Extravascular stent

Abstract

The invention discloses an extravascular stent, which belongs to the technical field of intravascular stents, and comprises: a fixed seat comprising a fixed support and a belt body; the fixing support is suitable for being nested on a first blood vessel adjacent to an anastomotic stoma, a fixing part is arranged at one end of the fixing support, and a through hole is formed in the fixing part; one end of the shoelace body is fixed at the other end of the fixed support, and the other end of the shoelace body can penetrate through the through hole; the fixing piece is provided with a fixing structure capable of fixing the belt body on the through hole; the sleeve is connected to the fixed support, and the sleeve is suitable for being arranged on the periphery of the second blood vessel close to the anastomotic stoma in a sleeving mode. The extravascular stent is simple in structure, the fixing position of the belt body on the fixing piece can be adjusted according to the diameters of different first blood vessels, the fixing support of the extravascular stent can be firmly fixed to the anastomotic stoma position all the time, and applicability is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of vascular stents, and particularly relates to an external vascular stent. Background Art

[0002] Patients in the end stage of kidney disease generally need to undergo frequent hemodialysis to remove toxins from the blood and maintain an appropriate homeostasis. To effectively remove toxins, the blood must flow through the hemodialysis machine at a relatively large blood flow rate. This relatively large blood flow rate is optimally achieved by creating a permanent vascular access site that includes an arteriovenous (AV) anastomosis; among them, the vein is attached to the artery to form a large-flow shunt or fistula, which is usually called an AV fistula. Due to the excellent patency of the AV fistula, low complication rate, lower cost of the healthcare system, and low risk of patient death, it is widely used for hemodialysis vascular access.

[0003] When forming an AV fistula, usually the vein is directly attached to the artery, which will cause blood flow disorders at the arteriovenous anastomosis, or a sharp change in the blood pressure and blood circulation conditions on the venous side. This will generate excessive stress in the blood vessel wall of the arteriovenous anastomosis and the downstream vein, leading to pathological intimal hyperplasia, and sometimes causing blockage, stenosis, etc.

[0004] To solve the above problems, Chinese Patent CN104837514B discloses a device for forming an arteriovenous fistula. This device is actually an external vascular stent made of metal, which is used to provide external support for the arteriovenous anastomosis, so that the vein and the artery form an angle to facilitate the smooth entry of arterial blood into the vein, so as to alleviate the excessive blood flow change in the vein at the initial stage of arteriovenous fistula formation. The above device includes a joining member for sleeving around the periphery of the artery and a sleeve for sleeving around the periphery of the vein. The external shape structure of the joining member is very complex. The sleeve is woven from metal wires. The installation of the joining member and the sleeve at the arteriovenous fistula is not convenient, and the size cannot be adjusted appropriately according to the diameter of the blood vessel. Summary of the Invention

[0005] In view of this, the present invention provides an external vascular stent to solve the problems of the existing external vascular stent with complex structure and inability to adapt to blood vessels of different diameters.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows: An external vascular stent, comprising: A fixed seat, including a fixed support and a belt body; the fixed support is adapted to be nested on a first blood vessel adjacent to the anastomosis opening. One end of the fixed support is provided with a fixing member, and the fixing member is provided with a through hole; one end of the belt body is fixed to the other end of the fixed support, and the other end of the belt body can pass through the through hole; the fixing member is provided with a fixing structure capable of fixing the belt body on the through hole; A sleeve, connected to the fixed seat, is adapted to be sleeved on the outer periphery of a second blood vessel adjacent to the anastomosis; wherein, the anastomosis is the position where the second blood vessel is attached to the first blood vessel.

[0007] Further, when the other end of the belt body extends into the through hole and is fixed by the fixing structure, the belt body and the fixed support form a ring, and the fixed support is adapted to abut against the outer periphery of the first blood vessel adjacent to the anastomosis.

[0008] Further, one side surface of the fixed support is an arc surface, and the fixed support is a deformable structure with an adjustable radius of the arc surface; different positions of the belt body are fixed on the fixing member to adjust the radius of the arc surface of the fixed support.

[0009] Further, a plurality of saw teeth are arranged side by side along the length direction of one side of the belt body; the fixing structure is a convex structure arranged on the inner wall of the through hole corresponding to the fixing member, and the convex structure is stuck on the saw teeth to fix the belt body on the through hole.

