Intravascular stent and manufacturing method thereof

Abstract

The invention provides an intravascular stent and a manufacturing method thereof. The intravascular stent comprises a stent near end, a stent body and a stent far end which are sequentially arranged in the axial direction of the intravascular stent, and the supporting force of at least one of the stent near end and the stent far end is smaller than that of the stent body. By means of the configuration, the stimulation effect of one end or two ends of the stent on non-lesion blood vessels can be reduced, endothelialization of the non-lesion blood vessels is better facilitated, and the risk of long-term restenosis is reduced.

Description

Technical Field

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

[0002] Vascular stenosis and occlusions caused by atherosclerosis are the primary causes of limb and intracranial ischemia. Coronary artery stenosis or occlusion caused by coronary artery plaques is the primary cause of coronary heart disease. Stent intervention is one of the main clinical treatments for severe vascular stenosis and occlusions.

[0003] Due to the complex environment in which they reside, vascular stents must meet certain performance requirements before they can be used. Support force, a key mechanical property of stents, refers to their resistance to radial external pressure and the outward strain exerted by the stent. Appropriate support force ensures the stent adheres securely to the vessel wall after deployment, resisting plaque rebound after balloon expansion, ensuring vascular patency and preventing stent migration.

[0004] The design parameters (such as waveform, wave rod width, wall thickness, etc.) of the vascular stenosis stents currently used in clinical practice are relatively consistent throughout the body, so that the support force of the proximal and distal ends of the stent is highly consistent with that of the stent body. Therefore, the support force of the stent is uniform throughout the body. However, in clinical practice, the stent ends are often released in non-lesioned blood vessels far or near the lesion area to play an anchoring role, and the actual demand for support force is relatively low; while the stent body is released at the lesion site to support the blood vessels and prevent plaque rebound, and the actual demand for support force is higher than that of the anchoring section. In other words, based on the actual clinical situation, there are actual differences in the support force requirements of the proximal and distal ends of the stent. Therefore, there are the following problems with vascular stents designed with uniform support force throughout the body, including: (1) the support force is suitable for lesioned blood vessels, but has a strong stimulating effect on non-lesioned blood vessels; (2) it is not conducive to the endothelialization process of non-lesioned blood vessels, increasing the risk of long-term restenosis of the stent; (3) the support force design of the proximal and distal ends of the stent and the stent body is consistent with the actual clinical needs. Therefore, it is necessary to provide a vascular stent for stenosis treatment that matches the actual clinical needs. Summary of the Invention

[0005] The object of the present invention is to provide a vascular stent and a manufacturing method thereof, so as to solve the problem of uniform supporting force in the overall design of the existing vascular stent.

[0006] To achieve the above-mentioned purpose, the present invention provides a vascular stent, which includes a stent proximal end, a stent body and a stent distal end arranged in sequence along its own axis, and the supporting force of at least one of the stent proximal end and the stent distal end is smaller than the supporting force of the stent body.

[0007] Optionally, in the above-mentioned vascular stent, the supporting force at the proximal end of the stent and the supporting force at the distal end of the stent are both smaller than the supporting force of the stent body, and the supporting force at the proximal end of the stent and the supporting force at the distal end of the stent are the same.

[0008] Optionally, in the above-mentioned vascular stent, when the vascular stent is a cutting stent, the rod width of at least one of the proximal end of the stent and the distal end of the stent is smaller than the rod width of the stent body, and / or the wave height of at least one of the proximal end of the stent and the distal end of the stent is greater than the wave height of the stent body.

[0009] Optionally, in the above-mentioned vascular stent, the wave height at the proximal end of the stent is equal to the wave height at the distal end of the stent, and the wave height of the stent body is smaller than the wave height at the proximal end of the stent.

[0010] Optionally, in the above-mentioned vascular stent, the ratio of the wave height of the stent body to the wave height of the proximal end of the stent is 0.2-1.

[0011] Optionally, in the above-mentioned vascular stent, the rod width of the proximal end of the stent is equal to the rod width of the distal end of the stent, and the rod width of the stent body is greater than the rod width of the proximal end of the stent.

[0012] Optionally, in the above-mentioned vascular stent, the ratio of the rod width of the proximal end of the stent to the rod width of the stent body is 0.3-1.

[0013] Optionally, in the above-mentioned vascular stent, when the vascular stent is a braided stent, the braiding wire intercept of at least one of the proximal end of the stent and the distal end of the stent is greater than the braiding wire intercept of the stent body.

[0014] Optionally, in the above-mentioned vascular stent, the braided wire intercept at the proximal end of the stent is equal to the braided wire intercept at the distal end of the stent, and the braided wire intercept of the stent body is smaller than the braided wire intercept at the proximal end of the stent.

