Spherical expansion conical support

Abstract

The utility model provides a ball expansion conical support which comprises a design unit and a connecting unit, the design unit comprises a plurality of support rods and a plurality of wave heads, the support rods are arranged at intervals, and every two adjacent support rods are sequentially connected in series through each wave head to form an annular structure; the number of the design units is multiple, the connecting unit is connected between the wave heads of every two adjacent design units, the radial supporting force Fn of the nth design unit from the near end to the far end of the stent is smaller than the radial supporting force Fn-1 of the (n-1) th design unit, and n is larger than or equal to 2 and smaller than or equal to 200. According to the utility model, the radial supporting force of the stent from the near end to the far end is set, so that the expanded stent can retract to different degrees at different positions under the action of the return pressure of a blood vessel in a lesion area, thereby forming a conical stent which is very matched with the conical shape of the blood vessel. The support and the conical pipeline have good fitting degree.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of medical apparatus and instruments, specifically relates to a conical support, more specifically relates to a self -adaptation ball expansion conical support. BACKGROUND

[0002] There are many cavity structures in human body, including blood vessels, biliary tract, pancreas, esophagus, trachea, urethra and intestinal tract, etc. These cavity structures are prone to pathological changes under certain conditions, resulting in lumen stenosis or occlusion, and further causing a series of safety hazards. For example, vascular stenosis or occlusion leading to vascular ischemia is an important reason to threaten human health, and stent implantation is an important means to treat lumen stenosis or occlusion. The ball expansion stent is implanted by balloon expansion at the lesion site to support the stenosis and occlusion segment of the lumen and keep the lumen unobstructed. However, some lumens in the human body, such as femoral artery and below-knee artery, have significant tapering characteristics, with the diameter of the proximal end being significantly larger than that of the distal end. With the increase of the length of the lumen, the tapering effect becomes more and more significant, and the difference between the diameters of the proximal end and the distal end becomes more and more obvious.

[0003] At present, the ball expansion stent commonly used in clinical practice for tapered vascular lesion area is still of round straight design. However, the ball expansion stent of round straight design still has some problems in practical application. For example, when selecting a vascular stent, if the stent is selected according to the proximal vessel, after expansion with a round straight balloon, the stent will over-expand the small blood vessel at the distal end and maintain its close lumen to the proximal end, which not only damages the distal blood vessel, but also causes a large difference in lumen diameter between the over-expanded blood vessel at the distal end of the stent and the adjacent healthy blood vessel, resulting in blood flow stagnation and further causing dissection. If the stent is selected according to the diameter of the distal vessel, it is easy to cause over-expansion of the proximal stent and breakage, and also causes insufficient radial support of the proximal stent and cannot effectively support the blood vessel.

[0004] Although the above problems can be bypassed by directly using a conical balloon to expand a round-straight designed balloon stent into a conical shape to adapt to the conical blood vessel, this method not only has a great dependence on the shape of the balloon, but also will face new challenges. Since the shape of the round-straight designed stent after expansion mainly depends on the conical balloon, and the stent will have different degrees of recoil after expansion, it is easy to cause the final shape of the stent to not match the shape of the blood vessel itself (such as the taper), thereby causing poor adhesion of the stent to the blood vessel. In addition, since the diameters of the blood vessels corresponding to the proximal end and the distal end of the stent are different, the radial support force required by the completely occluded conical blood vessel at different positions in the length direction will also have certain differences. The larger the diameter of the blood vessel, the greater the recoil pressure of the blood vessel on the stent, and the greater the support force required by the stent; the smaller the diameter of the blood vessel, the smaller the recoil pressure of the blood vessel on the stent, and the smaller the support force required by the stent. The stent with a round-straight design has uniform pattern design, and the distal end of the stent is over-expanded, the proximal end of the stent is under-expanded, and the edge is peeled off, so that the stent has insufficient performance in some parts or excessive performance in some parts, thereby causing the round-straight stent to be unable to self-adjust the conical lesion in the application of the conical blood vessel, and still having the problem of poor adhesion. Practical new type content

[0005] In order to overcome the defects and deficiencies of the prior art, the present application provides a self-adaptive balloon-expanded conical stent which can be self-adapted to a conical shape matching the blood vessel in the blood vessel, has high adhesion to the blood vessel wall, and well meets the use requirement of the adhesion of the conical stent.

[0006] The present application provides a balloon-expanded conical stent, which comprises a design unit and a connecting unit, the design unit comprises a plurality of stent rods and a plurality of wave heads, each wave head sequentially connects two adjacent stent rods to form a ring structure, and the connecting unit is connected between the wave heads of two adjacent design units. And in the direction from the proximal end to the distal end of the stent, the radial support force F n of the nth design unit is set to be less than the radial support force F n-1 of the (n-1)th design unit.

[0007] In the above technical solution provided by the present application, the radial support force F n of the nth design unit from the proximal end to the distal end of the stent is [0.5-1]:1 or (0.7-1]:1 times the radial support force F n-1 of the (n-1)th design unit; or the radial support force F n of the nth design unit is [0.42-0.69]:1 or (0.7-1]:1 times the radial support force F1 of the first design unit; wherein 2≤n≤200.

[0008] In the above-mentioned technical solution provided in this application, the radial support force F of the nth design unit of the stent from the proximal end to the distal end is... n The radial support force F of the (n-1)th design unit n-1 The ratio is M n-1 The radial support force F of the (n-1)th design unit n-1 and the radial support force F of the (n-2)th design unit n-2 The ratio is M n-2 The M n-1 With M n-2 The difference is between [-0.25, 0.25]; and / or the M n-2 With M n-1 The following relationship must be satisfied: M n-2 =aM n-1 +b, where a∈[-1,4], b∈[-1,1]; 3≤n≤200.

[0009] In the above-mentioned technical solution provided in this application, the radial support force F1 of the first design unit of the stent from the proximal end to the distal end and the radial support force F of the nth design unit are... n The difference is between [2kPa, 200kPa].

[0010] In the above-mentioned technical solution provided in this application, the radial support force F1 of the first design unit is 60kPa-250kPa, and the radial support force F of the nth design unit is... n The magnitude is 50kPa-200kPa.

[0011] In the above-described technical solution provided in this application, the total length C of the nth design unit of the stent from the proximal end to the distal end is... n The total length C of the (n-1)th design unit n-1 Short, where 2≤n≤200.

[0012] In the above-mentioned technical solution provided in this application, the total length C of the nth design unit of the stent from the proximal end to the distal end is... n The total length C of the (n-1)th design unit n-1 The ratio is (0.9-1):1; where 2≤n≤200.

[0013] In the above-mentioned technical solution provided in this application, when the stent is expanded and fitted to a conical blood vessel, the length l of the nth design unit of the stent from the proximal end to the distal end is... n The length l of the (n-1)th design unit n-1 The length l of the design unit is 0.5-1 times that of the design unit.

[0014] In the above-mentioned technical solution provided in this application, the cross-sectional area S of the support rod of the nth design unit from the proximal end to the distal end of the support is... n The cross-sectional area S of the support rod of the (n-1)th design unit n-1 The ratio is 0.064:1-1:1; where 0.0040m 2 ≤S n ≤0.0625m 2 0.0040≤S n-1 ≤0.0625.

[0015] In the above-mentioned technical solution provided in this application, when the stent is expanded and fitted to the conical blood vessel, the included angle α formed by the extended lines of two adjacent stent struts of the nth design unit from the proximal end to the distal end of the stent is... n The angle α formed by the extension lines of the two adjacent support rods of the (n-1)th design unit n-1 The ratio is 1:1-1.67:1, and / or the included angle α formed by the extension lines of two adjacent support rods of the nth design unit from the proximal end to the distal end of the support. n The ratio of the angle α1 formed by the extended lines of the two adjacent support rods of the first design unit is 1:1-1.67:1, where 30°≤α n <50°, 30°≤α n-1 <50°.

[0016] In the above-mentioned technical solution provided in this application, the wall thickness of the nth design unit of the stent from the proximal end to the distal end is less than the wall thickness of the (n-1)th design unit; wherein, the wall thickness of each design unit is 10% or less of the radial diameter of the blood vessel lumen at the implantation site.

[0017] In the above-mentioned technical solution provided in this application, under the back pressure of the conical blood vessel, the maximum retraction rate of the design unit is 5%-80%; the retraction rate of the nth design unit from the proximal end to the distal end of the stent is greater than the retraction rate of the (n-1)th design unit.

[0018] In the above-mentioned technical solutions provided in this application, the total length of the spherical expansion conical support is 38mm-300mm.

[0019] In the above-mentioned technical solution provided in this application, the taper β of the spherical expansion tapered bracket is 72°-90°.

[0020] In the above-mentioned technical solution provided in this application, the fit between the balloon-expanding tapered stent and the blood vessel is ≥85%.

[0021] In the above-mentioned technical solution provided in this application, the proximal diameter of the spherical expansion conical stent is 2.5mm-8mm, and the distal diameter of the spherical expansion conical stent is 2mm-7.5mm.

