A vascular stent

Abstract

The present invention relates to a vascular stent, comprising a plurality of support rings, the support rings being arranged at the proximal end, distal end and middle portion of the vascular stent, the support rings being composed of a plurality of unit waves; a plurality of connecting rods, two adjacent support rings being connected by the connecting rods; the connecting rods between the support rings and the adjacent support rings being connected at the wave crests of the two adjacent unit waves, forming a "top-to-top" connection; the connecting rods being composed of at least one first connecting portion, the first connecting portion being one or a combination of an S-shaped connecting portion, an N-shaped connecting portion or a Z-shaped connecting portion. The advantages of the invention are that, through structural improvements, the number of segments of the vascular stent is reduced, the distance between the segments is increased, and the metal coverage of the stent is thereby reduced, thereby improving the flexibility and wall adhesion of the vascular stent; a plurality of holes are provided in the coating unit to increase the permeability of the coating unit; the coating unit is loaded with statins to accelerate the endothelialization process.

Description

Technical Field

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

[0002] The incidence of intracranial aneurysms (IAA) is approximately 0.2% to 8%, posing a serious threat to public health. While the continuous development of interventional embolic materials has effectively treated an increasing number of intracranial aneurysms, and endovascular interventional therapy has become increasingly accepted by patients due to its minimally invasive nature, wide-necked intracranial aneurysms (neck ≥4 mm or neck / body >1 / 2) have long been a challenge for endovascular treatment, with rates of incomplete embolization and recurrence exceeding 40%. Traditional endovascular treatments include occlusion of the recurrent aneurysm artery and stent-assisted coiling. The former can lead to delayed stroke and is therefore rarely used. Currently, stent-assisted coiling is the most commonly used approach. However, this treatment approach is technically challenging and carries complications, and it does not fundamentally eliminate aneurysm recurrence and enlargement. The fundamental reason for this is prolonged endothelialization or only partial endothelialization.

[0003] In recent years, blood flow diversion devices have emerged that can cure some difficult-to-treat wide-necked intracranial aneurysms. However, due to the curved design and material characteristics of these devices, complications such as delayed migration, thrombosis, and rebleeding remain, and they cannot be used for acutely ruptured intracranial aneurysms.

[0004] To address these issues, the Willis covered stent was developed. It allows for anatomical reconstruction of the parent vessel, replacing the traditional method of occluding the parent vessel. Compared with flow diversion devices, the Willis covered stent is suitable for treating acutely ruptured and bleeding cerebral aneurysms. However, this covered stent has several limitations, including poor overall stent adhesion and delayed endothelialization (>6 months) of the stented segment, which increases the risk of endoleak, thrombosis, restenosis, and even rebleeding.

[0005] Therefore, there is an urgent need for a vascular stent for treating intracranial aneurysms that can improve the overall wall adhesion performance of the stent, reduce the endothelialization time of the stent segment, and reduce the risk of complications. Summary of the Invention

[0006] The purpose of the present invention is to provide a vascular stent in view of the deficiencies in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A vascular stent, comprising:

[0009] A plurality of support rings, each of which is arranged at a proximal end, a distal end, and a middle portion of the vascular stent, and each of which is composed of a plurality of unit waves;

[0010] A plurality of connecting rods, two adjacent support rings are connected by the connecting rods;

[0011] The connecting rods between the supporting rings and the adjacent supporting rings are connected at the wave tops of two adjacent unit waves in a "top-to-top" connection;

[0012] The connecting rod is composed of at least one first connecting portion, which is an S-shaped connecting portion, an N-shaped connecting portion, or a Z-shaped connecting portion, or a combination of the two.

[0013] Preferably, the support ring is made of a cobalt-based alloy.

[0014] Preferably, the unit wave is a sine wave.

[0015] Preferably, in the radial direction of the vascular stent, two adjacent support rings are arranged in axisymmetry.

[0016] Preferably, the vascular stent is composed of 5 to 7 support rings.

[0017] Preferably, two adjacent support rings are connected by at least two connecting rods.

[0018] Preferably, the center line of the first connecting portion is arranged perpendicular to the axial direction of the vascular stent.

[0019] Preferably, the center line of the first connecting portion is arranged obliquely to the axial direction of the blood vessel stent.