[0015] The present invention also provides a method for manufacturing a vascular stent, which is used to prepare any one of the vascular stents described above, and the manufacturing method comprises:

[0016] One or more structural design parameters are adjusted so that the supporting force of the proximal end of the stent and / or the distal end of the stent is smaller than the supporting force of the stent body.

[0017] Optionally, in the above-mentioned method for manufacturing a vascular stent, when the vascular stent is a cutting stent, the structural design parameters include the rod width and wave height of the cutting stent, and only the rod width and / or wave height of the cutting stent are adjusted so that the supporting force of the proximal end and / or the distal end of the stent is smaller than the supporting force of the stent body.

[0018] Optionally, in the above-mentioned method for manufacturing a vascular stent, when adjusting the wave height, the wave height at the proximal end of the stent is made equal to the wave height at the distal end of the stent, and the wave height of the stent body is made smaller than the wave height at the proximal end of the stent.

[0019] Optionally, in the above-mentioned method for manufacturing a vascular stent, when adjusting the rod width, the rod width at the proximal end of the stent is made equal to the rod width at the distal end of the stent, and the rod width of the stent body is made greater than the rod width at the proximal end of the stent.

[0020] Optionally, in the above-mentioned method for manufacturing a vascular stent, when the vascular stent is a braided stent, the structural design parameters include the braiding wire intercept of the braided stent, and only the braiding wire intercept of the braided stent is adjusted so that the supporting force of the proximal end and / or the distal end of the stent is smaller than the supporting force of the stent body.

[0021] Optionally, in the above-mentioned method for manufacturing a vascular stent, the braided wire intercept at the proximal end of the stent is made equal to the braided wire intercept at the distal end of the stent, and the braided wire intercept of the stent body is made smaller than the braided wire intercept at the proximal end of the stent.

[0022] Optionally, when the vascular stent is a cut stent, the wall thickness of the vascular stent is uniform throughout.

[0023] The beneficial effects of the vascular stent and the manufacturing method thereof provided by the present invention are:

[0024] In the above-mentioned vascular stent, since the supporting force of at least one of the distal and proximal ends of the stent is smaller than the supporting force of the stent body, the stimulation of one or both ends of the stent on non-diseased blood vessels can be reduced, which is more conducive to the endothelialization of non-diseased blood vessels and reduces the risk of long-term restenosis.

[0025] In the above-mentioned manufacturing method of the vascular stent, the difference in supporting force between one end or both ends of the stent and the stent body can be achieved by adjusting one or more structural design parameters, thereby simplifying the manufacturing process and reducing the difficulty of the process technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0027] Figure 1 This is a schematic structural diagram of the cutting stent according to the first embodiment of the present invention when it is cut and flattened along its own axis;

[0028] Figure 2 This is a partial enlarged view of the cutting stent according to the first embodiment of the present invention when it is cut and flattened along its own axis;

[0029] Figure 3This is a partial enlarged view of the cutting stent in Example 1 of the present invention, in which the width of the stent body is greater than the width of the stent at the distal and proximal ends;

[0030] Figure 4 Schematic diagram of the structure of a braided stent according to Example 2 of the present invention; the red and blue lines are also braided wires, and the red and blue lines further highlight the intercepts between the proximal and distal ends of the stent and the stent body;

[0031] Figure 5 This is a partial enlarged view of the braided stent according to the second embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of an application scenario of the braided stent according to the second embodiment of the present invention when it is released into a diseased blood vessel;

[0033] Figure 7 for Figure 6 A partial enlarged view of the braided stent in use.

[0034] In the attached figure:

[0035] 11-cutting the proximal end of the stent; 12-cutting the stent body of the stent; 13-cutting the distal end of the stent; 14-wave ring; 15-connecting unit; 16-repeating unit;

[0036] 21 - the proximal end of the braided stent; 22 - the main body of the braided stent; 23 - the distal end of the braided stent. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer based on the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different proportions are used. It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to represent the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0038] In this application, "proximal" and "distal" refer to the relative position, location, or direction of components or actions relative to each other from the perspective of a physician using the stent. While the terms "proximal" and "distal" are not intended to be limiting, "proximal" generally refers to the end of the stent closest to the operator during normal operation, while "distal" generally refers to the end away from the operator. "Distal" and "proximal" in this application do not refer to ends of a structure, but rather to relative positions. For example, the distal end of a stent is not the end of the stent, but rather a position relatively close to the end of the stent.