[0022] The present application sets the relative size of the radial support force between two adjacent design units reasonably, so that the radial support force of different parts of the stent and the back pressure received from the external blood vessel are fully matched, so that after the stent is expanded, it can be well matched with the shape of the blood vessel and the severity of the plaque, fully resist the extrusion force of the blood vessel, ensure the stability of the shape of the stent, and perfectly fit the tapered cross section of the blood vessel, have good wall adhesion, provide good support for the blood vessel lesion area, and do not have clear requirements for the shape of the balloon used, which is convenient to use. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0024] Figure 1 is a planar expansion schematic diagram of the ball-expanding tapered stent provided by the embodiments of the present application;

[0025] Figure 2 is a schematic diagram of the ball-expanding tapered stent after expansion in air provided by the embodiments of the present application;

[0026] Figure 3 is a partial schematic diagram of the ball-expanding tapered stent after expansion in a blood vessel provided by the embodiments of the present application;

[0027] Figure 4 is a cross-sectional schematic diagram of the stent rod provided by the embodiments of the present application;

[0028] Figure 5 is a poor wall adhesion OCT schematic diagram provided by the embodiments of the present application.

[0029] 1, stent; 11, design unit; 111, stent rod; 112, wave head; 12, connection unit. DETAILED DESCRIPTION

[0030] The following is only a preferred embodiment of the present application, and the present application is not limited to the following preferred embodiment. As described in the embodiments, the stent is taken as an example, but it does not mean that the technical solutions of the present application are only applicable to the stent. It should be pointed out that, on the basis of the inventive concept of the present application, a number of modifications and improvements made by those skilled in the art all belong to the protection scope of the present application. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained from the market.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0032] Test Method:

[0033] Radial support force

[0034] The radial support force of the spherically-expanding conical stent 1 and each design unit 11 in the present application is obtained by testing with a radial support force tester produced by MSI Company through the following method:

[0035] After the spherically-expanding conical stent 1 is expanded to its nominal diameter D' in vitro, the part of the spherically-expanding conical stent 1 to be tested is put into the radial support force tester to simulate the actual force state of the spherically-expanding conical stent 1 in the blood vessel, so that the spherically-expanding conical stent 1 is compressed and deformed under the action of the pressure head. The pressure intensity of the spherically-expanding conical stent 1 is measured when the diameter of the spherically-expanding conical stent 1 is reduced to 90% of the nominal diameter D of the spherically-expanding conical stent 1 in the radial compression process. The "nominal diameter" refers to the diameter of the stent when it is fully expanded under the nominal pressure, and the "nominal pressure" refers to the pressure required to fully expand the stent in clinical practice. The "fully expanded" refers to the state when the stent is expanded to match the diameter of the lumen where it is applied. The radial support force of each design unit 11 can be characterized by cutting out a single design unit 11 as an independent spherically-expanding conical stent 1 to represent its radial support force.

[0036] Fitting degree

[0037] The "fitting degree" described in the present application refers to the degree of fit between the stent rod 111 of the spherically-expanding conical stent 1 and the blood vessel wall after implantation and expansion. That is, the fitting degree M is equal to the total number of stent rods 111 of the spherically-expanding conical stent that are well fitted with the blood vessel wall after implantation 贴合 to the total number of all stent rods 111 of the spherically-expanding conical stent 总 :

[0038]

[0039] Wherein "well fitted" refers to the distance between the stent rod 111 and the blood vessel wall being less than or equal to 0.2 mm. The fitting degree in the present application is observed by using intravascular imaging devices such as OCT (optical coherence tomography) and IVUS (intravascular ultrasound) to observe the fitting condition of each stent rod 111 of the spherically-expanding conical stent 1 with the blood vessel wall, and then determine the overall fitting degree value of the spherically-expanding conical stent 1.

[0040] In this application embodiment, "proximal" and "distal" are defined as follows: with the distance between the entire bulbous conical stent 1 and the heart after it is implanted into the living body as a reference, the end closer to the heart is the proximal end, and the end farther from the heart is the distal end.

[0041] like Figure 1 and Figure 2 As shown in the embodiment of this application, an adaptive spherical conical support 1 includes a design unit 11 and a connecting unit 12. The design unit 11 includes multiple support rods 111 and multiple corrugated heads 112. The support rods 111 are spaced apart, and the corrugated heads 112 sequentially connect adjacent support rods 111 to form a ring structure. Specifically, each support rod 111 is constructed into a corresponding shape according to design requirements, such as adjacent support rods 111 being inclined or parallel to each other. Then, adjacent support rods 111 are sequentially connected by corrugated heads 112 to form a closed ring structure. Optionally, the design unit 11 formed by connecting the support rods 111 and corrugated heads 112 can be a continuous corrugated structure. In this way, with the support from the near end to the far end as the reference direction, each corrugated head 112 becomes the crest and trough of the corrugated structure, respectively. Multiple design units 11 are provided, and the number of design units 11 can be selected according to the length requirements of the support to be constructed. Two adjacent design units 11 can be arranged with peaks opposite each other, troughs opposite each other, or peaks and troughs opposite each other. The connecting unit 12 connects the wave heads 112 of two adjacent design units 11. That is, the connecting unit 12 can connect between peaks, between peaks and troughs, or between troughs. The specific connection method can be selected according to design requirements. (Refer to...) Figure 1 Between two adjacent design units 11, the two opposite wave heads 112 are set as a group. This can be done by setting two or more groups apart and then connecting the two opposite wave heads 112 with connecting units 12. This can achieve the connection between each design unit 11, while reducing the number of connecting units 12 on the entire support, which is beneficial to reducing the amount of material used in the support.

[0042] In this embodiment, the radial support force F of the nth design unit 11 of the bracket is used. n Set to a radial support force F less than that of the (n-1)th design unit 11. n-1Where 2≤n≤200. In this way, by reasonably setting the relative magnitude of the radial support force between two adjacent design units 11, after the stent expands, under different back pressures from the external blood vessels, different parts of the stent will deform differently according to the pressure magnitude. This allows it to match well with the shape of the blood vessel and the severity of the plaque, effectively resisting the squeezing force of the blood vessel, ensuring the stability of the stent shape, and perfectly conforming to the conical blood vessel. It has good wall adhesion, provides good support to the vascular lesion area, and does not have specific requirements for the shape of the balloon used, making it easy to use.

[0043] The balloon-expandable conical stent 1 provided in this embodiment achieves adjustable radial support force along its length by adopting the above design, and can be expanded into a conical shape using a round straight balloon. The radial support force of the conical stent 1 decreases along the axial direction of the stent. Utilizing the differences in plaque size, plaque hardness, and vascular taper at different locations in the vascular lesion area, different back pressures are applied to the corresponding design units 11 of the stent. As a result, the design units 11 at different positions of the expanded stent will retract to different degrees under the action of the corresponding back pressure, thus forming a certain taper from the proximal end to the distal end. Moreover, the taper of the stent can be well matched with the taper of the blood vessel, thereby achieving a good wall apposition effect.

[0044] In this embodiment, the support rod 111 and the wave head 112 can be made of the same material or different materials. The materials can be non-degradable or degradable materials that meet the requirements for use with the support. Degradable materials can be such as iron, iron-based alloys, magnesium, magnesium-based alloys, zinc, zinc-based alloys, or absorbable polymers, while the non-degradable parts can be made of materials such as nickel-titanium alloys, cobalt-chromium alloys, or stainless steel.

[0045] The spherical expansion cone bracket 1 provided in this application, along the direction from the proximal end to the distal end, has a radial support force F of the nth design unit 11. n The radial support force F of the (n-1)th design unit 11 n-1 The value is [0.5, 1] ​​times, where 2 ≤ n ≤ 300. Further, the radial support force F of the nth design unit 11 from the proximal end to the distal end of the spherical conical support 1... n The radial support force F of the (n-1)th design unit 11 n-1 The values ​​are [0.55, 1] ​​times, [0.6, 1] times, [0.65, 1] ​​times, [0.7, 1] times, [0.75, 1] ​​times, [0.8, 1] times, [0.85, 1] ​​times, [0.88, 1] times, [0.5, 0.999] times, [0.5, 0.99] times, [0.55, 0.95] times, or [0.6, 0.95] times. In some embodiments of this application, F n For Fn-1 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.98, 0.99, 0.999 or 0.9999 times; in other embodiments, F n may be F n-1 0.52, 0.58, 0.62, 0.72, 0.78, 0.82, 0.88, 0.9, 0.92, 0.95, 0.96, 0.98 or 0.985 times, in yet other embodiments, F n may be F n-1 any value between [0.5, 1], such as 0.63 times, and so on. In still other embodiments, F n may be F n-1 any value between [0.5, 1), such as F n may be F n-1 [0.63, 0.87] times, and so on.

[0046] In some possible embodiments of the present application, the ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can be [0.42, 0.69]: 1 or (0.7, 1]: 1. n The ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can also be [0.42, 0.69]: 1 or (0.7, 1]: 1. Further, the ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can be [0.42, 0.69]: 1 or (0.7, 1]: 1. n The ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can also be [0.42, 0.69]: 1 or (0.7, 1]: 1. Further, the ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can be [0.42, 0.69]: 1 or (0.7, 1]: 1. n The ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can also be [0.42, 0.69]: 1 or (0.7, 1]: 1. Further, the ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can be [0.42, 0.69]: 1 or (0.7, 1]: 1. n The ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can also be [0.42, 0.69]: 1 or (0.7, 1]: 1. Further, the ratio of the radial support force Fn of the nth design unit 11 to the radial support force F1 of the first design unit 11 can be [0.42, 0.69]: 1 or (0.7, 1]: 1.