[0010] Further, a plurality of the saw teeth are all helical teeth, and a plurality of the helical teeth all incline towards one end where the belt body is fixedly connected to the fixed support.

[0011] Further, a plurality of hollow holes are provided on the fixed support.

[0012] Further, the fixed support includes an inner ring section arranged circumferentially around the sleeve, an outer ring section located on the outer periphery of the inner ring section and integrally formed with the inner ring section, and a connecting section integrally connected between the inner ring section and the outer ring section; an opening formed by enclosing the outer ring section, the inner ring section and the connecting section is the hollow hole; the fixing member is connected to the outer peripheral edge of the outer ring section.

[0013] Further, the inner side surface of the inner ring section, the inner side surface of the outer ring section and the inner side surface of the connecting section are on the same arc surface.

[0014] Further, the connecting section and the fixing member are connected to the same segment of the outer ring section, and the fixing member extends radially outward along the outer ring section.

[0015] Further, the sleeve and the fixed support are integrally formed.

[0016] The technical solution of the present invention has the following advantages: This kind of extracorporeal blood vessel stent has a simple structure, can adjust the fixing position of the belt body on the fixing member according to the diameters of different first blood vessels, so that the fixed support of the extracorporeal blood vessel stent can always be firmly fixed at the anastomosis position, and has stronger applicability. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 FIG. 4 is a perspective structural view of the extracorporeal stent in the use state in the embodiment of the present invention, and the arrow direction in the figure is the blood flow direction in the arterial blood vessel; Figure 2 FIG. 7 is a rear view of the extracorporeal stent in the use state in the embodiment of the present invention; Figure 3 FIG. 10 is an overall structural view of the extracorporeal stent in the embodiment of the present invention; Figure 4 FIG. 13 is a left view of the extracorporeal stent in the use state in the embodiment of the present invention; Figure 5 is Figure 4 an enlarged view of part A in

[0019] Explanation of reference numerals: 1, fixing seat; 11, fixing support; 11a, hollow hole; 111, inner ring section; 112, outer ring section; 113, connecting section; 12, belt body; 121, saw teeth; 13, fixing member; 2, sleeve; 3, second blood vessel; 4, first blood vessel. Specific Embodiments

[0020] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] In the description of the present invention, it should 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 directly connected, or indirectly connected through an intermediate medium. 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.

[0022] As Figures 1 - 5 shown, an extracorporeal stent is mainly used for external support of blood vessels, especially for external support at the anastomosis of arteries and veins. The extracorporeal stent includes a fixing seat 1 and a sleeve 2, and the fixing seat 1 includes a fixing support 11, a belt body 12, and a fixing member 13.

[0023] Among them, the inner side surface of the fixed support 11 is an arc surface, and the fixed support 11 is a deformable structure with an adjustable radius of the inner arc surface; the fixed support 11 can be deformed under an external force to match first blood vessels 4 with different diameters. During the operation, the arc surface of the fixed support 11 can be abutted against the outer wall of the first blood vessel 4 adjacent to the anastomosis. The sleeve 2 is fixedly connected to the fixed support 11, and the sleeve 2 is used to sleeve the outer periphery of the second blood vessel 3 adjacent to the anastomosis during the operation. Among them, the anastomosis is the position where the second blood vessel 3 is attached to the first blood vessel 4. The fixing member 13 is fixedly connected to one end of the fixed support 11, and a through hole is formed in the fixing member 13. The belt body 12 is a strip-shaped bendable structure, one end of the belt body 12 is fixedly connected to the other end of the fixed support 11 away from the fixing member 13, and the other end of the belt body 12 can pass through the through hole in the fixing member 13. The fixing member 13 is provided with a fixing structure capable of fixing the belt body 12 on the through hole.

