Lower limb artery stent with closed-loop spiral structure

Abstract

The invention belongs to the technical field of intravascular stents, and particularly discloses a closed-loop spiral structure lower limb artery stent, the cross section of the closed-loop spiral structure lower limb artery stent is of an annular structure, the closed-loop spiral structure lower limb artery stent is applied to human body lower limb artery blood vessels, the closed-loop spiral structure lower limb artery stent comprises a plurality of supporting units parallel in the axial direction and connecting units located between the supporting units, and the adjacent supporting units are connected through the connecting units; the supporting units comprise end supporting units and a middle supporting unit, the end supporting units are located at the two ends of the lower limb artery stent, and the middle supporting unit is located between the end supporting units at the two ends of the lower limb artery stent. The lower limb artery stent body is made of a medical magnesium alloy pipe through laser cutting at a time, and the integrity and safety of the structure are improved. According to the lower limb artery stent of the closed-loop spiral structure, the radial supporting performance, the flexibility and the wall attaching performance of the stent are effectively improved, meanwhile, magnesium alloy serves as an intravascular stent material, and the problem that the stent exists in a blood vessel for a long time, and consequently inflammatory response is caused is greatly solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vascular stents, and in particular to a lower limb artery stent with a closed-loop spiral structure. Background Art

[0002] Lower extremity arteriosclerosis obliterans is a disease caused by atherosclerosis affecting the lower extremity arteries, leading to arterial stenosis or occlusion, which reduces the blood flow into the lower extremities, causing insufficient blood supply to the lower extremities, and causing limb necrosis. The lesion is characterized by the involvement of large and medium arteries, which is more common in elderly patients. The femoral artery, as a branch of the lower extremity artery, is currently the most common site of peripheral arterial disease. Although the patency of the narrowed artery has been improved after interventional treatment, clinical data show that its patency is still poor compared with other sites. This is attributed to the complex mechanical environment of the lower extremities during exercise, and the arteries undergo a wide range of mechanical deformations, including torsion, bending and compression. Currently, interventional treatment has been widely used in lower extremity arteries. In addition to good radial support, the bending, torsion and wall adhesion performance of the stent used for arterial reconstruction are also key factors to be considered in the stent structure design. Good structural design helps to restore vascular function and reduce the occurrence of postoperative arterial restenosis and late adverse events.

[0003] In addition, with the development of technology, the materials of stents are constantly being updated, and degradable materials such as magnesium alloys have made breakthrough progress in degradation speed. Clinical data show that 6-9 months after stent implantation, vascular remodeling has been completed and the stent is no longer necessary. Therefore, as a new generation of stents, degradable stents have good tissue compatibility and biodegradability. After being placed in the narrow part of the blood vessel, they can effectively dilate the blood vessels in the early stage and can be gradually degraded. The degradation products can be excreted from the body through metabolism or absorbed and utilized by the human body without affecting the long-term vascular function. It also alleviates the need for patients to take lifelong medication in the future, so it has great market potential.

[0004] In traditional stent design, there is a contradiction between the flexibility and radial support of the stent, and it is difficult to achieve good results at the same time. The present invention overcomes this problem through structural design and provides a magnesium alloy degradable vascular stent structure that has good flexibility and wall adhesion while ensuring that the stent has sufficient radial support force. Summary of the invention

[0005] The purpose of the present invention is to provide a closed-loop spiral structure lower limb artery stent, which effectively improves the flexibility and radial support performance of the vascular stent. At the same time, magnesium alloy is used as the vascular stent material to greatly avoid the problem of the stent existing in the blood vessel for a long time and thus inducing an inflammatory response.

[0006] To achieve the above-mentioned purpose, the present invention provides a closed-loop spiral structure lower limb artery stent, whose cross-section is a ring-shaped structure, which is applied to the lower limb artery blood vessels of the human body, and includes a plurality of groups of axially parallel support units and connecting units located between the support units. Adjacent support units are connected by connecting units. The support units include end support units and intermediate support units. The end support units are located at both ends of the lower limb artery stent, and the intermediate support unit is located between the end support units at both ends of the lower limb artery stent.

[0007] Preferably, the end support unit and the middle support unit are both closed-loop structures composed of six ellipses, and the six ellipses are interconnected along the middle positions of the long axis directions of the ellipses to form a closed loop.

[0008] Preferably, a raised portion is provided on an ellipse in the end support unit, and an outer surface of the raised portion is coated with a metal coating that is opaque to X-rays.

[0009] Preferably, the connection unit is six spiral curves, and both ends of the spiral curves are respectively connected to adjacent support units.

[0010] Preferably, the lower limb artery stent is made of magnesium alloy material.

[0011] Preferably, the outer surface of the lower limb artery stent is provided with a rapamycin drug coating.

[0012] The advantages and beneficial effects of the closed-loop spiral structure lower limb artery stent of the present invention are: The lower limb artery stent of the present invention effectively improves the radial support performance, compliance performance and wall adhesion performance of the vascular stent. At the same time, magnesium alloy is used as the vascular stent material, which greatly avoids the problem of the stent existing in the blood vessel for a long time and thus inducing an inflammatory response.

