Subcutaneous tunneler assembly for artificial vascular arteriovenous fistula

Abstract

The present invention relates to a medical device, specifically to a subcutaneous tunneler assembly for artificial vascular arteriovenous fistulas, which includes a dilator, a guidewire, and a sleeve. The dilators are two open-ended, tubular structures, each with a bendable segment. The sleeve has a sleeve cavity that fits the artificial vascular graft. The guidewire is placed in the communicating cavity formed by the abutment of the two dilators. The bendable segments bend the two dilators to fit a predetermined path of the subcutaneous tunnel. After the dilators are introduced subcutaneously through a skin incision, the ends are abutted to form a continuously curved U-shaped subcutaneous tunnel, reducing the size of the skin incision, minimizing surgical trauma, and preventing infection. The sleeve protects the artificial vascular graft from contact with the skin, reducing the risk of infection during surgery. After the artificial vascular graft is inserted into the sleeve, there is no need to adjust its position, preventing twisting, bending, or bending of the artificial vascular graft during insertion.

Description

[Technical Field]

[0001] The present invention is in the field of medical devices, and more particularly relates to a subcutaneous tunneler assembly for an artificial vascular arteriovenous fistula. [Background technology]

[0002] Arteriovenous fistula surgery is a surgical procedure that involves anastomosis of the patient's own limb artery (always the radial or brachial artery) with a vein (always the cephalic or noble vein) to arterialize the vein and create an arteriovenous fistula. However, during the actual procedure, several factors may affect the formation of the patient's own arteriovenous fistula. For example, the patient's own vascular condition may be poor, making the fistula impossible to form, or the formed fistula may become blocked and unable to be re-formed. If these patients still require hemodialysis treatment, an artificial vascular arteriovenous fistula surgery is required, in which an artificial blood vessel is inserted into a subcutaneous tunnel to connect the artery and vein.

[0003] The typical steps in a U-shaped artificial vascular loop surgery are as follows: First, a skin incision (first incision) is made at the planned anastomosis site (where the artificial vascular graft is anastomosed to the patient's own artery and vein). Then, a second incision (approximately 2 cm) is made at the planned location of the artificial vascular loop's tip. A tunneler is inserted through the first incision and then advanced along the predesigned tunnel path at a certain arc to the second incision, thereby placing the artificial vascular graft within the tunneler. At this point, 50% of the artificial vascular graft is introduced. Next, the tunneler is inserted through the second incision and advanced along the predesigned tunnel path at a certain arc to the first incision, thereby completing the formation of the remaining 50% of the subcutaneous tunnel. Finally, both ends of the artificial vascular graft are anastomosed to the patient's own artery and vein at the first incision, and subsequent procedures are performed.

[0004] As can be seen from the above, when using a conventional tunneler to form a highly curved U-shaped subcutaneous tunnel, a second incision must be made at the apex of the U-shaped tunnel path (the intended location of the tip of the artificial blood vessel loop), which causes significant surgical damage and is prone to postoperative infection. The artificial blood vessel must be tied to the tunneler, which makes the operation relatively complicated and inefficient. The formed subcutaneous tunnel is not continuous, and is prone to twisting, bending, or angles during the introduction of the artificial blood vessel, making it easy for it to come into contact with the skin, increasing the risk of infection. Furthermore, the tunneler consists of a handle, inner rod, outer sheath, bullet tip, etc., and has many parts. Summary of the Invention

[0005] The object of the present invention is to overcome the drawbacks of the prior art and to provide a subcutaneous tunneler assembly for an artificial vascular arteriovenous fistula, which can reduce the surgical incision required when forming a subcutaneous tunnel using the subcutaneous tunneler assembly, thereby facilitating postoperative recovery for the patient, avoiding infection at the second incision at the tip of the artificial vascular loop, and providing a continuous subcutaneous tunnel that is convenient for introducing the artificial vascular system.

[0006] In order to solve the above technical problems, the technical means of the present invention are as follows.