[0024] When this extracorporeal blood vessel stent is in use, after the fixed support 11 is placed on the first blood vessel 4, the belt body 12 is passed through the through hole in the fixing member 13. According to the diameter of the first blood vessel 4, the position of the belt body 12 on the fixing member 13 is adjusted. The fixed support 11 deforms under the action of the belt body 12 to adapt to the outer wall surface of the first blood vessel 4 until the fixed support 11 is closely abutted against the outer wall surface of the first blood vessel 4. Then, the other end of the belt body 12 is fixed on the fixing member 13 by using the fixing structure, so that the fixed support 11 can be firmly fixed at the position of the anastomosis. This extracorporeal blood vessel stent has a simple overall structure, and the fixing position of the belt body 12 on the fixing member 13 can be adjusted according to the diameters of different first blood vessels 4, so that the fixed support 11 of the extracorporeal blood vessel stent can always be firmly fixed at the anastomosis, and the applicability is stronger.

[0025] In this embodiment, the belt body 12 and the fixed support 11 are an integrally formed structure, and one end of the belt body 12 is integrally connected to the edge of the fixed support 11. In other alternative embodiments, the belt body 12 can also be fixed to the fixed support 11 by means of welding, knotting, perforating, riveting, etc., as long as one end where the belt body 12 and the fixed support 11 are connected is not easily pulled off.

[0026] In this embodiment, a plurality of saw teeth 121 are arranged side by side along the length direction on the inner side of the belt body 12; the fixing structure is specifically a convex structure provided on the inner wall of the through hole corresponding to the fixing member 13, and the convex structure is stuck on the saw teeth 121 to fix the belt body 12 on the fixing member 13. The method of fixing the belt body 12 by the cooperation of the convex structure and the saw teeth 121 has a simple structure and is easy to implement. Further, the plurality of saw teeth 121 on the inner side of the belt body 12 are all inclined teeth, and the plurality of inclined teeth are all inclined towards the end where the belt body 12 is fixedly connected to the fixed support 11; in the way that the plurality of saw teeth 121 are inclined unidirectionally, once the belt body 12 passes through the through hole on the fixing member 13, the belt body 12 cannot move in the reverse direction, making it relatively labor-saving to pull the belt body 12 forward and the operation is relatively convenient. In some alternative embodiments, the fixing structure can also be an elastic buckle provided on the fixing member 13. When the saw teeth 121 on the belt body 12 pass by the elastic buckle, the inclined surface of the saw teeth 121 contacts the elastic buckle, pushing the elastic buckle to undergo elastic deformation and allowing the belt body 12 to pass through smoothly; after the saw teeth 121 of the belt body 12 pass through, the elastic buckle rebounds under the action of the elastic restoring force, and the elastic buckle snaps into the tooth groove of the adjacent saw teeth 121 to form mechanical engagement.

[0027] In some alternative embodiments, a plurality of saw teeth 121 may not be provided on the inner side of the belt body 12. The fixing structure is specifically an elastic pressing rod provided on the fixing member 13. One end of the elastic pressing rod extends into the through hole. When adjusting the fixing position of the belt body 12 on the fixing member 13, first pull the elastic pressing rod to make the elastic pressing rod move away from the through hole inside the fixing member 13, and the belt body 12 is allowed to pass through the through hole inside the fixing member 13 smoothly. After the position of the belt body 12 is adjusted in place, release the elastic pressing rod, and the elastic pressing rod presses the belt body 12 tightly in the through hole to realize the fixing of the belt body 12. This fixing method of the belt body 12 does not require machining a plurality of saw teeth 121 on the inner side of the belt body 12, nor does it require structures such as protrusions on the fixing member 13 that cooperate with the saw teeth 121, and the production is relatively simple.

[0028] In some other alternative embodiments, a plurality of round holes are arranged along the length direction of the belt body 12, and a movable insertion rod is provided on the fixing member 13. When adjusting the fixing position of the belt body 12 on the fixing member 13, adjust the insertion rod to a position that allows the belt body 12 to pass through the through hole on the fixing member 13 smoothly. After the position of the belt body 12 is adjusted in place, move the insertion rod and make the insertion rod pass through one of the round holes on the belt body 12, thereby fixing the belt body 12 on the fixing member 13. This fixing method of the belt body 12 also does not require machining a plurality of saw teeth 121 on the inner side of the belt body 12, nor does it require structures such as protrusions on the fixing member 13 that cooperate with the saw teeth 121, and the production is relatively simple.

