CN219645967U - Extravascular support device - Google Patents

Abstract

The utility model provides an extravascular support device which is applied to autologous arteriovenous fistula and comprises an arterial covering section and a venous covering section, wherein a through hole is formed in the side face of the arterial covering section, the proximal end of the venous covering section is connected with one side, far away from an artery, of the through hole, the diameter of the venous covering section gradually increases from the proximal end to the distal end in a nonlinear change mode, and the length of the venous covering section is 15-25 mm. When the utility model is used for preventing the autologous arteriovenous fistula, the influence of the vein end part near the anastomotic stoma on the later puncture can be reduced, the shearing force of blood flow can be reduced, and the occurrence of turbulence can be reduced.

Description

Extravascular support device

Technical Field

The utility model relates to the technical field of medical appliances, in particular to an extravascular support device for autologous arteriovenous fistula.

Background

Over 70% of patients with end stage renal disease (End Stagerenal Disease, ESRD for short) worldwide use hemodialysis as the first renal replacement therapy, and a well-functioning, smooth and durable vascular access is particularly important to ensure dialysis treatment.

Autologous arteriovenous fistulae (Arterio Venous Fistula, AVF for short) have lower total mortality, risk of fatal infections, and adverse cardiovascular events compared to vascular prostheses and central venous catheters, and the U.S. KDOQI guidelines also suggest AVF as a long-term vascular access for hemodialysis, as statistically, over 50 tens of thousands of global annual arteriovenous fistulae creation procedures. But the failure rate of arteriovenous internal fistula is high, and about half of patients need to be repaired or rebuilt within 1 year after operation due to vascular stenosis, frequent Dunalization and the like. The incidence of early failure of arteriovenous internal fistulae is statistically about 40%, and is usually a progressive intimal hyperplasia and luminal stenosis caused by changes in hemodynamics around the stoma. The general autologous arteriovenous internal fistula has the following defects: along with the continuous expansion of the vein after operation, the angle formed by the vein and the artery is also changed, and the internal fistula is easy to change in angle or deform due to internal tissue compression and external compression, so that abnormal hemodynamics occurs, turbulence is generated at an anastomotic stoma, and a large friction force is generated with the inner surface of a lumen, which is also called wall shear stress (Wall Shear Stress, WSS for short). High shear stress can damage endothelial cells, leading to stenosis on the one hand, and thrombosis on the other hand.

At present, no effective treatment mode exists for arteriovenous fistula stenosis, and balloon dilatation, internal stents, artificial blood vessels and the like are generally adopted for treating the stenosis in the later period; however, the balloon expansion cannot be solved at one time and needs repeated operation; the internal stent and the artificial blood vessel increase the occurrence rate of thrombus. At present, no effective apparatus is available, and only VasQ (extravascular stent implant) at a large clinical stage can be used for preventing the problems of arteriovenous fistula stenosis and the like. The VasQ consists of two nickel-titanium alloy components, one part is a supporting part cut by laser and wraps the artery of the arteriovenous fistula anastomosis, so that the anastomosis is at a certain angle, the other part is an external reticular braided fabric, the diameter and gradient of the blood vessel are determined, and the VasQ is positioned at the proximal end of the vein of the anastomosis and is not in contact with blood flow. However, the disadvantage of VasQ is mainly that the proximal end portion of the anastomotic stoma is too long, may affect the puncture at a later stage, and is susceptible to hemodynamic effects, leading to proximal anastomotic venous segment Yi Xiazhai and hyperplasia.

Disclosure of Invention

The utility model aims to provide an extravascular support device which is used for preventing stenosis and intimal hyperplasia near an anastomotic stoma of an autologous arteriovenous fistula, reduces the influence of a vein end part near the anastomotic stoma on later puncture, reduces the shearing force of blood flow and reduces the occurrence of turbulent flow.

