Extravascular stent

Abstract

The invention discloses an extravascular stent, and relates to the technical field of medical instruments. The extravascular stent comprises a first supporting piece and a second supporting piece, the first supporting piece is suitable for being fixed outside a vein blood vessel; the second supporting piece and the first supporting piece are connected to form a V-shaped outer stent body, the second supporting piece is suitable for being fixed to the outer side of an artery blood vessel, and the outer stent body is provided with an included angle with an opening opposite to the flowing direction of blood in the blood vessel. The structure of the external vascular stent is improved, the structure of the external vascular stent is optimized to a great extent, the blood vessel does not need to be subjected to incision and suture operation during installation, the first supporting piece and the second supporting piece are fixed to the corresponding outer wall faces of the blood vessel through glue and other modes, and installation convenience is greatly reduced; and the operation difficulty and risk are reduced.

Description

Technical Field

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

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

[0003] When forming an arteriovenous fistula, usually the vein is directly attached to the artery, which will cause blood flow disorder at the arteriovenous anastomosis, or a sharp change in blood pressure and blood circulation conditions on the venous side. In this way, excessive stress will be generated in the blood vessel wall in the arteriovenous anastomosis and the vein on its downstream side, leading to pathological intimal hyperplasia and sometimes causing blockage, stenosis, etc. In order to solve the above problems, the prior art proposes a solution of setting an extravascular stent on the vascular anastomosis to alleviate the excessive blood flow change in the vein at the initial stage of anastomosis formation.

[0004] The existing extravascular stent includes an arterial base segment, a venous base segment and at least one adjustment clamp; the arterial base segment has an arterial sleeve tube body and a squeezing incision arranged axially on the arterial sleeve tube body; the adjustment clamp is sleeved outside the arterial sleeve tube body to adjustably squeeze and support the artery. However, the structure of this extravascular stent is complex, the installation is inconvenient, and the operation difficulty is great. 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, so as to improve the convenience of installation and reduce the operation difficulty and risk.

[0006] To achieve the above object, the present invention proposes an extravascular stent, including: A first support member, adapted to be fixed to the outside of the venous blood vessel; and A second support member, connected to the first support member to form a "V"-shaped outer stent body, the second support member is adapted to be fixed to the outside of the arterial blood vessel, and the outer stent body has an included angle with the opening facing away from the blood flow direction in the blood vessel.

[0007] Optionally, the size of the included angle is 30° - 60°.

[0008] Optionally, both the first support member and the second support member include a support rod and bionic scales arranged at the end of the support rod to adapt to the curvature change of the blood vessel.

[0009] Optionally, the bionic scales include a plurality of overlapping scale units, and each scale unit is adapted to deform under the extrusion of the blood vessel.

[0010] Optionally, the first support member and the venous blood vessel, and the second support member and the arterial blood vessel are each adapted to be adhesively fixed by a medical glue.

[0011] Optionally, the medical glue is made of a degradable material.

[0012] Optionally, the degradable material includes at least one of fibrin glue, polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, polyethylene glycol, and gelatin methacrylate.

[0013] Optionally, a first drug-containing groove for accommodating a drug is formed in the first support member, and the notch of the first drug-containing groove is adapted to face the venous blood vessel; and / or a second drug-containing groove for accommodating a drug is formed in the second support member, and the notch of the second drug-containing groove is adapted to face the arterial blood vessel.

[0014] Optionally, the drug is an anti-inflammatory drug or a sustained-release anti-proliferative drug.

[0015] 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 semi-circular.