[0047] In some embodiments, the ratio of the radial support force of each two adjacent design units 11 is equal, such as F3 / F2=F2 / F1=F4 / F3=F5 / F4=F6 / F5=F8 / F7, and so on; in other embodiments, the ratio of the radial support force of any two adjacent design units 11 is not equal, such as F3 / F2≠F2 / F1≠F4 / F3≠F5 / F4≠F6 / F5≠F8 / F7, and so on; in still other embodiments, the ratio of the radial support force of some two adjacent design units 11 is equal, and the ratio of the radial support force of some other two adjacent design units 11 is not equal, such as F3 / F2≠F2 / F1≠F4 / F3, while F5 / F4=F6 / F5=F8 / F7, or F3 / F2≠F5 / F4≠F8 / F7, while F2 / F1=F4 / F3=F6 / F5, that is, the radial support force of each design unit 11 in the present application can decrease at equal proportions or at non-equal proportions.

[0048] In the embodiments, the ratio of the radial support force F n of the nth design unit to the radial support force F n-1 of the (n-1)th design unit is M n-1 , the ratio of the radial support force F n-1 of the (n-1)th design unit to the radial support force F n-2 of the (n-2)th design unit is M n-2 , the difference between M n-1 and M n-2 is between [-0.25, 0.25], and / or M n-2 and M n-1 satisfy M n-2 =aM n-1 +b, where a∈[-1, 4], b∈[-1, 1], and 3≤n≤200. Further, the difference between M n-1 and M n-2 is between [-0.15, 0.15], and / or M n-2 and M n-1 satisfy M n-2 =aM n-1 +b, where a∈[-1, 3], b∈[-1, 1], and 3≤n≤200. By using such a design, the support performance of each design unit 11 in the ball-expanding conical stent 1 has a large adjustment space, and can be designed to have different performances according to actual application needs, thereby obtaining a stent having a practical shape, which can well adhere to the vessel wall at the implantation site, avoiding the problems of increased thrombosis risk and restenosis in the stent caused by poor stent adhesion.

[0049] In some embodiments provided in the present application, the difference between the radial support force F1 of the first design unit 11 and the radial support force F n of the nth design unit 11 is located in the interval [2kPa, 200kPa] along the direction from the proximal end to the distal end of the spherically-expanding conical stent 1. Further, the difference between the radial support force F1 of the first design unit 11 and the radial support force F n of the nth design unit 11 can be located in a new interval range formed by any two values in the interval [2kPa, 200kPa], such as the difference between F1 and F n is located in the interval [2kPa, 180kPa], [2kPa, 160kPa], [5kPa, 180kPa], [5kPa, 160kPa], [6kPa, 150kPa], [8kPa, 145kPa], [5kPa, 145kPa], [2kPa, 145kPa], [10kPa, 145kPa], [12kPa, 145kPa] or [15kPa, 145kPa]. Further, the difference between the radial support force F1 of the first design unit 11 and the radial support force F n of the nth design unit 11 is located in the interval [3kPa, 150kPa]; further, the difference between the radial support force F1 of the first design unit 11 and the radial support force F n of the nth design unit 11 is located in the interval [8kPa, 140kPa]; further, the difference between the radial support force F1 of the first design unit 11 and the radial support force F n of the nth design unit 11 is located in the interval [12kPa, 110kPa]. The difference between the radial support force F1 and F n is too large or too small, which is easy to cause the proximal end support force of the stent to be excessive or the distal end support force to be insufficient, which is easy to cause the proximal end support force of the stent to be excessive and excessively bind the blood vessel, the distal end support force to be insufficient and the blood vessel to rebound excessively, so that the stent cannot well support the blood vessel, and at the same time, the adhesion performance of the stent is also easy to be greatly affected, and finally, the problems of increased risk of thrombosis in the blood vessel and restenosis of the stent are caused. In the present application, by adopting the above setting mode of the radial support force of each design unit 11 in the stent, the use requirements of the support performance and the adhesion performance of the stent are well met.

[0050] In the above technical solutions provided in the present application, the radial support force F1 of the proximal end of the spherically-expanding conical stent 1 is 60kPa-250kPa, and the radial support force F nThe magnitude is 50kPa-200kPa. Further, the radial support force at the proximal end of the spherical expansion conical stent 1 is 65kPa-200kPa, and the radial support force at the distal end is 50kPa-180kPa; even further, the radial support force at the proximal end of the spherical expansion conical stent 1 is 70kPa-180kPa, and the radial support force at the distal end is 55kPa-150kPa; even further, the radial support force at the proximal end of the spherical expansion conical stent 1 is 75kPa-140kPa, and the radial support force at the distal end is 55kPa-130kPa.

[0051] In this embodiment of the application, along the direction of the stent from the proximal end to the distal end, the total length C of the nth design unit 11 is used. n The total length C of the (n-1)th design unit 11 n-1 The ratio is (0.9-1):1; where 2≤n≤200. Specifically, as can be seen from the above, each design unit 11 consists of multiple support rods 111 and multiple wave heads 112. Therefore, the total length of each design unit 11 refers to the sum of the lengths of all support rods 111 and wave heads 112 on that design unit 11. This application sets the total length C of the nth design unit 11. n The total length C of the (n-1)th design unit 11 n-1 The proportional relationship can be adjusted by changing the total length of the support rods 111 and wavefronts 112 on each design unit 11 to change the magnitude of the radial support force. That is, the longer the total length of the support rods 111 and wavefronts 112 on each design unit 11, the higher the metal coverage of the design unit 11 under the same expansion diameter, thus its resistance to radial deformation is greater, and the radial support force is greater. Furthermore, the longer the total length of the support rods 111 and wavefronts 112 on each design unit 11, the more material is available to meet the material length requirements during expansion deformation, thereby enabling expansion into different shapes to adapt to different blood vessel shapes and improve the fit with the blood vessel. In this application, the radial support force can be changed by adjusting the number of support rods on the design unit 11 and the length of the design unit 11. n This can be achieved through at least one of the following methods, such as adjusting the size and shape of the wave head. When the total length C of the design unit 11 is achieved by adjusting the number of support rods of the design unit 11, the total length C of the design unit 11 is realized. n When the size is such that the number of support rods in the first design unit 11 from proximal to distal is less than 15% more than the number of support rods in the nth design unit 11; further, the number of support rods in the first design unit 11 from proximal to distal is less than 10% more than the number of support rods in the nth design unit 11; and even further, the number of support rods in the first design unit 11 from proximal to distal is less than 5% more than the number of support rods in the nth design unit 11.

[0052] In this embodiment of the application, when the stent is expanded and conforms to the conical blood vessel, the length l of the nth design unit 11 is increased along the direction of the stent from the proximal end to the distal end. n Set as the (n-1)th design unit, length l n-1 0.5-1 times. Further, the length of the nth design unit 11 is 0.55-1, 0.58-1, 0.6-1, 0.55-0.98, 0.6-0.95, 0.65-1, or 0.65-0.98 times the length of the (n-1)th design unit 11; even further, the length of the nth design unit 11 is 0.65-0.9, 0.7-0.98, or 0.7-0.95 times the length of the (n-1)th design unit 11.

[0053] In the technical solutions provided in this application embodiment, when the stent is expanded and conforms to the conical blood vessel, the length l of the stent design unit 11 is 0.4mm-2.0mm. Further, the length of the stent design unit 11 is 0.5mm-2.0mm; even further, the length l of the stent design unit 11 is 0.8mm-2.0mm. (Refer to...) Figure 1 The length l of the design unit 11 mentioned above refers to the distance between two wave heads 112 in the same design unit 11, along the direction from the proximal end to the distal end of the support.

[0054] In the above-mentioned technical solution provided in this application, along the direction of the support from the proximal end to the distal end, the cross-sectional area S of the support rod 111 of the nth design unit 11 is... n The cross-sectional area S of the support rod 111 of the (n-1)th design unit 11 n-1 The ratio is 0.064:1-1:1; where 0.0040m 2 ≤S n ≤0.0625m 2 0.0040m 2 ≤S n-1 ≤0.0625m 2 . Reference Figure 4The cross-sectional area of ​​the support rod 111 is obtained by multiplying the width W of the support rod at the cross-section by the wall thickness H of the support rod. Since the wall thickness H of the support rod gradually decreases from the near end to the far end, while the width W of the support rod remains constant or gradually decreases, the cross-sectional area of ​​the support rod 111 also gradually decreases. Specifically, the wall thickness of the nth design unit 11 is less than the wall thickness of the (n-1)th design unit 11. This can be because the average wall thickness of the nth design unit 11 is less than the average wall thickness of the (n-1)th design unit 11; or the wall thickness of each design unit 11 gradually and uniformly decreases from the near end to the far end, meaning the wall thickness of the support rod in a single design unit 11 gradually and uniformly decreases; or the wall thickness of the support rod in a single design unit 11 is a fixed value, but the wall thickness of adjacent design units 11 shows a decreasing trend. This design allows the radial support force of the stent to decrease gradually from the proximal end to the distal end. After the stent is implanted in the blood vessel, the different back pressures from the external blood vessel will cause it to retract to varying degrees, forming a taper that matches the blood vessel well. This results in good apposition performance and meets the requirements for stent apposition performance.

[0055] like Figure 1 and Figure 4 As shown, in the spherical expansion conical support 1 provided in this embodiment, the support rod wall thickness H gradually decreases from the proximal end to the distal end. In some other embodiments, from the proximal end to the distal end, the support rod width W may gradually narrow; in some embodiments, from the proximal end to the distal end, the support rod width W of some design units 11 remains unchanged, while the support rod width W of some design units 11 gradually narrows; and in some embodiments, the support rod width W remains unchanged from the proximal end to the distal end.

