Film-covered double-layer stent

Abstract

The invention discloses a film-covered double-layer stent, and belongs to the technical field of medical instruments. Comprising a first stent layer and a second stent layer, the first stent layer and the second stent layer are each of a self-expanding structure, the second stent layer is sleeved with the first stent layer, and a covering film is arranged between the first stent layer and the second stent layer; the length and the position of the covering film are adjustable, at least one lead is arranged on the covering film and used for adjusting the position of the covering film in the stent, a release point is arranged between the lead and the covering film, and the lead can be separated from the covering film and withdrawn after adjustment is completed. The double-layer stent inherits the advantages that a self-expanding stent is easy to convey, good in vascular shape compliance and the like, meanwhile, the double-layer stent can firmly fix the covering film between the double-layer stent, the phenomenon of inner leakage of the covered stent caused by untight combination of the covering film and the stent can be effectively reduced, meanwhile, the covering film length and the covering film position of the stent are adjustable, and the stent is convenient to use. Therefore, the possibility that the covered stent blocks the blood vessel through the branch is greatly reduced.

Description

Technical Field

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

[0002] Minimally invasive interventional surgery is an important method for treating intracranial aneurysms, arteriovenous fistulas, and vascular defects. Currently, stent grafts are a key device that provide immediate therapeutic effects by blocking abnormal blood flow, but their clinical application still faces significant challenges.

[0003] The current mainstream covered stent technology has the following core defects: Insufficient delivery performance: Traditional covered stents are difficult to pass through tortuous intracranial blood vessels due to their complex structure or high rigidity, which makes surgical operation difficult, prolongs operation time and increases patient risks.

[0004] Stent leakage problem: The coating and the stent are not tightly combined, and are prone to displacement or separation under the impact of blood flow, causing blood to seep into the aneurysm cavity and reduce the treatment effect.

[0005] Poor compliance: The stent is not compatible enough with the vascular morphology, which can easily cause damage to the vascular wall or incomplete adhesion, thereby affecting long-term efficacy and increasing the risk of thrombosis.

[0006] Risk of perforator occlusion: The coverage of the membrane is fixed and cannot be flexibly adjusted according to the lesion morphology. It may compress branch vessels and cause ischemic complications.

[0007] For example, existing single-layer covered stents often utilize a single stent structure, with the covered membrane secured by simple bonding or suturing. This can easily lead to detachment due to hemodynamic effects or vessel tortuosity. Furthermore, the non-adjustable cover position limits the surgeon's flexibility during surgery. This makes precise coverage of the target area difficult, especially in complex lesions (such as wide-necked aneurysms or vascular bifurcations), potentially leading to perforator vessel occlusion or residual aneurysms.

[0008] These technical deficiencies severely restrict the clinical applicability and therapeutic efficacy of covered stents. Therefore, a new covered double-layer stent design is urgently needed to address existing issues such as weak cover fixation, difficult delivery, insufficient compliance, and non-adjustable coverage, thereby improving surgical success rates and reducing the risk of complications. Summary of the Invention

[0009] The present invention provides a coated double-layer stent, which aims to achieve adjustable coating length and coating position of the stent, thereby greatly reducing the possibility of the coated stent occluding vascular perforators and giving clinicians more operating space.

[0010] The present invention provides a coated double-layer stent, which adopts the following technical solution: it includes a first stent layer and a second stent layer, both of which are self-expanding structures, the first stent layer is arranged outside the second stent layer, and a coating is arranged between the first stent layer and the second stent layer; the length and position of the coating are adjustable, and at least one lead is provided on the coating, the lead is used to adjust the position of the coating in the stent, and a release point is provided between the lead and the coating, and after the adjustment is completed, the lead can be detached from the coating and withdrawn.

[0011] Furthermore, the first stent layer may be a laser engraved stent or a woven stent, and the second stent layer may be a laser engraved stent or a woven stent.

[0012] Furthermore, the material of the first support layer and the second support layer is selected from any one of nickel-titanium alloy, stainless steel or cobalt-chromium alloy.

[0013] Furthermore, the material of the coating is selected from any one of expanded polytetrafluoroethylene, polyurethane or polyethylene terephthalate.

