Self-expanding intravascular stent

Abstract

The invention discloses a self-expanding intravascular stent, and relates to the field of medical instruments, the self-expanding intravascular stent comprises a net-shaped stent and a covering film, the net-shaped stent comprises a net-shaped outer cylinder and a net-shaped inner cylinder, the net-shaped inner cylinder is arranged in the net-shaped outer cylinder, and the two ends of the net-shaped inner cylinder are connected with the two ends of the net-shaped outer cylinder respectively; the net-shaped outer cylinder and the net-shaped inner cylinder are both formed by weaving shape memory alloy wires, the net-shaped outer cylinder and the net-shaped inner cylinder are both provided with covering films, in the expansion state, the net-shaped outer cylinder is used for being supported on the inner wall of a blood vessel, and a center flow channel used for reducing blood flow is formed in the net-shaped inner cylinder. The self-expanding intravascular stent solves the problem that blood flow supply of left and right pulmonary arteries is unbalanced, namely the blood flow of the left pulmonary artery is far lower than the blood flow of the right pulmonary artery, in a child patient suffering from Fallot quadruple syndrome and pulmonary artery atresia.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a self-expanding vascular stent. Background Technology

[0002] Tetralogy of Fallot (TOF) is a common cyanotic congenital heart disease characterized by right ventricular outflow tract obstruction, ventricular septal defect, rightward displacement of the aortic origin, and concentric hypertrophy of the right ventricle. Pulmonary artery stenosis is a crucial factor in the pathophysiology of TOF, leading to right-to-left shunting and causing cyanosis and other related symptoms. In some complex TOF cases, such as those complicated by pulmonary atresia, a severe imbalance in blood flow between the left and right pulmonary arteries occurs, typically with significantly lower blood flow in the left pulmonary artery compared to the right. This imbalance further exacerbates the cardiopulmonary burden on the child, affecting treatment outcomes and prognosis.

[0003] To address this issue, the medical community has been exploring various treatment methods, including surgical and interventional procedures. While surgical treatment is highly effective, it is invasive, has a long recovery time, and carries significant challenges and risks for certain complex cases. Interventional procedures, on the other hand, are relatively less invasive and have a faster recovery time, but require appropriate interventional equipment and technical support.

[0004] Regarding interventional treatments, existing techniques such as balloon angioplasty or stent implantation are primarily used to address pulmonary artery stenosis. These techniques dilate blood vessels and increase blood flow by implanting balloons or stents. However, these techniques are not specifically designed to address the imbalance in blood flow between the left and right pulmonary arteries, and therefore cannot reduce blood flow, resulting in limited effectiveness in addressing this imbalance. Summary of the Invention

[0005] To address the above technical problems, this invention provides a self-expanding vascular stent, which solves the problem of unbalanced blood flow between the left and right pulmonary arteries in children with tetralogy of Fallot and pulmonary atresia, i.e., the blood flow in the left pulmonary artery is much lower than that in the right pulmonary artery.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a self-expanding vascular stent, comprising a mesh stent and a covering. The mesh stent includes a mesh outer cylinder and a mesh inner cylinder, with the mesh inner cylinder disposed inside the mesh outer cylinder. The two ends of the mesh inner cylinder are respectively connected to the two ends of the mesh outer cylinder. Both the mesh outer cylinder and the mesh inner cylinder are woven from shape memory alloy wires. The covering is disposed on both the mesh outer cylinder and the mesh inner cylinder. When in an expanded state, the mesh outer cylinder is used to support the inner wall of the blood vessel, and the interior of the mesh inner cylinder forms a central flow channel for reducing blood flow.

[0008] Preferably, the inner diameter of the central flow channel decreases sequentially from one end of the mesh inner cylinder to the center of the mesh inner cylinder, and increases sequentially from the center of the mesh inner cylinder to the other end of the mesh inner cylinder.

