Open-loop dense-net stent for repairing endovascular intima

Abstract

The invention provides an open-loop dense net stent for repairing endovascular intima, and relates to the technical field of artery implantable medical instruments, the open-loop dense net stent for repairing endovascular intima is cylindrical and comprises a plurality of sine curve spiral open-loop structures, and the structures deform to adapt to tortuous blood vessels. Compared with a dense net stent in the prior art, the dense net stent has the advantages that the rigidity of the whole structure is high, the dense net stent is difficult to fully unfold in a continuously bent area or an area with non-uniform blood vessel diameter, and the wall adhesion is poor, so that the rigidity of the whole structure of the dense net stent is greatly improved. Through the open-loop design (partial or all inflection points of the sine open-loop are not mutually connected) and the independent sine-shaped ring structure, the stent is segmented to adapt to different bending angles and blood vessel diameters, gaps between the stent and the blood vessel wall are reduced, and connection of the dense net units and the sine-shaped rings also ensures blood flow guidance.

Description

Technical Field

[0001] The present invention relates to the technical field of arterial implantable medical devices, in particular to an open-loop dense-mesh stent for repairing vascular endothelium. Background Art

[0002] Aneurysm is a common vascular disease. If not treated promptly, it may lead to aneurysm rupture and arterial bleeding, which will seriously endanger the patient's life. Currently, the main treatment methods for aneurysms are: (1) For the treatment of aneurysms, surgical resection or clipping is mainly used in the early stage; (2) embolization of the aneurysm with coils or using stents to assist with coil embolization to form a thrombus in the aneurysm, thereby blocking blood flow to the aneurysm; (3) implanting a dense mesh stent in the blood vessels at the aneurysm to block blood flow to the aneurysm.

[0003] The existing dense mesh stent is a blood flow remodeling device developed on the basis of the study of intracranial aneurysm hemodynamics. Its basic principle is to place the device in the parent artery at the neck of the aneurysm to change the direction of blood flow, reduce blood flow velocity and pressure, reduce the burden in the aneurysm, prevent the rupture of the intracranial aneurysm, and provide conditions for the growth of the endothelium to promote endothelialization, thereby reconstructing the parent artery. Indications: Initially mainly used for unruptured, large or giant internal carotid artery aneurysms, it has now been expanded to almost all intracranial aneurysms. For example, in the treatment of vertebral artery dissecting aneurysms (VADA), blood flow diversion devices such as the Pipeline blood flow diversion device (PED) are used for treatment, with a high success rate and good safety.

[0004] However, existing dense mesh stents are all woven, which have the following drawbacks: difficulty opening, especially in vessels with large bends or multiple consecutive bends, resulting in poor adhesion. Stents also have difficulty adhering to the vessel wall when opening vessels of varying thicknesses, creating large gaps between the stent and the vessel wall, which can easily cause perforating artery occlusion. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an open-loop dense mesh stent for repairing the vascular endothelium, so as to solve the technical problem that the dense mesh stent used in the prior art is a woven stent, which is difficult to open and has poor wall adhesion, which can easily cause occlusion of the perforating artery.

[0006] In order to achieve the above-mentioned objectives, the present invention provides an open-loop dense mesh stent for repairing the vascular endothelium, which is cylindrical and includes a plurality of sinusoidal rings. The sinusoidal rings are deformed to adapt to tortuous blood vessels, and some or all of the inflection points of adjacent sinusoidal rings are not connected to each other, and dense mesh units are provided between adjacent sinusoidal rings.

[0007] Optionally, the sinusoidal ring includes a plurality of sinusoidal units, which are connected end to end to form a ring structure.

[0008] Optionally, the extension direction of the sinusoidal unit is consistent with the axial direction of the sinusoidal ring.

[0009] Optionally, the edge of the dense mesh unit is fixedly connected to the sinusoidal unit.