[0016] In the technical solution of the present invention, the extracorporeal blood vessel stent includes a first support member and a second support member; the first support member is adapted to be fixed to the outside of the venous blood vessel; the second support member is connected to the first support member to form a "V"-shaped extracorporeal stent main body, and the second support member is adapted to be fixed to the outside of the arterial blood vessel, and the extracorporeal stent main body has an angle with the opening facing away from the flowing direction of the blood in the blood vessel. It can be understood that the present invention improves the structure of the extracorporeal blood vessel stent, greatly optimizes the structure of the extracorporeal blood vessel stent, and does not require incision and suture operations on the blood vessel during installation. The first support member and the second support member can be fixed on the corresponding outer wall surfaces of the blood vessel by means of glue, etc., which greatly improves the convenience of installation and reduces the difficulty and risk of the operation. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0018] Figure 1 It is a schematic application diagram of an embodiment of the extracorporeal blood vessel stent of the present invention; Figure 2 It is a cross-sectional view of an embodiment of the extracorporeal blood vessel stent of the present invention; Figure 3 It is a cross-sectional view of another embodiment of the extracorporeal blood vessel stent of the present invention; Figure 4 This is a schematic diagram of the application of another embodiment of the extracorporeal stent of the present invention.

[0019] Explanation of the reference numerals in the drawings: 10. First support member; 20. Second support member; 101. Venous blood vessel; 102. Arterial blood vessel; 111. Support rod; 112. Bionic scale; 30. Medical glue; 10a. First drug-loading groove.

[0020] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0023] In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0024] In addition, the descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. The meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where both A and B are satisfied simultaneously. The technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] An autogenous arteriovenous fistula is a common way to construct a vascular access for patients with end-stage renal disease during hemodialysis treatment. The vascular access is a route to continuously draw the patient's blood out of the body and then return it to the body.

[0026] When forming an arteriovenous fistula, usually the vein is directly attached to the artery, which will result in the disorder of blood flow at the arteriovenous anastomosis, or a sharp change in the blood pressure and blood circulation conditions on the venous side. In this way, excessive stress will be generated in the blood vessel wall at the arteriovenous anastomosis and the vein on its downstream side, leading to pathological intimal hyperplasia and sometimes causing blockage, stenosis, etc. To solve the above problems, the prior art has proposed a solution of setting an external vascular stent at the vascular anastomosis to relieve the excessive blood flow change of the vein in the initial stage of anastomosis formation.

[0027] The existing external vascular stent includes an arterial base segment, a venous base segment, and at least one adjusting snap ring; the arterial base segment has an arterial sleeve tube body and a squeezing incision disposed axially on the arterial sleeve tube body; the adjusting snap ring is sleeved outside the arterial sleeve tube body to adjustably squeeze and support the artery. However, the structure of this external vascular stent is complex, inconvenient to install, and has a high surgical difficulty.

[0028] In view of this, the present invention proposes an external vascular stent aimed at solving the above problems.

[0029] Referring to Figure 1 and Figure 2 , in an embodiment of the present invention, the external vascular stent includes a first support member 10 and a second support member 20; the first support member 10 is adapted to be fixed outside the venous blood vessel 101; the second support member 20 is connected to the first support member 10 to form a "V"-shaped external stent main body, and the second support member 20 is adapted to be fixed outside the arterial blood vessel 102. The external stent main body has an angle with the opening facing away from the blood flow direction in the blood vessel, so as to avoid being detached from the blood vessel due to blood flow impact and help improve the support stability.

[0030] In this embodiment, the materials of the first support member 10 and the second support member 20 of the outer stent body can both be selected as poly (lactic-co-glycolic acid) (PLGA). This material can maintain a support time ranging from several months to 2 years by adjusting the polymer ratio (such as the ratio of lactic acid to glycolic acid in poly (lactic-co-glycolic acid)). Of course, the first support member 10 and the second support member 20 can also be made of other materials, which is not limited here.

[0031] Both the first support member 10 and the second support member 20 can be regular long bar-shaped structures, or irregular curved bar-shaped structures. They can be composed of one rod body, or can be composed of two or more rod bodies connected in sequence, which is not limited here. Preferably, the cross-sectional shapes of the first support member 10 and the second support member 20 in the radial direction of the blood vessel can be set as triangles, semi-circles, etc., which is not limited here.