[0007] The present invention provides a subcutaneous tunneler assembly for an artificial vascular arteriovenous fistula, the subcutaneous tunneler assembly for an artificial vascular arteriovenous fistula including a dilator, a guide wire, and a sleeve; Two dilators are provided, each of which has a tubular structure with both ends open, and each has an independently bendable segment, and the bendable segment is bent to make the curved shape of each dilator conform to the predetermined path of the subcutaneous tunnel, and after the two dilators are introduced subcutaneously, their ends abut against each other to form a continuously curved U-shaped subcutaneous tunnel; the guide wire is disposed in a communicating cavity formed by the two dilators to guide the sleeve into the U-shaped subcutaneous tunnel; The sleeve has a sleeve cavity that fits the artificial blood vessel to be introduced and accommodates the artificial blood vessel.

[0008] Preferably, in the subcutaneous tunneler assembly according to the present invention, each of the two dilators includes an enlarged head segment having a conical structure, and the rear end of the enlarged head segment is integrally formed with the front end of the bendable segment.

[0009] More preferably, in the subcutaneous tunneler assembly according to the present invention, the abutting ends of the two expandable head segments are provided with matching protrusions and recesses, respectively.

[0010] More preferably, in the subcutaneous tunneler assembly according to the present invention, the outer wall surface of the outlet of one of the expansion head segments gradually narrows in the direction of the central axis to form the protrusion, and the inner wall surface of the outlet of the other expansion head segment gradually widens in the direction away from the central axis to form the recess.

[0011] More preferably, in the subcutaneous tunneler assembly according to the present invention, each of the two dilators includes an extension tail segment, the front end of which is integrally formed with the rear end of the bendable segment.

[0012] Preferably, in the subcutaneous tunneler assembly of the present invention, in each dilator, the connection between the expandable head segment and the bendable segment is a smooth transition, and the bendable segment and the expandable tail segment have the same outer diameter.

[0013] Preferably, in the subcutaneous tunneler assembly according to the present invention, the material of the dilator is polypropylene.

[0014] Preferably, in the subcutaneous tunneler assembly according to the present invention, the sleeve is a tubular structure open at both ends, fitted over the guide wire, and guided by the guide wire to be introduced into the U-shaped subcutaneous tunnel.

[0015] More preferably, in the subcutaneous tunneler assembly according to the present invention, the outer diameter of the sleeve gradually increases from the front end to the rear end thereof, and is adapted to the inner diameters of the two dilators, respectively; The inner diameter of the sleeve gradually widens in steps from the front end to the rear end, and the sleeve cavity is located in the rear segment of the sleeve.

[0016] More preferably, in the subcutaneous tunneler assembly according to the present invention, the sleeve is a silicone tube.

[0017] The technical solution of the present invention has the following advantages:

[0018] 1. The subcutaneous tunneler assembly for an artificial blood vessel arteriovenous fistula according to the present invention includes a dilator, a guidewire, and a sleeve. Two dilators are provided, each of which has a tubular structure with open ends and each having a bendable segment. The guidewire is placed in a communicating cavity formed by the two dilators. The sleeve has a sleeve cavity that fits the artificial blood vessel to be inserted.

[0019] This subcutaneous tunneler assembly utilizes a bendable segment to bend and deform the two dilators, allowing the curved shapes of each to fit the predetermined path of the subcutaneous tunnel (for example, both dilators form a J-shape). After being introduced subcutaneously through a skin incision (first incision), the ends of the two dilators come together to form a continuously curved U-shaped subcutaneous tunnel. Compared to conventional tunnelers, this invention can avoid the need to form a second incision at the apex of the U-shaped tunnel path (the planned location of the tip of the artificial vascular loop), thereby minimizing surgical trauma and preventing secondary infection.

[0020] In addition, the sleeve protects the artificial blood vessel from contact with the skin, reducing the risk of infection during surgery. Furthermore, there is no need to adjust the position of the artificial blood vessel after it is introduced into the sleeve, which prevents the artificial blood vessel from twisting, bending, or bending during the introduction process.

[0021] 2. In the subcutaneous tunneler assembly according to the present invention, each of the expanded head segments has a cone-shaped structure, which can minimize damage to the subcutaneous tissue when the expanded head segments pass through the subcutaneous tissue.

[0022] 3. In the subcutaneous tunneler assembly of the present invention, the dilator tail segment and the bendable segment of each dilator have the same outer diameter, which can reduce subcutaneous traction damage and reduce patient discomfort. [Brief explanation of the drawings]

[0023] In order to more clearly describe the specific embodiments of the present invention or the technical means in the prior art, the drawings that need to be used in the description of the specific embodiments or the prior art will be briefly described below. Obviously, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without any creative work.