[0010] Optionally, the edge of the dense mesh unit is welded to the sinusoidal unit.

[0011] Optionally, the sizes of the sinusoidal units are consistent or inconsistent.

[0012] Optionally, the sinusoidal ring is formed by laser cutting.

[0013] Optionally, the sinusoidal ring is made of nickel-titanium alloy.

[0014] Optionally, the dense mesh unit is a sealed structure woven from metal spring wires or polymer spring wires, and has elasticity in different blood vessels.

[0015] Optionally, the diameter of the metal spring wire or the polymer spring wire is 0.02-0.10 mm.

[0016] The open-loop dense mesh stent for repairing the vascular endothelium provided by the present invention has the following technical effects:

[0017] This open-loop dense-mesh stent for repairing the vascular endothelium is cylindrical and includes several sinusoidal rings. The sinusoidal rings are deformed to adapt to tortuous blood vessels. Some or all of the inflection points of adjacent sinusoidal rings are not connected to each other, and dense-mesh units are provided between adjacent sinusoidal rings. Compared with the dense-mesh stents in the prior art, which have high overall structural rigidity and are difficult to fully deploy in areas with continuous bends or uneven blood vessel diameters, resulting in poor wall adhesion, the present invention uses an open-loop design (some or all of the inflection points of the sinusoidal rings are not connected to each other) and an independent sinusoidal ring structure to enable the stent to adapt to different bending angles and blood vessel diameters in segments, reduce gaps with the blood vessel wall, and the connection between the dense-mesh units and the sinusoidal rings also ensures blood flow guidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1This is a schematic diagram of the three-dimensional structure of a preferred embodiment of an open-loop dense mesh stent for repairing vascular intima according to the present invention;

[0020] Figure 2 yes Figure 1 Side view of an open-loop dense mesh stent used to repair the vascular endothelium;

[0021] Figure 3 yes Figure 1 Schematic diagram of the structure of the sinusoidal ring of the open-loop dense mesh stent for repairing the vascular endothelium.

[0022] in, Figure 1-Figure 3 :

[0023] 1. Sinusoidal ring; 11. Sinusoidal unit; 2. Dense mesh unit. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0025] Current treatments for aneurysms include surgery, coil embolization, and the implantation of dense mesh stents. Existing dense mesh stents reduce intra-aneurysmal pressure by redirecting blood flow, but they can be difficult to deploy in curved vessels and exhibit poor adhesion. This can lead to gaps between the stent and the vessel wall, increasing the risk of perforating artery occlusion. For example, in vessels with large bends or continuous curves, the stent has difficulty fully deploying, compromising treatment effectiveness.

[0026] To address these issues, researchers considered improving stent adhesion in complex vascular morphologies. Traditional braided stents, due to structural limitations, struggle to adapt to the highly tortuous environment of vessels. Analysis revealed that insufficient stent flexibility was the primary cause of poor adhesion, necessitating a design that maintained structural stability while also allowing for flexible deformation. This led to the concept of decomposing the stent into independently deformable units and reducing structural constraints through an open design.

[0027] Therefore, if Figure 1 and Figure 2 As shown, the present invention proposes an open-loop dense mesh stent for repairing the vascular endothelium. The open-loop dense mesh stent is cylindrical and includes a plurality of sinusoidal rings 1. The sinusoidal rings 1 are deformed to adapt to tortuous blood vessels. Some or all of the inflection points of adjacent sinusoidal rings 1 are not connected to each other, and dense mesh units 2 are provided between adjacent sinusoidal rings 1.

[0028] The sinusoidal ring 1 is an annular structure composed of multiple periodically arranged sinusoidal units 11, specifically formed by laser cutting a thin nickel-titanium alloy tube. Its deformability allows the stent to adjust its shape as the blood vessel bends. The inflection points of adjacent sinusoidal rings 1 are not interconnected, meaning that the connection points between the rings are reduced or completely disconnected. This can be achieved by controlling the laser cutting path. The dense mesh unit 2 is a mesh structure woven from metal spring wire or polymer spring wire, specifically connected to the sinusoidal ring 1 by welding, used to seal the stent mesh and provide blood flow guidance.