[0039] In this application document, "axial" usually refers to the direction corresponding to the central axis of the vascular stent, "radial" usually refers to the direction corresponding to the diameter of the vascular stent, and "circumferential" usually refers to the direction around the central axis of the vascular stent; "wave height" is the projected length of the wave rod and the bending sections on both sides of the wave rod in the axial direction of the stent, that is, the height between circumferentially adjacent wave crests and troughs on the same wave ring; "rod width" usually refers to the rod width of the wave rod body excluding the bending sections (corresponding to wave crests or troughs); if the cut stent has designs that increase the rod width, such as grooved drug loading, developing point crimping, etc., the rod width is still the rod width of the wave rod body.

[0040] The present invention provides a vascular stent and a manufacturing method thereof, so as to solve the problem of uniform supporting force in the overall design of the existing vascular stent.

[0041] The vascular stent provided by the present invention is mainly suitable for treating stenosis, and can be used to treat stenosis in various parts of the body, such as intracranial artery stenosis, vertebral artery stenosis, peripheral artery stenosis, etc.

[0042] The vascular stent provided by the present invention comprises a proximal end, a stent body, and a distal end, arranged in sequence along its axial direction. The support force of at least one of the proximal end and the distal end is less than that of the stent body. This reduces the support force of one or both ends of the stent on a non-diseased blood vessel segment, thereby reducing irritation to the non-diseased blood vessel segment.

[0043] The present invention provides a method for manufacturing a vascular stent, comprising: adjusting one or more structural design parameters so that the supporting force of the stent proximal end and / or the stent distal end is smaller than the supporting force of the stent body.

[0044] The present invention also provides a method for using a vascular stent, comprising: releasing the ends of the vascular stent into a non-lesioned area and releasing the main body of the vascular stent into a diseased area. This method reduces the irritation of the stent's ends to the non-lesioned vessel while ensuring the main body's support for the diseased vessel. This ensures that the stent's support force matches actual clinical needs, thereby improving the effectiveness of stenosis treatment.

[0045] The vascular stents provided herein can be either cut or braided. Cut stents are typically prepared by laser cutting a tubular material, followed by heat treatment, acid washing, and electrochemical treatment to obtain a desired stent structure. Alternatively, a braided wire can be woven into a desired pattern and then heat-set to obtain the desired stent. Alternatively, the vascular stent can be manufactured using additive manufacturing. The vascular stent is then integrated into a stent delivery system.

[0046] The delivery method of the vascular stent of the present invention is not limited. The more commonly used delivery methods are microcatheter delivery or pre-loaded delivery.

[0047] The vascular stent of the present invention is mainly made of metal or polymer materials, and the specific materials are not limited. Among them, the more common metal materials include nickel-titanium alloy, stainless steel, cobalt-chromium alloy, etc.

[0048] The vascular stent of the present invention can be biodegradable or non-degradable. For the biodegradable stent, commonly used biodegradable materials such as aluminum alloy, magnesium alloy, polylactic acid, polyester, etc. can be selected.

[0049] The vascular stent of the present invention can be a drug-eluting stent, which is loaded with drugs by groove loading and / or coating loading. The function of the drug in the drug-eluting stent is not limited, but preferably contains drugs such as rapamycin or paclitaxel that can reduce restenosis.

[0050] In order to enable those skilled in the art to better understand the technical solutions provided by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] <Example 1>

[0052] In Example 1 of the present application, the vascular stent is a cutting stent. Figure 1 This is a schematic side view of the cutting bracket provided in Example 1 of the present application.

[0053] like Figure 1 As shown, the vascular stent of this embodiment includes a proximal end 11, a main body 12, and a distal end 13, arranged in sequence along its axis. Both the proximal end 11 and the distal end 13 are anchoring segments, serving as anchors to prevent stent displacement. During use, the proximal end 11 and the distal end 13 are deployed in a non-lesioned location near or beyond the lesion area, while the main body 12, the lesion treatment segment, is deployed in the lesion area to support the blood vessel.

[0054] The vascular stent of this embodiment is a mesh-tube structure as a whole, wherein the meshes can be designed in various shapes, including but not limited to diamond shapes.

[0055] Furthermore, the vascular stent is formed by connecting a plurality of wave rings 14 in sequence in its own axial direction, and two axially adjacent wave rings 14 are connected by a connecting unit 15. Among them, the wave ring 14 is a ring structure formed by a plurality of repeating units 16 surrounding in sequence in a wavy manner. The number of connecting units 15 can be less than the number of peaks or troughs on the wave ring 14 connected thereto, or equal to the number of peaks or troughs on the wave ring 5 connected thereto. The connecting unit 15 can have various shapes, such as: one of a straight line shape, a curved line shape, a broken line shape, or a combination of multiple thereof. As an example, the connecting unit 15 adopts an "I" shape, an "S" shape, an "Ω" shape, or a "W" shape, or a combination of these shapes.