[0029] In this embodiment, the fixed support 11 is provided with a plurality of hollow holes 11a. The arrangement of the plurality of hollow holes 11a can not only reduce the weight of the fixed support 11 and lower the material cost of the fixed support 11, but also increase the deformability of the fixed support 11, so that the deformation amount of the fixed support 11 under an external force can be larger, thereby adapting to blood vessels within a larger diameter change range.

[0030] In some embodiments, the fixed support 11 includes an inner ring section 111 arranged circumferentially around the sleeve 2, an outer ring section 112 located on the outer periphery of the inner ring section 111 and integrally formed with the inner ring section 111, and a connecting section 113 integrally connected between the inner ring section 111 and the outer ring section 112. Among them, the inner ring section 111 surrounds the outer periphery of the sleeve 2 or the anastomosis. A part of the outer ring section 112 coincides with the inner ring section 111, and this coincident part of the outer ring section 112 is located on the opposite sides of the outer ring section 112. There is a distance between other partial segments of the outer ring section 112 and the outer wall of the inner ring section 111. The connecting section 113 is connected between the outer ring section 112 and the partial segments of the inner ring section 111 with a distance therebetween. The opening formed by enclosing the outer ring section 112, the inner ring section 111, and the connecting section 113 is the hollow hole 11a. The fixed support 11 with this structural form has the advantages of simple structure, large deformation amount, and low manufacturing cost.

[0031] In an alternative embodiment, there may be no overlapping part between the outer ring section 112 and the inner ring section 111, that is, there is a distance between the outer ring section 112 and the inner ring section 111 at each position, and each distance position is connected into one body through connecting sections 113 with different lengths; for example, the length of the connecting section 113 extending in the axial direction of the first blood vessel 4 is relatively short, and the length of the connecting section 113 extending in the circumferential direction of the first blood vessel 4 is relatively long, so that the entire fixed support 11 can have relatively good bending deformation ability.

[0032] In some embodiments, the length extension direction of the connecting section 113 is the same as the circumferential direction of the fixed support 11; the inner side surfaces of the inner ring section 111, the outer ring section 112, and the connecting section 113 are on the same arc surface. When the fixed support 11 is in contact with the outer wall of the first blood vessel 4, the inner side surfaces of the inner ring section 111, the outer ring section 112, and the connecting section 113 are all in contact with the outer wall of the first blood vessel 4, increasing the contact area between the fixed support 11 and the outer wall of the first blood vessel 4, thereby ensuring that the fixed support 11 can be firmly fixed at the anastomosis position. Further, the fixing member 13 is connected to the outer peripheral edge of the outer ring section 112, and the connecting section 113 and the fixing member 13 are connected to the same segment of the outer ring section 112. The force received by the fixing member 13 can be directly transmitted to the connecting section 113 through the outer ring section 112; with such an arrangement, on the one hand, the connecting section 113 can strengthen the structural strength of the outer ring section 112 and prevent the outer ring section 112 from being deformed by tension; on the other hand, the connecting section 113 is prone to bending itself after being stressed, which is conducive to realizing the bending of the entire fixed support 11.

[0033] In this embodiment, the fixing member 13 is specifically a fixing frame with a through hole inside, and the fixing frame and the outer ring section 112 do not extend in the same plane; for example, the outer ring section 112 is on the circumferential side wall of the fixed support 11, while the fixing frame extends radially outward along the fixed support 11. With such an arrangement, it is convenient for the belt body 12 to pass through the through hole of the fixing member 13, and the ring formed by enclosing the belt body 12 and the fixed support 11 is a regular ring. The gap between the belt body 12 and the fixed support 11 at the position of the fixing member 13 and the outer wall of the first blood vessel 4 is very small, and the entire fixed support 11 can fit more firmly against the outer wall of the first blood vessel 4.

[0034] In this embodiment, the inner ring section 111 of the fixed support 11 and the sleeve 2 are integrally formed. In other alternative embodiments, the inner ring section 111 of the fixed support 11 can also be fixed to the sleeve 2 by means of socket connection, bonding, etc.