[0029] Specifically, the stent of the present invention is composed of a plurality of independent sinusoidal rings 1 arranged axially, and each ring adapts to the curvature of the blood vessel through local deformation. The inflection point disconnection design of adjacent rings reduces the rigid connection between the rings, allowing the stent to deform in segments in tortuous blood vessels, making the stent more flexible. The dense mesh unit 2 covers between the sinusoidal rings 1 and is fixed by edge welding, which not only maintains the overall continuity of the stent, but also allows the dense mesh unit 2 to adjust with the deformation of the stent. After release, the sinusoidal ring 1 can provide a strong radial support force, making it easier to adhere to the area where the blood vessel diameter changes, that is, it helps to keep the blood vessel open, and the sinusoidal ring 1 is difficult to shift after release, which makes it more stable during treatment.

[0030] Compared to existing technologies, traditional dense mesh stents, due to their high overall structural rigidity, struggle to fully deploy in areas with continuous bends or uneven vessel diameters, leading to poor wall adhesion. The present invention, through its open-loop design and independent sinusoidal rings (1), allows the stent to adapt to varying bend angles and vessel diameters in sections, minimizing gaps with the vessel wall. Furthermore, the connection between the dense mesh units (2) and the sinusoidal rings (1) ensures proper blood flow guidance.

[0031] In detail, the sinusoidal ring 1 includes a plurality of sinusoidal units 11 , which are connected end to end to form a ring structure.

[0032] The sinusoidal unit 11 is an independent structural unit with a broken line or wave-shaped geometric feature, and can be specifically implemented by a V-shaped or U-shaped curved segment. Adjacent units are connected through inflection points to form an overall ring structure.

[0033] Specifically, the sinusoidal ring 1 is composed of multiple sinusoidal units 11 connected end-to-end to form a closed loop. Each sinusoidal unit 11 extends in the same or opposite directions, aligned with the ring axis. When the stent is implanted in a curved vessel, the bending angles of the sinusoidal units 11 can be independently adjusted to follow the vessel's curvature, while the ring structure maintains overall support. For example, when a vessel has multiple continuous bends, each sinusoidal unit 11 can deform independently to conform to the vessel's inner wall at different curvatures. At the same time, the nodes between adjacent units allow the ring structure to compress or stretch axially.

[0034] Compared to existing braided stents, which have interlaced grid cells, adjacent cells cannot deform independently due to the limitations of the braiding process. The present invention, however, connects sinusoidal cells 11 end-to-end to form a ring structure. While maintaining support performance, each cell also has the ability to deform independently, enabling segment-by-segment conformity to curved blood vessels.

[0035] Through the above technical solution, the present invention solves the problem that existing braided stents are difficult to open and poorly adhere to the wall in multi-bend sections of blood vessels. The independent deformation ability of the annular structure reduces the gap between the stent and the blood vessel wall, thereby reducing the risk of perforating artery occlusion.

[0036] It should be noted that the extending direction of the sinusoidal unit 11 of the present invention is consistent with the axial direction of the sinusoidal ring 1 .

[0037] The extension direction is consistent with the axial direction, which means that the direction of the unit fold line is parallel to the longitudinal center axis of the stent. This can be achieved by adjusting the laser cutting path or weaving parameters so that the peaks and troughs of the unit fold line are arranged along the length direction of the stent.

[0038] Specifically, when the stent is implanted in a curved vessel, the fold lines of the sinusoidal units 11 extend axially, ensuring that the force applied to each unit during radial deformation aligns with the stent's deployment direction. This evenly distributes stress within the bend, preventing localized stress concentration that can lead to deployment difficulties or poor adherence. Furthermore, the alignment of the unit fold lines with the axial direction reduces the torsional forces generated during compression or expansion, maintaining a stable stent configuration within the vessel and reducing friction against the vessel wall.