[0056] Furthermore, in order to address the problem of uniform support force throughout the existing vascular stent, this embodiment proposes to set at least one of the proximal end 11 of the stent and the distal end 13 of the stent to have a support force (i.e., radial support force) that is less than the support force (radial support force) of the stent body 12. With this arrangement, when the vascular stent is released in the body, the high support force of the stent body 12 at the lesion position can ensure the patency of the blood vessels and prevent plaque rebound, while the stent end at the non-lesion position provides a low support force, which can reduce the stimulation to the non-lesioned blood vessels, not only facilitating the endothelialization of the non-lesioned blood vessels, but also reducing the risk of long-term restenosis. In this way, the support force design of the cutting-type vascular stent is matched with actual clinical needs.

[0057] The supporting force of the proximal end 11 of the stent and the supporting force of the distal end 13 of the stent can be equal or unequal, especially considering that the supporting force of the proximal end 11 of the stent and the supporting force of the distal end 3 of the stent are equal, thereby simplifying the manufacturing process and reducing the manufacturing difficulty.

[0058] In one embodiment of the present invention, the support force at the proximal end 11 of the stent is less than the support force of the stent body 12, and the support force at the distal end 13 of the stent is equal to the support force of the stent body 12. The change in support force between the low support force section provided by the proximal end 11 of the stent and the high support force section provided by the stent body 12 can be gradual or abrupt.

[0059] In another embodiment of the present invention, the support force of the stent distal end 13 is less than the support force of the stent body 12, and the support force of the stent proximal end 11 is equal to the support force of the stent body 12. Similarly, the change in support force between the low support force section provided by the stent distal end 13 and the high support force section provided by the stent body 12 can be gradual or abrupt.

[0060] The above-mentioned gradual change in support force refers to a gradual increase in support force from the corresponding stent end to the stent body 12, so that the support force smoothly transitions from a lower support force segment to a higher support force segment. The above-mentioned sudden change in support force refers to a sudden increase in support force from the corresponding stent end to the stent body 12, so that the support force suddenly changes from a lower support force segment to a higher support force segment.

[0061] In a preferred embodiment of the present invention, the supporting force of the proximal end 11 of the stent and the supporting force of the distal end 13 of the stent are both smaller than the supporting force of the stent body 12, so that both ends of the vascular stent can provide low support sections, thereby better reducing stimulation to non-diseased blood vessels.

[0062] It should be understood that when the vascular stent of the present invention is deployed in a blood vessel with an inner diameter of D, the support force at the proximal end 11 of the stent is F1, the support force at the distal end 13 of the stent is F3, and the support force of the stent body 12 is F2. Preferably, F3 ≤ F1 < F2, and more preferably, F3 = F1, so that the support force at both ends of the stent remains the same, thereby reducing the difficulty of stent manufacturing.

[0063] Preferably, the ratio of the support force of the stent body 12 to the support force of the stent ends is 3 to 1. This ensures the anchoring performance of the stent ends while reducing irritation to non-diseased blood vessels. It should be understood that when the support force ratio is 1, the support force at one end of the vascular stent is consistent with the support force of the stent body 12, while the support force at the other end of the vascular stent is less than that of the stent body 12.

[0064] Optionally, F1, F2 and F3 are 0.1-500 KPa, more preferably, F1, F2 and F3 are 1-300 KPa. The support force data described herein can provide more stable support, prevent stent displacement, and better support blood vessels.

[0065] In practice, the difference between the supporting force of the stent end and the supporting force of the stent body 12 is achieved by adjusting one or more structural design parameters of the vascular stent.

[0066] The structural design parameters of the cut stent primarily include: wave bar width (i.e., rod width), stent wall thickness, number of repeating units, wave height, wave ring density, number of connecting units, connecting unit shape, connecting unit length, stent pattern design, stent material, stent outer diameter, and stent axial length. Preferably, the support force at the stent end can be reduced to be less than the support force of the stent body 12 by one or more measures, such as reducing the wave bar width, reducing the stent wall thickness, increasing the number of repeating units, increasing the wave height, reducing the wave ring density, reducing the number of connecting units, changing the connecting unit shape, increasing the connecting unit length, and changing the stent pattern design.

