WO2011079806A1

WO2011079806A1 - Self-expanding stent

Info

Publication number: WO2011079806A1
Application number: PCT/CN2010/080504
Authority: WO
Inventors: 罗七一; 李�雨; 谢志永; 金巧蓉; 王森
Original assignee: 微创医疗器械(上海)有限公司
Priority date: 2009-12-30
Filing date: 2010-12-30
Publication date: 2011-07-07
Also published as: CN102113927A

Abstract

A self-expanding stent (3) includes a tubular body, and hollowed-out meshes (31) are formed in the tubular body. Stent bar members (32) surround the meshes (31). Each of stent bar members (32) forms a closed mesh (31) with adjacent stent bar member (32) so as to uniformly and continuously cover plaque at stenosis and provide uniform and annular support force for lumen.

Description

Self-expanding stent

TECHNICAL FIELD The present invention relates to the field of medical device technology, and more particularly to a self-expanding stent.

BACKGROUND OF THE INVENTION Intracranial atherosclerotic stenosis is an important cause of ischemic stroke, which is caused by up to 33% of strokes in China, and more than 50% of transient cerebral ischemia (TIA) is related to it. . As shown in Fig. 1, 1 is a cerebral artery, and 2 is a cerebral artery stenosis plaque. Because cerebral artery 1 produces lesions of cerebral artery stenosis 2, it is easy to cause transient cerebral hypoxia (TIA) and die. Intracranial arterial stenosis occurs mainly at the bifurcation of the aortic bifurcation, such as the beginning of the internal carotid artery and the siphon, the trunk of the middle cerebral artery, the basilar artery, the beginning of the artery, and the cranium.

Cerebral artery stenosis has always been a difficult point in clinical treatment. Traditional medical drug treatment studies have failed due to higher ischemic stroke (including TIA and cerebral infarction) and mortality; and surgical treatment - clinical results of intracranial and extracranial bypass surgery have shown intracranial and extracranial vascular bypass surgery for intracranial stenosis Or occlusion is ineffective, especially in patients with stenosis or occlusion of the middle cerebral artery.

Endovascular treatment has opened up new treatments for intracranial stenosis. Neurologists have used the experience of interventional treatment of coronary artery stenosis to try angioplasty and stent implantation for intracranial artery stenosis. However, the coronary stents used in earlier studies were not satisfactory enough. The coronary catheter and stent material cannot pass through the curved part of the intracranial artery, especially the siphon segment of the internal carotid artery; the anatomy of the intracranial artery is more distorted, the lumen is thinner, and the diameter of the tube is larger than that of the coronary artery. It lacks support around it and is suspended in the cerebrospinal fluid. American company boston developed a self-expanding stent designed for the softening of the open-loop stent for the characteristics of the intracranial artery. However, due to its developmental structure, the support force is uneven.

1 The extension of the rod at the vessel to the vessel wall causes mechanical irritation and stenosis to the lumen of the vessel, as well as tissue hyperplasia caused after implantation. The stent has a clinically high rate of restenosis.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a self-expanding stent to solve the problem of uneven support force of the self-expanding stent of the ring design, and to avoid tissue hyperplasia and restenosis caused after implantation.

To achieve the above object, the present invention provides the following technical solutions:

A self-expanding stent, which is a hollow tubular mesh structure;

Around the mesh is a bracket rod;

Each of the bracket members can form a closed mesh with an adjacent bracket member. Preferably, in the self-expanding stent, the mesh has a polygonal structure.

Preferably, in the above self-expanding stent, the mesh is a three-, four-, five- or six-sided structure. Preferably, in the self-expanding stent, the mesh is an equilateral polygonal structure.

Preferably, in the self-expanding stent, the mesh has a length along the axial direction of the bracket that is smaller than a radial length along the bracket. Preferably, the self-expanding stent described above employs an elastic memory material.

Preferably, the self-expanding stent is made of a temperature-sensitive memory alloy material. Preferably, in the above self-expanding stent, the outer surface of the stent rod facing the blood vessel wall is provided with a drug layer.

Preferably, in the self-expanding stent, the stent rod member is provided with a drug-loading groove facing the outer surface of the blood vessel wall;

The drug layer is disposed in the drug loading tank.

Preferably, in the above self-expanding stent, the drug layer specifically comprises a bonding layer, a drug-loading coating layer and a surface encapsulating layer;

The bonding layer is located at the bottom of the drug layer;

The drug loading layer is located at an upper portion of the bonding layer; The surface encapsulation layer is located at an upper portion of the drug-loading layer, and an outer surface thereof is flush with a surface of the stent.