[0020] Preferably, the center line of the first connecting portion is arranged parallel to the axial direction of the vascular stent.

[0021] Preferably, the connecting rod is composed of two first connecting parts.

[0022] Preferably, the two first connection parts are arranged axially symmetrically or centrally symmetrically.

[0023] Preferably, the connecting rod further comprises:

[0024] a second connecting portion, the second connecting portion being arranged at a proximal end and a distal end of the first connecting portion;

[0025] The second connecting portion is a straight connecting portion.

[0026] Preferably, the connecting rods are connected to the wave tops of the unit waves of the adjacent support rings through the linear connecting parts.

[0027] Preferably, it also includes:

[0028] A coating unit is provided, wherein the coating unit covers the outer surface of the vascular stent.

[0029] Preferably, the coating unit is an expanded polytetrafluoroethylene membrane or a biodegradable electrostatic nanofiber membrane.

[0030] Preferably, the laminating unit is provided with a plurality of holes.

[0031] Preferably, the hole is a circular hole, an elliptical hole, a rectangular hole, or a rounded rectangular hole.

[0032] Preferably, the holes are regularly arranged at certain intervals on the coating unit.

[0033] Preferably, the film thickness of the coating unit is 15 μm to 40 μm.

[0034] Preferably, the membrane gap of the laminating unit is 35 μm to 60 μm.

[0035] Preferably, the coating unit is loaded with statins.

[0036] The present invention adopts the above technical solution, which has the following technical effects compared with the prior art:

[0037] A vascular stent of the present invention reduces the number of segments of the vascular stent and increases the distance between segments through structural improvements, thereby reducing the metal coverage of the stent and improving the flexibility and wall adhesion of the vascular stent; utilizes an "S"-shaped, "N"-shaped, or "Z"-shaped first connecting portion to provide good radial support force, reduce the compression and gripping pressure of the vascular stent, improve expansion consistency, and increase anti-extrusion strength; multiple holes are provided in the coating unit to increase the permeability of the coating unit; the coating unit is loaded with statins to accelerate the process of vascular endothelialization, making the vascular endothelialization process ≤3 months, promoting lesion healing, and reducing the occurrence of complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the planar structure of the vascular stent according to the first embodiment of the present invention when deployed along the axial direction.

[0039] Figure 2 yes Figure 1 A partial enlarged schematic diagram.

[0040] Figure 3 FIG. 1 is a partial cross-sectional view of a laminating unit according to an exemplary embodiment of the present invention.

[0041] Figure 4 It is a schematic planar structural diagram of the vascular stent according to the second embodiment of the present invention when deployed along the axial direction.

[0042] Figure 5 yes Figure 4 A partial enlarged schematic diagram.

[0043] Figure 6 It is a schematic planar structural diagram of the vascular stent according to the third embodiment of the present invention when deployed along the axial direction.

[0044] Figure 7 yes Figure 6 A partial enlarged schematic diagram.

[0045] Figure 8 It is a partial structural diagram of the connecting rod of the third embodiment of the present invention.

[0046] Figure 9 It is a partial structural diagram of the connecting rod of the third embodiment of the present invention.

[0047] Figure 10 It is a schematic planar structural diagram of the vascular stent according to the fourth embodiment of the present invention when deployed along the axial direction.

[0048] Figure 11 yes Figure 10 A partial enlarged schematic diagram.

[0049] Figure 12 It is a schematic planar structural diagram of the vascular stent according to the fifth embodiment of the present invention when deployed along the axial direction.

[0050] Figure 13 yes Figure 12 A partial enlarged schematic diagram.

[0051] The reference numerals are: support ring 1 ; unit wave 2 ; connecting rod 3 ; first connecting portion 4 ; second connecting portion 5 ; coating unit 6 ; hole 7 . DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention. Example

[0055] An exemplary embodiment of the present invention is as follows Figures 1 and 2As shown, a vascular stent includes multiple support rings 1 and multiple connecting rods 3. The support rings 1 are sequentially arranged at the proximal end, distal end and middle part of the vascular stent, and two adjacent support rings 1 are connected by the connecting rod 3.

[0056] The vascular stent is made of a chromium-based alloy, preferably L605 chromium-based alloy.