[0009] Preferably, the mesh inner cylinder includes a mesh intermediate cylinder and two mesh connecting parts respectively disposed at both ends of the mesh intermediate cylinder, and the end of each mesh connecting part away from the mesh intermediate cylinder is connected to one end of the mesh outer cylinder.

[0010] Preferably, the mesh connector is trumpet-shaped.

[0011] Preferably, the mesh intermediate cylinder adopts an arc-shaped scaling structure.

[0012] Preferably, the mesh outer cylinder expands into a cylindrical shape with a uniform diameter.

[0013] Preferably, the outer surface of the mesh outer cylinder is provided with the coating.

[0014] Preferably, the inner surface of the mesh inner cylinder is provided with the coating.

[0015] Preferably, the coating is a polytetrafluoroethylene coating or a polyester coating.

[0016] Preferably, the shape memory alloy wire is a nickel-titanium shape memory alloy wire.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] The self-expanding vascular stent of the present invention includes a mesh stent and a covering. The mesh stent includes a mesh outer cylinder and a mesh inner cylinder. The mesh inner cylinder is disposed inside the mesh outer cylinder. The two ends of the mesh inner cylinder are respectively connected to the two ends of the mesh outer cylinder. Both the mesh outer cylinder and the mesh inner cylinder are woven from shape memory alloy wires. Both the mesh outer cylinder and the mesh inner cylinder are covered with a covering. When in the expanded state, the mesh outer cylinder is used to support the inner wall of the blood vessel, and the interior of the mesh inner cylinder forms a central flow channel to reduce blood flow. In use, the self-expanding vascular stent of this invention is implanted into the right pulmonary artery. The inner diameter of the self-expanding vascular stent installation site in the right pulmonary artery is reduced, which increases the resistance of the right pulmonary artery, thereby reducing the blood flow in the right pulmonary artery and increasing the blood flow in the left pulmonary artery. By adjusting the blood flow resistance and blood flow in the left and right pulmonary arteries, the blood supply to the left and right pulmonary arteries can be effectively balanced. This solves the problem of unbalanced blood supply to the left and right pulmonary arteries in children with tetralogy of Fallot and pulmonary atresia, i.e., the blood flow in the left pulmonary artery is much lower than that in the right pulmonary artery, thereby reducing the cardiopulmonary burden on patients and improving treatment effects and prognosis. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of the self-expanding vascular stent provided by the present invention in an expanded state;

[0021] Figure 2 A schematic diagram of the structure of the mesh stent in the self-expanding vascular stent provided by the present invention when it is in an expanded state;

[0022] Figure 3 This is a schematic diagram of the self-expanding vascular stent provided by the present invention after expansion in a blood vessel;

[0023] Figure 4 This is a schematic diagram of the mesh stent in the self-expanding vascular stent provided by the present invention after expansion in the blood vessel.

[0024] Explanation of reference numerals in the attached drawings: 1. Mesh outer cylinder; 2. Mesh inner cylinder; 21. Mesh intermediate cylinder; 22. Mesh connecting part; 3. Covering membrane; 4. Central flow channel. Detailed Implementation

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] The purpose of this invention is to provide a self-expanding vascular stent that solves the problem of unbalanced blood flow between the left and right pulmonary arteries in children with tetralogy of Fallot and pulmonary atresia, namely, the blood flow in the left pulmonary artery is much lower than that in the right pulmonary artery.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1-Figure 4As shown, this embodiment provides a self-expanding vascular stent, including a mesh stent and a covering 3. The mesh stent includes a mesh outer cylinder 1 and a mesh inner cylinder 2, with the mesh inner cylinder 2 disposed inside the mesh outer cylinder 1. Both ends of the mesh inner cylinder 2 are connected to the ends of the mesh outer cylinder 1. Both the mesh outer cylinder 1 and the mesh inner cylinder 2 are woven from shape memory alloy wires, which possess excellent biocompatibility and corrosion resistance. A covering 3 is provided on both the mesh outer cylinder 1 and the mesh inner cylinder 2. When in an expanded state, the mesh outer cylinder 1 supports the inner wall of the blood vessel, and the interior of the mesh inner cylinder 2 forms a central flow channel 4 to reduce blood flow.