In order to achieve the above object, the present utility model provides an extravascular support device applied to an autologous arteriovenous fistula, which comprises an arterial covering section and a venous covering section, wherein a through hole is arranged on the side surface of the arterial covering section, the proximal end of the venous covering section is connected with one side of the through hole far away from an artery, the diameter of the venous covering section gradually increases from the proximal end to the distal end in a nonlinear variation manner, and the length of the venous covering section is 15 mm-25 mm.

Optionally, a proximal anastomosis opening with a certain included angle is formed at the joint of the proximal end of the vein covering section and the through hole, and the included angle of the proximal anastomosis opening is 45-65 degrees.

Optionally, the included angle of the proximal anastomosis is 55 ° to 60 °.

Optionally, the proximal anastomosis has a radius of curvature of 0.5mm to 1.5 mm.

Optionally, the minimum diameter of the vein covering section is 2.5 mm-5 mm, and the maximum diameter is 6 mm-10 mm.

Optionally, the vein covering section in a natural state is arranged in an arc shape along the length direction of the vein covering section.

Optionally, the junction area of the arterial cover section and the venous cover section is provided with a stiffening sheet.

Optionally, the arterial cover section is one of a woven structure, a cut structure and a 3D printing structure, and/or the venous cover section is one of a woven structure, a cut structure and a 3D printing structure.

Optionally, the arterial cover section has a length of 10mm to 15mm.

Optionally, the arterial cover section is open or closed on the side.

Compared with the prior art, the utility model has the beneficial effects that:

the above support device outside the blood vessel is applied to autologous arteriovenous fistula, including arterial cover section and vein cover section, arterial cover section's side is provided with the through-hole, venous cover section's proximal end with the through-hole is kept away from one side of artery and is connected, venous cover section's diameter is by the proximal end to the distal end with nonlinear change's mode increase gradually, can reduce the shearing force that blood flows like this, reduces turbulent flow's emergence, and then effectual reduction intimal hyperplasia and lumen stenosis, will simultaneously venous cover section's length design is 15mm ~ 25mm, can also avoid near anastomotic stoma venous end part overlength, and later stage can produce the problem that influences to the puncture. Further preferably, the included angle between the vein covering section and the artery covering section at the proximal anastomosis is 45-65 degrees, and the included angle is combined with the structural design of the vein covering section, so that the shearing force of blood flow can be reduced better, and turbulent flow is avoided.

Drawings

Those of ordinary skill in the art will appreciate that the figures are provided for a better understanding of the present utility model and do not constitute any limitation on the scope of the present utility model. Wherein:

fig. 1 is a schematic structural view of an extravascular support device according to a first embodiment of the present utility model, wherein the venous coverage section is a tapered mesh structure that varies non-linearly;

fig. 2 is a schematic structural view of an extravascular support device according to a second embodiment of the present utility model, wherein the venous coverage section is a tapered mesh structure that varies non-linearly;

fig. 3 is a schematic structural view of an extravascular support device according to a third embodiment of the present utility model, wherein the venous access segment is a non-linearly varying conical mesh structure and is cut from tubing.

In the accompanying drawings:

100-extravascular support device; 110-arterial covered segment; 111-through holes; 112-opening; 130-venous coverage segment; an angle of the alpha-proximal anastomosis; r-radius of curvature.

Detailed Description

The utility model is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present utility model will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the utility model. Furthermore, the structures shown in the drawings are often part of actual structures. In particular, the drawings are shown with different emphasis instead being placed upon illustrating the various embodiments. It should be further understood that the terms "first," "second," and the like in this specification are used solely to distinguish one from another component, element, step, or the like in the specification and do not necessarily denote a logical or sequential relationship between the individual components, elements, steps, or the like, unless otherwise indicated.