[0067] It should be recognized that many factors affect support force, and comprehensive consideration is needed to select the most appropriate structural design solution. This not only ensures the quality of the vascular stent, but also improves processing efficiency and reduces the technical difficulty of the process. Priority should be given to structural designs that are more convenient to design and process. For example, structural design parameters such as rod width and wave height can be adjusted to achieve different support forces between the distal and proximal ends of the stent and the stent body. This is relatively easier to achieve in terms of process and has lower difficulty.

[0068] refer to Figure 2 In the cutting stent, the main width of the wave rod is W (i.e., rod width), and the wave height is H. The wave height of the proximal end 11 of the stent is defined as the first wave height H1, the wave height of the stent body 12 is defined as the second wave height H2, and the wave height of the distal end 13 of the stent is defined as the third wave height H3.

[0069] In one embodiment of the present invention, H2 ≤ H1. Preferably, H2 / H1 = 0.2-1, and more preferably, H2 / H1 = 0.6-1. That is, the wave height (H1) of the stent proximal end 11 is greater than or equal to the wave height (H2) of the stent body 12. To reduce the support force of the stent proximal end 11 to that of the stent body 12, the wave height of the stent proximal end 11 can be increased or decreased. To ensure the flexibility and support of the stent, the wave heights of both the stent proximal end 11 and the stent body 12 must be adjusted to an appropriate range, neither too large nor too small.

[0070] In one embodiment of the present invention, H2 ≤ H3. Preferably, H2 / H3 = 0.2-1, and more preferably, H2 / H3 = 0.6-1. In this case, the wave height (H3) of the stent distal end 13 is greater than or equal to the wave height (H2) of the stent body 12. To reduce the support force of the stent distal end 13 to that of the stent body 12, the wave height of the stent distal end 13 can be increased or decreased. Similarly, the wave heights of both the stent distal end 13 and the stent body 12 must be adjusted to an appropriate range to ensure the stent's flexibility and support.

[0071] Preferably, H1=H3.

[0072] refer to Figure 3 In the cutting stent, the proximal end 11 of the stent has a first rod width W1, the stent body 12 has a second rod width W2, and the distal end 13 of the stent has a third rod width W3.

[0073] In one embodiment of the present invention, W1<W2, which makes the rod width of the proximal end 11 of the stent smaller than the rod width of the stent body 12, thereby making the supporting force of the proximal end 11 of the stent smaller than the supporting force of the stent body 12.

[0074] In one embodiment of the present invention, W3<W2, which makes the rod width of the stent distal end 13 smaller than the rod width of the stent body 12, thereby making the supporting force of the stent distal end 13 smaller than the supporting force of the stent body 12.

[0075] Preferably, W1=W3<W2, and W3:W2=0.3-1, whereby the support forces at the distal and proximal ends of the bracket are both smaller than the support forces of the bracket body 12, and the distal and proximal ends of the bracket also have the same rod width to reduce the difficulty of processing and manufacturing.

[0076] The width of the stents should not be too small, otherwise the stents will break easily. However, the width should not be too large, otherwise it will increase the stent material. Optionally, the first stent width W1 is between 15 μm and 200 μm, more preferably between 20 μm and 150 μm. Optionally, the second stent width W2 is between 15 μm and 300 μm, more preferably between 20 μm and 200 μm. Optionally, the third stent width W3 is between 15 μm and 200 μm, more preferably between 20 μm and 150 μm.

[0077] The proximal end 11 of the stent also has a first wall thickness B1, the stent body 12 has a second wall thickness B2, and the distal end 13 of the stent has a third wall thickness B3. Preferably, B1=B2=B3, that is, the wall thickness of the vascular stent is equal throughout, which is conducive to processing and manufacturing without increasing the difficulty of the process. Of course, in other embodiments, in order to make the supporting force of the stent end different from the supporting force of the stent body 12, the wall thickness of the stent end may be less than the wall thickness of the stent body 12. Optionally, B1, B2 and B3 are 15μm-200μm, and more preferably, B1, B2 and B3 are 40μm-150μm.

[0078] In one embodiment of the present invention, the number of repeating units 16 in the proximal end 11 of the stent is N1, the number of repeating units 16 in the main body 12 of the stent is N2, and the number of repeating units 16 in the distal end 13 of the stent is N3. N1, N2, and N3 can be the same or different. Preferably, N1 = N2 = N3. Optionally, N1, N2, and N3 are 4 to 20.

[0079] In one embodiment of the present invention, the structure of the corrugated ring 14 is modified to achieve different supporting forces. This can be achieved by changing the overall circumferential structure of the corrugated ring 5 or by changing a portion of the circumferential structure of the corrugated ring 5, ultimately resulting in the supporting force at the stent end being less than that of the stent body 12. In practice, the shape and size of the repeating units 16 in the corrugated ring 14 can be changed to increase or decrease the supporting force.

