Covered stent

Abstract

The invention discloses a covered stent, and belongs to the technical field of medical instruments. Comprising a stent body which is of a self-expanding structure, and the near end of the stent body is connected with a conveying guide wire capable of being mechanically disengaged or electrolytically disengaged and used for being released after being adjusted in place; the film covering layer covers the whole area or part of the area of the stent main body; the film covering layer is fixedly connected with the stent main body. X-ray-impermeable mark points are arranged at the two ends of the film covering layer and used for indicating the relative position of the film covering layer in the operation. According to the covered stent, an overall covered stent and a local covered stent are provided, the proper covered length can be selected according to lesions of different lengths, so that the influence of the covered stent on a branch penetrating blood vessel is reduced, the covered layer of a curled structure is additionally arranged, and the curled structure can further reduce the conveying resistance of the covered stent.

Description

Technical Field

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

[0002] Minimally invasive interventional surgery is a common treatment for intracranial aneurysms. For the treatment of intracranial aneurysms, the commonly used techniques currently include coil packing, stent-assisted coil packing, blood flow diversion device placement, covered stent implantation, and other methods. For large and giant saccular aneurysms, wide-necked aneurysms, fusiform and dissecting aneurysms, if traditional coil or stent-assisted coil packing techniques are used, there are problems such as long intraoperative time, incomplete aneurysm occlusion, and high postoperative complication rate. The blood flow diversion device, due to its high weaving density, may also have incomplete wall adhesion and bending flexibility, which has a certain impact on the postoperative aneurysm occlusion rate and the occurrence of ischemic complications.

[0003] Covered stents can, to a certain extent, solve the problem of incomplete aneurysm occlusion. Covered stents can completely block blood flow into the aneurysm cavity, achieving immediate complete cure of the aneurysm. At the same time, covered stents can also be used to treat intracranial arteriovenous fistulas or repair vascular defects caused by trauma. Therefore, covered stents have great potential for clinical application as an intravascular stent. However, existing covered stents have a series of problems such as difficulty in delivery, stent leakage, poor compliance, and easy to cause perforator occlusion. The existence of these problems has greatly limited the clinical application prospects of covered stents, resulting in extremely small clinical applications of covered stents.

[0004] In view of the above shortcomings, the present invention proposes a new type of covered stent to solve the above problems. Summary of the Invention

[0005] The present invention provides a covered stent, which aims to reduce the influence of the covered membrane on the perforating blood vessels and further reduce the transport resistance of the covered stent.

[0006] The present invention provides a stent graft, which adopts the following technical solutions, including: The stent body has a self-expanding structure, and the proximal end of the stent body is connected to an electrolytically detachable delivery guide wire for release after adjustment into position; a coating layer covering the entire region or a portion of the region of the stent body; The coating layer and the bracket body are fixedly connected.

[0007] Furthermore, when the covering layer covers the entire area of the stent body, it is used for aneurysms with wider necks.

[0008] Furthermore, when the covering layer covers a partial area of the stent body, it is used for aneurysms with narrow necks or aneurysms with many parent artery branches.

[0009] Furthermore, the stent body is made of nickel-titanium alloy, the length of the stent body is in the range of 10-70 mm, and the outer diameter is in the range of 1.5-10 mm; the outer diameter of the stent body is less than or equal to the inner diameter of the stent coating layer.

[0010] Furthermore, the stent body and the coating layer are fixedly connected by any one of bonding, welding or suturing.

[0011] Furthermore, the end of the stent body contains an X-ray opaque developing marking point; and both ends of the coating layer contain X-ray opaque developing marking points.

[0012] Furthermore, the stent body is a curled structure, and the coating layer is a curled structure or a continuous structure.

[0013] Furthermore, the coating layer is made of at least one polymer material selected from expanded polytetrafluoroethylene, PU or PET.

[0014] Furthermore, the thickness of the polymer film of the coating layer is 5 microns to 100 microns.

[0015] Furthermore, the material of the development mark point can be composed of one or more materials of platinum, platinum iridium, platinum tungsten.

[0016] Beneficial effects of the present invention: 1. The proximal end of the stent body of the present invention is connected to a delivery guide wire that can be mechanically or electrically released. The stent body can be completely released after being adjusted into place.

[0017] 2. In the present invention, when the stent body is a curled structure and the coating layer is a continuous structure, the aneurysm can be effectively blocked without worrying about endoleakage.