In the present document, "proximal" and "distal" are relative orientations, relative positions, directions of elements or actions relative to each other from the perspective of a physician using the extravascular support device, and "proximal" and "distal" are not limiting, as herein, "proximal" of a venous cover section refers to the end of the venous cover section that is connected to an arterial cover section, and "distal" of a venous cover section refers to the end opposite the "proximal". The "distal" and "proximal" in the present document are not directed to the ends of the structure, but rather to relative positions, e.g. the proximal end of the venous coverage section is not the end of the venous coverage section, but rather a position relatively close to the end of the venous coverage section. In the present document, "axial" generally refers to a direction along the central axis of the venous or arterial cover segment, wherein the central axis of the arterial cover segment is perpendicular to the autologous arterial axis, the central axis of the venous cover segment is along the autologous venous axis, and the coating of the arterial cover segment circumferentially around the autologous arterial axis is defined as a lateral surface. Herein, as shown in fig. 1, the length of the venous covered section is the dimension of the venous covered section along the direction of the central axis of the venous covered section, the length of the venous covered section generally refers to the linear distance between two points farthest from each other on the venous covered section, the length of the arterial covered section is the dimension of the arterial covered section along the direction of the axis of the autologous artery, and the length of the arterial covered section generally refers to the linear distance between two points farthest from each other on the arterial covered section.

The following description refers to the accompanying drawings, and the following embodiments and features of the embodiments may be mutually complementary or combined without conflict.

[ embodiment one ]

Fig. 1 shows an exemplary structure of an extravascular support device 100 according to the first embodiment of the present utility model. As shown in fig. 1, the extravascular support device 100 may be positioned outside of an autologous arteriovenous fistula stoma to prevent stenosis near the autologous arteriovenous fistula stoma.

The extravascular support device 100 of this embodiment includes an arterial cover section 110 and a venous cover section 130. The arterial cover section 110 is provided with a through hole 111 on its side, and the proximal end of the venous cover section 130 is connected to the side of the through hole 111 of the arterial cover section 110 remote from the artery. In one embodiment, the sides of the arterial cover section 110 are open and form an opening 112, the diameter of the opening 112 being larger than the diameter of the through-hole 111, which allows the arterial cover section 110 to be introduced into and partially cover the artery with the larger opening 112. In other embodiments, the sides of the arterial cover segment 110 are closed to fully cover the artery. In practice, the arterial cover section 110 wraps the artery of the stoma of the arteriovenous fistula, and the venous cover section 130 wraps the vein of the stoma of the arteriovenous fistula.

The venous cover section 130 is designed to progressively increase in diameter from the proximal end (i.e., corresponding to the proximal anastomosis) to the distal end in a non-linear fashion, thereby configuring the venous cover section 130 into a tapered mesh tube structure that varies non-linearly (i.e., a non-linear horn shape). By adopting the mode, the vein end stenosis of the near-anastomotic stoma caused by hemodynamics can be better relieved, and the problem of turbulence of the near-anastomotic stoma can be better solved. In one embodiment, the venous cover section 130 extends in a direction of its central axis substantially unbent, as shown in FIG. 1.

The length of the venous covering section 130 should not be too long to avoid later-stage puncture. The length of the vein covering section 130 is set to be 15-25 mm according to the vein length of most people, and the vein of the anastomotic stoma of the autologous arteriovenous fistula is wrapped by the length, so that the influence on puncture in the later period is reduced.

According to the arterial length of most people, the arterial cover section 110 is set to be 10-15 mm in length, so that the arterial cover section 110 can be suitable for different people.

Fig. 1 shows the arterial cover segment 110 in its natural state without external forces, in an embodiment the arterial cover segment 110 in its natural state is open on its sides and forms an opening 112, the arterial cover segment 110 being wrapped around the outside of the artery through the opening 112 on its sides. The opening 112 is sized as desired, preferably with the sides of the arterial cover segment 110 semi-wrapping the artery. It will be appreciated that the arterial cover section 110 is curved and the sides are curved surfaces; or the arterial covered section is cylinder-like, and the side surface is a cylinder-like outer surface.

Fig. 1 also shows the natural state of the venous covering section 130 when no external force is applied, the venous covering section 130 in the natural state is tubular, and the venous covering section 130 can be sleeved outside the vein. In this embodiment, the venous covering section 130 in the natural state has a tapered circular tube shape that varies non-linearly.