[0080] In one embodiment of the present invention, the shapes of the wave rings 14 in the stent proximal end 11, the stent body 12 and the stent distal end 13 are the same or different. Preferably, the wave rings 14 have the same shape.

[0081] In one embodiment of the present invention, the number of connection units 15 connected to two axially adjacent wave rings 14 in the stent proximal end 11, the stent body 12 and the stent distal end 13 is the same or different. Preferably, the number of connection units 15 is the same.

[0082] In one embodiment of the present invention, the shapes of the connection units 6 in the proximal end 11 of the stent, the main body 12 of the stent and the distal end 13 of the stent are the same or different. Preferably, the proximal end 11 of the stent, the main body 12 and the distal end 13 of the stent use connection units 15 of the same shape.

[0083] It should also be recognized that, when used clinically, the specifications of the vascular stent should be adapted to the size of the blood vessel, including the outer diameter of the stent and the axial length of the stent.

[0084] In this embodiment, the stent proximal end 11 has a first outer diameter D1 (maximum outer diameter), the stent body 12 has a second outer diameter D2, and the stent distal end 13 has a third outer diameter D3 (maximum outer diameter). The stent outer diameter refers to the size of the stent after full expansion, and the stent outer diameter is adapted to the inner diameter of the vessel to be intervened.

[0085] The outer diameter of the stent is designed based on the blood vessel size of most patients. In any embodiment of the present invention, the vascular stent preferably meets at least one of the following conditions:

[0086] The first outer diameter D1 is 1.5 mm to 20 mm, more preferably, the first outer diameter D1 is 2 mm to 10 mm;

[0087] The second outer diameter D2 is 1.5 mm to 20 mm, more preferably, the second outer diameter D2 is 2 mm to 10 mm;

[0088] The third outer diameter D3 is 1.5 mm to 20 mm, and more preferably, the third outer diameter D3 is 2 mm to 10 mm.

[0089] In particular, the following is considered: D<D2≤D1≤D3. In this way, the stent body 12 can better support the blood vessel and better anchor the two ends of the stent to prevent the stent from shifting. Where D is the inner diameter of the blood vessel.

[0090] In one embodiment of the present invention, D < D2 = D1 = D3, making the overall outer diameter of the stent uniform. In another embodiment of the present invention, D < D2 < D1 and D3, forming a flared shape at both ends of the stent, providing stronger anchoring. Preferably, D1 = D3.

[0091] In this embodiment, the stent proximal end 11 has a first axial length L1, the stent body 12 has a second axial length L2, and the stent distal end 13 has a third axial length L3. Axial length refers to the length of the stent along its axis after full expansion. The axial length of the stent body 12 is adapted to the length of the diseased area, while the axial lengths of the stent ends are adapted to the lengths of the non-lesioned area.

[0092] The axial length of the stent is designed based on the lesion size of most patients. In various embodiments of the present invention, the vascular stent preferably meets at least one of the following conditions:

[0093] The first axial length L1 is 1 mm to 20 mm, more preferably, the first axial length L1 is 3 mm to 15 mm;

[0094] The second axial length L2 is 5 mm to 200 mm, more preferably, the second axial length L2 is 10 mm to 80 mm;

[0095] The third axial length L3 is 1 mm to 20 mm. More preferably, the third axial length L3 is 3 mm to 15 mm.

[0096] In order to better understand the present invention, an exemplary structural design scheme is further provided. In this exemplary embodiment, other structural design parameters of the cutting stent are the same, such as the outer diameter, wall thickness, shape and number of repeating units, wave height, shape and number of connecting units are all the same, and it is suitable for blood vessel size D = 2.5mm-3.0mm. In this case, only the rod width is different, and only the rod width is changed to achieve different supporting forces. This is more convenient from the perspective of processing and design. Specifically, the rod width W2 of the stent body 12 is 35μm-40μm, the rod width W1 of the proximal end 11 of the stent is equal to the rod width W3 of the distal end 13 of the stent, and W1 = W3 = 20μm-30μm; when the vascular stent with this structural design is released in a blood vessel with an inner diameter of D, the support force F2 of the stent body 12 is 6KPa-7KPa, and the support forces F1 and F3 of the proximal end 11 and distal end 13 of the stent are 2.5KPa-3.5KPa, so that the support force of the cutting type vascular stent meets the actual clinical needs.