[0018] 3. In the present invention, when the stent body is a curled structure and the coating layer is also a curled structure, the stent and the coating can be curled at the same time when transported in a catheter, so the stent has lower transport resistance.

[0019] 4. Marking points are set at both ends of the stent body and the coating layer, forming a clear three-dimensional positioning reference under X-ray fluoroscopy, which facilitates the surgeon to judge the stent position in real time, especially in areas with overlapping or tortuous blood vessels, significantly improving positioning accuracy and reducing surgical risks caused by position deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the structure of a partially covered stent of the present invention, in which both the stent end and the membrane end have developing marking points; Figure 2 This is a side view of a partially coated stent of the present invention, wherein both the stent end and the membrane end have imaging marking points; Figure 3 is a top view of a portion of the stent graft of the present invention; Figure 4 1 is a schematic structural diagram of the integral covered stent of the present invention; Figure 5 This is a side view of the integral coated stent of the present invention Figure 6 is a top view of the integral stent graft of the present invention; Figure 7 This is a schematic structural diagram of the present invention in which the coating layer and the stent body are both curled structures; Figure 8 This is a top view of the present invention in which the coating layer and the stent body are both in a curled structure; Figure 9 It is a structural schematic diagram of the connection between the coated stent and the delivery guide wire of the present invention.

[0022] In the figure: 1. Stent body; 2. Coating layer; 3. Delivery guide wire; 4. Development marking point. DETAILED DESCRIPTION

[0023] The following are specific embodiments of the present invention, which, in conjunction with the accompanying drawings, further describe the technical solutions of the present invention. However, the present invention is not limited to these embodiments. In the following description, specific details such as specific configurations and components are provided only to facilitate a comprehensive understanding of the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, for the sake of clarity and brevity, descriptions of known functions and structures have been omitted.

[0024] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0025] like Figures 1 to 9 A specific embodiment of a coated stent is shown, in which a metal tube is cut into a hollow structure using a laser, and is shaped into a stent body 1 of the required size through heat treatment, and then a coating layer 2 is wound around the surface of the stent body 1, and the two are fixed together by bonding, welding or sewing.

[0026] Specifically, the stent body 1 is made of nickel-titanium alloy laser cutting into a self-expanding tubular structure, and the proximal end of the stent body 1 is connected to a delivery guide wire 3 that can be mechanically or electrolytically released, for release after adjustment into position; Specifically, the self-expandable structural stent body 1 and the mechanically or electrolytically detachable delivery guide wire 3 are existing mature technologies and will not be described in detail here.

[0027] Specifically, the coating layer 2 covers the entire region or a portion of the region of the stent body 1 , and the coating layer 2 is made of at least one polymer material selected from expanded polytetrafluoroethylene, PU, or PET.

[0028] Specifically, the thickness of the polymer film of the coating layer 2 is 5 micrometers to 100 micrometers.

[0029] Specifically, both ends of the coating layer 2 and the end of the stent body 1 contain X-ray-opaque developing marking points 4, which form a clear three-dimensional positioning reference under X-ray fluoroscopy, making it easier for the surgeon to judge the position of the stent in real time, especially in areas where blood vessels overlap or are tortuous, significantly improving positioning accuracy and reducing surgical risks caused by position deviation.

[0030] Specifically, the material of the development mark point 4 can be one or more of platinum, platinum-iridium, and platinum-tungsten.

[0031] Specifically, X-ray-opaque markers 4 at both ends of the coating layer 2 are evenly distributed circumferentially, with a number of 3 or 2n (where n ≥ 1 is a positive integer), forming a symmetrical spatial coordinate reference system. When X-rays are viewed from different angles (e.g., anteroposterior, lateral, and oblique), the relative positions of the markers 4 clearly reflect the stent's axial rotation angle, radial deployment state, and conformity to the vessel wall, avoiding positioning errors caused by a single marker.

[0032] Specifically, the coating layer 2 is fixedly connected to the stent body 1 , and the stent body 1 and the coating layer 2 are fixedly connected by any one of bonding, welding or suturing.

[0033] Specifically, the length of the stent body 1 ranges from 10 to 70 mm, with an outer diameter of 1.5 to 10 mm. The outer diameter of the stent body 1 is less than or equal to the inner diameter of the stent graft 2. This ensures that after the stent body 1 expands, the graft 2 adheres tightly to the vessel wall, minimizing the gap between the stent body 1 and the graft 2, effectively preventing postoperative endoleakage (blood seeping into the tumor) and improving the sealing effect.