[0014] Furthermore, the coating covers part of the surface of the second stent layer or the entire surface of the second stent layer.

[0015] Furthermore, developing points are provided at both ends of the coating for marking the coating position under X-ray.

[0016] Furthermore, the coating is fixed by the clamping force between the first support layer and the second support layer.

[0017] Furthermore, the lead and the coating are fixed by any one of bonding, welding or sewing.

[0018] Beneficial effects of the present invention: 1. The present invention utilizes the synergistic effect of a double-layer stent structure (laser-engraved stent, braided stent, or a combination thereof) to securely clamp the membrane between the two layers of the stent, effectively reducing endoleakage caused by separation of the membrane from the stent and improving the blood flow blocking effect.

[0019] 2. Inheriting the flexibility and easy-delivery characteristics of the expandable stent, the double-layer design further optimizes the stent's bending adaptability, making it easier to pass through tortuous intracranial blood vessels, reducing intraoperative operational difficulty and the risk of vascular damage.

[0020] 3. The membrane is equipped with wires and imaging points. Doctors can precisely control the membrane coverage by adjusting the wires to avoid compression of perforating vessels, significantly reducing the incidence of postoperative ischemic complications. Once adjusted, the wires can be safely released and removed, simplifying the operation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For ease of explanation, the present invention is described in detail with reference to the following specific implementations and accompanying drawings.

[0022] Figure 1 Schematic diagram of the structure of the double-layer coated stent of the present invention; Figure 2 Schematic diagram of the structure of the double-layer coated stent of the present invention; Figure 3 Schematic diagram of the structure of the double-layer coated stent of the present invention; Figure 4 This is a schematic diagram of the structure of the cover film of the present invention with adjustable leads; Figure 5 This is a schematic diagram of the overall structure of the membrane position adjustable stent of the present invention Figure 6 It is a structural schematic diagram of a coated double-layer stent in which the first stent layer is a woven stent and the second stent layer is a cut stent.

[0023] In the figure: 1. First support layer; 2. Second support layer; 3. Covering; 4. Lead wire. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] like Figures 1 to 6 A specific embodiment of a coated double-layer stent is shown, comprising a first stent layer 1 and a second stent layer 2, both of which are self-expanding structures, the first stent layer 1 being sleeved outside the second stent layer 2, and a coating 3 being provided between the first stent layer 1 and the second stent layer 2; the length and position of the coating 3 are adjustable, and at least one lead 4 is provided on the coating 3, the lead 4 being used to adjust the position of the coating 3 in the stent, and a release point being provided between the lead 4 and the coating 3, and the lead 4 can be detached from the coating 3 and withdrawn after the adjustment is completed.

[0027] Specifically, the coating 3 may be provided with a plurality of leads 4, such as Figure 4 As shown, the lead 4 and the coating 3 are fixed by bonding, welding, suturing, etc. After the stent is released, as shown in FIG. Figure 5As shown, the position of the coating 3 between the stents can be adjusted by pulling the guide wires 4 from the proximal end, thereby better covering the lesion. In this design, several imaging points are present at both ends of the coating 3, clearly marking the position of the coating 3 under X-ray. A release point is also provided between the guide wires 4 and the coating 3. After the coating 3 is adjusted, all guide wires are released from the coating 3 and withdrawn from the patient's body from the proximal end.

[0028] Specifically, the length of the coating 3 between the first stent layer 1 and the second stent layer 2 and the position of the coating 3 are adjustable through the lead 4, thereby greatly reducing the possibility of the coated stent occluding the vascular perforator and giving clinicians more operating space.

[0029] Specifically, the coating 3 is provided with a lead 4 and a development point (e.g., a visible marker under X-ray). The doctor can precisely control the coverage of the coating 3 by adjusting the lead 4, avoiding compression of perforating vessels and significantly reducing the incidence of postoperative ischemic complications. Once adjusted, the lead 4 can be safely released and removed, simplifying the operation process.

[0030] In other preferred embodiments, the first stent layer 1 may be a laser-engraved stent or a woven stent, and the second stent layer 2 may be a laser-engraved stent or a woven stent.

[0031] Specifically, such as Figure 6 As shown, the first stent layer 1 is a woven stent, the second stent layer 2 is a laser-engraved stent, and the coating 3 is located between the two stents.