[0029] In use, the self-expanding vascular stent of this embodiment is implanted into the right pulmonary artery. The inner diameter of the self-expanding vascular stent installation site in the right pulmonary artery is reduced, which increases the resistance of the right pulmonary artery, thereby reducing the blood flow in the right pulmonary artery and increasing the blood flow in the left pulmonary artery. By adjusting the blood flow resistance and blood flow of the left and right pulmonary arteries, the blood supply of the left and right pulmonary arteries can be effectively balanced. This solves the problem of unbalanced blood supply in the left and right pulmonary arteries in children with tetralogy of Fallot and pulmonary atresia, i.e., the blood flow in the left pulmonary artery is much lower than that in the right pulmonary artery, thereby reducing the cardiopulmonary burden on patients and improving treatment effects and prognosis.

[0030] Specifically, the inner diameter of the central flow channel 4 decreases progressively from one end of the mesh inner cylinder 2 to its center, and increases progressively from its center to its other end. In this embodiment, the central flow channel 4 employs a gradually contracting and then gradually expanding structure, ensuring a gradual decrease in blood flow as it passes through the central flow channel 4. This prevents sudden obstruction of blood flow at narrow points, thus avoiding the formation of violent turbulence and reducing the risk of vascular damage.

[0031] In this embodiment, the mesh inner cylinder 2 includes a mesh intermediate cylinder 21 and two mesh connecting parts 22 respectively disposed at both ends of the mesh intermediate cylinder 21. The end of each mesh connecting part 22 away from the mesh intermediate cylinder 21 is connected to one end of the mesh outer cylinder 1.

[0032] Specifically, the mesh connecting part 22 is trumpet-shaped. The larger diameter end of the trumpet-shaped mesh connecting part 22 is connected to the end of the mesh outer cylinder 1, and the smaller diameter end is connected to the end of the mesh middle cylinder 21.

[0033] Specifically, the mesh intermediate cylinder 21 adopts an arc-shaped scaling structure, which is a smooth structure that gradually shrinks and then gradually expands. This structure ensures that there is no sudden change in the inner diameter of the middle section of the central flow channel 4, thereby reducing blood flow while ensuring that blood flows smoothly.

[0034] Specifically, after the mesh outer cylinder 1 expands, it becomes a cylindrical shape with a uniform diameter, which can support the inner wall of the blood vessel.

[0035] Specifically, the outer surface of the mesh outer tube 1 is provided with a membrane 3, and the inner surface of the mesh inner tube 2 is provided with a membrane 3. This allows the self-expanding vascular stent to adhere tightly to the inner wall of the blood vessel after implantation without causing damage to the vascular intima. Since the mesh stent has a mesh structure, the membrane 3 can also prevent blood flow from passing through the pores of the mesh stent.

[0036] In this specific embodiment, the coating 3 is a polytetrafluoroethylene coating or a polyester coating.

[0037] In this specific embodiment, the shape memory alloy wire is a nickel-titanium shape memory alloy wire.

[0038] The specific process is as follows: First, patient assessment and preparation are carried out. Specifically, a detailed medical assessment is conducted on the patient to determine the specific situation of the imbalance in blood flow supply between the left and right pulmonary arteries, and a personalized treatment plan is developed.

[0039] The selection and customization of stents involves choosing a suitable self-expanding vascular stent based on the patient's vascular structure and blood flow requirements, and making necessary customized adjustments.

