An arteriovenous fistula flow field protection device

Abstract

The application discloses an arteriovenous fistula flow field protection device, which comprises a flow field corrector and a flow limiting protection net, characterized in that the flow field corrector and the flow limiting protection net are welded and connected by a nickel-titanium wire at a welding area; the flow field corrector is located at an arterial end and is combined with an arterial blood vessel; the flow limiting protection net is located at a venous end and is sleeved with a venous end blood vessel; the flow field corrector and the flow limiting protection net are connected at a fistula opening, and the overall structure is a space three-dimensional spiral shape, thereby protecting the fistula opening. The application increases the blood rotation flow direction by arranging a space three-dimensional spiral fluid correction device near the fistula opening, increases the smooth flushing of the blood vessel wall, reduces the probability of thrombosis near the fistula opening, reduces the pressure borne by the venous wall through the flow limiting protection net, reduces the probability of intimal hyperplasia and venous stenosis, and thereby increases the success probability of the internal fistula.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of extravascular shape correction, in particular to a arteriovenous fistula flow field protection device. BACKGROUND

[0002] The dialysis patient needs to establish a blood access that meets the dialysis requirements before treatment, and connect the relevant dialysis equipment for treatment. At present, the establishment of arteriovenous fistula and then dialysis surgery has become the choice of most blood access establishment methods, as high as 90%. The limbs become the main fistula area, and the effective long-term dialysis channel is established by connecting the arteriovenous.

[0003] However, during the establishment of arteriovenous fistula, arterial blood needs to be introduced into venous blood vessels. Under normal physiological conditions, the venous circulation pressure is 3-5mmHg, and after the fistula is created, the average pressure in the vein can reach 100mmHg. The high pressure difference between the arteriovenous causes the venous pressure to be too large and the flow rate to be too fast, which exceeds the physiological characteristics of the vein. Early venous stenosis and neointimal hyperplasia become arteriovenous fistula high incidence symptoms, and are also one of the failure factors of arteriovenous fistula.

[0004] On the basis of the rotational flow theory, the aortic arch is in the shape of a circular arc umbrella handle, and the bending is in a three-dimensional spiral shape. It is this three-dimensional spiral configuration that makes the blood flow at the ascending aorta present a rotational flow state. The rotation of the blood flow at the aortic arch is a high embodiment of the nature "form follows function", and is a guarantee for the smoothness of the ascending aorta blood vessel wall to prevent the formation of atherosclerosis. The rotational phenomenon of blood flow not only exists in the aorta, but also exists in other parts of the arterial system. Caro et al. used nuclear magnetic resonance angiography to study blood flow and found that the blood flow in the right common iliac artery was counterclockwise rotational flow, but in the left it was clockwise. Stonebridge et al. observed rotational flow in the human inguinal artery through endoscopy and first proposed the concept of rotational flow in human peripheral arteries. In order to prove this point, they used multiple color Doppler technology to observe the blood flow at three places: the left common femoral artery, the right common femoral artery, and the distal superficial femoral artery. Although the direction of blood flow rotation was observed to be different, the presence of rotational components was observed in all subjects during the systolic period. It is these spiral structures that make the blood flow in these arteries present a rotational flow state. From the existing research, it can be known that the spatial configuration of the blood vessel, the spatial motion, the compliance of the blood vessel, the propagation and reflection of the pulse wave under the condition of pulsation are important factors affecting the rotational state of the blood flow SUMMARY

[0005] In order to solve the above-mentioned problems, the present application provides an arteriovenous fistula flow field protection device.

[0006] The application provides a kind of arteriovenous fistula flow field protection device, including flow field corrector and flow limiting protection net, the flow field corrector with the flow limiting protection net is welded by nickel-titanium wire in welding area connection;The flow field corrector is located at arterial end, and is engaged with arterial blood vessel;The flow limiting protection net is located at venous end, and is sleeved with venous end blood vessel;Flow field corrector and flow limiting protection net are connected at fistula, and the overall structure is space three-dimensional spiral, and the fistula is protected.

[0007] Further, the distance between the venous connection port of the flow field corrector and the fistula is 2-10 mm.

[0008] Further, the flow field corrector includes a venous connection port, a first inflow section, a second liquid rotating section and a third outflow section, and the first inflow section, the second liquid rotating section and the third outflow section form an S-shaped structure in the top view of the flow field corrector.

[0009] Further, the flow field corrector has an arc-shaped planar shape in the front view, and the horizontal length of the arc-shaped planar shape in the front view of the flow field corrector should be less than 10 times the total length of the arc-shaped section, greater than 0.1 times the total length of the arc-shaped section, and the curvature radius of the arc-shaped structure of the flow field corrector is greater than 3 times the diameter of the outflow port; the central angle of the arc-shaped structure is 5°-30°; the venous connection port of the flow field corrector is circular or elliptical, and the center of the circular or elliptical shape is on the normal axis of the cross section of the second liquid rotating section.