[0032] Specifically, the braided stent in the first stent layer (1) is woven from metal wires, offering excellent bending adaptability, making it easier for the stent system to navigate tortuous intracranial vessels, significantly reducing delivery difficulties and the risk of vascular damage. The laser-engraved stent in the second stent layer (2) is formed by laser-cutting a metal tube. It offers high radial support and a precise structure, ensuring stable adherence to the wall after deployment and preventing collapse or displacement of the coating (3).

[0033] In other preferred embodiments, the material of the first stent layer 1 and the second stent layer 2 is selected from any one of nickel-titanium alloy, stainless steel or cobalt-chromium alloy, and the material of the coating 3 is selected from expanded polytetrafluoroethylene, polyurethane or polyethylene terephthalate to meet different lesion morphologies and clinical needs.

[0034] In other preferred embodiments, the coating 3 covers part or all of the surface of the second stent layer 2. The coating 3 may not be connected to the first stent layer 1 and the second stent layer 2, but is fixed by the clamping force between the first stent layer 1 and the second stent layer 2.

[0035] Specifically, the coating 3 is clamped between the first stent layer 1 and the second stent layer 2 and fixed by the coordinated clamping force of the double-layer structure, thereby avoiding the internal leakage problem caused by the loose combination of the coating 3 and the single-layer stent, and significantly improving the blood flow blocking effect.

[0036] Specifically, the double-layer stent structure enhances mechanical stability and reduces the possibility of stent displacement or deformation; the coating 3 can cover the surface of the second stent layer 2 or the entire surface of the second stent layer 2, taking into account both blood flow blocking and blood vessel branch protection, thereby improving long-term treatment effects.

[0037] Specifically, the coating 3 does not need to be fixed to the stent layer by bonding, welding or suturing, which eliminates complicated connection steps, significantly reduces production difficulty and manufacturing costs, and reduces quality problems caused by process errors.

[0038] Specifically, traditional fixation methods (such as welding and suturing) may cause local perforation or weakening of the coating material, while fixation relying solely on clamping force can maintain the integrity of the coating, reduce the risk of leakage and extend the service life of the device.

[0039] Specifically, the coating 3 can fine-tune its position between the double-layer stents. Especially when treating bifurcated vessels or wide-necked aneurysms, doctors can more flexibly adjust the coverage of the coating to avoid compressing branch vessels and reduce ischemic complications.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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 double-layer stent with a membrane, characterized in that: The invention comprises a first support layer (1) and a second support layer, wherein the first support layer (1) and the second support layer (2) are both self-expanding structures, the first support layer (1) is sleeved outside the second support layer, and a coating (3) is provided between the first support layer (1) and the second support layer (2); the length and position of the coating (3) are adjustable, and at least one lead (4) is provided on the coating (3), and the lead (4) is used to adjust the position of the coating (3) in the support, and a release point is provided between the lead (4) and the coating (3), and after the adjustment is completed, the lead (4) can be separated from the coating (3) and withdrawn.

2. The double-layer stent graft according to claim 1, characterized in that: The first stent layer (1) may be a laser engraved stent or a woven stent, and the second stent layer (2) may be a laser engraved stent or a woven stent.

3. The double-layer stent graft according to claim 1, characterized in that: The material of the first support layer (1) and the second support layer (2) is selected from any one of nickel-titanium alloy, stainless steel or cobalt-chromium alloy.

4. The double-layer stent graft according to claim 1, characterized in that: The material of the coating (3) is selected from any one of expanded polytetrafluoroethylene, polyurethane or polyethylene terephthalate.

5. The double-layer stent graft according to claim 1, characterized in that: The covering film (3) covers part of the surface of the second support layer (2) or the entire surface of the second support layer (2).

6. The double-layer stent graft according to claim 1, characterized in that: Both ends of the coating (3) are provided with developing points for marking the position of the coating (3) under X-ray.

7. The double-layer stent graft according to claim 1, characterized in that: The covering film (3) is fixed by the clamping force between the first support layer (1) and the second support layer (2).

8. The double-layer stent graft according to claim 1, characterized in that: The lead wire (4) and the coating (3) are fixed by any one of bonding, welding or sewing.

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