one or more of the features disclosed above, the vascular stent is obtained by a manufacturing method of a vascular stent as described in any of the above items, the vascular stent has an axial direction, and the vascular stent includes a plurality of ribs extending along the axial direction, and the radial dimensions of at least some of the ribs vary in the axial direction.

[0022] One of the above technical solutions has the following advantages or beneficial effects: This technical solution can accurately adjust the radial size or radial force of different areas of the vascular stent to meet the natural transition requirements of the vascular diameter and improve the adaptability of the product. In addition, this application can process the finished stent that has been designed and formed without changing the overall design or function of the stent. It is suitable for stents of different types, materials, and sizes to obtain vascular stents with a variety of different performances, reducing the number of design samples and reducing production costs. This technical solution can also accurately process the finished stent according to the patient's personalized vascular morphology to improve the matching of the vascular stent and reduce the risk of postoperative complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0024] Figure 1 is a flowchart of the steps of a method for manufacturing a vascular stent according to an embodiment of the present invention;

[0025] Figure 2 is a process flow chart of a method for manufacturing a vascular stent according to an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of a vascular stent provided according to an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 A schematic diagram of the enlarged structure at A in the middle;

[0028] In the figure: 10, the stent to be processed; 11, the ribs; 20, the vascular stent; 201, the first connecting part; 202, the second connecting part; 203, the third connecting part. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and beneficial effects of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are only for explaining the present invention, not for limiting the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] See also Figure 1 , Figure 1 The present invention shows a method for manufacturing a vascular stent according to an embodiment of the present invention. The method for manufacturing a vascular stent provided by an embodiment of the present application includes:

[0034] S1, providing a support to be processed, wherein the support to be processed has an axial direction and comprises a plurality of ribs extending along the axial direction;

[0035] S2, performing directional processing on at least part of the ribs so that the radial dimensions of at least part of the ribs vary in the axial direction, so as to obtain a blood vessel stent;

[0036] Wherein, the radial size and / or radial force of the part of the vascular stent that has completed the directional processing is changed compared with the stent to be processed.

[0037] Step S1 to step S2 will be described in detail below.

[0038] Combination Figure 2 As shown, in step S1, a stent 10 to be processed is provided, and the types of the stent 10 to be processed include a woven stent or a cut stent. The stent 10 to be processed is a mesh tube structure, and the stent 10 to be processed extends along the axial direction X. The stent 10 to be processed includes a plurality of ribs 11 extending along the axial direction X, and the plurality of ribs 11 are interlaced and woven to form the stent 10 to be processed. The size of each rib 11 is uniform, that is, in the axial direction X, the radial sizes of all ribs 11 are uniform. The radial cross-section of the rib 11 can be circular, square or other shapes, which are not specifically limited here.

[0039] In this embodiment, the size of the bracket 10 to be processed is uniform, that is, the diameter of the radial cross section of the bracket 10 to be processed at any position in the axial direction X is uniform. In other embodiments, the bracket 10 to be processed can be a variable diameter bracket, which is not specifically limited here.

[0040] In step S2, at least part of the ribs 11 are subjected to directional processing at a part of the position, so that the radial dimension of the ribs 11 subjected to directional processing changes in the axial X direction, so as to obtain the vascular stent 20. The radial dimension of the ribs 11 changes in the axial X direction, which will cause at least one of the radial force or radial dimension of the partial vascular stent 20 formed by weaving the ribs 11 subjected to directional processing to change compared with the stent 10 to be processed. The change can be an increase in the radial dimension or radial force at a local position of the vascular stent 20, so as to improve the support performance and anchoring ability of the local position of the vascular stent 20, and avoid displacement and fracture of the stent due to insufficient support force; the change can also be a decrease in the radial dimension or radial force at a local position of the vascular stent 20, so as to improve the flexibility and wall adhesion ability of the vascular stent 20, and avoid damage and rupture of the blood vessel caused by excessive support force. The present application performs directional processing on part of the ribs 11 to change the radial dimension or radial force at different positions of the vascular stent 20, so as to meet the requirements of the vascular stent 20 for radial support force at different positions.

[0041] Preferably, the bracket 10 to be processed is a cutting type bracket, the radial cross-section of the rib 11 is a square cross-section, the radial dimensions of the rib 11 include thickness and width, the thickness change value of the rib 11 after the directional processing is △T, and the width change value of the rib 11 is △W, wherein 0.05mm≤|△T|≤0.5mm, 0.1mm≤|△W|≤1mm.

[0042] The method of directional processing at least part of the ribs 11 at a part position includes: removing material from a part of the ribs 11, or adding material to a part of the ribs 11. The method of removing material from a part of the ribs 11 includes: performing at least one of a sandblasting process, a polishing process or a pickling process on a part of the ribs 11, so as to reduce the radial size of a part of the ribs 11, thereby reducing the radial size of a part of the vascular stent 20 or reducing the radial force. The method of adding material to a part of the ribs 11 includes: performing at least one of an electroplating process and a coating process on a part of the ribs 11, so as to increase the radial size of a part of the ribs 11, thereby increasing the radial size of a part of the vascular stent 20 or increasing the radial force.

