Vascular reconstruction stent

Abstract

A main body of the vascular reconstruction stent is a hollow tubular stent formed by winding and weaving a plurality of strands of wires in a staggered mode, after the vascular reconstruction stent is placed in a vascular tumor carrying section, blood flow can flow through a hollow inner cavity, part of blood flows into an aneurysm from a stent grid, the stent covers the position of a tumor opening, the inflow amount of the blood is limited, and therefore the vascular reconstruction stent can be used for vascular reconstruction. The wire material is zinc alloy and a small amount of elastically deformable wire material, such as nickel-titanium alloy, cobalt-chromium alloy and the like; by means of the mode that the zinc alloy wires and a small amount of elastically-deformable wires are woven in a mixed mode, overall degradability is achieved, long-term medicine taking is not needed, and stimulation to the blood vessel wall due to long-term implantation is greatly reduced.

Description

Technical Field

[0001] The utility model belongs to the field of implantable medical devices, and in particular relates to a vascular reconstruction stent. Background Art

[0002] Aneurysm is a potentially life-threatening disease. Common treatments include: 1. Surgical clipping of aneurysms, using metal clips to clip the neck of the aneurysm during craniotomy, but this method requires craniotomy and is often accompanied by serious sequelae. 2. Intravascular interventional therapy, using detachable coils (or microwire coils or other embolic materials such as detachable balloons, curable liquids, etc.) to embolize aneurysms, but the devices used for embolization may touch nerves or other biological tissues and cause adverse neurological symptoms. 3. Intravascular interventional stent implantation. In contrast, intravascular interventional therapy has the advantages of less trauma, fewer complications, higher safety, less pain for patients, easier acceptance, shorter hospital stays, and tolerance even for the elderly and seriously ill.

[0003] However, because this type of device is a material that is directly implanted into the cerebral artery, the thrombogenicity-induced thrombosis is the most important factor affecting the effect. Long-term antiplatelet aggregation drug treatment after surgery is a powerful measure to reduce the occurrence of ischemic complications. However, continuous medication also greatly increases the economic and physical burden after surgery, and continuous antiplatelet aggregation treatment can also cause additional health problems. At the same time, long-term implanted stents may also cause problems such as hyperplasia or vascular occlusion. Utility Model Content

[0004] The utility model discloses a vascular reconstruction stent, which is made overall degradable by mixing zinc alloy wires with a small amount of elastically deformable wires, thus avoiding the risks of permanent implantation and not requiring long-term medication, and greatly reducing the stimulation of long-term implantation to the vascular wall.

[0005] To achieve the above objectives, this application adopts the following technical solutions.

[0006] A vascular reconstruction stent, comprising a hollow tubular stent body formed by interlacing and braiding a plurality of wires in the form of spirals and reverse spirals, wherein the stent body has two states: a compressed state and an expanded state, and can be restored from the compressed state to the expanded state when there is no external force restriction; the wires are zinc alloy and elastically deformable wires, wherein the number of zinc alloy wires is greater than the number of elastically deformable wires, and the wires have at least two thickness specifications;

[0007] Furthermore, in the wire material, the ratio of the number of zinc alloy wires to the number of elastically deformable wires is between 5:1 and 20:1.

[0008] Furthermore, the wire diameter of the elastically deformable wire is greater than the wire diameter of the zinc alloy.

[0009] Furthermore, the wire diameter of the zinc alloy is larger than the wire diameter of the elastically deformable wire.

[0010] Furthermore, the cross-sectional shape of the wire material includes one or more combinations of circular, elliptical, rectangular, and trapezoidal.

[0011] Furthermore, the elastically deformable wire includes but is not limited to nickel-titanium alloy and cobalt-chromium alloy.

[0012] Furthermore, the elastically deformable wire is a nickel-titanium alloy.

[0013] Furthermore, the stent body has segments with different densities, and the denser segments are located at the lesion part.