[0010] Further, the spatial angle between the normal axis of the cross section of the first inflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section is less than 30°, and the spatial angle between the normal axis of the cross section of the third outflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section should be less than 30°.

[0011] Further, the spatial angle between the normal axis of the cross section of the first inflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section is less than 30°, and the spatial angle between the normal axis of the cross section of the third outflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section should be less than 30°.

[0012] Further, the spatial angle between the normal axis of the cross section of the first inflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section is less than 30°, and the spatial angle between the normal axis of the cross section of the third outflow section of the flow field corrector and the normal axis of the cross section of the second liquid rotating section should be less than 30°.

[0013] Further, the flow field corrector adds a polymer vapor deposition layer at any position in the first inflow section, the second rotating liquid section and the third outflow section to increase the surface smoothness, protect the adjoining blood vessels, increase the blood vessel surface coverage by adding a rubber film, and improve the shear stress. Preferably, the added polymer vapor deposition layer is made of pairuolin or ptfe.

[0014] Further, the flow field corrector is an open structure, and a closed structure is formed by mechanical structure combination. The closed structure is a reverse buckle structure, a sticky structure or a binding wire structure.

[0015] Further, the flow field corrector is an open structure, and a closed structure is formed by mechanical structure combination. The closed structure is a reverse buckle structure, a sticky structure or a binding wire structure.

[0016] Based on the above technical solutions, the embodiments of the present application can at least produce the following technical effects:

[0017] The arteriovenous fistula flow field protection device provided by the present application increases the blood rotation flow direction by making a spatial three-dimensional spiral fluid correction device near the fistula, increases the smooth flushing of the blood vessel wall to reduce the probability of thrombosis near the fistula, reduces the pressure on the vein wall by the flow limiting protection net, reduces the probability of intimal hyperplasia and vein stenosis, and thus increases the success probability of the internal fistula. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0019] Figure 1 The structure of the arteriovenous fistula flow field protection device of the present application is shown.

[0020] Figure 2 The arteriovenous fistula flow field protection device of the present application is shown.

[0021] Figure 3 The arteriovenous fistula flow field protection device of the present application is shown.

[0022] Figure 4 The three-dimensional structure of the flow field corrector in the arteriovenous fistula flow field protection device of the present application is shown.

[0023] Figure 5 Fig. 2 is a schematic diagram of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application, shown from a top perspective view;

[0024] Figure 6 Fig. 3 is a schematic diagram of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application, shown from a front perspective view;

[0025] Figure 7 Fig. 4 is a structural schematic diagram of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application; Figure 1

[0026] Figure 8 Fig. 5 is a structural schematic diagram of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application; Figure 2

[0027] Figure 9 Fig. 6 is a structural schematic diagram of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application; Figure 3

[0028] Figure 10 Fig. 7 is a schematic diagram of the mechanical friction-increasing structure at the two ends of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application;

[0029] Figure 11 Fig. 8 is a schematic diagram of the center angle and the arc-shaped curvature radius of the circular arc structure of the flow field corrector in the arteriovenous fistula flow field protection device according to the present application.

[0030] Fig. 1 is a schematic diagram of the arteriovenous fistula flow field protection device according to the present application;

[0031] 10, flow field corrector; 101, arterial blood vessel; 11, venous connection port; 12, first inflow section; 121, first inflow section phase axis; 13, second liquid rotation section; 131, second liquid rotation section phase axis; 14, third outflow section; 141, third outflow section phase axis;

[0032] 20, flow-limiting protection net; 201, venous blood vessel;

[0033] 30, fistula port; 33, welding area; 35, closed structure area; DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0035] ​​​It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order

[0036] indicated, unless otherwise explicitly provided herein. It is also to be understood that additional or alternative steps can be employed. Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first", "second", and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0037] Spatially relative terms, such as "inner", "outer", "beneath", "below", "lower", "above", "upper", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0038] In the description of the present application, it should be noted that the embodiments of the present application and the features in the embodiments of the present application can be combined with each other without conflict.

[0039] As shown in the drawings, a dynamic arteriovenous fistula flow field protection device is provided in the embodiments of the present application, Figure 1 Figure 1 ​The overall structural arrangement is schematically provided, wherein the flow-restricting protective net 20 and the flow field corrector 10 are connected to constitute the whole device.

[0040] For the convenience of illustration and understanding, an arteriovenous fistula creation method for promoting hemodialysis is shown in the embodiment of the present application, as shown in Figure 2 The arteriovenous fistula is created by connecting the arterial blood vessel 101 and the venous blood vessel 201 through sewing, and the sewing area is the fistula 30.

