WO2011023105A1

WO2011023105A1 - Intravascular reconstructive stent

Info

Publication number: WO2011023105A1
Application number: PCT/CN2010/076333
Authority: WO
Inventors: 刘建民; 罗七一; 谢志永; 李�雨; 王森; 李建军; 金巧蓉; 向勇刚
Original assignee: 微创医疗器械(上海)有限公司
Priority date: 2009-08-27
Filing date: 2010-08-25
Publication date: 2011-03-03
Also published as: CN101991477A; CN101991477B

Abstract

A vascular remodeling stent (10, 40, 50) has a mesh tubular structure which includes multiple pores formed by interleaved braiding several filaments (20). Every filament is continuous and the nodes (30) of the pores are moveable. The vascular remodeling stent is soft and flexible to pass through sinuous and tenuous brain blood vessels and reach the target diseased part, and is compliant with derious blood vessels to maintain the lumen passage in blood vessels. Furthermore, the stent includes pores with high density, and can remarkably change the blood stream in the aneurysm to stagnate the blood to form blood clots and organized thrombus.

Description

The present invention claims priority to Chinese Patent Application No. 200910194688.0, entitled "A Vascular Remodeling Stent", filed on August 27, 2009, the entire contents of which are hereby incorporated by reference. Combined in this application. Technical field

The present invention relates to an intravascular implant device, and more particularly to a vascular remodeling stent capable of altering blood flow of a lesion, which can be implanted into a blood vessel for treating a lesion such as an vascular dilatation, deformation, or deformity, such as an aneurysm. Background technique

Local abnormal augmentation or bulging may occur in the vessel wall, particularly the arterial vessel wall, which we call an aneurysm. Due to factors such as disease, injury or congenital local weakness, under the impact of long-term blood flow, the weak point of the arterial wall protrudes outward and gradually expands to form a round, elliptical or prismatic bulge. An aneurysm is a potentially life-threatening disease. An aneurysm grows under the impact of blood flow. When an aneurysm breaks due to high blood pressure or other factors, sharp bleeding occurs. The ruptured aneurysm is extremely high. Causing mortality. Aneurysms can occur in different parts of the body, most commonly cerebral aneurysms and abdominal aortic aneurysms.

The cerebral artery wall is thin, complex in distortion, large in curvature, high in bifurcation, sensitive to stimuli, and lack of tissue support around it. The most common cerebral aneurysms usually occur in the branching, bifurcation or bending of blood vessels, mainly due to the hemodynamic factors of the site, that is, the impact of axial blood flow on the distal end of the blood vessel to form shear stress, resulting in the elastic layer of blood vessels. The destruction, the formation of ridges, and shear stress stimulation promote the division and growth of damaged vascular endothelial cells, and then grow into an aneurysm, this shear stress is the basic cause of aneurysm formation. The blood formed in the aneurysm is disordered, forming eddy currents, inducing fluid resonance, triggering oscillation of the blood vessel wall and promoting denaturation, growth and rupture.

Common methods of aneurysm treatment include: 1. surgically clamping an aneurysm, clamping the aneurysm neck with a metal clip through craniotomy; 2. endovascular intervention, using a detachable coil (or microwire ring or Other embolic materials such as detachable globules, curable fluids, etc.) embolization of aneurysms; 3. Endovascular interventional stent implantation. Due to the traumatic, high-risk and high-complication of surgical treatment, endovascular intervention has gradually become the main method of aneurysm treatment, which has less trauma, less complications, high safety, less patient pain, easy acceptance, and hospitalization time. Short, high-grade illness can also tolerate and other advantages.

The detachable coil is filled with a percutaneous vascular puncture, which is introduced into the blood vessel through a microcatheter, and a metal coil is placed in the aneurysm to fill the aneurysm, thereby preventing blood flow into the aneurysm. Coil Embolization materials and microcatheters are designed to reach aneurysmal lesions that distort complex cerebral arteries and block blood flow impact through the filling of the tumor lumen. However, this packing also carries the risk of further enlargement and rupture of the aneurysm lumen.

The goal of aneurysm treatment is to reduce the risk of aneurysm rupture. The most fundamental method is to achieve the healing of the parental artery and the reconstruction of the anatomy of the artery wall.