[0024] [Figure 1] 1 is a schematic structural diagram of a subcutaneous tunneler assembly according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram of the J-shaped structure of the dilator in FIG. 1. [Figure 3] 3A and 3B are schematic structural diagrams of protrusions and recesses. [Figure 4] FIG. 10 is a schematic structural diagram of a state in which a protrusion and a recess are in contact with each other. [Figure 5] FIG. 2 is a schematic structural diagram of a sleeve cavity. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be described in more detail below with reference to the drawings. The above and other objects, features, aspects, and advantages of the present invention will become more apparent to those skilled in the art upon reading the specification. The drawings are exaggerated in shape and size for clarity, and the same or similar parts are designated by the same reference numerals throughout the drawings. In the following description, terms such as center, thickness, height, length, front, back, rear, left side, right side, top, bottom, upper part, and lower part are based on the orientation or positional relationship shown in the drawings. In particular, "height" corresponds to the dimension from top to bottom, "width" corresponds to the dimension from left side to right side, and "depth" corresponds to the dimension from front to rear. These relative terms are used for convenience of explanation and generally do not require a specific orientation. Terms relating to attachment, coupling, and the like (e.g., "connection" and "attachment") refer to a relationship in which these structures are directly or indirectly fixed or attached to each other via an intermediate structure, and to a movable or rigid attachment relationship, unless otherwise specified.

[0026] The present invention provides a subcutaneous tunneler assembly for artificial vascular arteriovenous fistula, which includes a dilator 1, a sleeve 2, and a guide wire 3, as shown in FIG.

[0027] The dilator 1 has an elongated structure, and its function is to insert it subcutaneously through an incision in the skin and expand the subcutaneous tissue along a predetermined path to form a subcutaneous tunnel, which may be linear or curved (e.g., U-shaped).

[0028] When a subcutaneous tunnel is U-shaped, two skin incisions must be made using a conventional tunneler: a first incision (i.e., a skin incision at the planned anastomosis site between the graft and the patient's own artery and vein) and a second incision (i.e., a skin incision at the planned location of the distal end of the graft loop (the apex of the curve of the U-shaped tunnel)). A conventional tunneler can be inserted subcutaneously through the first incision and then through the second incision, and then through the second incision and back into the first incision. This allows the graft to be introduced into the tunnel in segments. Therefore, when a U-shaped subcutaneous tunnel is formed using a conventional tunneler, at least the following drawbacks exist: 1. The additional skin incision (the second incision, approximately 2 cm) results in significant surgical loss and a high risk of infection. 2. The formed subcutaneous tunnel is not continuous, and a blind spot exists, particularly at the second incision, making it prone to twisting, bending, or bending during the introduction of the graft.

[0029] To solve this technical problem, the dilator 1 of the present invention is composed of two dilators: a first dilator 11 and a second dilator 12. The first dilator 11 and the second dilator 12 are each provided with an independently bendable segment. The first dilator 11 includes a first bendable segment 111, and the second dilator 12 includes a second bendable segment 121. As shown in FIG. 2, the curvature of the first bendable segment 111 and the second bendable segment 121 can be adjusted arbitrarily under the action of an external force, causing the first dilator 11 and the second dilator 12 to bend and deform, respectively, to fit the predetermined path of the subcutaneous tunnel. For example, the first dilator 11 and the second dilator 12 bend and deform synchronously, both forming a J-shape. Therefore, the first dilator 11 and second dilator 12, which are identical in J-shape, are introduced subcutaneously through the first incision, and then their ends come into contact to form a continuously curved U-shaped subcutaneous tunnel, eliminating the need to form a second incision.

[0030] To facilitate the subcutaneous passage of the first dilator 11 and the second dilator 12, the two dilators each include an independent extended head segment. Along the passage direction, the first extended head segment 112 is provided at the front end of the first bendable segment 111, and the second extended head segment 122 is provided at the front end of the second bendable segment 121.

[0031] In one specific embodiment of the present invention, the first enlarged head segment 112 and the second enlarged head segment 122 are both conical structures.