As shown in fig. 1, a proximal anastomosis port with a certain included angle alpha is formed at the connection position between the proximal end of the venous covering section 130 and the through hole 111 of the arterial covering section 110, and the included angle of the proximal anastomosis port is preferably 45-65 degrees, more preferably 55-60 degrees, so that the included angle of the proximal anastomosis port reduces progressive intimal hyperplasia and lumen stenosis, and reduces the early failure rate of the arteriovenous fistula. Further, the proximal anastomosis has a radius of curvature R of 0.5mm to 1.5mm, such as 0.5mm, 1.0mm, 1.5mm, to reduce intimal hyperplasia and luminal stenosis caused by hydrodynamic disorders.

It should be understood that if the diameter of the venous covered segment 130 is too small, it will affect the smoothness of the blood flow in the vein, while if the diameter is too large, it will not function to adequately bind the vein (the vein segment will expand under the influence of arterial blood pressure, and will need to be properly bound), further, in order to solve this problem, the minimum diameter of the venous covered segment 130 is 2.5 mm-5 mm, and the maximum diameter is 6 mm-10 mm. Further, the diameter of the through hole 111 of the arterial cover section 110 is 2.5mm to 5mm. In this embodiment, the vein covering section 130 may be shaped into a nonlinear network management structure with a diameter from small to large by a conical mold, and making the vein covering section 130 into a nonlinear cone is beneficial to improving hemodynamics.

The extravascular support device 100 according to the present embodiment may include various manufacturing methods such as braiding, cutting (e.g., laser cutting) or 3D printing, depending on the material. Further, the arterial cover segment 110 may be one of a braided structure, a cut structure, and a 3D printed structure. Further, the venous cover section 130 may be one of a braided structure, a cut structure, and a 3D printed structure. In this embodiment, the vein covering section 130 is a woven structure, and the artery covering section 110 is a cut structure. It is understood that the braiding structure is braided from wire, the cutting structure is cut from tubing, and the 3D printing structure prints the material to shape by using 3D printing technology.

The utility model is not limited to the manner in which arterial cover segment 110 and venous cover segment 130 are joined at the proximal anastomosis, and they may be joined together in a variety of ways in practice and formed as a single unit. For example, arterial cover segment 110 and venous cover segment 130 may be welded, sewn, or snapped together at the proximal anastomosis.

The artery and vein junction is unstable due to the arterial pressure, and in this case, it is preferable to provide a reinforcing sheet in the junction between the arterial cover section 110 and the vein cover section 130, and the stability of the junction is increased by the reinforcing sheet.

Further, at least one of the arterial cover section 110 and the venous cover section 130 is made of a degradable material, and then foreign materials remain in the body as little as possible after the vein is mature. In other embodiments, then, the arterial cover segment 110 and the venous cover segment 130 are not degradable.

When at least one of the arterial cover segment 110 and the venous cover segment 130 is made of a degradable material, preferably the arterial cover segment 110 is made of a non-degradable material and the venous cover segment 130 is made of a degradable material, in which case it is convenient to provide sufficient support extravascular by the arterial cover segment 110.

The utility model has no special requirement on the type of degradable material, and common biodegradable materials such as Polydioxanone (PDO), lactide-epsilon-caprolactone copolymer (PLC), polylactic acid (PLA), polylactic acid-glycolic acid copolymer (PLGA) and mixtures thereof can be adopted.

If the arterial and venous cover segments 110, 130 are not degradable, they may be made of a memory alloy material or a polymer material with good elasticity to ensure support. Most of the memory alloy materials are nickel-titanium alloy (Ni-Ti), nickel-titanium-cobalt alloy (Ni-Ti-Co), double-layer composite metal wires (Ni-Ti@Pt) and the like. The polymer material with good elasticity can be selected from polymer materials with certain shape recovery capability, such as Polydioxanone (PDO), lactide-epsilon-caprolactone copolymer (PLC), polyurethane (PU), polynorbornene amorphous polymer and the like.