[0039] As a preferred embodiment, the edge of the dense mesh unit 2 is fixedly connected to the sinusoidal unit 11, and the fixed connection here is preferably welding.

[0040] The dense mesh unit 2 is a sealing structure woven from metal spring wires or polymer spring wires, which can be realized by laser welding. This connection method can ensure the continuity of mechanical transmission between the dense mesh unit 2 and the stent body.

[0041] Specifically, a dense mesh unit 2, woven from metal or polymer spring wire, is positioned between the stent's sinusoidal rings 1. The edges of the dense mesh unit 2 are welded to the sinusoidal units 11. This connection allows the dense mesh unit 2 to form a mechanical synergy with the sinusoidal rings 1. When the stent is implanted in a curved vessel, the fixed points between the dense mesh unit 2 and the sinusoidal units 11 evenly distribute stress, preventing structural deformation caused by localized stress concentration. Under the pressure of the vessel wall, the junction between the dense mesh unit 2 and the sinusoidal units 11 maintains morphological consistency, thereby improving the stent's overall adhesion to the vessel wall.

[0042] It should be noted that the sizes of the sinusoidal units 11 of the present invention may be consistent or inconsistent.

[0043] Size consistency or inconsistency means that the length, height or peak spacing of the sinusoidal units 11 at adjacent or different positions remain the same or differ. This can be achieved by adjusting the laser cutting path parameters or using a segmented processing method. The size difference can adapt to the local curvature or diameter changes of the blood vessel.

[0044] During stent deployment, if a vessel experiences localized dilation or stenosis, uniformly sized sinusoidal elements 11 provide uniform support. However, the varying sizes of sinusoidal elements 11 enhance the stent's adaptability to complex vessel morphologies through differentiated deformation. For example, in curved sections of the vessel, smaller sinusoidal elements 11 deform preferentially, preventing excessive stent stretching and poor adhesion. In areas of varying vessel diameter, larger sinusoidal elements 11 provide additional support, reducing gaps between the stent and the vessel wall.

[0045] As a preferred embodiment, the present invention further proposes that the sinusoidal ring 1 is formed by laser cutting.

[0046] Laser cutting refers to a method of using a high-energy laser beam to perform precision processing on materials. Specifically, it can be achieved by using a pulsed laser or a continuous laser to cut a specific pattern on the surface of the nickel-titanium alloy tube. This process can ensure the geometric accuracy and edge smoothness of the sinusoidal ring 1.

[0047] Specifically, the laser cutting process first generates a cutting path for the sinusoidal ring 1 using computer-aided design software. The nickel-titanium alloy tube is then secured to the workbench of the laser cutting machine. The laser beam is controlled according to preset parameters to move along the path and remove material, ultimately forming a ring structure with uniform sinusoidal units 11. During the cutting process, parameters such as laser power, cutting speed, and focus position can be adjusted to ensure the dimensional consistency and structural integrity of the sinusoidal ring 1. The resulting sinusoidal ring 1 can be combined with the dense mesh units 2 to maintain a stable geometric shape when deployed within a blood vessel.

[0048] As a preferred embodiment, the present invention further proposes that the material of the sinusoidal ring 1 is nickel-titanium alloy.

[0049] Nickel-titanium alloy is a metal material that exhibits shape memory and superelasticity, achieved by alloying nickel and titanium in equal atomic proportions. This material can recover its preset shape at body temperature and exhibits high fatigue and corrosion resistance, allowing it to adapt to the repeated stresses of blood vessel bending and deformation.