[0032] Because the subcutaneous tunnel is U-shaped, a soft artificial blood vessel cannot pass through the U-shaped subcutaneous tunnel on its own. Therefore, the present invention utilizes sleeve 2 to guide the artificial blood vessel through the U-shaped subcutaneous tunnel. Specifically, sleeve 2 is hollow and has sleeve cavity 21 that accommodates the artificial blood vessel to be introduced, and the shape of the interior of the cavity matches the shape of the artificial blood vessel, allowing the artificial blood vessel to be fixed. Furthermore, when introducing the artificial blood vessel into the formed U-shaped subcutaneous tunnel, sleeve 2 also prevents the artificial blood vessel from twisting, bending, or flexing within the U-shaped subcutaneous tunnel.

[0033] The U-shaped subcutaneous tunnel is formed by the abutment of the expansion head segments (first expansion head segment 112 and second expansion head segment 122) of two J-shaped dilators 1 (first dilator 11 and second dilator 12), resulting in a smaller tube diameter in the two expansion head segments. The present invention uses a guidewire 3 as a medium to guide the sleeve 2 so that it is first introduced into the two J-shaped dilators 1 and then into the U-shaped subcutaneous tunnel. Therefore, both the first dilator 11 and the second dilator 12 have a tubular structure with both ends open, and the guidewire 3 can be inserted into the communicating cavities between them, thereby guiding the sleeve 2 so that it is introduced into the U-shaped subcutaneous tunnel.

[0034] In the present invention, the dilator 1, sleeve 2, and guide wire 3 cooperate with each other, and the bendable segments of the two dilators 1 are bent and deformed to fit the predetermined path of the subcutaneous tunnel, thereby forming a continuously curved U-shaped subcutaneous tunnel. The guide wire 3 is placed in the communicating cavity formed by the two dilators 1 and guides the sleeve 2 for introduction into the U-shaped subcutaneous tunnel. The sleeve 2 has a sleeve cavity 21 that fits the artificial blood vessel to be introduced and can accommodate the artificial blood vessel. During the process of introducing the artificial blood vessel into the U-shaped subcutaneous tunnel, the artificial blood vessel is protected from contact with the skin, reducing the risk of infection. It also allows the position of the artificial blood vessel to be adjusted, preventing the artificial blood vessel from twisting, bending, or flexing in the U-shaped subcutaneous tunnel.

[0035] <Dilator 1> Bendable Segments The present invention does not particularly limit the structure of the bendable segments, and those skilled in the art can select one according to actual needs, for example, the cross section may be circular, elliptical, etc. In some preferred embodiments of the present invention, the first bendable segment 111 and the second bendable segment 121 both have a circular cross section and a smooth outer surface, which can reduce damage to subcutaneous tissue.

[0036] The present invention does not particularly limit the material of the bendable segment, and those skilled in the art can select it according to actual needs, for example, medical metal material, medical polymer material (e.g., polypropylene), etc. In some preferred embodiments of the present invention, both of the above two bendable segments are made of polypropylene.

[0037] The present invention does not particularly limit the length of the bendable segment, and those skilled in the art can select it according to actual needs, and the present invention does not individually limit the length of the bendable segment.

[0038] The present invention does not particularly limit the diameter of the bendable segments, and those skilled in the art can select it according to actual needs. The diameters of the two bendable segments may be equal or unequal. In some preferred embodiments of the present invention, the diameter of the first bendable segment 111 is equal to the diameter of the second bendable segment 121. In some specific embodiments of the present invention, the diameters of the first bendable segment 111 and the second bendable segment 121 are 8.9 to 9.1 mm. For example, the diameters of both segments are 8.9 mm, 9.0 mm, 9.1 mm, etc.

[0039] Extended Head Segment The present invention does not particularly limit the specific structure of the expanded head segments, and those skilled in the art can select according to actual needs, for example, a conical structure or a polygonal pyramid structure. In some preferred embodiments of the present invention, the first expanded head segment 112 and the second expanded head segment 122 are both conical structures, which can reduce damage to subcutaneous tissue compared to polygonal pyramid structures.

[0040] In some more preferred embodiments of the present invention, the first and second dilated head segments 112, 122 are both blunt cone-shaped structures, such as truncated cone-shaped structures, which can further reduce damage to the subcutaneous tissue.