The reconstructed stent of the cerebral blood vessel must have the following characteristics by implanting a vascular stent to treat and reconstruct the maternal tumor-bearing artery of the cerebral aneurysm:

1) The stent can be compressed into the lumen of the microconveyor. After compression, the stent is soft enough to be transported through the tortuous, slender, complex cerebrovascular vessels to the target;

2) After stent implantation, it has sufficient compliance to conform to the tortuous cerebrovascular;

3) The stent mesh significantly affects the hemodynamics within the aneurysm while maintaining the patency of the normal branch artery covered by the stent. The coronary stent is implanted into the cerebral artery of the cerebral aneurysm to assist the coil embolization. However, the anatomy of the cerebral blood vessels is complex and has more curvature than the coronary arteries, so the rigidity of the coronary stent makes it very difficult to reach the cerebral blood vessels.

Special intracranial stents are used to increase the softness of the stent system. They are often designed with a small amount of metal covering and an open mesh with a large mesh area. It has been confirmed from animal experiments and long-term clinical follow-up that this stent cannot effectively change the hemodynamics in the aneurysm, and the expanded stent has poor adherence in the curved vessel and is discounted in the lumen. Summary of the invention

In view of the above problems, the present invention provides a highly flexible and flexible vascular remodeling stent capable of traversing a tortuous and delicate cerebral blood vessel to reach a target lesion, and conforming to a tortuous blood vessel to maintain a lumen of the blood vessel. Road. The stent has a high-density mesh that can significantly alter the flow of blood in the aneurysm to cause it to form blood clots and mechanized solids.

According to the vascular remodeling stent of the present invention, it can be implanted into a blood vessel for treating a lesion such as a vasodilatation, a deformity, a deformity, or the like, such as an aneurysm or the like. Specifically, the vascular remodeling stent has a mesh tubular structure and has a plurality of meshes formed by interlacing a plurality of silk chains. Wherein each of the chains is continuous and the nodes of the mesh are movable. Here, the silk chain refers to a silk or filament structure.

The silk chain forms an angle β ₀ with the radial direction of the vascular remodeling stent, and the angle β ₀ is 15. ~85. . It is preferably 30. ~ 75. More preferably, it is 45. ~ 60. The goal is to maintain a proper support of the vascular remodeling stent while providing optimal adherence and compliance within the curved vessel for vascular remodeling.

The vascular remodeling stent has a mesh density greater than 5 pores/mm ² .

The metal coverage of the vascular remodeling stent is 12% to 60%, preferably 30% to 50%, more preferably 35% to 45%.

Depending on the implantation and treatment site of the vascular remodeling stent, different portions of the vascular remodeling stent have different metal coverage.

For example, the metal coverage of the vascular remodeling stent varies in the axial direction. At the aneurysm segment, the metal coverage is 30% to 50%, and at other locations, the metal coverage is 12% to 20%.

Alternatively, the metal coverage of the vascular remodeling stent varies in the circumferential direction. At the aneurysm mouth, the metal coverage is 50% to 60%, and at other locations, the metal coverage is 12% to 20%.

The compression ratio of the vascular reconstruction scaffold can reach 2:1 - 10:1.

The number of strands is from 8 to 108, preferably from 24 to 96, more preferably from 32 to 56, in order to achieve an optimal balance of support and compliance of the vascular remodeling stent.

The cross-section of the wire chain may be a different shape such as a rectangle, a trapezoid, a circle or an ellipse or the like.

When the cross section of the wire chain is circular, the diameter of the wire chain is 0.01 to 0.2 mm, preferably 0.025 to 0.1 mm, more preferably 0.03 to 0.08 mm. When the cross section of the wire chain is rectangular, the length and width of the rectangle are 0.01 to 0.2 mm, preferably 0.025 to 0.1 mm, more preferably 0.03 to 0.08 mm, and the aspect ratio of the rectangle is 1:1 to 4:1. The purpose of determining the size of the silk chain in this way is to ensure that the silk of the vascular remodeling stent has a suitable mechanical strength, and can effectively eliminate the influence of the small perforating artery in the intracranial artery (the diameter of the perforating artery is usually larger than 0.1 mm). The pitch of the wire chain is 0.01 to 3 mm. The silk chains can have different pitches depending on the implantation and treatment sites of the vascular remodeling stent. Here, "pitch" refers to the distance traveled by any point on a single wire chain after 2π.

The material of the silk chain may be a biocompatible metal or/and a polymer.

According to the present invention, the above-mentioned vascular remodeling stent can be used to support or block the embolic material in the aneurysm to ensure that the embolic material is only in the aneurysm and maintain the patency of the parent artery.