[0056] like Figure 4As shown, the cross-sectional area of ​​the support rod 111 is the product of the support rod width W and the support rod wall thickness H. In one embodiment, the support rod width W in the leftmost design unit 11 can be 105 μm and the support rod wall thickness H can be 70 μm, while the support rod width W in the rightmost design unit 11 can be 92 μm and the support rod wall thickness H can be 55 μm. Or in another embodiment, the support rod width W in the leftmost design unit 11 is 160 μm and the support rod wall thickness H is 115 μm, while the support rod width W in the rightmost design unit 11 is 136 μm and the support rod wall thickness H is 90 μm. Or in yet another embodiment, the support rod width W in the leftmost design unit 11 is 160 μm and the support rod wall thickness H is 115 μm, while the support rod width W in the rightmost design unit 11 is 105 μm and the support rod wall thickness H is 70 μm. Alternatively, in another embodiment, the support rod width W in the leftmost design unit 11 is 160 μm, and the support rod wall thickness H is 115 μm; the support rod width W in the rightmost design unit 11 is 92 μm, and the support rod wall thickness H is 55 μm. The specific dimensions can be selected according to design requirements. The "support rod wall thickness" of the design unit mentioned in this application refers to the average wall thickness of the support rod in the design unit. This can be a fixed, definite value, or it can be a gradually changing, non-fixed, definite value.

[0057] In the above-mentioned technical solution provided in this application, the stent wall thickness is 10% or less of the radial diameter of the implanted blood vessel lumen. Generally speaking, the smaller the diameter of the blood vessel, the more sensitive it is to the stent rod wall thickness H. This is because, for the same stent rod wall thickness, although the space occupied in the radial direction of the blood vessel lumen is the same for different blood vessel diameters, the radial proportion of the stent rod wall thickness varies greatly. For example, when the stent rod wall thickness H is 100 μm, the proportion of the stent rod wall thickness in the radial direction of blood vessel diameters of 2 mm, 3 mm, and 4 mm is 10%, 6.7%, and 5%, respectively. When the proportion of the stent wall thickness in the radial direction of the blood vessel is large, it will significantly affect the hemodynamics of local blood flow through the stent rod 111, making it easier for blood to adhere and deposit on the stent rod 111, increasing the risk of thrombosis within the stent. Therefore, this application can effectively improve the impact of stent rod wall thickness on hemodynamics by designing the stent rod wall thickness. Furthermore, the stent 1 provided in this application has a wall thickness of 6% or less of the radial diameter of the implanted blood vessel lumen, such as 5%, 3%, etc.

[0058] Please refer to Figure 1 In some possible implementations, when the stent is expanded and conforms to a tapered vessel, the included angle α formed by the extension lines of two adjacent stent struts 111 of the nth design unit 11 is... nThe angle α formed by the extension lines of the two adjacent support rods 111 of the (n-1)th design unit 11 n-1 Large. Furthermore, in the direction from the near end to the far end, the included angle α formed by the extension lines of two adjacent support rods 111 of the nth design unit 11. n The angle α formed by the extension lines of the two adjacent support rods 111 of the (n-1)th design unit 11 n-1 The ratio is [1-1.67]:1, and / or the included angle α formed by the extension lines of two adjacent support rods of the nth design unit from the proximal end to the distal end of the support. n The ratio of the angle α1 formed by the extended lines of the two adjacent support rods of the first design unit is 1:1-1.67:1, where 30°≤α n <50°, 30°≤α n-1 <50°. The angle formed by the extensions of two adjacent stent struts 111 directly affects the stent's support force. As the angle increases, it helps reduce the radial support force of the stent, thus allowing the stent to ultimately form a taper that matches the shape of the blood vessel well. The angle α formed by the extensions of two adjacent stent struts 111 is also simply called the stent angle.

[0059] In some possible implementations, after stent expansion, under the action of the conical vessel, the shrinkage rate B of design unit 11 is 0%-80%; further, after stent expansion, under the action of the conical vessel, the shrinkage rate B of design unit 11 is 2%-80%; further, after stent expansion, under the action of the conical vessel, the shrinkage rate B of design unit 11 is 2%-66%; further, after stent expansion, under the action of the conical vessel, the shrinkage rate B of design unit 11 is 2%-50%; and even further, after stent expansion, under the action of the conical vessel, the shrinkage rate B of design unit 11 is 3%-45%. In some embodiments of this application, after stent expansion, under the action of the conical vessel, the retraction rate B of design unit 11 is 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 38%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%; in other embodiments of this application, after stent expansion, under the action of the conical vessel, the retraction rate B of design unit 11 is 6%, 9%, 12%, 18%, 22%, 28%, 32%, 38%, 42%, 48%, 52%, 58%, 62%, 68%, or 69%.

[0060] Understandably, according to design requirements, the length of the stent is formed by connecting multiple design units 11, and the recoil rate B of each design unit 11 is between 0% and 80%. The recoil rate B of some design units 11 being 0% means that one or more of these design units 11 may not recoil after expansion, resulting in a recoil rate of 0%. The other design units 11, under the influence of the cone-shaped vessel, undergo a certain amount of recoil, and ultimately the overall shape of the stent remains essentially cone-shaped.

[0061] In some possible implementations, under the back pressure of the tapered vessel, the maximum recoil rate of each design unit 11 is 5%-80%. That is, each design unit 11 of the stent has a certain recoil rate, but the maximum recoil rate of the stent design unit 11 is within the range of 5%-80%. In other words, among the multiple design units 11 of the stent, some design units 11 have a recoil rate of less than 5%, or even 0%, while the largest design unit among the many design units 11 has a recoil rate between 5% and 80%. Specifically, in some implementations, the maximum recoil rate of the stent design unit 11 may be 5%; in some implementations, the maximum recoil rate of the stent design unit 11 may be 10%; in some implementations, the maximum recoil rate of the stent design unit 11 may be 15%; in some implementations, the maximum recoil rate of the stent design unit 11 may be 25%; in some implementations, the maximum recoil rate of the stent design unit 11 may be 35%; and in some other implementations, the maximum recoil rate of the stent design unit 11 may be 45%, and so on. The "retraction rate" B mentioned in this application is 100% * (D2 - D1) / D2, where: D1 is the diameter of the middle part of the design unit 11 after it is expanded and retracted in a blood vessel by a balloon of a certain magnitude; D2 is the diameter of the middle part of the same design unit 11 of the stent after it is expanded in vitro by the same balloon of the same magnitude. For example, when a design unit 11 of the stent is expanded in a blood vessel by a balloon with a force of 8 atm (atm is a commonly used unit of atmospheric pressure, the value of 1 standard atmosphere is denoted as 1 atm), after the balloon retracts and is subjected to the back pressure of the blood vessel wall, the final diameter D1 of the design unit 11 is 2.1 mm, while the diameter D2 of the design unit 11 after being expanded in vitro by the same balloon with a force of 8 atm is 2.5 mm. Then the retraction rate B of the design unit 11 is... n =100%*(2.5-2.1) / 2.5=16%.

[0062] In this application, the recoil rate of a certain part of the stent depends on the diameter of the reference vessel at that location, the magnitude of the stent's supporting force at that location, and the relative relationship between the two. After the stent expands within the vessel, it is affected by the vessel's back pressure. The larger the reference vessel diameter, the smaller the back pressure on the stent; conversely, if the stent's supporting force is greater, the stent will recoil less. The smaller the reference vessel diameter, the greater the back pressure on the stent; and if the stent's supporting force is smaller, the stent will recoil more. If the stent does not adaptively conform to the vessel wall, the stent strut 111 may easily become suspended inside the vessel, thereby increasing the risk of in-stent thrombosis.

[0063] In the above-mentioned technical solutions provided in this application, the length of the bracket is 38mm-300mm.

[0064] The “length of the stent” as described in this application refers to the axial length of the stent when it is implanted in the body and expanded to its final state.

[0065] The “reference vessel diameter” mentioned in this application refers to the vessel diameter within 5 mm at both ends of the vascular lesion location.

[0066] In the above-mentioned technical solutions provided in this application, the proximal diameter of the stent is 2.5-8mm, and the distal diameter is 2mm-7.5mm.

[0067] In the above-mentioned technical solutions provided in this application, the taper β of the stent is 72°-90°. Further, the taper β of the stent is 75°-90°; further still, the taper β of the stent is 80°-90°; and even further, the taper β of the stent is 85°-90°. The "taper" mentioned in this application refers to the overall tilt of the stent from proximal to distal in its final state after implantation and retraction under the force of the blood vessel. Specifically, refer to... Figure 3 Draw a straight line a1 perpendicular to the proximal cross-section from one end of the stent, and draw a straight line a2 between the two ends of the stent, which is the taper of the stent. The angle between the straight lines a1 and a2 is β, which is the taper of the stent.

[0068] In the above-mentioned technical solutions provided in this application, the stent substrate is any material suitable for ball-and-socket stents, including but not limited to pure iron-based, iron-based alloys, cobalt-chromium alloys, magnesium-based alloys, pure magnesium-based, pure zinc-based, zinc-based alloys and polymer-based materials.

[0069] Among them, iron-based alloys are iron-based alloys with a carbon content of no more than 2.11 wt.%.