[0041] In some specific embodiments of the present invention, the front end outer diameter of the first expanded head segment 112 along the passing direction is 4 to 6 mm, and illustratively the front end outer diameter may be 4 mm, 5 mm, 6 mm, etc., and the front end outer diameter of the second expanded head segment 122 is 4 to 6 mm, and illustratively the front end outer diameter may be 4 mm, 5 mm, 6 mm, etc.

[0042] In some specific embodiments of the present invention, the minimum diameter of the front end of the first expanded head segment 112 along the passing direction is 2 to 4 mm, exemplarily, the minimum diameter of the front end may be 2 mm, 3 mm, 4 mm, etc., and preferably 2 mm, and the minimum outer diameter of the front end of the second expanded head segment 122 is 2 to 4 mm, exemplarily, the minimum outer diameter of the front end may be 2 mm, 3 mm, 4 mm, etc., and preferably 4 mm.

[0043] In some specific embodiments of the present invention, as shown in Figures 3 and 4, the abutting ends of the two expanded head segments are provided with matching protrusions and recesses, respectively, and the fitting of the protrusions into the recesses helps the ends of the first dilator 11 and the second dilator 12 to abut against each other.

[0044] In some specific embodiments of the invention, the outlet outer wall surface of one expanded head segment narrows toward the cavity axis to form a protrusion, and the outlet inner wall surface of the other expanded head segment widens away from the cavity axis to form a recess.

[0045] Specifically, as shown in Figures 3 and 4, along the passage direction, the outlet outer wall surface of the first expansion head segment 112 gradually narrows toward the central axis of the cavity to form a protrusion 1121, and along the outlet inner wall surface of the second expansion head segment 122 gradually widens in the direction away from the central axis of the cavity to form a recess 1221, and the protrusion 1121 can enter into the recess 1221, thereby realizing the abutment of the ends of the first dilator 11 and the second dilator 12.

[0046] In some specific embodiments of the present invention, as shown in Figures 3 and 4, the gradually narrowing angle of the outlet outer wall surface of the first expanded head segment 112 relative to the cavity central axis is complementary to the gradually widening angle of the outlet inner wall surface of the second expanded head segment 122 in the direction away from the cavity central axis (the sum of the angles is 180°), thereby achieving a smooth transition of the outer wall surfaces after the two abut.

[0047] In some specific embodiments of the present invention, along the passing direction, the outer diameter of the rear end of the first expansion head segment 112 is equal to the outer diameter of the first bendable segment 111, and a smooth transition is made at the connection point between the two to avoid damage to the subcutaneous tissue. Similarly, the second expansion head segment 122 also uses the same installation method, and the technical effects thereof are the same, so the description here is omitted.

[0048] In some specific embodiments of the present invention, the lengths of the first and second extended head segments 112 and 112 along the direction of passage are independently 5 to 7 mm, and preferably are equal. Exemplary lengths may be 5 mm, 6 mm, 7 mm, etc.

[0049] The present invention does not particularly limit the materials of the first expandable head segment 112 and the second expandable head segment 122, and those skilled in the art can select them according to actual needs, for example, medical metal materials, medical polymer materials (e.g., polypropylene), etc. In some specific embodiments of the present invention, the first expandable head segment 112 and the second expandable head segment 122 are both made of polypropylene, and are integrally molded with the front ends of the first bendable segment 11 and the second bendable segment 21 via their rear ends, respectively.

[0050] Extended Tail Segment In some specific embodiments of the present invention, as shown in Figure 1, the two dilators each independently include an extended tail segment. The first dilator 1 includes a first extended tail segment 113, which is located at the rear end of the first bendable segment 111 along the passage direction, and both have the same outer diameter. Similarly, the second dilator 2 includes a second extended tail segment 123, which is located at the rear end of the second bendable segment 121, and both have the same outer diameter. The first extended tail segment 113 and the second extended tail segment 123 can be held by a medical professional and pushed to pass the two dilators through the subcutaneous tissue.

[0051] The present invention does not particularly limit the specific structures of the two dilator tail segments, and those skilled in the art can select them according to practice. In some specific embodiments of the present invention, the first dilator tail segment 113 has a cylindrical structure and its outer diameter is equal to that of the first bendable segment 111. Similarly, the second dilator tail segment 123 has a cylindrical structure and its outer diameter is equal to that of the second bendable segment 121. For each dilator, the outer diameter of the rear end of the dilator head segment, the outer diameter of the bendable segment, and the outer diameter of the dilator tail segment are all equal and have circular cross sections, which can reduce damage to subcutaneous tissue.