[0097] <Example 2>

[0098] In the second embodiment of the present application, the vascular stent is a braided stent. Figure 4 This is a schematic diagram of the structure of the braided stent provided in Example 2 of this application. Figure 5 for Figure 4 The structural design and use method of the braided stent provided in Example 2 are substantially the same as those of the cutting stent provided in Example 1, and the same parts will not be described again. The following mainly describes the differences.

[0099] like Figure 4 and Figure 5 As shown, the vascular stent of this embodiment is formed by interlacing multiple braided wires, with interlacing points formed between the braided wires. The vascular stent of this embodiment also includes a stent proximal end 21, a stent body 22, and a stent distal end 23, which are arranged in sequence along its own axis. Basically the same as the first embodiment, the stent proximal end 21 and the stent distal end 23 are both stent anchoring segments, which serve as anchoring. The stent proximal end 21 and the stent distal end 23 are used to release the stent at a non-lesioned position near or far from the lesion area, while the stent body 22 is the lesion treatment segment, which is released in the lesion area.

[0100] In the second embodiment of the present application, at least one of the stent proximal end 21 and the stent distal end 23 is configured to have a supporting force less than that of the stent body 22. Preferably, the supporting forces of both the stent proximal end 21 and the stent distal end 23 are less than that of the stent body 22, and more preferably, the supporting forces of the stent proximal end 21 and the stent distal end 23 are equal.

[0101] Figure 6 and Figure 7 The figure further illustrates the use of the braided stent when it is released into the diseased blood vessel. Figure 6 and Figure 7 As shown, when plaque causes vascular stenosis or occlusion, interventional stent placement can be used for treatment. During treatment, the stent body 22 is deployed in the diseased area to support the vessel and prevent plaque rebound. The proximal end 21 and distal end 23 of the stent are deployed in non-lesioned areas proximal and distal to the lesion, respectively, acting as anchors for the stent. This structure better matches the clinical characteristics of the diseased vessel, minimizing irritation to non-lesioned vessels and promoting endothelialization in non-lesioned vessels, thereby reducing the risk of long-term restenosis.

[0102] The structural design parameters of the braided stent mainly include: braiding wire diameter, braiding wire number, braiding density, braiding mesh area, braiding wire material, stent outer diameter, and stent axial length. Among them, the stent outer diameter and stent axial length can refer to Example 1 and will not be repeated here. The design concept of the braided stent also follows the comprehensive consideration of various factors to select the most appropriate structural design scheme, with the focus on simplifying the preparation process and reducing the difficulty of process technology. Simply put, the effect of the stent end support force being less than the stent main body support force can be achieved by replacing the proximal and distal ends with soft materials, reducing the number of braiding wires, replacing braiding wires with smaller diameters, reducing the braiding mesh density, and increasing the area of ​​a single braided mesh, and one or more of these methods can be selected for execution. It should also be noted that when adjusting the braiding mesh density and the braiding mesh area, the proximal and distal ends of the stent can be completely changed along the circumference or partially changed along the circumference, which can be adaptively adjusted according to actual needs.

[0103] Preferably, the braided wire material, number of braided wires, and diameter of the braided wires of the stent body 22 and the proximal and distal ends of the stent are the same, and only the braided mesh density is adjusted to adjust the support force of the stent body 22 and the proximal and distal ends of the stent. In more detail, the distance that a single braided wire rotates around the center of the stent is the intercept P. Figure 4 and Figure 5 As shown, the proximal end 11 of the stent has a first intercept P1, the stent body 12 has a second intercept P2, and the distal end 13 of the stent has a third intercept P3. Preferably, P2 < P1 ≤ P3, so that the support force of the proximal end 21 and the distal end 23 of the stent is less than the support force of the stent body 22, and the support force of the proximal end 21 and the support force of the distal end 23 are the same or different. Preferably, P1 = P3. Optionally, P1, P2, and P3 are 2 mm to 40 mm, and more preferably, P1, P2, and P3 are 4 mm to 15 mm.

[0104] For example, in an exemplary embodiment, the outer diameter of the stent, the braiding wire material, the number of braiding wires, the braiding wire diameter and the braiding method are all the same, and only the intercept is adjusted to change the support force, wherein the intercept P2 of the stent body 22 is 8mm-10mm, the intercept P1 of the proximal end 21 of the stent is equal to the intercept P3 of the distal end 23 of the stent, and P1 is equal to P3 and is equal to 11mm-13mm; when a vascular stent of this structure is released in an applicable blood vessel (blood vessel size D is equal to 2.5mm-3.0mm), the support force F2 of the stent body 22 is 0.6KPa-1.2KPa, and the support forces F1 and F3 of the proximal end 21 and distal end 2 of the stent are 0.2KPa-0.5KPa, thereby making the support force of the braided vascular stent meet the actual clinical needs.