[0070] In the above-mentioned technical solutions provided in this application, the stent is at least one of vascular stents, biliary stents, pancreatic stents, esophageal stents, tracheal stents, urethral stents, and intestinal stents. Further, the vascular stent includes a peripheral stent; even further, the vascular stent includes a femoral artery stent and an infrakal stent.

[0071] In the above-mentioned technical solution provided in this application, the fit between the stent and the blood vessel is ≥85%. Further, the fit between the stent and the blood vessel is ≥88%; even further, the fit between the stent and the blood vessel is ≥90%.

[0072] The balloon-expandable conical stent 1 provided in this application embodiment is formed by adjusting at least one of the following parameters: the circumference of the stent rod 111 in each design unit 11, the cross-sectional area of ​​the stent rod 111, and the included angle between two adjacent stent rods 111. This results in a balloon-expandable conical stent 1 with radial support force decreasing along the stent axis. When this balloon-expandable conical stent 1 is delivered to the lumen, such as the vascular lesion area, by the delivery system, it expands and depressurizes in the lesion area. Due to the different radial support forces at different parts of the stent, the back pressure from the external blood vessel also varies, causing it to retract to varying degrees and eventually rebound to form an ideal cone shape. This effectively matches the taper of the blood vessel and provides good apposition to the vessel wall. That is, the stent provided in this application can adaptively form a cone shape from the proximal end to the distal end under the back pressure of the blood vessel wall in the cone-shaped vascular lesion area. The balloon-expandable cone-shaped stent 1 does not have specific requirements for the shape of the balloon used during the expansion process. Even when a round and straight balloon is present, it can adaptively form a cone shape with good wall adhesion according to the shape of the cone-shaped blood vessel in the lesion area. The requirements for the shape of the balloon used for expansion are low, which greatly improves the convenience of use and operation.

[0073] To facilitate understanding of this application, the design features of this application are illustrated below with reference to some specific embodiments. It should be understood that the relevant embodiments are merely illustrative examples of the solution presented in this application and do not constitute a limitation on the scope of application.

[0074] Example One

[0075] A spherical expansion conical support 1 is provided, which is composed of 38 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are Ω-shaped. The axial length l of each design unit 11 gradually decreases from the proximal end to the distal end, and is successively 1.17mm, 1.16mm, 1.15mm, 1.14mm, 1.12mm, 1.11mm, 1.10mm, 1.09mm, 1.08mm, 1.07mm, 1.06mm, 1.05mm, 1.04mm, 1.03mm, 1.02mm, 1.01mm, and 1.00mm. The lengths are 0.99mm, 0.98mm, 0.97mm, 0.96mm, 0.95mm, 0.94mm, 0.93mm, 0.92mm, 0.91mm, 0.90mm, 0.89mm, 0.88mm, 0.87mm, 0.87mm, 0.86mm, 0.85mm, 0.84mm, 0.83mm, 0.82mm, 0.81mm, and 0.80mm. The total length C of the support rods and wavefronts in each design unit decreases proportionally from the near end to the far end. The total length C1 of the first design unit 11 is 22.31mm, and the total length C of the 38th design unit 11 is... 38 It is 12.75mm in diameter and has a common ratio of 0.985.

[0076] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases proportionally from the near end to the far end along the axial direction. The included angle α1 of the first design unit 11 is 31.0°, and the common ratio is 1.002. The wall thickness of the design unit at the nearest end of the support is 70μm, and the wall thickness of the design unit at the farthest end is 55μm. Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod decreases proportionally from the near end to the far end along the axial direction. The cross-sectional area S1 of the support rod in the first design unit 11 is 0.00735 mm². 2 The cross-sectional area S of the support rod in design unit 11 of the 38th design unit 38 It is 0.00507mm 2 The common ratio is 0.99.

[0077] refer to Figure 1The radial support forces of each design unit from proximal to distal in the above-mentioned stent design are 150 kPa, 148 kPa, 147 kPa, 145 kPa, 144 kPa, 142 kPa, 140 kPa, 139 kPa, 137 kPa, 136 kPa, 134 kPa, 133 kPa, 131 kPa, 130 kPa, 128 kPa, 127 kPa, and 126 kPa, respectively. a, 124kPa, 123kPa, 122kPa, 120kPa, 119kPa, 118kPa, 116kPa, 115kPa, 114kPa, 113kPa, 11 1kPa, 110kPa, 109kPa, 108kPa, 106kPa, 105kPa, 104kPa, 103kPa, 102kPa, 101kPa and 100kPa.

[0078] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 4 mm using a straight balloon, with the diameters of each design unit 11 at both the distal and proximal ends remaining consistent. The stent length was 40 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 4 mm, a distal reference vessel diameter of 2 mm, a length of 40 mm, and a vessel taper of 88.6°. Because the radial support force of the stent decreased along its length, and this decreasing trend perfectly matched the conical structure of the vessel and the location and size of plaques on the vessel, when the stent was implanted under the expansion force of the cylindrical balloon, the stent shrank to a conical shape that fully conformed to the conical vessel, without over-dilation of the vessel or residual stenosis. The maximum recoil rate of each design unit was 50%, and the fit was calculated to be 96% using OCT testing, indicating good stent apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 5.5%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0079] Example Two

[0080] A spherical expansion conical support 1 is provided, which is composed of 40 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are S-shaped. The axial length of each design unit 11 gradually decreases from the proximal end to the distal end, and the lengths l of each design unit are 1.49mm, 1.48mm, 1.48mm, 1.47mm, 1.47mm, 1.46mm, 1.46mm, 1.45mm, 1.45mm, 1.44mm, 1.44mm, 1.43mm, 1.43mm, 1.42mm, 1.41mm, 1.41mm, 1.40mm, and 1.4... 0mm, 1.39mm, 1.39mm, 1.38mm, 1.38mm, 1.37mm, 1.37mm, 1.36mm, 1.36mm, 1.35mm, 1.35mm, 1.34mm, 1.34mm, 1.33mm, 1.33mm, 1.32mm, 1.32mm, 1.31mm, 1.31mm, 1.30mm, 1.30mm, 1.29mm, 1.29mm. The total length C of the support rod and wave head of each design unit decreases proportionally from the near end to the far end. The total length C1 of the first design unit 11 is 35.76mm, and the common ratio is 0.993.

[0081] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases proportionally from the near end to the far end along the axial direction. The included angle α1 of the first design unit 11 is 31.0°, and the common ratio is 1.007. The wall thickness of the design unit at the nearest end of the support is 115μm, and the wall thickness of the design unit at the farthest end is 90μm. Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod decreases proportionally along the axial direction from the near end to the far end. The cross-sectional area S1 of the support rod in the first design unit 11 is 0.01840 mm². 2 The cross-sectional area S of the support rod in the 40th design unit 11 40 It is 0.01195mm 2 The common ratio is 0.989.

[0082] refer to Figure 1The radial support forces of each design unit of the above-mentioned stent, from proximal to distal, are 200 kPa, 198 kPa, 197 kPa, 195 kPa, 194 kPa, 192 kPa, 191 kPa, 189 kPa, 188 kPa, 186 kPa, 185 kPa, 183 kPa, 182 kPa, 181 kPa, 179 kPa, 178 kPa, 176 kPa, and 175 kPa, respectively. 174kPa, 172kPa, 171kPa, 170kPa, 168kPa, 167kPa, 166kPa, 164kPa, 163kPa, 162kPa, 161kPa, 159kPa, 158kPa, 157kPa, 156kPa, 154kPa, 153kPa, 152kPa, 151kPa, 150kPa, 149kPa, 147kPa.

[0083] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 8 mm using a straight balloon, with the diameters of the distal and proximal design units 11 remaining consistent, and the stent length being 58 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 5 mm, a length of 55 mm, and a vessel taper of 88.4°. Due to the decreasing radial support force along the length of the stent, it shrank to a conical shape that fully conformed to the conical vessel, without over-dilation or residual stenosis. The maximum shrinkage rate was 37.5%, and the fit was calculated to be 97% using OCT testing, indicating good stent apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 3.6%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0084] Example Three

[0085] A spherical expansion conical support 1 is provided, which is composed of 80 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are Ω-shaped. The axial length of each design unit 11 gradually decreases from the proximal end to the distal end. Specifically, the lengths l1-l of the 1st to 20th design units are... 20 All are 1.49mm, and the length l of the 21st to 40th design units 21 -l 40 All are 1.40mm, and the length l of the 41st to 60th design units 41 -l 60 All are 1.37mm, and the length l of the 61st to 80th design units 61 -l 80All are 1.30mm. The total length C of the support rod and wave head of each design unit decreases proportionally from the near end to the far end, with a common ratio of 0.997. The total length C1 of the first design unit is 35.76mm.

[0086] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases axially from the proximal end to the distal end. The included angle α1-α in the 1st to 20th design units 11 is... 20 The included angle α of design units 11 from the 21st to the 40th is 31.0°. 21 -α 40 The included angle α is 34.7°, from the 41st to the 60th design unit 11. 41 -α 60 The included angle α of design units 11 from the 61st to the 80th is 36.2°. 61 -α 80 The angle is 40.2°. The wall thickness of the design unit at the closest end of the support is 115 μm, and the wall thickness of the design unit at the furthest end is 90 μm. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod gradually decreases along the axial direction from the proximal end to the distal end. The cross-sectional areas of the support rods in design units 1 to 20 are S1-S. 20 It is 0.01840mm 2 The cross-sectional area S of the support rods in design units 11 from the 21st to the 40th 21 -S 40 It is 0.01542mm 2 The cross-sectional area S of the support rods in design units 11 from the 41st to the 60th 41 -S 60 It is 0.01443mm 2 The cross-sectional area S of the support rods in design units 11 from the 61st to the 80th 61 -S 80 It is 0.01222mm 2 .