Taking the example that the arterial cover section 110 is not degradable, the manner of making and connecting the venous cover section 130 and the arterial cover section 110 will be further described.

When the arterial cover section 110 is cut from nitinol tubing and the venous cover section 130 is braided from nitinol wires: the arterial cover section 110 can be shaped into an open shape by a die, and the diameter of the through hole 111 of the arterial cover section 110 is 2.5 mm-5.0 mm; the manufacturing method of the vein covering section 130 comprises the steps of firstly braiding nickel-titanium alloy wires around a core rod into a linear net pipe, wherein the diameter of the linear net pipe is 2.5-5 mm, and then sleeving the linear net pipe on a conical die for heat setting to obtain the conical vein covering section 130; after the arterial covering section 110 and the venous covering section 130 are manufactured and molded, the proximal end of the venous covering section 130 is connected and fixed with the through hole 111 of the arterial covering section 110 by means of welding, stitching or buckling.

When the arterial cover segment 110 is cut from nitinol tubing and the venous cover segment 130 is braided from degradable filaments: the arterial cover section 110 can be shaped into an open shape by a die, and the diameter of the through hole 111 of the arterial cover section 110 is 2.5 mm-5.0 mm; the vein covering section 130 is manufactured by braiding degradable filaments around a conical mandrel to form a conical net pipe, wherein one end of the conical net pipe has a diameter of 2.5-5 mm and the other end has a diameter of 6-10 mm; after the arterial covering section 110 and the venous covering section 130 are respectively manufactured and molded, the proximal end of the venous covering section 130 and one side of the through hole 111 of the arterial covering section 110 far away from the artery are connected and fixed by means of suture or clamping. It will be appreciated that the snap-fit connection may be provided in such a way that the proximal end of the venous cover section 130 is arranged between the side of the through hole 111 of the arterial cover section 110 remote from the artery and the outer Zhou Kakou, such that the proximal end of the venous cover section 130 is clamped.

Alternatively, the arterial cover segment 110 may be degradable, at which time the arterial cover segment 110 may be formed using a degradable silk weave, or the arterial cover segment 110 may be formed by cutting from a degradable polymer tubing, or alternatively, the arterial cover segment 110 may be formed by 3D printing of a degradable polymer material. Similarly, when the venous covering section 130 is degradable, the venous covering section 130 can be formed by braiding degradable filaments, or the venous covering section 130 can be formed by cutting a degradable polymer tube, or the venous covering section 130 can be formed by 3D printing of the degradable polymer material.

[ example two ]

Fig. 2 shows an exemplary structure of an extravascular support device 100 according to the second embodiment of the present utility model. As shown in fig. 2, the extravascular support device 100 of this embodiment is the same as the extravascular support device 100 of the first embodiment in that the diameter of the venous covered section 130 is gradually increased from the proximal end to the distal end in a nonlinear variation manner, but is different in that the venous covered section 130 of this embodiment is curved toward the side where the proximal anastomosis angle α is located so as to be curved along its length direction, preferably in an arc shape, so that the venous covered section 130 is configured as a tapered mesh tube structure that is curved and nonlinear variation. At this time, the angle α of the proximal anastomosis of the venous covering section 130 in the natural state is substantially the same as that of the first embodiment. By adopting the mode, the vein end stenosis of the near-anastomotic stoma caused by hemodynamics can be better relieved, and the problem of turbulence of the near-anastomotic stoma can be better solved.

When the vein covering section 130 is arranged in an arc shape, a shaping treatment step is added, and the vein covering section is sleeved on a bending die for heat shaping. Taking a braiding structure as an example, firstly braiding wires around a core rod to form a linear net pipe, wherein the diameter of the linear net pipe is 2.5-5 mm, and then sleeving the linear net pipe on a reducing bending die for heat setting to form an arc shape.

The present embodiment is mainly described for the differences from the first embodiment, and the same parts as the first embodiment refer to the first embodiment, and will not be described in detail.