[0035] During the arteriovenous (AV) anastomosis operation, the venous blood vessel is cut, the sleeve 2 of the extracorporeal blood vessel stent described in the above embodiment is sleeved on the venous blood vessel, an incision is made on the arterial blood vessel, the open end of the venous blood vessel is sutured to the opening of the arterial blood vessel to form an arteriovenous fistula, the belt body 12 is inserted into the through hole of the fixing member 13, and after adjusting the belt body 12 to a suitable position, the belt body 12 is fixed to the fixing member 13. At this time, the installation of the extracorporeal blood vessel stent is completed. The extracorporeal blood vessel stent can provide reliable external support for the arteriovenous fistula after installation.

[0036] In summary, the extravascular stent provided by the embodiment of the present invention adopts a structural design with an adjustable fixing position of the belt body 12 on the fixing member 13, and uses the belt body 12 to drive the fixing support 11 to deform, so that the fixing support 11 can fit the outer wall surface of the first blood vessel 4 with different diameters. Therefore, the fixing support 11 can be firmly fixed at the anastomosis position of arteries with different diameters, and has stronger applicability.

[0037] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An extravascular stent, characterized in that: include: A fixing seat (1) comprises a fixing support (11) and a belt body (12); the fixing support (11) is suitable for being nested on a first blood vessel (4) adjacent to an anastomotic opening; one end of the fixing support (11) is provided with a fixing member (13), and the fixing member (13) is provided with a through hole; one end of the belt body (12) is fixed to the other end of the fixing support (11), and the other end of the belt body (12) can pass through the through hole; the fixing member (13) is provided with a fixing structure capable of fixing the belt body (12) on the through hole; A sleeve (2) is connected to the fixed support (11), and the sleeve (2) is suitable for being sleeved on the periphery of a second blood vessel (3) adjacent to an anastomosis; wherein the anastomosis is the position where the second blood vessel (3) is attached to the first blood vessel (4).

2. The extravascular stent according to claim 1, characterized in that: When the other end of the belt body (12) extends into the through hole and is fixed by the fixing structure, the belt body (12) and the fixing support (11) form a ring, and the fixing support (11) is suitable for being attached to the outer periphery of the first blood vessel (4) adjacent to the anastomosis.

3. The extravascular stent according to claim 2, characterized in that: One side surface of the fixed support (11) is an arc surface, and the fixed support (11) is a deformable structure with an adjustable arc surface radius; different positions of the belt body (12) are fixed on the fixing member (13) to adjust the arc surface radius of the fixed support (11).

4. The extravascular stent according to any one of claims 1 to 3, characterized in that: One side of the belt body (12) is provided with a plurality of saw teeth (121) arranged side by side along its length direction; the fixing structure is a protruding structure arranged on the inner wall of the fixing member (13) corresponding to the through hole, and the protruding structure is clamped on the saw teeth (121) to fix the belt body (12) on the through hole.

5. The extravascular stent according to claim 4, characterized in that: The plurality of saw teeth (121) are all bevel teeth, and the plurality of bevel teeth are all inclined toward one end at which the belt body (12) is fixedly connected to the fixed support (11).

6. The extravascular stent according to claim 1, characterized in that: The fixed support (11) is provided with a plurality of hollow holes (11a).

7. The extravascular stent according to claim 6, characterized in that: The fixed support (11) comprises an inner ring segment (111) arranged around the circumference of the sleeve (2), an outer ring segment (112) located at the outer circumference of the inner ring segment (111) and integrally formed with the inner ring segment (111), and a connecting segment (113) integrally connected between the inner ring segment (111) and the outer ring segment (112); an opening enclosed by the outer ring segment (112), the inner ring segment (111) and the connecting segment (113) is the hollow hole (11a).

8. The extravascular stent according to claim 7, characterized in that: The inner side surface of the inner ring segment (111), the inner side surface of the outer ring segment (112) and the inner side surface of the connecting segment (113) are located on the same arc surface.

9. The extravascular stent according to claim 7, characterized in that: The fixing member (13) is connected to the outer peripheral edge of the outer ring segment (112), the connecting segment (113) and the fixing member (13) are connected to the same segment of the outer ring segment (112), and the fixing member (13) extends radially outwardly along the outer ring segment (112).

10. The extravascular stent according to claim 1, characterized in that: One end of the belt body (12) is integrally formed with the fixed support (11), and the sleeve (2) and the fixed support (11) are integrally formed.

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