[0041] Figure 3 The arteriovenous fistula flow field protection device and the arterial and venous blood vessels are schematically shown in the cooperation diagram, wherein the flow-restricting protective net 20 mainly protects the venous blood vessel 201, and the flow field corrector 10 mainly borders the arterial blood vessel 101, and the overall arrangement is shown.

[0042] Figure 4 The overall structure of the arteriovenous fistula flow field protection device is schematically shown, which can be a woven and shaped structure, and the stress is finally eliminated through heat setting to achieve the shaping effect; or the overall structure can be formed in a space three-dimensional spiral state through laser cutting, pipe cutting and mold shaping, and the processing method can be diversified, and mechanical processing can also complete the processing of the structure.

[0043] Figure 5 The top view of the flow field corrector in the arteriovenous fistula flow field protection device is schematically shown, which is in the form of S shape in the top view, which can be a micro-S shape or even not macroscopically exhibit S shape, or a Z-shaped structure with more severe turning.

[0044] Figure 6 The front view of the flow field corrector in the arteriovenous fistula flow field protection device is schematically shown, which is in the form of S shape in the top view, which can be a micro-S shape or even not macroscopically exhibit S shape, or a Z-shaped structure with more severe turning.

[0045] The flow field corrector 10 is composed of five parts, wherein Figure 7 The first inflow section 12, the second liquid-rotating section 13 and the third outflow section 14 are shown in the embodiment. Figure 8The figure shows a venous connection port 11, a first inflow section 12, a second vortex section 13, a third outflow section 14, and a closed structural area 35. The first inflow section 12 and the second vortex section 13 are connected, and the spatial angle between the normal axes of the two axes should be no greater than 30°. The second vortex section 13 and the third outflow section 14 are connected, and the spatial angle between the normal axes of the two axes should be no greater than or less than 30°. Above the connection with the second vortex section 13 is the venous connection port 11. The distance from the upper end face of the venous connection port 11 to the axis of the second vortex section 13 is 2-10mm. The spatial angle between the normal axis of the venous connection port 11 and the normal axis of any cross section of the second vortex section 13 should be no less than 30° and no greater than 70°. Below the connection with the second vortex section 13 is the closed structural area 35 of the flow field corrector. There are many possibilities for its structural area, which can be a mechanically closed structure or a two-end suture structure.

[0046] Figure 9 The total length of the horizontal section in the quasi-arch plane shape is composed of two parts, L1 and L2, and its length is a multiple limit relationship with the length L3 of the quasi-arch plane shape. The total length of the horizontal section in the quasi-arch plane shape of the flow field straightener 10 in the front view should be less than 10 times the total length of the arch section and greater than 0.1 times the total length of the arch section. Figure 11 The curvature radius R and its circular angle θ are indicated in the schematic diagram. The flow field straightener 10 is in an arc shape when viewed from the front. The central angle of the arc structure should be less than 30° and greater than 5°.

[0047] The current limiting protection net 20 is woven from nickel-titanium alloy wires. The flow field corrector 10 and the current limiting protection net 20 are welded and connected by nickel-titanium wire in the welding area 33. The wire diameter of the current limiting protection net 20 should be no more than 0.10 mm and no less than 0.01 mm. The shape of the current limiting protection net 20 can be a truncated cone or a combination of a truncated cone and other shapes. The end face of the truncated cone can be combined with a cylindrical structure to form a rod, and the end face of the truncated cone can be combined with a spherical structure.

[0048] In the embodiment of the present invention, the flow field straightener can increase the friction between the flow field straightener and the blood vessel by mechanical structure at the head and tail ends of the semi-circular tubular structure area formed by the first inflow section 12, the second cyclone section 13 and the third outflow section 14, such as Figure 10 One way to add friction to a wave-like mechanical structure.

[0049] Example 1

[0050] Through laser cutting of pipe drawing, the initial original cutting structure is obtained, then the heat setting mold is sleeved for setting, the setting temperature is 480 DEG C, and the heat treatment setting is carried out for 20 minutes, then the flow field corrector setting state is obtained, then the laser spot welding of the flow limiting protection net nickel-titanium net welding area is carried out, the protection gas needs to be more than 99.9% argon with high purity in the spot welding process, after the welding of the whole product is completed, the whole product is put into the gas phase deposition machine to carry out parylene gas phase deposition to increase the coating thickness of the surface by about 50-100um, so that the whole structure is wrapped by the parylene coating, and the effect of more smooth fitting of the blood vessel is achieved.