[0034] In other preferred embodiments, Figure 1 and Figure 4 As shown, when the covering layer 2 covers the entire area of the stent body 1, it is used for aneurysms with narrow necks or aneurysms with many parent artery branches.

[0035] Specifically, for an aneurysm with a larger and wider neck, the local coating may not be able to cover the entire neck, resulting in poor aneurysm healing. Therefore, when the aneurysm neck is wider, the covering layer 2 covers the entire area of the stent body 1.

[0036] In other preferred embodiments, Figure 3 and Figure 6 As shown, when the covering layer 2 covers a partial area of the stent body 1, it is used for aneurysms with narrow necks or aneurysms with many parent artery branches.

[0037] Specifically, for some aneurysms with narrow necks, using the entire coating may block blood flow in the perforating vessels of the parent artery, leading to cerebral infarction. Therefore, when the aneurysm neck is narrow, the covering layer 2 covers a portion of the stent body 1.

[0038] In other preferred embodiments, the stent body 1 is a curled structure, and the coating layer 2 is a curled structure or a continuous structure.

[0039] Specifically, such as Figure 3 and Figure 6 As shown, when the stent body 1 is a curled structure and the coating layer 2 is a continuous structure, that is, the stent body 1 has an opening, since the coating layer 2 is tightly attached to the blood vessel wall in the circumferential direction, the stent does not need to be deliberately adjusted in position after implantation, and the aneurysm neck can be covered by the coating layer 2, thereby achieving effective occlusion of the aneurysm without worrying about internal leakage.

[0040] Specifically, such as Figure 7 and Figure 8 As shown, when the stent body 1 is a curled structure and the coating layer 2 is also a curled structure, that is, both the stent body 1 and the coating layer 2 have openings, when transported in the catheter, the stent body 1 and the coating layer 2 can be curled at the same time, which is convenient for compression into the slender transport catheter, reducing friction damage to the blood vessels during implantation, and is particularly suitable for passing through tortuous or narrow blood vessel pathways. It can have higher flexibility during the transport process, and the overall stiffness of the stent is reduced, so the stent has lower transport resistance.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] In the description of the present invention, it should be understood that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0044] Those skilled in the art may make various modifications or additions to the described embodiments or replace them with similar methods without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A stent graft, characterized in that: include: The stent body (1) has a self-expanding structure, and the proximal end of the stent body (1) is connected to a delivery guide wire (3) that can be mechanically or electrolytically released, and is used for release after adjustment into position; A coating layer (2) covers the entire area or a portion of the area of the stent body (1); The coating layer and the bracket body (1) are fixedly connected.

2. The stent graft according to claim 1, characterized in that: When the covering layer (2) covers the entire area of the stent body (1), it is used for aneurysms with wider necks.

3. The stent graft according to claim 1, characterized in that: When the covering layer (2) covers a partial area of the stent body (1), it is used for aneurysms with narrow necks or aneurysms with many parent artery branches.

4. The stent graft according to claim 1, wherein: The stent body (1) is made of nickel-titanium alloy, the length of the stent body (1) is in the range of 10 to 70 mm, and the outer diameter is in the range of 1.5 to 10 mm; the outer diameter of the stent body (1) is less than or equal to the inner diameter of the stent coating layer (2).

5. The stent graft according to claim 1, characterized in that: The stent body (1) and the coating layer (2) are fixedly connected by any one of bonding, welding or suturing processes.

6. The stent graft according to claim 1, characterized in that: The end of the stent body (1) contains an X-ray-proof developing marking point (4); and both ends of the coating layer (2) contain an X-ray-proof developing marking point (4).

7. The stent graft according to claim 1, characterized in that: The stent body (1) is a curled structure, and the coating layer (2) is a curled structure or a continuous structure.

8. The stent graft according to claim 1, characterized in that: The coating layer (2) is made of at least one polymer material selected from expanded polytetrafluoroethylene, PU or PET.

9. The stent graft according to claim 8, wherein the polymer film thickness of the graft layer (2) is 5 microns to 100 microns.

10. The stent graft according to claim 6, characterized in that: The material of the development marking point (4) can be composed of one or more materials including platinum, platinum iridium, and platinum tungsten.

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