[0032] In this embodiment, the included angle formed by the connection of 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.

[0033] It can be understood that the present invention improves the structure of the extracorporeal blood vessel stent, greatly optimizes the structure of the extracorporeal blood vessel stent. During installation, there is no need to make incisions and sutures on the blood vessel. Just fix the first support member 10 and the second support member 20 on the corresponding outer wall surface of the blood vessel by using glue or other means, which greatly improves the convenience of installation and reduces the operation difficulty and risk.

[0034] Refer to Figure 1 and Figure 2 , in an embodiment, the first support member 10 and the venous blood vessel 101, and the second support member 20 and the arterial blood vessel 102 can be adhesively fixed by medical glue 30. In this way, the operation difficulty and risk can be further reduced.

[0035] In this embodiment, the medical glue 30 can be made of degradable materials, including but not limited to fibrin glue, polylactic acid, poly (lactic-co-glycolic acid), polycaprolactone, polyethylene glycol, gelatin methacrylate, etc., and can be any one or several of them, which is not limited here.

[0036] To prevent stenosis of the arteriovenous fistula anastomosis and further improve the treatment effect, mainly referring to Figure 3 , in another embodiment, a first drug-loading groove 10a for accommodating drugs is formed on the first support member 10, and the notch of the first drug-loading groove 10a is adapted to face the venous blood vessel 101; a second drug-loading groove for accommodating drugs is formed on the second support member 20, and the notch of the second drug-loading groove is adapted to face the arterial blood vessel 102.

[0037] In this embodiment, the drug may be a solid drug such as an anti-inflammatory drug or a sustained-release anti-proliferative drug. After contacting the in-vivo environment, the solid drug can be slowly released.

[0038] Mainly referring to Figure 4 , in another embodiment, both the first support member 10 and the second support member 20 may include a support rod 111 and a bionic scale 112 provided at the end of the support rod 111.

[0039] In this embodiment, the bionic scale 112 includes a plurality of overlapping scale units (similar to fish scales or tiles). The shape of the scale unit may be fan-shaped, oval, hexagonal, etc., and is not limited herein. Each scale unit can be deformed under the extrusion of the blood vessel to adapt to the curvature change of the blood vessel, reduce stress concentration, and help to further enhance the stability of the blood vessel outer stent in supporting the blood vessel.

[0040] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the description and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. An extravascular stent for supporting at an arteriovenous anastomosis site, characterized in that, Comprising: A first support member, adapted to be fixed to the outside of a venous blood vessel; And A second support member, connected to the first support member and forming 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 included angle with the opening facing away from the direction of blood flow in the blood vessel; Both the first support member and the second support member include support rods and bionic scales provided at the ends of the support rods to adapt to the curvature change of the blood vessel; A first drug-containing groove for accommodating drugs is provided on the first support member, and the notch of the first drug-containing groove is adapted to face the venous blood vessel; and / or, a second drug-containing groove for accommodating drugs is provided on the second support member, and the notch of the second drug-containing groove is adapted to face the arterial blood vessel.

2. The extracorporeal stent according to claim 1, wherein The size of the included angle is 30° - 60°.

3. The extracorporeal stent according to claim 1, wherein, The bionic scale includes a plurality of overlapping scale units, and each scale unit is adapted to be deformed under the extrusion of the blood vessel.

4. The extravascular stent according to claim 1, wherein The first support member and the venous blood vessel, and the second support member and the arterial blood vessel are all adapted to be adhesively fixed by medical glue.

5. The extracorporeal stent according to claim 4, characterized in that, The medical glue is made of a degradable material.

6. The extracorporeal stent according to claim 5, wherein The degradable material includes at least one of fibrin glue, polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, polyethylene glycol, and gelatin methacrylate.

7. The extracorporeal stent according to claim 1, wherein The drug is an anti-inflammatory drug or a sustained-release anti-proliferative drug.

8. The extracorporeal 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 semi-circular.

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