[0014] The utility model has at least the following beneficial effects:

[0015] By mixing zinc alloy wires with a small amount of elastically deformable wires, the device can be made biodegradable as a whole, wherein the zinc alloy wires are completely degraded, while the small amount of elastically deformable wires are completely endothelialized, without further irritating the blood vessels, thereby reducing the occurrence of complications. Additionally, since the zinc alloy itself has only good developing properties and is combined with the relatively dense structure of the device, a good developing effect can be achieved without the need for additional developing structures. It also has the property of elastic deformation and self-expansion, which is beneficial to intraoperative operations during implantation.

[0016] A stent design with different densities is adopted, and the denser section is also provided with a membrane layer to further enhance the blood guidance effect. The denser segment can effectively support the membrane layer to avoid its damage, while the sparser segment can effectively reduce the impact on the blood flow direction of the branch vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The use state diagram of the present application is schematically shown;

[0019] Figure 2 The structural diagram of an embodiment of the present application is schematically shown;

[0020] Figure 3 Schematically shows Figure 2 A partial enlarged view of part A.

[0021] In the figure:

[0022] 1-stent body, 11-thick wire, 12-thin wire, 2-blood vessel, 3-aneurysm. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation methods of the utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the technical solution, and do not indicate that the device or element referred to must have a specific orientation. Therefore, it cannot be understood as a limitation on the utility model. It should also be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or one or more intervening elements may also exist. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0024] In the following description, for the purpose of illustration and not limitation, as used herein, "lumen" refers to a cavity defined by a tubular structure in a mammal, including but not limited to blood vessels, ureters, urethra, and bile ducts. Specific details such as specific system structures and technologies are provided to provide a thorough understanding of the embodiments of the utility model; however, it should be clear to those skilled in the art that the utility model can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, and methods are omitted to avoid unnecessary details that hinder the description of the utility model. Example

[0025] The vascular reconstruction stent of the present application is placed in the tumor-bearing segment of the blood vessel to support the blood vessel and limit the impact of blood on the aneurysm, thereby preventing the aneurysm from further expanding and greatly reducing the risk of aneurysm rupture. Figure 1As shown, the stent is located at the aneurysm opening where the aneurysm connects to the blood vessel. The blood flow is blocked by the stent and can only flow in through the mesh of the stent. Obviously, the free flow of blood into the aneurysm is greatly restricted, which is conducive to the reconstruction of the tumor-bearing blood vessel. In addition, when performing vascular reconstruction, it is only necessary to select a stent with a suitable length and diameter and implant it into the artery according to the specific situation of the hemangioma to be treated. After the stent reaches the lesion site, traditional balloon dilation and other steps are no longer required, avoiding the problem of restenosis of the blood vessel caused by radial elastic recovery after the traditional balloon dilation stent is expanded. The operation is simpler and safer.

[0026] The vascular reconstruction stent includes a stent body 1, which is a hollow tubular structure formed by interlacing and weaving multiple strands of wire in a spiral form and a reverse spiral form, and adopts a non-tight weaving method, that is, when the same wire is spirally wound into a circle, a certain gap is left between adjacent circles. Multiple strands of wire will form a number of meshes after interlacing and winding, and are combined in a weaving manner. Compared with other processing methods such as laser engraving, the weaving method does not involve cutting, and its outer surface is smoother and not easy to scratch the blood vessel. It also has higher flexibility and is easy to be placed in complex blood vessels.

[0027] like Figure 2~3 As shown, in the present application, zinc alloy and nickel-titanium alloy wires are mixed, wherein the ratio of zinc alloy wire to elastically deformable wire is between 5:1 and 20:1. As a metal material, compared with polymer materials such as polylactic acid used in the prior art, it has higher strength and lighter weight, and the zinc alloy can be degraded. After a certain period of time, the zinc alloy will be completely degraded. The nickel-titanium alloy can optimize the mechanics of the stent and assist in the expansion of the stent. The mixing of the two overcomes the problem of poor self-expansion performance of the stent caused by the poor elastic deformation ability of the zinc alloy wire, and the nickel-titanium alloy is used in small amounts and exists in the form of wire. Therefore, after the zinc alloy is degraded, it will gradually endothelialize, and its impact can be ignored. Therefore, there is no need for lifelong medication.

[0028] Moreover, due to the mixed weaving with zinc alloy wire, a small amount of elastically deformable wire is woven in a spiral or reverse spiral, which drives the overall uniform self-expansion of the stent during the elastic recovery process, thereby optimizing the mechanical performance of the stent.