[0050] Specifically, a sinusoidal ring 1 made of nickel-titanium alloy is laser-cut to form a pre-set wavy structure, with adjacent rings connected by dense mesh units 2. After implantation into a blood vessel, the superelasticity of nickel-titanium alloy enables it to deform elastically under external forces, conforming to the curved shape of the vessel. When the external force is removed, the material returns to its original shape to provide radial support. Because nickel-titanium alloy is more flexible than traditional stent materials, the stent can achieve uniform adhesion in continuously curved vessels or areas with varying diameters, avoiding gaps caused by insufficient local deformation.

[0051] As a preferred embodiment, the dense mesh unit 2 is a sealed structure woven from metal spring wires or polymer spring wires.

[0052] Metal spring wire is a linear structure made of metal materials, specifically stainless steel, platinum, platinum-tungsten, platinum-iridium, or nickel-titanium. It possesses high mechanical strength and biocompatibility, maintaining structural stability within blood vessels. Polymer spring wire is a linear structure made of polymer materials, specifically PEBAX, PET, NYLON, or PTFE. It exhibits flexibility and plasticity, adapting to changes in vascular morphology.

[0053] Specifically, metal spring wire or polymer spring wire is braided to form a dense mesh structure covering the main area of ​​the stent. The porosity of this mesh can be controlled by braiding parameters. The dense mesh woven with metal spring wire expands after implantation through its self-expansion properties, while the dense mesh woven with polymer spring wire recovers its shape through the elasticity of the material. This braided sealing structure covers the stent skeleton formed by the sinusoidal rings 1, generating uniform support force when in contact with the vessel wall and maintaining conformity through localized deformation in curved vessels.

[0054] In some embodiments, the metal spring wire can have a diameter of 0.02-0.10 mm, for example, triaxially braided using 0.05 mm nickel-titanium alloy wire. The polymer spring wire can be plain-woven using 0.08 mm PEBAX material to form a diamond mesh structure. The densely woven mesh is fixed to the sinusoidal ring 1 by laser welding or hot-melt bonding to form the overall stent structure.

[0055] In the description of the present invention, it should be noted that, unless otherwise specified, "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

[0057] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An open-loop dense mesh stent for repairing vascular intima, characterized in that: It is a columnar body comprising a plurality of sinusoidal rings which are deformed to adapt to tortuous blood vessels. Some or all of the inflection points of adjacent sinusoidal rings are not connected to each other, and dense mesh units are provided between adjacent sinusoidal rings.

2. The open-loop dense mesh stent for repairing vascular intima according to claim 1, characterized in that: The sinusoidal ring includes a plurality of sinusoidal units, which are connected end to end to form a ring structure.

3. The open-loop dense mesh stent for repairing vascular intima according to claim 2, characterized in that: The extending direction of the sinusoidal unit is consistent with the axial direction of the sinusoidal ring.

4. The open-loop dense mesh stent for repairing vascular intima according to claim 2, characterized in that: The edge of the dense mesh unit is fixedly connected to the sinusoidal unit.

5. The open-loop dense mesh stent for repairing vascular intima according to claim 4, characterized in that: The edges of the dense mesh unit are welded to the sinusoidal unit.

6. The open-loop dense mesh stent for repairing vascular intima according to claim 2, characterized in that: The sizes of the sinusoidal units may be uniform or non-uniform.

7. The open-loop dense mesh stent for repairing vascular intima according to any one of claims 1 to 6, characterized in that: The sinusoidal ring is formed by laser cutting.

8. The open-loop dense mesh stent for repairing vascular intima according to claim 7, characterized in that: The material of the sinusoidal ring is nickel-titanium alloy.

9. The open-loop dense mesh stent for repairing vascular intima according to any one of claims 1 to 6, characterized in that: The dense mesh unit is a sealed structure woven from metal spring wires or polymer spring wires and has elasticity in different blood vessels.

10. The open-loop dense mesh stent for repairing vascular intima according to claim 9, characterized in that: The diameter of the metal spring wire or the polymer spring wire is 0.02-0.10 mm.

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