[0057] Vascular stents made of chromium-based alloys have high strength and can maintain the required radial support strength after the metal wire becomes thinner. At the same support strength, they use less material, have good flexibility, can be clearly visualized under X-rays, have good MRI compatibility, good biocompatibility, and are inexpensive.

[0058] The support ring 1 is composed of a plurality of unit waves 2 . Specifically, each support ring 1 is composed of at least five unit waves 2 .

[0059] Furthermore, two adjacent support rings 1 are arranged axially symmetrically along the radial direction of the vascular stent.

[0060] Furthermore, the unit wave 2 is a sine wave.

[0061] Furthermore, the shape, height, width, inner diameter and outer diameter of each unit wave 2 are all equal.

[0062] Furthermore, the unit wave 2 may be composed of an arc and two straight lines, the arc center angle of the arc is less than 180°, and the two straight lines are tangent to the arc respectively.

[0063] Furthermore, the unit wave 2 can be composed of an arc and four straight lines, the arc center angle of the arc is equal to 180°, wherein the first straight line and the second straight line are tangent to the arc respectively, the third straight line is connected to the first straight line to form an obtuse angle, and the fourth straight line is connected to the second straight line to form an obtuse angle.

[0064] Furthermore, the unit wave 2 may be composed of an arc and two straight lines, the arc center angle of the arc is greater than 180°, the two ends of the arc are respectively connected to the two straight lines, and the straight lines and the ends of the arc form an obtuse angle.

[0065] The connecting rod 3 is composed of a first connecting portion 4 , which is an S-shaped connecting portion.

[0066] Two adjacent support rings 1 are connected via a connecting rod 3 , and the connecting rod 3 is connected at the wave tops of two adjacent unit waves 2 , forming a “top-to-top” connection.

[0067] Furthermore, two adjacent support rings 1 are connected by at least two connecting rods 3 .

[0068] Furthermore, in the axial direction of the blood vessel stent, the connecting rods 3 are staggered, that is, arranged in a wave shape.

[0069] Furthermore, if Figure 2 As shown, the center line of the first connecting portion 4 (ie, the dotted line in the figure) is arranged perpendicular to the axial direction of the blood vessel stent.

[0070] Furthermore, the outer surface of the vascular stent is covered with a coating unit 6 , which covers most of the outer surface of the vascular stent, leaving only part or all of the support rings at the proximal and distal ends of the vascular stent exposed.

[0071] The film covering unit 6 may be a non-biodegradable film or a biodegradable film.

[0072] If the coating unit 6 is a non-biodegradable film, the coating unit 6 is made of expanded polytetrafluoroethylene (ePTFE).

[0073] If the coating unit 6 is a biodegradable film, the coating unit 6 is made of biodegradable electrospun nanofibers, specifically made of L-lactic acid (LLA) and caprolactone (CL), forming an LLC-CL film.

[0074] Furthermore, if Figure 3 As shown, the laminating unit 6 is further provided with a plurality of holes 7, and the holes 7 are evenly arranged at certain intervals on the laminating unit.

[0075] By providing a plurality of holes 7 , the permeability of the coating unit 6 can be improved.

[0076] Furthermore, the hole 7 can be a circular hole, an elliptical hole, a rectangular hole, a rounded rectangular hole, or a combination of any two of the above shapes, or a combination of any three of the above shapes, or a combination of four of the above shapes.

[0077] Furthermore, the coating unit 6 is also loaded with statins.

[0078] Specifically, if the membrane covering unit 6 is an ePTFE membrane, the membrane covering unit 6 is loaded with the statin by soaking or other methods.

[0079] If the coating unit 6 is an LLC-CL membrane, the coating unit 6 can be loaded with statins during the preparation process, or loaded with statins immediately after the preparation is completed by soaking.

[0080] Furthermore, if the coating unit 6 is an LLC-CL membrane, the coating unit 6 is also loaded with heparin.

[0081] Furthermore, statins are hydroxymethylglutaryl coenzyme A reductase inhibitors.

[0082] Furthermore, the film thickness of the coating unit 6 is 15 μm to 40 μm, preferably 20 μm to 30 μm.

[0083] Furthermore, the film spacing of the coating unit 6 is 35 μm to 60 μm, preferably 40 μm to 50 μm.