[0052] The present invention does not limit the lengths of the two extension tail segments individually, and those skilled in the art can select them according to their actual needs. In some specific embodiments of the present invention, the total length of the bendable segment and the extension tail segment of each dilator is equal, and both are 242 to 246 mm, for example, 242 mm, 244 mm, 246 mm, etc.

[0053] The present invention does not particularly limit the material of the extender tail segments, and those skilled in the art can select it according to actual needs, for example, medical metal materials, medical polymer materials (e.g., polypropylene), etc. In some specific embodiments of the present invention, the first extender tail segment 113 and the second extender tail segment 123 are both made of polypropylene (i.e., the entire dilator 1 is made of polypropylene), and are integrally molded with the first bendable segment 111 and the second bendable segment 121, respectively, with smooth surfaces to avoid damage to the subcutaneous tissue.

[0054] <Sleeve 2> The sleeve 2 secures the artificial blood vessel and introduces it into the U-shaped subcutaneous tunnel. The present invention does not particularly limit the specific structure of the sleeve 2, and those skilled in the art can select it according to actual needs. In one specific embodiment of the present invention, as shown in Figures 1 and 5, the sleeve 2 has a tubular structure with both ends open, and is fitted over the guide wire 3 so that it can be introduced into the U-shaped subcutaneous tunnel under the guidance of the guide wire 3. In this technical solution, the cavity of the sleeve 2 is the sleeve cavity 21, which can accommodate the artificial blood vessel. After the guide wire 3 is withdrawn, the artificial blood vessel is introduced into the sleeve cavity 21, thereby realizing the introduction of the artificial blood vessel into the U-shaped subcutaneous tunnel.

[0055] In some preferred embodiments of the present invention, the outer diameter of the sleeve 2 gradually increases (e.g., gradually increases in steps or uniformly) from the front end to the rear end along the passage direction, respectively matching the inner diameter of the dilator 1. In this technical means, the inner diameter of the sleeve 2 also gradually increases (e.g., gradually increases in steps or uniformly), and the cavity adjacent to its end is the sleeve cavity 21 for accommodating the artificial blood vessel.

[0056] In some preferred embodiments of the present invention, the outer diameter of the sleeve 2 gradually increases in stages from the front end to the rear end along the passage direction. For example, the sleeve 2 is configured by connecting three to five sub-sleeves with successively increasing outer diameters. In one specific embodiment of the present invention, the sleeve 2 is connected by three sub-sleeves. The outer diameter of the front segment is 4 mm, the outer diameter of the middle segment is 7 mm, and the outer diameter of the rear segment is 11 mm. The connection points of the three sub-sleeves are smoothly processed. In this technical solution, the inner diameter of the sleeve 2 also gradually increases in stages, corresponding to an installation method in which the outer diameter gradually increases in stages. Specifically, the inner diameter of the front segment is 2 mm, the inner diameter of the middle segment is 4 mm, and the inner diameter of the rear segment is 8 mm. The cavity of the rear segment is configured as the sleeve cavity 21 for accommodating the artificial blood vessel.

[0057] The present invention does not particularly limit the length of the sleeve 2, and those skilled in the art can select it according to actual needs.

[0058] The present invention does not particularly limit the material of the sleeve 2, and those skilled in the art can select it according to actual needs, and silicone is preferred.

[0059] <Guidewire 3> The present invention does not particularly limit the length of the guide wire 3, and those skilled in the art can select it according to actual needs.

[0060] The present invention does not particularly limit the diameter of the guide wire 3, and those skilled in the art can select it according to actual needs.

[0061] The present invention does not particularly limit the material of the guide wire 3, and those skilled in the art can select it according to actual needs, for example, medical metal material (e.g., stainless steel) or medical polymer material. In one specific embodiment of the present invention, the guide wire 3 is made of stainless steel.

[0062] The principle of operation of the subcutaneous tunneler assembly according to the present invention is as follows.

[0063] 1. A subcutaneous tunnel route is set in advance, and the curvature of the first dilator 11 and the second dilator 12 is adjusted in advance to fit the set route.