[0087] Reference Figure 1 The radial support force F1-F of the first to 20th design units 11 of the above-mentioned stent design from proximal to distal end is... 20 All are 200 kPa, the radial support force F of design units 11 from the 21st to the 40th is 200 kPa. 21 -F 40 All are 176 kPa, the radial support force F of design units 11 from the 41st to the 60th is 176 kPa. 41 -F 60 All are 168 kPa, the radial support force F of design units 11 from the 61st to the 80th is 168 kPa.61 -F 80 Both are 150 kPa.

[0088] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 8 mm using a straight balloon, with all design units 11 having the same diameter from distal to proximal end, and a stent length of 120 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 7.5 mm, a length of 120 mm, and a vessel taper of 89.9°. Due to the decreasing radial support force along the length of the stent, it shrank to a conical shape that fully conformed to the conical vessel, without over-dilation or residual stenosis. The maximum shrinkage rate was 6.25%, and the fit was calculated to be 95% using OCT testing, indicating good stent apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 3.6%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0089] Example Four

[0090] A spherical expansion conical support 1 is provided, which is composed of 200 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are S-shaped. The axial length of each design unit 11 gradually decreases from the proximal end to the distal end, specifically the length l1-l of the 1st to the 50th design units. 50 All are 1.40mm, design units 51 to 100. 51 -l 100 All are 1.37mm, design units 101 to 150. 101 -l 150 All are 1.30mm, design units 151 to 200. 151 -l 200 All are 1.175mm. The total length of the support rod and wave head of each design unit decreases proportionally from the near end to the far end, with a common ratio of 0.998. The total length C1 of the first design unit is 35.76mm.

[0091] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases axially from the proximal end to the distal end. The included angle α1-α in the 1st to 50th design units 11 is... 50 The included angle α is 34.7°, from the 51st to the 100th design unit 11. 51 -α 100The included angle α is 36.2°, from the 101st to the 150th design unit 11. 101 -α 150 The included angle α is 40.2°, from the 151st to the 200th design unit 11. 151 -α 200 The angle is 42.2°. The wall thickness of the design unit at the closest end of the support is 115 μm, and the wall thickness of the design unit at the furthest end is 70 μm. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod gradually decreases along the axial direction from the proximal end to the distal end. The cross-sectional areas S1-S of the support rods in design units 11 from the 1st to the 50th are as follows. 50 All are 0.01840mm 2 The cross-sectional area S of the support rods in design units 11 from the 51st to the 100th 51 -S 100 It is 0.01542mm 2 The cross-sectional area S of the support rods in design units 101 to 150 is... 101 -S 150 It is 0.01222mm 2 The cross-sectional area S of the support rods in design units 11 from the 151st to the 200th is... 151 -S 200 It is 0.00735mm 2 .

[0092] refer to Figure 1 The radial support force F1-F of the above-mentioned stent from the proximal end to the distal end of the 1st to 50th design units. 50 The radial support force F of design units 51 to 100 is 200 kPa. 51 -F 100 The radial support force F of design units 101 to 150 is 176 kPa. 101 -F 150 The radial support force F of the 151st to 200th design units is 150 kPa. 151 -F 200 The value is 140 kPa.

[0093] like Figure 2As shown, the stent was expanded in air to a nominal diameter of 8 mm using a straight balloon, with the diameters of the distal and proximal design units 11 being consistent, and the stent length being 300 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 4 mm, a length of 300 mm, and a vessel taper of 89.6°. Due to the decreasing radial support force along the length of the stent, it shrank to a conical shape that fully conformed to the conical vessel, without over-dilation or residual stenosis. The maximum shrinkage rate was 50%, and the fit was calculated to be 93% using OCT testing, indicating good stent apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 3.5%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0094] Example Five

[0095] A spherical expansion conical support 1 is provided, which is composed of 27 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are S-shaped. The axial length of each design unit 11 gradually decreases from the proximal end to the distal end. Specifically, the lengths ι1-ι9 of the 1st to 9th design units 11 are all 1.49 mm, and the lengths ι1-ι9 of the 10th to 18th design units 11 are... 10 -l 18 The length l of design unit 11 from the 19th to the 27th is 1.30mm. 19 -l 27 The length is 1.17 mm. The total length C of the support rods 111 and wavefronts 112 in each design unit 11 decreases proportionally from the proximal end to the distal end, with a common ratio of 0.987. The total length C1 of the first design unit 11 is 35.76 mm. Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases from the proximal end to the distal end. Specifically, the included angles α1-α9 of the 1st to 9th design units 11 are all 31.0°, and the included angles α1-α9 of the 10th to 18th design units 11 are... 10 -α 18 All are 34.7°, and the included angle α of design units 11 from the 19th to the 27th is 34.7°. 19 -α 27 Both are 36.2°. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod gradually decreases along the axial direction from the near end to the far end. Specifically, the cross-sectional areas S1-S9 of the support rod 111 in design units 1 to 9 are 0.01840 mm². 2The cross-sectional area S of the support rod 111 in design units 10 to 18 10 -S 18 It is 0.01222mm 2 The cross-sectional area S of the support rod 111 in design units 19 to 27 19 -S 27 It is 0.00735mm 2 .

[0096] refer to Figure 1 The radial support force F1-F9 of the first to ninth design units 11 in the above-mentioned design bracket, from proximal to distal, is 200 kPa, and the radial support force F of the tenth to eighteenth design units 11 is... 10 -F 18 The radial support force F of design units 11 from the 19th to the 27th is 150 kPa. 19 -F 27 The value is 100 kPa.

[0097] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 8 mm using a straight balloon. The diameter of the design unit 11 at the distal and proximal ends of the stent remained consistent, and the stent length was 40 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 2 mm, a length of 40 mm, and a vessel taper of 85.7°. Because the radial support force of the stent decreased along its length, and this decreasing trend perfectly matched the conical structure of the vessel and the location and size of plaques on the vessel, the stent shrank to a cone shape that fully conformed to the conical vessel, without over-dilation of the vessel or residual stenosis. The maximum recoil rate of each design unit 11 was 75%, and the fit was calculated to be 88% using OCT testing, indicating good stent wall adhesion. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 5.5%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0098] Example Six

[0099] A spherical expansion conical support 1 is provided, which is composed of 38 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are Ω-shaped. The axial length l of each design unit 11 gradually decreases from the proximal end to the distal end, and is successively 1.17mm, 1.16mm, 1.15mm, 1.14mm, 1.12mm, 1.11mm, 1.10mm, 1.09mm, 1.08mm, 1.07mm, 1.06mm, 1.05mm, 1.04mm, 1.03mm, 1.02mm, 1.01mm, and 1.00mm. 0.99mm, 0.98mm, 0.97mm, 0.96mm, 0.95mm, 0.94mm, 0.93mm, 0.92mm, 0.91mm, 0.90mm, 0.89mm, 0.88mm, 0.87mm, 0.87mm, 0.86mm, 0.85mm, 0.84mm, 0.83mm, 0.82mm, 0.81mm, 0.80mm. The total length C of the support rods and wavefronts in each design unit decreases proportionally from the near end to the far end, with C1 being 22.31mm. The total length C5-C1 for design units 5 to 10 is... 10 Decrease by a ratio of 0.905, and decrease the rest by a ratio of 0.985.

[0100] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases proportionally from the proximal end to the distal end along the axial direction, with α1 being 31.0°. The included angle α1-α2 in the 1st to 11th design units 11 is... 11 Increasing by a ratio of 1.002, the included angle α of design units 11 from the 12th to the 36th is... 12 -α 36 Increasing by a ratio of 1.01, the included angle α of the 37th design unit 11... 37 Increasing by a ratio of 1.45, the included angle α of the 38th design unit 11... 38 Increase by a scale of 1.008. The wall thickness of the design unit at the closest end of the support is 70 μm, and the wall thickness of the design unit at the furthest end is 55 μm. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod decreases proportionally from the proximal end to the distal end along the axial direction, and the cross-sectional area S1 of the support rod is 0.00735 mm². 2 S 38 It is 0.00507mm 2 The common ratio is 0.99.

[0101] refer toFigure 1 The support forces of each design unit in the above-mentioned stent design, from proximal to distal, are 150 kPa, 148 kPa, 147 kPa, 144 kPa, 141 kPa, 138 kPa, 134 kPa, 131 kPa, 128 kPa, 125 kPa, 128 kPa, 126 kPa, 125 kPa, 124 kPa, 123 kPa, 122 kPa, 121 kPa, 120 kPa, 119 kPa, 118 kPa, 116 kPa, 115 kPa, 114 kPa, 112 kPa, 110 kPa, 109 kPa, 108 kPa, 107 kPa, 106 kPa, 105 kPa, 104 kPa, 102 kPa, 101 kPa, 99 kPa, 98 kPa, 97 kPa, 90 kPa, and 88 kPa, respectively.