Preferably, in the above self-expanding stent, the bonding layer has a micro-nano uneven structure. Preferably, in the self-expanding stent, the drug-loading layer is a drug capable of inhibiting proliferation of a degradable polymer blend.

Preferably, in the above self-expanding stent, the surface encapsulating layer is a hydrophilic lubricating coating.

Preferably, in the self-expanding stent, the drug-loading tank is a single groove along the rod, a plurality of grooves along the rod or a plurality of grooves of the vertical rod.

Preferably, the above self-expanding stent is used in a cerebral artery.

It can be seen from the above technical solution that the cerebral vascular stent in the embodiment of the present invention has a hollow tubular shape and a uniform mesh structure, which is transported to the cerebral vascular lesion, and the stenosis lesion is released through the delivery rod, the lesion is expanded, and the vascular flow channel is reconstructed. Since the structure is designed as a uniformly continuous mesh structure, each rod can form a closed mesh with adjacent rods, uniformly and continuously covering the narrow plaques, providing a uniform annular support force, especially in curved At the vessel, closure can form a continuous lumen channel.

BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and obviously, in the following description The drawings are only some of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Figure 1 is a schematic diagram of cerebral artery stenosis;

2 is a schematic view of a self-expanding stent implanted in a cerebral artery according to an embodiment of the present invention; FIG. 3 is a partial enlarged view of a self-expanding stent according to an embodiment of the present invention; Schematic;

FIG. 5 is a schematic structural view of a drug-loading tank according to an embodiment of the present invention; FIG. FIG. 6 is a schematic structural view of a three drug loading tank according to an embodiment of the present invention; FIG.

FIG. 7 is a schematic structural view of a drug loading layer according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention discloses a self-expanding stent to solve the problem of uneven support of the self-expanding stent of the ring design, and to avoid tissue hyperplasia and restenosis caused by implantation.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Referring to FIG. 2, FIG. 3, FIG. 2 is a schematic diagram of a self-expanding stent implanted in a cerebral artery according to an embodiment of the present invention, and FIG. 3 is a partial enlarged view of the self-expanding stent according to an embodiment of the present invention.

Among them, 3 is a self-expanding stent, 31 is a mesh, and 32 is a stent rod.

The self-expanding stent 3 provided by the invention is a hollow tubular mesh structure;

Around the mesh 31 is a bracket member 32;

Each of the bracket members 32 can form a closed mesh 31 with an adjacent bracket member. The stent is a uniformly continuous closed mesh structure, uniformly and continuously covering the narrow plaque, providing a uniform annular supporting force, especially at the curved blood vessel, and closing can form a continuous lumen channel, overcoming the open loop structure The extension of the rod to the vessel wall at the bend causes mechanical stimulation and bulging into the lumen of the vessel causing restenosis.

The structure of the single closed mesh 31 may be a polygon, and the optimized selection is three, four, five or hexagonal, and further, in order to make the force more uniform, the mesh 31 is equilateral.

Further, in order to optimize the above technical solution, the length of the mesh 31 along the axial direction of the stent 3 is smaller than the radial length along the stent 3, which is advantageous for maintaining the circular lumen passage of the stent 3 at the curved blood vessel.

The material of the bracket 3 is made of an elastic memory material, and further may be a temperature-sensitive memory alloy.

4 The temperature-sensitive elastic polymer, which can be bound to a micro-single lumen, is delivered to the target lesion for release and can be restored to its pre-constrained size at body temperature.

In summary, the stent 3 for treating cerebrovascular stenosis disclosed in the present invention has an open tubular shape and a uniform mesh structure; the stent adopts an elastic memory material and can be compressed and bound in a micro single lumen tube, and is transported to At the cerebral vascular lesion, the stenotic lesion is released through the delivery rod, the lesion is expanded, and the vascular flow channel is reconstructed; the unilateral outer layer of the stent has a drug-loading layer, and the drug is released into the blood vessel wall to inhibit restenosis. And a uniformly closed mesh structure, each of the rods can form a closed mesh with the adjacent rods, and the hooks continuously cover the narrow plaques, providing a uniform annular supporting force, especially at the curved blood vessels. The closure can form a continuous lumen channel, overcoming the developmental structure causing mechanical stimulation at the bending of the rod to the vessel wall and causing stenosis to protrude into the lumen of the vessel.

Referring to FIG. 4-8, FIG. 4 is a schematic structural view of a drug-loading tank according to an embodiment of the present invention, FIG. 5 is a schematic structural view of a drug-loading tank provided by an embodiment of the present invention, and FIG. 6 is a drug-loading provided by an embodiment of the present invention. FIG. 7 is a schematic structural view of a drug loading layer according to an embodiment of the present invention.