The beneficial effects of the invention are:

The vascular remodeling stent of the present invention is highly flexible and flexible, and is capable of traversing a tortuous and delicate cerebral blood vessel to reach a target lesion, and conforms to a tortuous blood vessel to maintain a vascular lumen passage. Moreover, continuously variable high-density meshes can significantly alter blood flow in the aneurysm to cause it to form blood clots and mechanized solids. At the same time, high-density mesh as a support for endothelial cell growth or migration can accelerate the growth process of the intima, and the retention of blood flow in the aneurysm ensures the physical conditions of intimal growth, making the diseased vessel intimalization real. Anatomical cure. DRAWINGS

1 is a schematic structural view of a preferred embodiment of a vascular remodeling stent according to the present invention; FIG. 2 is a perspective view showing a structure of a preferred embodiment of a vascular remodeling stent according to the present invention; and FIG. 3 is a vascular remodeling stent according to the present invention. A partially enlarged schematic view of a preferred embodiment; Figure 4 is a schematic illustration of the use of a preferred embodiment of a vascular remodeling stent in accordance with the present invention; Figures 5a, 5b are schematic illustrations of other preferred embodiments of a vascular remodeling stent in accordance with the present invention; _ 6d is a schematic cross-sectional view of different silk chains of a vascular remodeling stent according to the present invention. Description of the reference numerals

10, 40, 50 vascular reconstruction stent

20 silk chain

30, 31, 32 nodes

41, 51 aneurysm mouth

42, 52 other parts

43 , 53 tumor artery

44, 54 branches 45, 55 normal blood vessel wall embodiment

Different embodiments in accordance with the present invention are described in detail below with reference to the accompanying drawings.

Referring to Figures 1 through 3, there is shown a highly flexible and flexible implant device in accordance with the present invention: a vascular remodeling stent 10. The vascular remodeling stent 10 shown in the drawing is a mesh tubular structure formed by interlacing a continuous filament chain 20 having a plurality of meshes. The braided points of the chain 20 interlaced are also referred to as the nodes of the mesh, and the nodes 30 of the mesh are movable or movable. Each of the strands 20 of the stent forms an angle β with the radial direction of the stent. , angle β. It is from 15 ° to 85 °, preferably from 30 ° to 75 °, more preferably 45. ~ 60. This provides sufficient diameter/loop support.

According to the vascular remodeling stent of the present invention, since the nodes 30 of the mesh are movable, the wire chain 20 is not fixed to the nodes, and the wire chains 20 can move relative to each other. The relative mobility of the wire chain 20 allows the stent to be flexible enough to flex or twist the space to be closer to the natural vessel morphology, conforming to and conforming to the tortuous cerebrovascular vessels while maintaining the intravascular lumen morphology.

Preferably, the mesh density of the stent (ie, the number of cells per unit area) is greater than 5 pores/mm ² .

The stent metal coverage is 12% to 60%, preferably 30% to 50%, more preferably 35% to 45%.

The number of the chains used for weaving may be from 8 to 108, preferably from 24 to 96, more preferably from 32 to 56. Depending on the implantation and treatment site of the stent, there may be different numbers of silk chains.

The pitch of the wire chain is preferably controlled to be 0.01 to 3 mm. The metal coverage and mesh density of the stent can be achieved by the number of braided chains, the size, the weaving pitch, and the like. Here, "pitch" refers to the distance traveled by any point on a single wire chain after 2π. For example, the distance between nodes 31 and 32 in Figure 3.

As shown in FIG. 4, the stent of the present invention has a soft continuous structure and high compressibility, and the compression ratio can reach 2:1 to 10:1, and can be compressed and loaded into the diameter Φ of 0.3 mm to 1.5 mm. Inside the conveyor, the stent can pass through the tortuous, slender cerebrovascular.

As shown in Figures 5a and 5b, in accordance with another preferred embodiment of the present invention, the vascular remodeling stents 40, 50 have a non-uniform grid structure, i.e., the stents have different metal coverage at different locations. For example, the aneurysm segments 41, 51 covering the parent artery 43, 53 have a high metal coverage to maximize blood flow in the aneurysm, while the other portions of the stent 42, 52 have a low metal coverage structure. The normal vessel wall 45, 55 is attached with a support bracket to minimize the coverage of the branches 44, 54 while keeping the lumen open.

For example, at the aneurysm segment, the metal coverage is 30% to 50%, and at other locations, the metal coverage is 12% to 20%.