[0043] It should be noted that the directional processing of at least part of the ribs 11 includes performing different, different combinations or different degrees of directional processing on different positions of the ribs 11. For example, by adjusting the order, position or parameters (such as processing time, speed, etc.) of the directional processing, the local ribs 11 of the bracket are directional processed to selectively increase or decrease the cross-section of the ribs 11. No specific limitation is made here.

[0044] Preferably, the parameters of the sandblasting process include: particle type, particle size s, sandblasting air pressure p and rotation speed n; wherein the particle type includes at least one of aluminum oxide or glass beads, 5μm≤s≤100μm, 0.01MPa≤p≤1MPa, 5rpm≤n≤120rpm.

[0045] Preferably, the parameters of the pickling process include: a pickling solution formula and a pickling time t1; wherein the pickling solution formula includes a mixed solution of hydrofluoric acid, nitric acid and water, and 4s≤t1≤20s.

[0046] Preferably, the polishing process is electrochemical polishing, and the parameters of the polishing process include: polishing liquid formula, polishing voltage U, and polishing time t2; wherein, the polishing liquid formula includes methanol-perchloric acid solution or sulfuric acid-methanol solution, 10V≤U≤30V, 3s≤t2≤25s.

[0047] Combination Figure 3 , Figure 4As shown, in this embodiment, the vascular stent 20 that has undergone directional processing has a first connection portion 201, a second connection portion 202, and a third connection portion 203 arranged in sequence along the axial X direction at A. The radial dimensions of the ribs 11 at the first connection portion 201, the second connection portion 202, and the third connection portion 203 are gradually reduced in sequence, and the radial forces of the vascular stent 20 at the first connection portion 201, the second connection portion 202, and the third connection position are increased in sequence to meet the natural transition requirements of the blood vessel diameter.

[0048] Furthermore, the radial dimensions of the ribs 11 that have undergone directional processing have a change in the axial X direction, and the change forms include step distribution or gradual distribution. Among them, the step distribution means that the ribs 11 are divided into a number of connecting segments in the axial X direction, and the radial dimensions of the ribs 11 in each connecting segment are uniform, and the radial dimensions of the ribs 11 in adjacent connecting segments are not equal. In the axial X direction, the radial dimensions of the ribs 11 in all connecting segments can be regularly increased or decreased, or can be arranged irregularly, which is not specifically limited here. The gradual distribution means that in the axial X direction, the radial dimensions of the ribs 11 show a trend of gradual change, and the trend of gradual change can be a trend of gradually increasing, a trend of gradually decreasing, or a regular gradual change trend in a waveform, and other trends.

[0049] Furthermore, after the step of orienting at least part of the ribs 11 is completed, the vascular stent 20 is passivated to reduce biological reactions on the surface of the stent in the blood vessel and prevent thrombosis and vascular stenosis. Passivation can be achieved by coating and drugs.

[0050] Furthermore, the material of the vascular stent 20 includes at least one of stainless steel, titanium-nickel alloy or cobalt-chromium alloy.

[0051] Compared with the prior art, the present application can accurately adjust the radial size or radial force of different areas of the vascular stent 20 to meet the natural transition requirements of the blood vessel diameter and improve the adaptability of the product. In addition, the present application can process the finished stent that has been designed and formed without changing the overall design or function of the stent. It is suitable for stents of different types, materials, and sizes to obtain a variety of vascular stents 20 with different performances, reducing the number of design samples and reducing production costs. The present application can also accurately process the finished stent according to the patient's personalized vascular morphology to improve the matching of the vascular stent 20 and reduce the risk of complications such as post-operative thrombosis, vascular restenosis, and bleeding.

[0052] Embodiment 1

[0053] First, a bracket 10 to be processed is provided, and the nickel-titanium tube is laser cut, and a cut bracket 10 to be processed is formed after heat treatment and shaping.

[0054] Secondly, at least a portion of the ribs 11 are oriented, including:

[0055] The processing support 10 is subjected to a sandblasting process, and the parameters of the sandblasting process include: the sandblasting particles are 10-20um aluminum oxide medium, the sandblasting gas pressure is 0.5MPa, and the sandblasting speed is 40-50rpm. The steps of performing segmented sandblasting on the processing support 10 include: the rotating axis is slowly fed at a speed of 1mm / s for the first 20 seconds, fed at a medium speed of 2mm / s for 20-40 seconds, fed at a speed of 3mm / s for 40-60 seconds, and then immediately returned to the origin, and reciprocated feeding is performed 3 times according to the above steps to complete the sandblasting process.