[0105] In summary, in the vascular stent of the present invention, because the support force at at least one of the proximal and distal ends of the stent is less than that of the stent main body, the irritation of one or both ends of the stent on non-diseased blood vessels is reduced, thereby facilitating the endothelialization process of non-diseased blood vessels and reducing the risk of long-term restenosis. Furthermore, during the manufacture of the vascular stent, by adjusting one or more structural design parameters to achieve a difference in the support force between one or both ends of the stent and the stent main body, particularly considering adjusting only one structural design parameter while leaving the other parameters unchanged, this can significantly reduce the difficulty of process design and make the manufacture of the vascular stent easier.

[0106] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. The systems disclosed in the embodiments are described briefly because they correspond to the methods disclosed in the embodiments. For relevant details, refer to the method description.

[0107] It should also be noted that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or to modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A vascular stent, characterized in that: The stent comprises a stent proximal end, a stent main body and a stent distal end which are sequentially arranged along its own axial direction, and the supporting force of at least one of the stent proximal end and the stent distal end is smaller than the supporting force of the stent main body.

2. The vascular stent according to claim 1, wherein: The supporting force of the proximal end of the stent and the supporting force of the distal end of the stent are both smaller than the supporting force of the stent body, and the supporting force of the proximal end of the stent and the supporting force of the distal end of the stent are the same.

3. The vascular stent according to claim 1 or 2, characterized in that: When the vascular stent is a cutting stent, the rod width of at least one of the proximal end of the stent and the distal end of the stent is smaller than the rod width of the stent body, and / or the wave height of at least one of the proximal end of the stent and the distal end of the stent is greater than the wave height of the stent body.

4. The vascular stent according to claim 3, wherein: The wave height of the proximal end of the stent is equal to the wave height of the distal end of the stent, and the wave height of the stent body is smaller than the wave height of the proximal end of the stent.

5. The vascular stent according to claim 4, characterized in that: The ratio of the wave height of the stent body to the wave height of the proximal end of the stent is 0.2-1.

6. The vascular stent according to claim 3, wherein: The rod width of the proximal end of the bracket is equal to the rod width of the distal end of the bracket, and the rod width of the bracket body is greater than the rod width of the proximal end of the bracket.

7. The vascular stent according to claim 6, wherein: The ratio of the width of the proximal end of the stent to the width of the stent body is 0.3-1.

8. The vascular stent according to claim 1 or 2, characterized in that: When the vascular stent is a braided stent, the braiding wire intercept of at least one of the proximal end of the stent and the distal end of the stent is greater than the braiding wire intercept of the stent body.

9. The vascular stent according to claim 8, wherein: The braided wire intercept at the proximal end of the stent is equal to the braided wire intercept at the distal end of the stent, and the braided wire intercept of the stent body is smaller than the braided wire intercept at the proximal end of the stent.

10. A method for manufacturing a vascular stent, characterized in that: For preparing the vascular stent according to any one of claims 1 to 9, the manufacturing method comprises: One or more structural design parameters are adjusted so that the supporting force of the proximal end of the stent and / or the distal end of the stent is smaller than the supporting force of the stent body.

11. The method for manufacturing a vascular stent according to claim 10, wherein: When the vascular stent is a cutting stent, the structural design parameters include the rod width and wave height of the cutting stent. Only the rod width and / or wave height of the cutting stent are adjusted so that the supporting force of the proximal end and / or the distal end of the stent is smaller than the supporting force of the stent body.

12. The method for manufacturing a vascular stent according to claim 11, wherein: When adjusting the wave height, the wave height at the proximal end of the bracket is made equal to the wave height at the distal end of the bracket, and the wave height of the bracket body is made smaller than the wave height at the proximal end of the bracket.

13. The method for manufacturing a vascular stent according to claim 11, wherein: When adjusting the rod width, the rod width at the proximal end of the bracket is made equal to the rod width at the distal end of the bracket, and the rod width of the bracket body is made greater than the rod width at the proximal end of the bracket.

14. The method for manufacturing a vascular stent according to claim 10, wherein: When the vascular stent is a braided stent, the structural design parameters include the braiding wire intercept of the braided stent. Only the braiding wire intercept of the braided stent is adjusted to make the supporting force of the proximal end and / or the distal end of the stent smaller than the supporting force of the stent body.

15. The method for manufacturing a vascular stent according to claim 14, wherein: The braided wire intercept at the proximal end of the stent is made equal to the braided wire intercept at the distal end of the stent, and the braided wire intercept of the stent body is made smaller than the braided wire intercept at the proximal end of the stent.

Images