[0051] Example 2

[0052] Through laser cutting of pipe drawing, the initial original cutting structure is obtained, then the heat setting mold is sleeved for setting, the setting temperature is 480 DEG C, and the heat treatment setting is carried out for 20 minutes, then the flow field corrector setting state is obtained, then the laser spot welding of the flow limiting protection net nickel-titanium net welding area is carried out, the protection gas needs to be more than 99.9% argon with high purity in the spot welding process, after the welding of the whole product is completed, the whole product is put into the rubber film coating liquid for immersion coating, the immersion coating film is formed through the vulcanization time of 120 DEG C for 15 minutes, then the film thickness is increased through secondary immersion coating, finally the dense rubber film is formed between the first inflow section, the second liquid rotating section and the third outflow section unit cell, the blood vessel loading area is increased, and the blood vessel confinement force is improved.

[0053] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, the above examples and the description in the specification are only to illustrate the principles of the present application, various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. An arteriovenous fistula flow field protection device, comprising a flow field corrector (10) and a flow limiting protection net (20), characterized in that: The flow field corrector (10) and the flow limiting protection net (20) are welded together by nickel-titanium wire in the welding area (33); the flow field corrector (10) is located at the arterial end and is joined to the arterial blood vessel (101); the flow limiting protection net (20) is located at the venous end and is fitted with the venous blood vessel (201); the flow field corrector (10) and the flow limiting protection net (20) are connected at the fistula opening (30), and the overall structure is in a three-dimensional spiral shape to protect the fistula opening (30); the flow field corrector (10) includes a venous The flow field corrector comprises four regions, namely, a connecting port (11), a first inflow section (12), a second swirl section (13), and a third outflow section (14); the first inflow section (12), the second swirl section (13), and the third outflow section (14) are S-shaped when viewed from above; the current limiting protection net (20) is formed by weaving nickel-titanium alloy wire; the wire diameter of the current limiting protection net (20) is 0.01 mm to 0.1 mm; and the overlapping mode of the current limiting protection net is one-on-one, one-on-two, or two-on-two.

2. The arteriovenous fistula flow field protection device according to claim 1, characterized in that: The distance between the venous connection port (11) of the flow field corrector (10) and the fistula opening (30) is 2-10 mm.

3. The arteriovenous fistula flow field protection device according to claim 1, characterized in that: The flow field corrector (10) is in an arch-like plane shape in a frontal view, and the total length of the horizontal section of the flow field corrector (10) in an arch-like plane shape in a frontal view should be less than 10 times the total length of the arch section and greater than 0.1 times the total length of the arch section. The flow field corrector (10) is in an arch-like arc shape, and the radius of curvature of the arch is greater than 3 times the diameter of the outflow port; the central angle of the arc structure is 5°-30°; the venous connection port (11) of the flow field corrector (10) is circular or elliptical, and its center is on the normal axis and the normal axis of the cross section of the second hydrocyclone section (13).

4. The arteriovenous fistula flow field protection device according to claim 1, characterized in that: The spatial angle between the normal axis of the cross section of the first inflow section (12) of the flow field straightener (10) and the normal axis of the cross section of the second hydrocyclone section (13) is less than 30°; the spatial angle between the normal axis of the cross section of the third outflow section (14) of the flow field straightener (10) and the normal axis of the cross section of the second hydrocyclone section (13) should be less than 30°.

5. The arteriovenous fistula flow field protection device according to claim 1, characterized in that: The normal axis at any cross section of the arc-shaped inner wall surface of the arterial blood vessel (101) joined by the flow field corrector (10) and the normal axis of the cross section of the flow limiting protection net (20) combined with the venous blood vessel (201) have a three-dimensional spatial included angle of less than 90°; the normal axis of any cross section of the arterial blood vessel (101) joined by the flow field corrector (10) and the normal axis of the cross section of the flow limiting protection net (20) combined with the venous blood vessel (201) have a three-dimensional spatial included angle of greater than 20°.

6. The arteriovenous fistula flow field protection device according to claim 4, characterized in that: The flow field corrector (10) increases friction between the flow field corrector (10) and the blood vessel through a mechanical structure at the head and tail ends of the semi-circular tubular structure region formed by the first inflow section (12), the second cyclone section (13) and the third outflow section (14).

7. The arteriovenous fistula flow field protection device according to claim 6, characterized in that: The flow field straightener (10) is provided with a polymer vapor deposition coating at any position in the first inflow section (12), the second swirl section (13) and the third outflow section (14) to increase the surface smoothness thereof, thereby protecting the blood vessels at the borders, and increasing the blood vessel surface area coverage by the rubber coating to improve the shear stress.

8. The arteriovenous fistula flow field protection device according to claim 1, characterized in that: The flow field straightener (10) is an open structure, and a closed structure (35) is formed by combining mechanical structures; the closed structure (35) is a closed structure composed of an inverted structure, a closed structure composed of an adhesive structure, or a closed structure composed of a wire-binding structure.

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