[0056] The bracket 10 to be processed that has completed the sandblasting process is polished, and the polishing process is specifically electrochemical polishing. The parameters of the polishing process include: 3 mol / L methanol-perchloric acid solution, 16V constant voltage control. The steps of performing segmented polishing on the bracket 10 to be processed that has completed the sandblasting process include: first immersing 1 / 3 of the bracket 10 to be processed in the polishing liquid and polishing for 5 seconds; then increasing the immersion amount, polishing 2 / 3 of the bracket 10 to be processed for 5 seconds, and finally immersing the entire bracket 10 to be processed in the polishing liquid, polishing twice, each time for 5 seconds, to complete the polishing process.

[0057] Finally, a blood vessel stent 20 is obtained in which the radial dimensions of the ribs 11 change in steps.

[0058] Embodiment 2

[0059] First, a stent 10 to be processed is provided, nickel-titanium wires are braided and formed, and a braided stent 10 to be processed is formed after heat treatment.

[0060] Secondly, at least a portion of the ribs 11 are oriented, including:

[0061] The bracket 10 to be processed is subjected to an acid pickling process, and the parameters of the acid pickling process include: an acid pickling solution in which hydrofluoric acid, nitric acid and water are mixed in a ratio of 1:2:7. The steps of performing segmented acid pickling on the bracket 10 to be processed include: first immersing 1 / 3 of the bracket 10 to be processed in the acid pickling solution for 5 seconds; then increasing the immersion amount, immersing 2 / 3 of the bracket 10 to be processed for 5 seconds; finally, immersing the entire bracket 10 to be processed in the acid pickling solution for 8 seconds to complete the acid pickling, rinsing with clean water, blowing dry and setting aside, and completing the acid pickling process.

[0062] The bracket 10 to be processed that has completed the pickling process is polished, and the polishing process is specifically electrochemical polishing. The parameters of the polishing process include: a polishing liquid of sulfuric acid and methanol mixed in a ratio of 2:8, and a constant voltage control of 25V. The steps of performing segmented polishing on the bracket 10 to be processed include: first immersing 1 / 3 of the bracket 10 to be processed in the polishing liquid and polishing for 4 seconds; then increasing the immersion amount, polishing 2 / 3 of the bracket 10 to be processed for 4 seconds, and finally immersing the entire bracket 10 to be processed in the polishing liquid, polishing twice, each time for 4 seconds, to complete the polishing process.

[0063] Finally, a blood vessel stent 20 with ribs 11 having diameters that change in steps is obtained.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for manufacturing a vascular stent, characterized in that: include: Providing a support to be processed, wherein the support to be processed has an axial direction and comprises a plurality of ribs extending along the axial direction; Directingly processing at least part of the ribs so that the radial dimensions of at least part of the ribs vary in the axial direction, so as to obtain a blood vessel stent; Wherein, the radial size and / or radial force of the part of the vascular stent that has completed the directional processing is changed compared with the stent to be processed.

2. The method for manufacturing a vascular stent according to claim 1, characterized in that: The method for pricing at least part of the ribs comprises: Material is removed from a portion of the ribs, or material is added to a portion of the ribs.

3. The method for manufacturing a vascular stent according to claim 2, characterized in that: The method of removing material from at least part of the ribs comprises: performing at least one of a sandblasting process, a polishing process or a pickling process on a part of the ribs to reduce a radial dimension of the part of the ribs.

4. The method for manufacturing a vascular stent according to claim 3, characterized in that: The parameters of the sandblasting process include: particle type, particle size s, sandblasting air pressure p and rotation speed n; The particle types include at least one of aluminum oxide or glass beads, 5 μm≤s≤100 μm, 0.01 MPa≤p≤1 MPa, and 5 rpm≤n≤120 rpm.

5. The method for manufacturing a vascular stent according to claim 3, characterized in that: The radial dimensions of the ribs include thickness and width, the thickness variation value of the ribs is △T, and the width variation value of the ribs is △W, wherein 0.05mm≤|△T|≤0.5mm, and 0.1mm≤|△W|≤1mm.

6. The method for manufacturing a vascular stent according to claim 1, characterized in that: The radial dimensions of at least part of the ribs may vary in the axial direction in a form including: a step-like distribution or a gradual distribution.

7. The method for manufacturing a vascular stent according to claim 1, characterized in that: The stent to be processed includes: a cutting type stent or a braided type stent.

8. The method for manufacturing a vascular stent according to claim 1, characterized in that: The material of the vascular stent includes at least one of stainless steel, titanium-nickel alloy or cobalt-chromium alloy.

9. The method for manufacturing a vascular stent according to claim 1, characterized in that: Also includes: After the step of orienting at least part of the ribs is completed, the vascular stent is passivated.

10. A vascular stent, characterized in that: The vascular stent is obtained by the manufacturing method of the vascular stent according to any one of claims 1 to 9, the vascular stent has an axial direction, and the vascular stent includes a plurality of ribs extending along the axial direction, and the radial dimensions of at least some of the ribs vary in the axial direction.

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