[ example III ]

Fig. 3 shows an exemplary structure of an extravascular support device 100 according to the third embodiment of the present utility model. As shown in fig. 3, the extravascular support device 100 of this embodiment differs from the extravascular support device 100 of the first and second embodiments in that the venous covered segment 130 is of a cut structure and the venous covered segment 130 of the first illustrated embodiment is of a braided structure.

In summary, according to the extravascular support device provided by the utility model, by utilizing the vein covering section with the diameter gradually increased from the proximal end to the distal end, intimal hyperplasia and stenosis caused by hemodynamic disturbance can be corrected, particularly, when the diameter of the vein covering section gradually increases from the proximal end to the distal end in a nonlinear change manner, the shearing force of blood flow can be well reduced, the occurrence of turbulence is reduced, the stenosis of the vein end of the near anastomotic stoma caused by hemodynamics can be more effectively relieved, the problem of turbulence of the near anastomotic stoma can be better solved, and particularly, when the vein covering section with the nonlinear change of the diameter and the included angle of the near anastomotic stoma are combined, the effect of reducing turbulence is better. In addition, the extravascular support device provided by the utility model reduces the length of the vein end part near the anastomotic stoma, and can reduce the influence on the later puncture. Further, at least one of the arterial cover segment and the venous cover segment is degradable such that the retention of foreign matter in the patient's body after vein maturation is reduced, reducing postoperative complications.

It should be noted that, in the present description, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, the description is relatively simple because of corresponding to the method disclosed in the embodiment, and the relevant points refer to the description of the method section.

It should be further noted that although the present utility model has been disclosed in the preferred embodiments, the above embodiments are not intended to limit the present utility model. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present utility model still fall within the scope of the technical solution of the present utility model.

It should be further understood that the terms "first," "second," "third," and the like in this specification are used merely for distinguishing between various components, elements, steps, etc. in the specification and not for indicating a logical or sequential relationship between the various components, elements, steps, etc., unless otherwise indicated.

It should also be understood that the terminology described herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present utility model. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses, and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood as having the definition of a logical "or" rather than a logical "exclusive or" unless the context clearly indicates the contrary. Furthermore, implementation of the methods and/or apparatus in embodiments of the utility model may include performing selected tasks manually, automatically, or in combination.

Claims (10)

1. The utility model provides an extravascular support device, is applied to autologous arteriovenous fistula, its characterized in that includes arterial cover section and vein cover section, arterial cover section's side is provided with the through-hole, venous cover section's proximal end with the through-hole is kept away from one side of artery and is connected, venous cover section's diameter is by the proximal end to distal end with nonlinear variation's mode increase gradually, just venous cover section's length is 15mm ~ 25mm.

2. The extravascular support device of claim 1, wherein the venous cover section has a proximal anastomosis formed at an angle from 45 ° to 65 ° at the junction of the proximal end and the through hole.

3. The extravascular support device of claim 2, wherein the proximal anastomosis has an included angle of 55 ° to 60 °.

4. An extravascular support device according to claim 2 or 3, wherein the proximal stoma has a radius of curvature of 0.5mm to 1.5 mm.

5. The extravascular support device of claim 1, wherein the venous covered segment has a minimum diameter of 2.5mm to 5mm and a maximum diameter of 6mm to 10mm.

6. An extravascular support device according to any of claims 1-3, wherein the venous covered segment in its natural state is arcuately disposed along its length.

7. An extravascular support device according to any of claims 1-3, wherein the interface area of the arterial and venous cover sections is provided with a reinforcing tab.

8. An extravascular support device according to any of claims 1-3, wherein the arterial cover section is one of a braided structure, a cut structure and a 3D printed structure and/or the venous cover section is one of a braided structure, a cut structure and a 3D printed structure.

9. An extravascular support device according to any of claims 1-3, wherein the arterial cover section has a length of 10mm to 15mm.

10. An extravascular support device according to any of claims 1-3, wherein the arterial cover section is open or closed on the side.