Extravascular stent

Abstract

The present invention discloses an extravascular stent, which relates to the field of medical device technology. The extravascular stent includes a first support member and a second support member; the first support member is suitable for being fixed on the outside of a venous blood vessel; the second support member is connected to the first support member and forms a "V"-shaped extravascular stent body, the second support member is suitable for being fixed on the outside of an arterial blood vessel, and the extravascular stent body has an angle with the opening facing away from the direction of blood flow in the blood vessel. The present invention improves the structure of the extravascular stent and greatly optimizes the structure of the extravascular stent. During installation, there is no need to make an incision or suture operation on the blood vessel. The first support member and the second support member can be fixed on the corresponding outer wall surface of the blood vessel by means of glue or the like, which greatly reduces the convenience of installation and reduces the difficulty and risk of the operation.

Description

Technical Field

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

[0002] Autologous arteriovenous fistula is a common way to construct vascular access for patients with end-stage renal disease undergoing hemodialysis treatment. Vascular access is a way to continuously draw blood from the patient's body to the outside of the body and then return it to the body.

[0003] During arteriovenous fistula formation, a vein typically attaches directly to an artery, leading to turbulent blood flow at the anastomosis and dramatic changes in blood pressure and circulation on the venous side. This can cause excessive stress within the vascular walls of the anastomosis and the downstream vein, leading to pathological intimal hypertrophy and sometimes causing blockage and stenosis. To address these issues, existing technologies have proposed placing an extravascular stent at the anastomosis to mitigate the significant blood flow fluctuations in the vein during the initial stages of anastomosis formation.

[0004] Existing extravascular stents consist of an arterial base segment, a venous base segment, and at least one adjustment collar. The arterial base segment has an arterial sheath body and an extrusion notch axially located on the sheath body. The adjustment collar fits over the outer surface of the sheath body to provide flexible, adjustable compression and support for the artery. However, these extravascular stents are complex in structure, inconvenient to install, and difficult to perform. Summary of the Invention

[0005] The main purpose of the present invention is to provide an extravascular stent, aiming to reduce the structural complexity of the extravascular stent, thereby improving the convenience of installation and reducing the difficulty and risk of surgery.

[0006] To achieve the above object, the present invention provides an extravascular stent, comprising:

[0007] A first support member, adapted to be fixed to the outside of the vein; and

[0008] The second support member is connected to the first support member to form a "V"-shaped outer support body. The second support member is suitable for being fixed on the outside of the artery. The outer support body has an angle with its opening facing away from the flow direction of blood in the blood vessel.

[0009] Optionally, the angle is 30°~60°.

[0010] Optionally, the first support member and the second support member both include a support rod and a bionic scale provided on the end of the support rod to adapt to changes in the curvature of the blood vessel.

[0011] Optionally, the bionic scale includes a plurality of scale units overlapping each other, and each of the scale units is suitable for being deformed under the compression of a blood vessel.

[0012] Optionally, the first support member and the vein, and the second support member and the artery are suitable for being fixed by bonding with medical glue.

[0013] Optionally, the medical glue is made of degradable material.

[0014] Optionally, the degradable material includes at least one of fibrin glue, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyethylene glycol, and gelatin methacryloyl.

[0015] Optionally, a first drug loading groove for accommodating drugs is provided on the first support member, and the notch of the first drug loading groove is adapted to face the vein; and / or

[0016] The second supporting member is provided with a second drug loading groove for accommodating drugs, and the notch of the second drug loading groove is suitable for facing the artery.

[0017] Optionally, the drug is an anti-inflammatory drug or a sustained-release anti-proliferative drug.

[0018] Optionally, the cross-sectional shapes of the first support member and the second support member in the radial direction of the blood vessel are both triangular or semicircular.

[0019] In the technical solution of the present invention, the extravascular stent includes a first support member and a second support member; the first support member is adapted to be fixed to the outside of a venous vessel; the second support member is connected to the first support member to form a "V"-shaped extravascular stent body, which is adapted to be fixed to the outside of an arterial vessel. The extravascular stent body has an angle with its opening facing away from the direction of blood flow within the vessel. It can be understood that the present invention improves the structure of the extravascular stent and greatly optimizes the extravascular stent structure. During installation, there is no need to incise or suture the vessel; the first and second support members can be fixed to the corresponding outer wall surfaces of the vessel using glue or other means, greatly improving the convenience of installation and reducing the difficulty and risk of the procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the application of an embodiment of the extravascular stent of the present invention;

[0022] Figure 2 A cross-sectional view of an embodiment of an extravascular stent according to the present invention;

[0023] Figure 3 is a cross-sectional view of another embodiment of the extravascular stent of the present invention;

[0024] Figure 4 This is a schematic diagram of the application of another embodiment of the extravascular stent of the present invention.

[0025] Description of Figure Numbers:

[0026] 10. First support member; 20. Second support member; 101. Vein; 102. Artery; 111. Support rod; 112. Bionic scale; 30. Medical glue; 10a. First drug loading tank.

[0027] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0028] 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 creative work are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0031] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. The meaning of "and / or" appearing in the full text is to include three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution in which both A and B are satisfied. The technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] Autologous arteriovenous fistula is a common way to construct vascular access for patients with end-stage renal disease undergoing hemodialysis treatment. Vascular access is a way to continuously draw blood from the patient's body to the outside of the body and then return it to the body.

[0033] During arteriovenous fistula formation, a vein typically attaches directly to an artery, leading to turbulent blood flow at the anastomosis and dramatic changes in blood pressure and circulation on the venous side. This can cause excessive stress within the vascular walls of the anastomosis and the downstream vein, leading to pathological intimal hypertrophy and sometimes causing blockage and stenosis. To address these issues, existing technologies have proposed placing an extravascular stent at the anastomosis to mitigate the significant blood flow fluctuations in the vein during the initial stages of anastomosis formation.