[0084] Compared with the existing Willis covered stent, the vascular stent of this embodiment has higher expansion consistency and anti-extrusion strength, good radial rebound rate, and greatly reduced metal coverage; by using a covered unit with less thickness and larger gap, and utilizing the through holes provided on the covered unit, the permeability of the covered unit is greatly increased, and by loading statins, the vascular endothelialization process is made ≤3 months, thereby promoting lesion healing, shortening the time of antiplatelet aggregation drug treatment, and reducing related complications. Example

[0085] The vascular stent of this embodiment is substantially the same as the vascular stent of the first embodiment, except that the connecting rod 3 is different.

[0086] The vascular stent of this embodiment, such as Figures 4 and 5 As shown, a vascular stent includes multiple support rings 1 and multiple connecting rods 3. The support rings 1 are sequentially arranged at the proximal end, distal end and middle part of the vascular stent, and two adjacent support rings 1 are connected by the connecting rod 3.

[0087] The structures of the support ring 1 and the unit wave 2 are the same as those in the first embodiment and will not be described again here.

[0088] The connecting rod 3 is composed of a first connecting portion 4 , which is an N-shaped connecting portion or a Z-shaped connecting portion.

[0089] like Figure 5 As shown, the center line of the first connecting portion 4 (ie, the dotted line in the figure) is arranged parallel to the axial direction of the blood vessel stent.

[0090] The vascular stent in this embodiment also includes a coating unit 6 (not shown in the figure). The structure and connection method of the coating unit 6 are the same as those in the first embodiment and will not be described again here.

[0091] Compared with the first embodiment, by arranging the first connecting portion 4 parallel to the axial direction of the vascular stent, the spacing between adjacent support rings 1 can be further increased, thereby reducing the number of segments of the vascular stent and thus reducing the metal coverage of the vascular stent. Example

[0092] The vascular stent of this embodiment is substantially the same as the vascular stent of the first embodiment, except that the connecting rod 3 is different.

[0093] The vascular stent of this embodiment, such as Figures 6 and 7As shown, a vascular stent includes multiple support rings 1 and multiple connecting rods 3. The support rings 1 are sequentially arranged at the proximal end, distal end and middle part of the vascular stent, and two adjacent support rings 1 are connected by the connecting rod 3.

[0094] The structures of the support ring 1 and the unit wave 2 are the same as those in the first embodiment and will not be described again here.

[0095] The connecting rod 3 is composed of a first connecting portion 4 and a second connecting portion 5 , wherein the first connecting portion 4 is an S-shaped connecting portion and the second connecting portion 5 is a straight connecting portion.

[0096] The second connecting part 5 is arranged at the proximal end and the distal end of the first connecting part 4, and the two adjacent support rings 1 are connected by a connecting rod 3. The two second connecting parts 5 of the connecting rod 3 are connected at the wave tops of two adjacent unit waves 2, and are connected "top to top", that is, the wave top of the unit wave 2 at the proximal end is connected to the second connecting part 5 at the proximal end, and the wave top of the unit wave 2 at the distal end is connected to the second connecting part 5 at the distal end.

[0097] The vascular stent in this embodiment also includes a coating unit 6 (not shown in the figure). The structure and connection method of the coating unit 6 are the same as those in the first embodiment and will not be described again here.

[0098] Compared with the first embodiment, by providing the second connecting portion 5, the spacing distance between two adjacent support rings 1 can be increased, and the length of the vascular stent can be extended under the same metal coverage, or, under the same vascular stent length, the number of segments of the vascular stent can be reduced.

[0099] Furthermore, if Figure 8 As shown, the height b of the connecting rod 3 (ie, the height of the first connecting portion 4 ) is smaller than the width a of one unit wave 2 .

[0100] Or, further, Figure 9 As shown, the height b of the connecting rod 3 (ie, the height of the first connecting portion 4 ) is greater than the width a of one unit wave 2 .

[0101] Through the above arrangement, the compressive strength of the vascular stent can be increased and the flexibility can be improved. Example

[0102] The vascular stent of this embodiment is substantially the same as the vascular stent of the first embodiment, except that the connecting rod 3 is different.