[0064] 2. An incision is made in the skin in front of the elbow joint, and then the first dilator 11 and the second dilator 12 are used to expand the subcutaneous tunnels on both sides of the skin incision and bring them together at their ends, ultimately forming a U-shaped subcutaneous tunnel.

[0065] 3. After the guide wire 3 is introduced into the two dilators, the first dilator 11 and the second dilator 12 are pulled out.

[0066] 4. The sleeve 2 is introduced into the U-shaped subcutaneous tunnel along the guide wire 3, and the guide wire 3 is then withdrawn.

[0067] 5. The artificial blood vessel is introduced into the sleeve 2, the end of the artificial blood vessel is exposed outside the sleeve 2 and fixed, the position of the sleeve 2 is slowly adjusted along the U-shaped subcutaneous tunnel, and the sleeve 2 is slowly pulled out, so that the artificial blood vessel is placed in the U-shaped subcutaneous tunnel and a U-shaped loop is formed.

[0068] The number of devices and processing scales described herein are for the purpose of simplifying the description of the invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

[0069] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications described in the specification and the embodiments, but can be fully applied to various fields suitable for the present invention, and other modifications can be easily realized by those skilled in the art. Therefore, without departing from the general concept defined by the claims and the scope of equivalents thereof, the present invention is not limited to the specific details and examples shown and described herein. [Explanation of symbols]

[0070] 1 Dilator 11 First Dilator 111 First bendable segment 112 First expansion head segment 1121 Protrusion 113 First Extended Tail Segment 12 Second dilator 121 Second bendable segment 122 Second Extended Head Segment 1221 recess 123 Second Extended Tail Segment 2 sleeves 21 Sleeve cavity 3 Guidewire

Claims

1. a dilator, a guidewire, and a sleeve; Two dilators are provided, each having a tubular structure with both ends open, each having an independently bendable segment, and the bendable segment is bent to conform the curved shape of each dilator to a predetermined path of the subcutaneous tunnel, and after the two dilators are respectively introduced subcutaneously, the ends come into contact with each other to form a continuously curved U-shaped subcutaneous tunnel; the guide wire is disposed in a communicating cavity formed by the two dilators to guide the sleeve into the U-shaped subcutaneous tunnel; The sleeve has a sleeve cavity that fits the artificial blood vessel to be introduced and accommodates the artificial blood vessel. A subcutaneous tunneler assembly for an artificial vascular arteriovenous fistula, comprising:

2. Each of the two dilators includes an enlarged head segment having a conical structure, and the rear end of the enlarged head segment is integrally formed with the front end of the bendable segment.

2. The subcutaneous tunneler assembly of claim 1.

3. The abutting ends of the two expansion head segments are respectively provided with matching protrusions and recesses.

3. The subcutaneous tunneler assembly of claim 2.

4. The outlet outer peripheral wall surface of one of the expanded head segments gradually narrows toward the central axis to form the protrusion, and the outlet inner peripheral wall surface of the other expanded head segment gradually widens in a direction away from the central axis to form the recess.

4. The subcutaneous tunneler assembly of claim 3.

5. Each of the two dilators includes an extended tail segment, the front end of which is integrally formed with the rear end of the bendable segment.

5. The subcutaneous tunneler assembly of claim 4.

6. In each of the dilators, the connection between the extended head segment and the bendable segment is a smooth transition, and the bendable segment and the extended tail segment have the same outer diameter.

6. The subcutaneous tunneler assembly of claim 5.

7. The material of the dilator is polypropylene. A subcutaneous tunneler assembly according to any one of claims 1 to 5.

8. The sleeve has a tubular structure with both ends open, is fitted onto the guide wire, and is guided by the guide wire to be introduced into the U-shaped subcutaneous tunnel. A subcutaneous tunneler assembly according to any one of claims 1 to 5.

9. The outer diameter of the sleeve gradually increases from the front end to the rear end, and is adapted to fit the inner diameters of the two dilators, respectively; The inner diameter of the sleeve gradually widens in steps from the front end to the rear end, and the sleeve cavity is located in the rear segment of the sleeve.

9. The subcutaneous tunneler assembly of claim 8.

10. The sleeve is a silicone tube.

10. The subcutaneous tunneler assembly of claim 9.

Images