Alternatively, the metal coverage can vary in the circumferential direction of the stent. At the aneurysm of the aneurysm segment, the metal coverage is 50% to 60%, and at other locations, the metal coverage is 12% to 20%.

As shown in Figures 6a-6d, the cross-section of the wire chain can be of a different shape, such as rectangular, trapezoidal, circular or elliptical.

In addition, the continuous mesh of the implant device can also be used as an embolization material in the aneurysm (such as a releasable coil, embolic fluid, etc.) to support or block, to ensure that the embolic material is only in the aneurysm, thereby maintaining the tumor. The moon is always smooth.

Claims

Rights request

A vascular remodeling stent, characterized in that the vascular remodeling stent has a mesh tubular structure and has a plurality of meshes formed by interlacing a plurality of silk chains.

2. The vascular remodeling stent according to claim 1, wherein each of the filament chains is continuous.

3. The vascular remodeling stent of claim 1 wherein the nodes of the mesh are moveable.

The blood vessel reconstruction stent according to any one of claims 1 to 3, wherein an angle β ₀ formed by the wire chain and the radial direction of the blood vessel reconstruction stent is 15. ~85. .

The blood vessel reconstruction stent according to claim 4, wherein an angle β ₀ formed by the wire chain and the radial direction of the blood vessel reconstruction stent is 30° to 75°.

The blood vessel reconstruction stent according to claim 5, wherein an angle β ₀ formed by the wire chain and the radial direction of the blood vessel reconstruction stent is 45° to 60°.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the vascular remodeling stent has a mesh density of more than 5 pores/mm ² .

The vascular remodeling stent according to any one of claims 1 to 3, wherein the vascular remodeling stent has a metal coverage of 12% to 60%.

The vascular remodeling stent according to claim 8, wherein the vascular remodeling stent has a metal coverage of 30% to 50%.

The vascular remodeling stent according to claim 9, wherein the blood vessel remodeling stent has a metal coverage of 35% to 45%.

11. The vascular remodeling stent of claim 8, wherein different portions of the vascular remodeling stent have different metal coverage depending on the implantation and treatment site of the revascularized stent.

The vascular remodeling stent according to claim 11, wherein the metal coverage of the blood vessel remodeling stent changes in the axial direction.

The vascular remodeling stent according to claim 12, wherein the vascular remodeling stent has a metal coverage of 30% to 50% at the aneurysm segment and a metal coverage of 12 at other locations. %~20%.

The vascular remodeling stent according to claim 11, wherein the metal coverage of the blood vessel remodeling stent changes in the circumferential direction.

The vascular remodeling stent according to claim 14, wherein the vascular reconstructing stent has a metal coverage of 50% to 60% at the aneurysm opening and a metal coverage of 12% at other locations. ~20%.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the vascular remodeling stent has a compression ratio of 2:1 - 10:1.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the number of the filament chains is 8 to 108.

The vascular remodeling stent according to claim 17, wherein the number of the silk chains is 24 to 96.

The vascular remodeling stent according to claim 18, wherein the number of the chains is 32 to 56.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the wire chain has a trapezoidal or elliptical cross section.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the wire chain has a circular cross section.

The vascular remodeling stent according to claim 21, wherein the wire chain has a diameter of 0.01 to 0.2 mm.

The vascular remodeling stent according to claim 22, wherein the wire chain has a diameter of 0.025 to 0.1 mm.

The vascular remodeling stent according to claim 23, wherein the wire chain has a diameter of 0.03 to 0.08 mm.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the wire chain has a rectangular cross section.

The vascular reconstruction stent according to claim 25, wherein the rectangular aspect ratio is 1: 1 to 4: 1.

The vascular remodeling stent according to claim 26, wherein the rectangle has a length of 0.01 to 0.2 mm and a width of 0.01 to 0.2 mm.

The vascular remodeling stent according to claim 27, wherein the rectangle has a length of 0.025 to 0.1 mm and a width of 0.025 to 0.1 mm.

The vascular remodeling stent according to claim 28, wherein the rectangle has a length of 0.03 to 0.08 mm and a width of 0.03 to 0.08 mm.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the pitch of the silk chain is 0.01 to 3 mm.

31. The vascular remodeling stent of claim 30, wherein the filament chains have different pitches depending on the implantation and treatment sites of the revascularized stent.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the material of the silk chain is a biocompatible metal or/and a polymer.

The vascular remodeling stent according to any one of claims 1 to 3, wherein the stent is used to support or block an embolic material in the aneurysm.

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