[0013] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a lower limb artery stent of the present invention; Figure 2 This is an expanded view of the end support unit of the lower limb artery stent of the present invention; Figure 3 This is an expanded view of the intermediate support unit of the lower limb artery stent of the present invention; Figure 4 It is a planar expansion diagram of the lower limb artery stent according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 1. End support unit; 2. Intermediate support unit; 3. Connecting unit; 4. Raised portion; 5. Spiral curve. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0017] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Example like Figure 1 As shown, a closed-loop spiral structure lower limb artery stent has a ring-shaped cross-section and is applied to the lower limb artery of the human body. It includes a plurality of groups of axially parallel support units and connecting units 3 located between the support units. Adjacent support units are connected by the connecting units 3.

[0019] The support unit includes an end support unit 1 and an intermediate support unit 2. The end support unit 1 is located at both ends of the lower limb artery stent, and the intermediate support unit 2 is located between the end support units 1 at both ends of the lower limb artery stent.

[0020] like Figure 2 and Figure 3 As shown, the end support unit 1 and the middle support unit 2 are both closed-loop structures composed of six ellipses. The six ellipses are interconnected in the middle along the short axis direction of the ellipses to form a closed loop. The special closed-loop structure greatly improves the support performance of the bracket.

[0021] like Figure 2 As shown, a convex portion 4 is provided on an ellipse in the end support unit 1, and an X-ray-proof metal coating is applied to the outer surface of the convex portion 4. Since magnesium alloy does not work well under X-ray development, a layer of X-ray-proof metal coating is applied to the convex portion 4 of the end support unit 1 to facilitate the positioning of the stent after implantation into the blood vessel. In addition to the area of ​​the X-ray-proof coating, a rapamycin drug coating is applied to the outer surface of the lower limb artery stent, that is, the side facing the blood vessel wall.

[0022] like Figure 4As shown, the connection unit 3 is six spiral curves 5, and the two ends of the spiral curves 5 are respectively connected to the adjacent support units. The end support unit 1 and the middle support unit 2 are arranged alternately, and the two ends of each spiral curve 5 are respectively connected to the adjacent alternately arranged ellipses, so that when the six ellipses are connected to each other into a closed loop, the curve of the connection unit 3 is spiral. The connection structure has a great influence on the compliance performance of the stent, that is, the bending and torsion performance. The bending structure of the spiral curve 5 is more easily deformed after bending and torsion, which can better improve the compliance of the stent, comply with the needs of arterial morphological deformation caused by movement of the lower limbs, and can compensate for the axial shortening phenomenon that occurs when the stent is expanded. The connection position of the connection curve has a great influence on the radial support performance and expansion performance of the stent.

[0023] The lower limb artery stent is made of magnesium alloy material. Except for the outer surface of the protrusion 4 coated with an X-ray-proof metal coating, the rest of the parts are coated with rapamycin drug on the outer surface of the stent, that is, on the side facing the blood vessel wall. Magnesium alloy is a common degradable metal material. The standard electrode potential of magnesium and magnesium alloy is low and easy to degrade in the body. After the degradable stent is implanted in the stenotic part of the blood vessel, it can not only effectively dilate the blood vessel in the early stage, but also be gradually degraded. The degradation products can be eliminated from the body through metabolism or absorbed and utilized by the human body without affecting the long-term vascular function. During the degradation process, magnesium and magnesium alloy release non-toxic MgO, which can eventually be completely excreted through urine. Traditional metal stents exist in blood vessels for a long time, which can easily induce inflammatory reactions and cause restenosis in the stent. The magnesium alloy degradable stent can not only effectively support the blood vessel in the early stage, but also be gradually degraded. The degradation products can be eliminated from the body through metabolism or absorbed and utilized by the human body without affecting the long-term vascular function. The single-sided drug coating can avoid the risk of drug overdose while slowing down the degradation time of the stent, and also taking into account the durability of the radial support of the stent.

[0024] The main body of the lower limb artery stent is made of medical-grade magnesium alloy tube and is completed in one go through laser cutting, which greatly improves the integrity and safety of the structure and avoids local fractures. It has a simple structure and is more flexible and tougher than commonly used assembled stents.

[0025] Therefore, the present invention adopts the above-mentioned closed-loop spiral structure lower limb artery stent to effectively improve the radial support performance, flexibility and wall adhesion performance of the vascular stent. At the same time, magnesium alloy is used as the vascular stent material to greatly avoid the long-term presence of the stent in the blood vessel and thus induce inflammatory response.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A closed-loop spiral structure lower limb artery stent, whose cross section is a ring structure, is applied to the lower limb artery of the human body, characterized by: It includes several groups of axially parallel support units and connecting units located between the support units. Adjacent support units are connected by connecting units. The support units include end support units and middle support units. The end support units are located at both ends of the lower limb artery stent, and the middle support unit is located between the end support units at both ends of the lower limb artery stent.

2. The closed-loop helical structure lower limb artery stent according to claim 1, characterized in that: The end support unit and the middle support unit are both closed-loop structures composed of six ellipses, and the six ellipses are interconnected along the middle positions of the short axis directions of the ellipses to form a closed loop.

3. The closed-loop spiral structure lower limb artery stent according to claim 2, characterized in that: A raised portion is provided on an ellipse in the end support unit, and an outer surface of the raised portion is coated with a metal coating that is opaque to X-rays.

4. The closed-loop helical structure lower limb artery stent according to claim 1, characterized in that: The connection unit is six spiral curves, and both ends of the spiral curves are respectively connected to adjacent support units.

5. The closed-loop helical structure lower limb artery stent according to claim 1, characterized in that: The lower limb artery stent is made of magnesium alloy material.

6. The closed-loop helical structure lower limb artery stent according to claim 1, characterized in that: The outer surface of the lower limb artery stent is provided with a rapamycin drug coating.

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