[0029] Of course, since the stent body 1 is woven, it has two states: a clamped state and an expanded state. In the clamped state, the stent body 1 can be loaded into a delivery device and delivered to the lesion site; after the stent is delivered to the preset position in the blood vessel 2, the delivery device is separated from the stent, the restraining force acting on the stent disappears, and the stent gradually returns to an expanded state, and its radius is equivalent to the diameter of the blood vessel at that location.

[0030] Those skilled in the art should understand that the stent body 1 can be prepared into various sizes.

[0031] It should be noted that the cross-sectional shape of the wire includes but is not limited to: a combination of one or more of a circle, an ellipse, a rectangle, and a trapezoid. At the same time, the thickness of the wire also has different specifications, that is, a thick wire 11 and a thin wire 12, such as Figure 3 As shown, the thick wires 11 and the thin wires 12 are arranged alternately, and the thick wires 11 can obviously bear greater pressure and maintain the mechanical properties and performance of the stent.

[0032] In this embodiment, the thick wires 11 are elastically deformable wires, the thin wires 12 are zinc alloy, and the number of the thick wires 11 is less than the number of the thin wires 12 .

[0033] In another embodiment, the thick wires 11 are made of zinc alloy, the thin wires 12 are made of nickel-titanium alloy, and the number of the thick wires 11 is greater than the number of the thin wires 12 .

[0034] In another preferred embodiment, a stent body 1 is involved in which segments of different densities are present, wherein the denser segments are located in the middle of the stent and the sparser segments are located at the ends. The blood guiding effect thereof is greatly reduced, and the influence on the branch blood vessels 2 can be reduced. Of course, the sparser segments can also be located in the middle of the stent body 1.

[0035] It should be noted that the density refers to the difference in mesh area between the wires after the wires are interlaced and woven, which results in different density on a macro scale.

[0036] In addition, the stent body 1 also has a better development effect. Although the structure of the wire does not display well under the image, after the stent is formed by the preparation method in the present application, the wire is concentrated in a large number in a local area, which greatly increases the development performance. There is no need to set up an additional development structure or development coating, which greatly reduces its process and cost, and avoids the problem of excessive cross-sectional area caused by traditional technology of coating the nickel-titanium alloy wire with a development layer.

[0037] In various embodiments of the present application, the elastically deformable wire material includes, but is not limited to, nickel-titanium alloy wire and cobalt-chromium alloy wire. Preferably, the elastically deformable wire material in the present application is nickel-titanium alloy wire.

[0038] In various embodiments, the body wall is a blood vessel wall, and the blood vessel 2 is an intracranial blood vessel 2. In various embodiments, the pathology is an aneurysm 3, cancer, infection, coronary artery disease, carotid atherosclerotic disease, or intracranial atherosclerosis.

Claims

1. A vascular reconstruction stent, characterized in that: The stent body comprises a hollow tubular stent body formed by interlacing and weaving multiple strands of wire in the form of spirals and reverse spirals, wherein the stent body has two states: a compressed state and an expanded state, and can be restored from the compressed state to the expanded state when there is no external force restriction; The wires are zinc alloy and elastically deformable wires, wherein the number of zinc alloy wires is greater than the number of elastically deformable wires, and the wires have at least two thickness specifications.

2. The vascular reconstruction stent according to claim 1, characterized in that: In the wire material, the ratio of the number of zinc alloy wires to the number of elastically deformable wire materials is between 5:1 and 20:

1.

3. The vascular reconstruction stent according to claim 2, characterized in that: The wire diameter of the elastically deformable wire material is greater than the wire diameter of the zinc alloy.

4. The vascular reconstruction stent according to claim 2, characterized in that: The wire diameter of the zinc alloy is greater than the wire diameter of the elastically deformable wire material.

5. The vascular reconstruction stent according to claim 1, characterized in that: The cross-sectional shape of the wire material includes one or more combinations of circular, elliptical, rectangular, and trapezoidal.

6. The vascular reconstruction stent according to claim 1, characterized in that: The stent body has segments with different densities, and the denser segments are located at the lesion part.

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