[0034] Existing extravascular stents consist of an arterial base segment, a venous base segment, and at least one adjustment collar. The arterial base segment has an arterial sheath body and an extrusion notch axially located on the sheath body. The adjustment collar fits over the outer surface of the sheath body to provide flexible, adjustable compression and support for the artery. However, these extravascular stents are complex in structure, inconvenient to install, and difficult to perform.

[0035] In this regard, the present invention proposes an extravascular stent to solve the above-mentioned problem.

[0036] Reference Figure 1 and Figure 2 In one embodiment of the present invention, the external stent includes a first support member 10 and a second support member 20; the first support member 10 is suitable for being fixed on the outside of a venous vessel 101; the second support member 20 is connected to the first support member 10 and forms a "V"-shaped external stent body, and the second support member 20 is suitable for being fixed on the outside of an arterial vessel 102. The external stent body has an opening with an angle facing away from the flow direction of blood in the blood vessel to avoid separation from the blood vessel due to blood flow impact, which helps to improve support stability.

[0037] In this embodiment, the first and second support members 10, 20 of the external stent body can be made of poly(lactic-co-glycolic acid) (PLGA). This material can be adjusted to maintain support for a period ranging from several months to two years by adjusting the polymer ratio (e.g., the ratio of lactic acid to glycolic acid in the PLGA). Of course, other materials can also be used for the first and second support members 10, 20, without limitation.

[0038] The first support member 10 and the second support member 20 can each be a regular, elongated rod-shaped structure or an irregular, curved rod-shaped structure, and can be composed of a single rod body or two or more sequentially connected rod bodies, without limitation. Preferably, the cross-sectional shape of the first support member 10 and the second support member 20 in the radial direction of the blood vessel can be triangular, semicircular, or the like, without limitation.

[0039] In this embodiment, the angle formed by the connection between the first support member 10 and the second support member 20 can be set to 30°~60°, preferably 45°, to meet the support strength requirements of common arteriovenous anastomosis structures.

[0040] It can be understood that the present invention improves the structure of the extravascular stent and optimizes the structure of the extravascular stent to a great extent. During installation, there is no need to make incisions and sutures on the blood vessels. The first support member 10 and the second support member 20 can be fixed on the corresponding outer wall surface of the blood vessel by glue or other means, which greatly reduces the convenience of installation and reduces the difficulty and risk of the operation.

[0041] Reference Figure 1 and Figure 2 In one embodiment, the first support member 10 and the vein 101, and the second support member 20 and the artery 102 can be bonded and fixed by medical glue 30. In this way, the difficulty and risk of the operation can be further reduced.

[0042] In this embodiment, the medical glue 30 can be made of degradable materials, including but not limited to fibrin glue, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyethylene glycol, gelatin methacryloyl, etc. It can be any one or more of them, without limitation here.

[0043] In order to prevent stenosis of arteriovenous fistula anastomosis and further improve the treatment effect, the main reference is Figure 3 In another embodiment, a first drug loading groove 10a for accommodating drugs is provided on the first support member 10, and the groove of the first drug loading groove 10a is suitable for facing the venous blood vessel 101; a second drug loading groove for accommodating drugs is provided on the second support member 20, and the groove of the second drug loading groove is suitable for facing the arterial blood vessel 102.

[0044] In this embodiment, the drug may be a solid drug such as an anti-inflammatory drug or a sustained-release anti-proliferative drug. The solid drug can be slowly released after coming into contact with the internal environment.

[0045] Main reference Figure 4 In another embodiment, the first support member 10 and the second support member 20 may each include a support rod 111 and a bionic scale 112 provided on the end of the support rod 111 .

[0046] In this embodiment, the biomimetic scale 112 comprises a plurality of overlapping scale units (similar to fish scales or tiles). The scale units can be shaped like sectors, ovals, hexagons, and other shapes, without limitation. Each scale unit is capable of deforming under the compression of a blood vessel to adapt to changes in the vessel's curvature, reducing stress concentration and further enhancing the stability of the extravascular stent supporting the vessel.

[0047] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An extravascular stent for supporting an arteriovenous anastomosis, characterized in that: include: A first support member, adapted to be fixed to the outside of a vein; as well as a second support member connected to the first support member to form a V-shaped outer stent body, the second support member being adapted to be fixed to the outside of an arterial blood vessel, the outer stent body having an opening facing away from the direction of blood flow in the blood vessel; The first support member and the second support member each include a support rod and a bionic scale disposed on the end of the support rod to adapt to changes in the curvature of the blood vessel; the bionic scale includes a plurality of overlapping scale units, each of which is adapted to deform under the compression of the blood vessel; the first support member and the vein, and the second support member and the artery, are adapted to be bonded and fixed by medical glue; The first support member is provided with a first drug loading groove for accommodating drugs, and the groove of the first drug loading groove is suitable for facing the vein; and / or the second support member is provided with a second drug loading groove for accommodating drugs, and the groove of the second drug loading groove is suitable for facing the artery.

2. The extravascular stent according to claim 1, wherein: The angle is between 30° and 60°.

3. The extravascular stent according to claim 1, wherein: The medical glue is made of degradable material.

4. The extravascular stent according to claim 3, wherein: The degradable material includes at least one of fibrin glue, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyethylene glycol, and gelatin methacryloyl.

5. The extravascular stent according to claim 1, wherein: The drug is an anti-inflammatory drug or a slow-release anti-proliferative drug.

6. The extravascular stent according to claim 1, wherein: The cross-sectional shapes of the first support member and the second support member in the radial direction of the blood vessel are both triangular or semicircular.

Images