[0103] The vascular stent of this embodiment, such as Figures 10-11 As shown, a vascular stent includes multiple support rings 1 and multiple connecting rods 3. The support rings 1 are sequentially arranged at the proximal end, distal end and middle part of the vascular stent, and two adjacent support rings 1 are connected by the connecting rod 3.

[0104] The structures of the support ring 1 and the unit wave 2 are the same as those in the first embodiment and will not be described again here.

[0105] The connecting rod 3 is composed of two first connecting parts 4, and the first connecting part 4 is an S-shaped connecting part.

[0106] In the connecting rod 3 , the two first connecting parts 4 are arranged axially symmetrically.

[0107] Furthermore, the two first connecting portions 4 are connected via an n-shaped connecting portion.

[0108] The vascular stent in this embodiment also includes a coating unit 6 (not shown in the figure). The structure and connection method of the coating unit 6 are the same as those in the first embodiment and will not be described again here.

[0109] Compared with the first embodiment, each connecting rod 3 is provided with two first connecting parts 4 arranged axially symmetrically, which can increase the spacing distance between two adjacent support rings 1, thereby reducing the number of segments of the vascular stent and thus reducing the metal coverage of the vascular stent.

[0110] Compared with the existing Willis covered stent, the bending force of the vascular stent in this embodiment is greatly reduced, and the bending flexibility is good. Example

[0111] The vascular stent of this embodiment is substantially the same as the vascular stent of the first embodiment, except that the connecting rod 3 is different.

[0112] The vascular stent of this embodiment, such as Figures 12-13 As shown, a vascular stent includes multiple support rings 1 and multiple connecting rods 3. The support rings 1 are sequentially arranged at the proximal end, distal end and middle part of the vascular stent, and two adjacent support rings 1 are connected by the connecting rod 3.

[0113] The structures of the support ring 1 and the unit wave 2 are the same as those in the first embodiment and will not be described again here.

[0114] The connecting rod 3 is composed of two first connecting parts 4, and the first connecting part 4 is an S-shaped connecting part.

[0115] In the connecting rod 3 , the two first connecting parts 4 are centrally symmetrically arranged.

[0116] The vascular stent in this embodiment also includes a coating unit 6 (not shown in the figure). The structure and connection method of the coating unit 6 are the same as those in the first embodiment and will not be described again here.

[0117] Compared with the first embodiment, each connecting rod 3 is provided with two first connecting parts 4 arranged in a central symmetrical manner, which can increase the spacing distance between two adjacent support rings 1, thereby reducing the number of segments of the vascular stent and thus reducing the metal coverage of the vascular stent.

[0118] Compared with the existing Willis covered stent, the bending force of the vascular stent in this embodiment is greatly reduced, and the bending flexibility is good.

[0119] The above description is only a preferred embodiment of the present invention and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A vascular stent, characterized in that: include: A plurality of support rings (1), the support rings (1) being arranged at the proximal end, the distal end and the middle portion of the vascular stent, and the support rings (1) being composed of a plurality of unit waves (2); A plurality of connecting rods (3), wherein two adjacent support rings (1) are connected via the connecting rods (3); The connecting rod (3) between two adjacent support rings (1) is connected to the wave tops of two adjacent unit waves (2) in a "top-to-top" connection; Wherein, in the radial direction of the vascular stent, two adjacent support rings (1) are arranged axially symmetrically; Wherein, the connecting rod (3) is composed of two first connecting parts (4) and an N-shaped connecting part, and the first connecting part (4) is an S-shaped connecting part; In the connecting rod (3), the two first connecting parts (4) are arranged axially symmetrically; Wherein, the two first connecting parts (4) are connected via an n-shaped connecting part; Among them, also include: A coating unit (6), the coating unit (6) covering the outer surface of the vascular stent; The coating unit (6) is provided with a plurality of holes (7), and in the axial direction of the blood vessel stent, the connecting rods (3) are staggered and arranged in a wave shape.

2. The vascular stent according to claim 1, characterized in that: The vascular stent is composed of 5 to 7 support rings (1).

3. The vascular stent according to claim 1, characterized in that: Two adjacent support rings (1) are connected by at least two connecting rods (3).

4. The vascular stent according to claim 1, characterized in that: The coating unit (6) is loaded with statins.

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