[0102] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 4 mm using a straight balloon, with the diameters of each design unit 11 at both the distal and proximal ends remaining consistent. The stent length was 40 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 4 mm, a distal reference vessel diameter of 2 mm, a length of 40 mm, and a vessel taper of 88.6°. Because the radial support force of the stent decreased along its length, and this decreasing trend perfectly matched the conical structure of the vessel and the location and size of plaques on the vessel, when the stent was implanted under the expansion force of the cylindrical balloon, the stent shrank to a conical shape that fully conformed to the conical vessel, without over-dilation of the vessel or residual stenosis. The maximum recoil rate of each design unit was 50%, and the fit was calculated to be 93% using OCT testing, indicating good stent apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 5.5%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0103] Example Seven

[0104] A spherical expansion conical support 1 is provided, which is composed of 38 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are Ω-shaped. The axial length ι of each design unit 11 gradually decreases from the proximal end to the distal end, and is successively 1.17mm, 1.16mm, 1.15mm, 1.14mm, 1.12mm, 1.11mm, 1.10mm, 1.09mm, 1.08mm, 1.07mm, 1.06mm, 1.05mm, 1.04mm, 1.03mm, 1.02mm, 1.01mm, and 1.00mm. 0.99mm, 0.98mm, 0.97mm, 0.96mm, 0.95mm, 0.94mm, 0.93mm, 0.92mm, 0.91mm, 0.90mm, 0.89mm, 0.88mm, 0.87mm, 0.87mm, 0.86mm, 0.85mm, 0.84mm, 0.83mm, 0.82mm, 0.81mm, 0.80mm. The total length C of the support rod and wave head of each design unit decreases proportionally from the near end to the far end. The total length C1 of the first design unit 11 is 22.31mm, and the total length C5-C of the fifth to tenth design units 11 is... 10 Decrease by a ratio of 0.905, and decrease the rest by a ratio of 0.985.

[0105] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases proportionally from the proximal end to the distal end along the axial direction. The included angle α1 of the first design unit 11 is 31.0°, and the included angle α1-α of the first to eleventh design units 11 is... 11 Increasing by a ratio of 1.002, the included angle α of design units 11 from the 12th to the 36th is... 11 -α 36 Increasing by a ratio of 1.01, the included angle α of the 37th design unit 11... 37 Increasing proportionally by 1.1, the included angle α of the 38th design unit 11... 38 Increase by a scale of 1.008. The wall thickness of the design unit at the closest end of the support is 70 μm, and the wall thickness of the design unit at the furthest end is 55 μm. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod decreases proportionally from the proximal end to the distal end along the axial direction, and the cross-sectional area S1 of the support rod is 0.00735 mm². 2 S 38 It is 0.00507mm 2 The common ratio is 0.99.

[0106] refer to Figure 1 The supporting forces of each design unit of the above-mentioned stent, from proximal to distal end, are 150 kPa, 148 kPa, 147 kPa, 144 kPa, 141 kPa, 138 kPa, 134 kPa, 131 kPa, 128 kPa, 125 kPa, 128 kPa, 126 kPa, 125 kPa, 124 kPa, 123 kPa, 122 kPa, 121 kPa, 120 kPa, 119 kPa, 118 kPa, 116 kPa, 115 kPa, 114 kPa, 112 kPa, 110 kPa, 109 kPa, 108 kPa, 107 kPa, 106 kPa, 105 kPa, 104 kPa, 102 kPa, 101 kPa, 99 kPa, 98 kPa, 97 kPa, 96 kPa, and 95 kPa, respectively.

[0107] like Figure 2 As shown, the stent was expanded in air to a nominal diameter of 4 mm using a straight balloon, with the diameters of each design unit 11 at both the distal and proximal ends remaining consistent. The stent length was 40 mm. It was implanted into a conical vessel with a proximal reference vessel diameter of 4 mm, a distal reference vessel diameter of 2 mm, a length of 40 mm, and a vessel taper of 88.6°. Because the radial support force of the stent decreased along its length, and this decreasing trend perfectly matched the conical structure of the vessel and the location and size of plaques on the vessel, when the stent was implanted under the expansion force of the cylindrical balloon, the stent shrank to a conical shape that fully conformed to the conical vessel, without over-dilation of the vessel or residual stenosis. The maximum recoil rate of each design unit was 50%, and the fit was calculated to be 99.5% using OCT testing, indicating good stent wall apposition. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 5.5%. No thrombosis occurred after stent implantation, and the vessel remained patent one year after implantation.

[0108] To further illustrate the technical effects of the spherical expansion conical support 1 proposed in this application, five comparative examples are now described exemplarily.

[0109] Comparative Example One

[0110] The support structure comprises 38 design units, each with a length of 1.17 mm. The total length of the support rods and wavefronts within each unit is 22.31 mm. The included angle between any two adjacent support rods is 31°. The support rods are 105 μm wide and 100 μm thick, resulting in a cross-sectional area of ​​0.0105 mm². 2 The radial support force of the support is 150 kPa.

[0111] The obtained stent was expanded in air using a straight balloon to a nominal diameter of 4 mm, with consistent diameters at both proximal and distal ends, and a length of 48 mm. It was then implanted into a tapered vessel with a proximal reference vessel diameter of 4 mm, a distal reference vessel diameter of 2 mm, a length of 48 mm, and a vessel taper of 88.8°. Because the radial support force of the stent remained constant along the linear direction, the distal vessel was over-expanded due to excessive support force, resulting in severe tearing. The stent did not recoil. A thrombus quickly clung to the distal stent, leading to restenosis and occlusion within the stent. OCT testing showed a fit of 97%, and the stent wall thickness accounted for a maximum of 10% of the radial direction of the implanted vessel lumen, preventing excessive thrombosis.

[0112] Comparative Example Two

[0113] The support structure comprises 38 design units, each with a length of 1.17 mm. The total length of the support rods and wavefronts within each unit is 22.31 mm. The included angle between any two adjacent support rods is 31°. The support rods are 105 μm wide and 100 μm thick, resulting in a cross-sectional area of ​​0.0105 mm². 2 The radial support force of the support is 150 kPa.

[0114] The stent obtained above was expanded in air using a straight balloon to a nominal diameter of 4 mm, with consistent diameters at both proximal and distal ends, and a length of 48 mm. It was then implanted into a tapered vessel with a proximal reference vessel diameter of 5 mm, a distal reference vessel diameter of 3 mm, a length of 48 mm, and a vessel taper of 88.8°. Because the radial support force of the stent remained constant along the linear direction, the distal end of the vessel was over-expanded due to excessive support force, resulting in severe tearing. The maximum recoil rate in each design unit was 5%. Thrombi quickly climbed onto the distal stent, leading to restenosis and occlusion within the stent. At the proximal end, insufficient stent expansion prevented adequate adhesion to the vessel wall. OCT calculations showed an adhesion of only 70%, which also resulted in rapid thrombus climbing onto the suspended stent strut at the proximal end, causing restenosis and occlusion within the stent. Simultaneously, the maximum proportion of the stent wall thickness in the radial direction of the implanted vessel lumen was 6.6%, less than 10%, thus avoiding excessive irritation to the vessel and the risk of thrombosis.

[0115] Comparative Example Three

[0116] The support structure comprises 38 design units, each with a length of 1.17 mm. The total length of the support rods and wavefronts within each unit is 22.31 mm. The included angle between any two adjacent support rods is 31°. The support rods are 105 μm wide and 100 μm thick, resulting in a cross-sectional area of ​​0.0105 mm². 2The radial support force of the support is 150 kPa.

[0117] The stent obtained above was expanded in air using a straight balloon to a nominal diameter of 4 mm, with consistent diameters at both proximal and distal ends, and a length of 48 mm. It was then implanted into a tapered vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 4 mm, a length of 48 mm, and a vessel taper of 87.6°. Because the radial support force of the stent remained constant along the linear direction, the distal support force was appropriate, the stent expanded sufficiently, the stent adhered well to the vessel, and there was no stent recoil. (Reference) Figure 5 Due to insufficient stent expansion at the proximal end of the vessel, it could not fully adhere to the vessel wall. OCT testing showed that the fit was only 30%, which led to rapid thrombus formation on the suspended stent strut at the proximal end, resulting in restenosis and occlusion within the stent. Simultaneously, the stent wall thickness should not exceed 5% of the radial diameter of the implanted vessel lumen, and should not be less than 10%, to avoid excessive irritation to the vessel and subsequent thrombosis.

[0118] Comparative Example Four

[0119] The support structure comprises 38 design units, each with a length of 1.17 mm. The total length of the support rods and wavefronts within each unit is 22.31 mm. The included angle between any two adjacent support rods is 31°. The support rods are 105 μm wide and 100 μm thick, resulting in a cross-sectional area of ​​0.0105 mm². 2 The radial support force of the bracket is 150 kPa, the nominal diameter is 4 mm, and the bracket length is 48 mm.

[0120] The obtained circular straight stent was implanted into a conical blood vessel (proximal reference vessel diameter 8mm, distal reference vessel diameter 4mm, length 48mm, vessel taper 87.6°). After expansion into a conical structure using a conical balloon with a proximal diameter of 8mm and a distal diameter of 4mm, the distal vessel provided adequate support, the stent expanded sufficiently, and the stent adhered well to the vessel without recoil. However, in the proximal segment, the total length of each stent unit (stent strut and wavefront) was 22.31mm, less than the vessel circumference (25.12mm) with an 8mm diameter, preventing proper stent adhesion. Therefore, the proximal stent was suspended, resulting in poor adhesion; OCT testing showed an adhesion of only 60%. Furthermore, the stent wall thickness accounted for only 5.5% of the radial diameter of the implanted vessel lumen. Poor adhesion after stent implantation led to thrombosis and in-stent restenosis.