[0040] The procedure involves stent implantation. Specifically, under strict surgical conditions, the surgeon first delivers a compressed, self-expanding vascular stent to the predetermined location in the right pulmonary artery via a catheter. Then, the stent is released, allowing it to expand automatically. After implantation, the self-expanding stent automatically expands to its preset shape, closely conforming to the inner wall of the right pulmonary artery. Simultaneously, as the stent expands, the inner diameter of the right pulmonary artery gradually decreases, thereby regulating blood flow resistance and blood flow.

[0041] The self-expanding vascular stent in this embodiment not only has the characteristic of self-expanding, but can also automatically expand to a preset diameter after implantation, thereby ensuring the stability and support of the stent; at the same time, after expansion, it can reduce the inner diameter of the right pulmonary artery stent installation site, thereby increasing the resistance of the right pulmonary artery, thereby reducing the blood flow of the right pulmonary artery and increasing the blood flow of the left pulmonary artery, so as to achieve the purpose of balancing the blood supply of the left and right pulmonary arteries.

[0042] Postoperative monitoring, long-term follow-up, and maintenance are conducted. Specifically, the blood flow in the left and right pulmonary arteries is monitored in real time using a physiological feedback system after surgery. Patients are followed up long-term, and the working status and blood flow of the self-expanding vascular stent are checked regularly, with necessary adjustments and maintenance made as needed.

[0043] This embodiment allows for personalized treatment based on the patient's specific condition. From patient assessment and stent selection and customization to postoperative monitoring, the entire treatment process revolves around the patient's actual needs, ensuring maximum treatment effectiveness and improved patient satisfaction. It not only focuses on short-term treatment results but also emphasizes long-term follow-up and maintenance. By regularly checking the stent's operational status and blood flow, and making necessary adjustments and maintenance as needed, continuous and stable treatment support can be provided to the patient, reducing the risk of complications. The above constitutes a complete treatment process that ensures the effectiveness and safety of treatment, improving the patient's treatment experience and prognosis.

[0044] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A self-expanding vascular stent, characterized in that, The device includes a mesh support and a covering. The mesh support comprises a mesh outer tube and a mesh inner tube. The mesh inner tube is disposed inside the mesh outer tube, and its two ends are respectively connected to the two ends of the mesh outer tube. Both the mesh outer tube and the mesh inner tube are woven from shape memory alloy wires. The covering is disposed on both the mesh outer tube and the mesh inner tube. When in an expanded state, the mesh outer tube is used to support the inner wall of the blood vessel, and the interior of the mesh inner tube forms a central flow channel to reduce blood flow.

2. The self-expanding vascular stent according to claim 1, characterized in that, The inner diameter of the central flow channel decreases sequentially from one end of the mesh inner cylinder to the center of the mesh inner cylinder, and increases sequentially from the center of the mesh inner cylinder to the other end of the mesh inner cylinder.

3. The self-expanding vascular stent according to claim 2, characterized in that, The mesh inner cylinder includes a mesh intermediate cylinder and two mesh connecting parts respectively disposed at both ends of the mesh intermediate cylinder. The end of each mesh connecting part away from the mesh intermediate cylinder is connected to one end of the mesh outer cylinder.

4. The self-expanding vascular stent according to claim 3, characterized in that, The mesh connector is trumpet-shaped.

5. The self-expanding vascular stent according to claim 3, characterized in that, The mesh intermediate cylinder adopts an arc-shaped scaling structure.

6. The self-expanding vascular stent according to claim 1, characterized in that, The mesh outer cylinder expands into a cylindrical shape with a uniform diameter.

7. The self-expanding vascular stent according to claim 1, characterized in that, The outer surface of the mesh outer cylinder is covered with the film.

8. The self-expanding vascular stent according to claim 1, characterized in that, The inner surface of the mesh inner cylinder is provided with the coating.

9. The self-expanding vascular stent according to claim 1, characterized in that, The coating is a polytetrafluoroethylene coating or a polyester coating.

10. The self-expanding vascular stent according to claim 1, characterized in that, The shape memory alloy wire is a nickel-titanium shape memory alloy wire.

Images