Wherein, 321 is the base of the drug-loading tank, 4 is a drug-loading tank structure, 41 is a surface encapsulating layer, 42 is a drug-loading coating layer, and 43 is a bonding layer.

The outer surface of the stent rod facing the blood vessel wall is provided with a drug-loading groove; wherein the drug-loading groove structure 4 can be a single groove along the axial direction of the stent rod, and a plurality of grooves along the axial direction of the stent rod member, perpendicular to the stent rod member Multiple slots.

A drug layer is disposed in the drug loading tank. The drug layer specifically includes a bonding layer 43, a drug-loading coating layer 42 and a surface encapsulating layer 41;

The bonding layer 43 is located at the bottom of the drug layer, that is, on the drug carrier base 321; the drug loading layer 42 is located at the upper portion of the bonding layer 43;

The surface encapsulation layer 41 is located at an upper portion of the drug-loading layer 42 and has an outer surface that is flush with the surface of the support.

The drug layer is used to release the drug into the targeted vessel wall to inhibit smooth muscle hyperplasia. The inner surface of the stent in contact with the blood is still the scaffold matrix material, which has very good blood compatibility and avoids thrombus and endothelium caused by the drug coating. Barriers. The drug-loading layer 42 is partially recessed into the surface of the stent to overcome the frictional contact between the outer wall of the stent and the inner wall of the tube when the self-expanding stent is transported in the single-lumen tube, thereby causing damage or falling off of the drug-loading layer. The drug layer is evenly distributed on the stent rod to form a uniform coverage space covering the vessel wall.

The bonding layer 43 at the bottom of the drug layer has a micro-nano uneven structure, such as a hole or matrics result, for the purpose of enhancing the adhesion of the drug-loading layer 42 on the drug-carrying base 321; the drug-loading layer 42 located at the upper portion of the bonding layer 43 is used. The degradable polymer blend inhibits the proliferation of the drug; the surface encapsulating layer 41 located on the upper portion of the drug-loading layer 42 is a hydrophilic lubricating coating to reduce the friction between the outer layer and the inner layer of the transporting single-chamber tube, and provide the conveying ability After the stent is implanted, the surface encapsulation layer 41 is fused in the tissue fluid to expose the drug-loaded coating 42.

The invention is mainly used for the problem of blood vessel stenosis caused by vascular disease, and is especially suitable for stenosis of brain arteries.

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts may be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded to the broadest scope of the principles and novel features disclosed herein.

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Claims

Rights request

A self-expanding stent, characterized in that the stent is a hollow tubular mesh structure;

Around the mesh is a bracket rod;

Each of the bracket members can form a closed mesh with an adjacent bracket member.

2. The self-expanding stent of claim 1, wherein the mesh is a polygonal structure.

The self-expanding stent according to claim 2, wherein the mesh is a three-, four-, five- or six-sided structure.

The self-expanding stent according to claim 2 or 3, wherein the mesh is an equilateral polygonal structure.

5. The self-expanding stent of claim 1 wherein the mesh has a length along the axial direction of the stent that is less than a radial extent along the stent.

6. The self-expanding stent of claim 1 wherein the stent is of an elastic memory material.

7. The self-expanding stent of claim 6 wherein the stent is a temperature sensitive memory alloy material.

The self-expanding stent according to claim 1, wherein the stent rod is provided with a drug layer facing the outer surface of the blood vessel wall.

9. The self-expanding stent of claim 8, wherein the stent rod a drug-loading groove is arranged on an outer surface of the blood vessel wall;

The drug layer is disposed in the drug loading tank.

The self-expanding stent according to claim 8 or 9, wherein the drug layer specifically comprises a bonding layer, a drug-loading coating layer and a surface encapsulating layer;

The bonding layer is located at the bottom of the drug layer;

The drug loading layer is located at an upper portion of the bonding layer;

The surface encapsulation layer is located at an upper portion of the drug-loading layer, and an outer surface thereof is flush with a surface of the stent.

The self-expanding stent according to claim 10, wherein the bonding layer has a micro-nano uneven structure.

The self-expanding stent according to claim 10, wherein the drug-loading layer is a drug that inhibits proliferation by degradable polymer blending.

13. The self-expanding stent of claim 10, wherein the surface encapsulating layer is a hydrophilic lubricating coating.

14. The self-expanding stent of claim 9, wherein the drug-loading trough is a single trough along the rod, a plurality of grooves along the rod or a plurality of grooves of the vertical rod.

15. The self-expanding stent of claim 1 wherein the stent is for use in a cerebral artery.

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