[0121] Comparative Example Five

[0122] A spherical expansion conical support 1 is provided, which is composed of 80 design units 11 interconnected by connecting units. Each design unit consists of multiple support rods 111 and multiple wave heads 112 interconnected according to design requirements. Adjacent design units 11 are connected by connecting units 12, which are S-shaped. The axial length of each design unit 11 gradually decreases from the proximal end to the distal end. The lengths of the 1st to 20th design units are ι1-l. 20 The length l of the 21st to 40th design units is 1.49mm. 21 -ι 40 The length of the 41st to 60th design units is 1.30mm. 41 -ι 60 The length of the 61st to 80th design units is 1.17mm. 61 -ι 80 The length is 0.81 mm. The total length C of the support rod and wave head of each design unit gradually decreases axially from the near end to the far end. The total length C1-C of the 1st to 20th design units is... 20 The total length C of the 21st to 40th design units is 35.76mm. 21 -C 40 The total length C of the 41st to 60th design units is 28.61 mm. 41 -C 60 The total length C of the 61st to 80th design units is 22.89 mm. 61 -C 80 It is 18.31mm.

[0123] refer to Figure 1 Along the same axial reference direction, the included angle α between two adjacent support rods 111 in each design unit 11 gradually increases proportionally from the proximal end to the distal end along the axial direction. The included angle α1-α in the 1st to 20th design units 11 is... 20 The included angle α is 20.0°, from the 21st to the 40th design units. 21 -α 40 The included angle α between the 41st and 60th design units is 35.0°. 41 -α 60 The included angle α between the 61st and 80th design units is 50.0°. 61 -α 80 The angle is 60.0°. The wall thickness of the design unit at the closest end of the support is 115 μm, and the wall thickness of the design unit at the furthest end is 50 μm. For example... Figure 4 As shown, the cross-sectional area of ​​the support rod is the product of the support rod width and the support wall thickness. Figure 1 It can be seen that the cross-sectional area of ​​the support rod gradually decreases along the axial direction from the proximal end to the distal end. The cross-sectional areas S1-S of the support rods in design units 11 from the 1st to the 20th are as follows: 20 It is 0.01840mm2 The cross-sectional area S of the support rods in design units 11 from the 21st to the 40th 21 -S 40 It is 0.01222mm 2 The cross-sectional area S of the support rods in design units 11 from the 41st to the 60th 41 -S 60 It is 0.00735mm 2 The cross-sectional area S of the support rods in design units 11 from the 61st to the 80th 61 -S 80 It is 0.00425mm 2 .

[0124] refer to Figure 1 The radial support force F1-F of the above-mentioned stent from the proximal end to the distal end of the 1st to 20th design units. 20 The radial support force F of the 21st to 40th design units is 230 kPa. 21 -F 40 The radial support force F of design units 41 to 60 is 180 kPa. 41 -F 60 The radial support force F of the 61st to 80th design units is 150 kPa. 61 -F 80 The pressure is 80 kPa.

[0125] like Figure 2 As shown, the aforementioned stent was expanded in air to a nominal diameter of 8 mm using a straight balloon, with consistent diameters at both the proximal and distal ends, and a length of 120 mm. It was then implanted into a conical vessel with a proximal reference vessel diameter of 8 mm, a distal reference vessel diameter of 2 mm, a length of 120 mm, and a vessel taper of 88.6°. Due to the decreasing radial support force along the length of the stent, it shrank to a conical shape that adequately conformed to the conical vessel, without over-expansion or residual stenosis. However, because the total length of the design unit decreased in a stepwise manner, and the reduction ratio was too large, the support force in the intermediate transition areas differed significantly, resulting in poor stent conformation and retraction. The maximum retraction rate was only 50%, and OCT testing showed a conformation of only 60%. Simultaneously, the stent wall thickness accounted for a maximum of 5.5% of the radial direction of the implanted vessel lumen. After implantation, poor conformation led to thrombosis, resulting in in-stent restenosis.

[0126] In summary, the balloon-expandable conical stent provided in this application has a radial support force that gradually decreases along the axial direction of the stent. By utilizing the differences in plaque size, plaque hardness, and vascular taper at different locations in the vascular lesion area, different back pressures are applied to the stent design units and stent rods at the corresponding locations. As a result, the design units or stent rods at different positions of the expanded stent will retract to different degrees under the action of the corresponding back pressure, thereby forming a certain taper from the proximal end to the distal end. The taper of the stent can be well matched with the taper of the blood vessel, thereby achieving a good wall apposition effect.

[0127] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A spherical expansion conical support, comprising a design unit and a connecting unit, wherein the design unit includes multiple support rods and multiple wave heads, the support rods being spaced apart, and each wave head sequentially connecting two adjacent support rods in series to form a ring structure; multiple design units are provided, and the connecting unit connects the wave heads of two adjacent design units, characterized in that, The radial support force F of the nth design unit of the support from its proximal end to its distal end n The radial support force F is less than that of the (n-1)th design unit. n-1 , where 2≤n≤200.

2. The spherical expansion conical support according to claim 1, characterized in that, The radial support force F of the nth design unit from proximal to distal end of the support structure n The radial support force F of the (n-1)th design unit n-1 The ratio is [0.5-1]:1; or the radial support force F of the nth design unit. n The ratio of the radial support force F1 of the first design unit to the radial support force F1 is [0.42-0.69]:1 or (0.7-1]:1; where 2≤n≤200.

3. The spherical expansion conical support according to claim 1, characterized in that, The radial support force F of the nth design unit from proximal to distal end of the support structure n The radial support force F of the (n-1)th design unit n-1 The ratio is M n-1 The radial support force F of the (n-1)th design unit n-1 and the radial support force F of the (n-2)th design unit n-2 The ratio is M n-2 The M n-1 With M n-2 The difference is between [-0.25, 0.25]; and / or the M n-2 With M n-1 The following relationship must be satisfied: M n-2 =aM n-1 +b, where a∈[-1,4], b∈[-1,1]; 3≤n≤200.

4. The spherical expansion conical support according to claim 1, characterized in that, The radial support force F1 of the first design unit of the support structure from proximal to distal and the radial support force F of the nth design unit are... n The difference is between [2kPa, 200kPa].

5. The spherical expansion conical support according to claim 1, characterized in that, The radial support force F1 of the first design unit is 60kPa-250kPa, and the radial support force F of the nth design unit is... n The magnitude is 50kPa-200kPa.

6. The spherical expansion conical support according to claim 1, characterized in that, The total length C of the nth design unit of the stent from proximal to distal end is... n The total length C of the (n-1)th design unit n-1 Short, where 2≤n≤200.

7. The spherical expansion conical support according to claim 1, characterized in that, The total length C of the nth design unit of the stent from proximal to distal end is... n The total length C of the (n-1)th design unit n-1 The ratio is (0.9-1):1; where 2≤n≤200.

8. The spherical expansion conical support according to claim 1, characterized in that, When the stent is expanded and fitted to the tapered blood vessel, the length l of the nth design unit of the stent from proximal to distal end is... n The length l of the (n-1)th design unit n-1 The length l of the design unit is 0.5-1 times that of the design unit.

9. The spherical expansion conical support according to claim 1, characterized in that, The cross-sectional area S of the support rod in the nth design unit from proximal to distal end of the support structure. n The cross-sectional area S of the support rod of the (n-1)th design unit n-1 The ratio is 0.064:1-1:1; where 0.0040m 2 ≤S n ≤0.0625m 2 0.0040≤S n-1 ≤0.0625.

10. The spherical expansion conical support according to claim 1, characterized in that, When the stent is expanded and fitted to the conical blood vessel, the included angle α formed by the extended lines of two adjacent stent struts of the nth design unit from proximal to distal end of the stent n The angle α formed by the extension lines of the two adjacent support rods of the (n-1)th design unit n-1 The ratio is 1:1-1.67:1, and / or the included angle α formed by the extension lines of two adjacent support rods of the nth design unit from the proximal end to the distal end of the support. n The ratio of the angle α1 formed by the extended lines of the two adjacent support rods of the first design unit is 1:1-1.67:1, where 30°≤α n <50°, 30°≤α n-1 <50°.

11. The spherical expansion conical support according to claim 1, characterized in that, The wall thickness of the nth design unit from proximal to distal end of the stent is less than the wall thickness of the (n-1)th design unit; wherein the wall thickness of each design unit is 10% or less of the radial diameter of the blood vessel lumen at the implantation site.

12. The spherical expansion conical support according to any one of claims 1 to 11, characterized in that, Under the back pressure of the conical vessel, the maximum retraction rate of the design unit is 5%-80%; the retraction rate of the nth design unit from the proximal to the distal end of the stent is greater than the retraction rate of the (n-1)th design unit.

13. The spherical expansion conical support according to any one of claims 1 to 11, characterized in that, The total length of the spherical conical support is 38mm-300mm.

14. The spherical expansion conical support according to any one of claims 1 to 11, characterized in that, The taper β of the spherical expansion tapered support is 72°-90°.

15. The spherical expansion conical support according to any one of claims 1 to 11, characterized in that, The fit between the bulbous conical stent and the blood vessel is ≥85%.

16. The spherical expansion conical support according to any one of claims 1 to 11, characterized in that, The proximal diameter of the spherical expansion conical stent is 2.5mm-8mm, and the distal diameter of the spherical expansion conical stent is 2mm-7.5mm.

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