Subcutaneous tunneller assembly for arteriovenous graft

Abstract

The present invention relates to the field of medical instruments, and in particular to a subcutaneous tunneller assembly for an arteriovenous graft, comprising dilators, a guide wire, and a sleeve. Two dilators are provided and each are of a tubular structure having openings at two ends and each have a bendable segment. The sleeve has a cavity matching a vascular graft. The guide wire is arranged in a communicated internal cavity formed by the abutment of the two dilators. The bendable segments respectively enable the two dilators to bend and deform to match a preset path of a subcutaneous tunnel, and the dilators are respectively placed subcutaneously via a skin incision, and then abut against each other by means of the end portions, such that a continuous curved U-shaped subcutaneous tunnel can be established, thereby reducing skin incisions, minimizing surgical trauma, and preventing concurrent infections. The sleeve can protect the vascular graft from coming into contact with the skin, and lower the risk of intraoperative infection; after placing the vascular graft into the sleeve, there is no need to adjust the position, thereby preventing bending, kinking, or angulation during the placement of the vascular graft.

Description

Subcutaneous tunnel assembly for artificial blood vessel arteriovenous fistula Technical Field

[0001] The invention belongs to the field of medical devices, and in particular relates to a subcutaneous tunnel device component for artificial blood vessel arteriovenous fistula. Background Art

[0002] Arteriovenous fistula surgery involves surgically anastomosing a patient's own limb artery (usually the radial or brachial artery) with a vein (usually the cephalic or basilic vein), arterializing the vein and creating an arteriovenous fistula. However, in practice, certain factors may affect the creation of a patient's own arteriovenous fistula, such as poor vascular conditions that prevent the fistula from being established or occlusion of an established arteriovenous fistula that prevents reestablishment. If these patients still need to continue hemodialysis treatment, they will need an artificial vascular arteriovenous fistula surgery, in which an artificial blood vessel is placed in a subcutaneous tunnel to connect the artery and vein.

[0003] If a U-shaped artificial vascular loop is formed, the conventional steps of internal fistula surgery are: first, the skin is cut at the intended anastomosis (anastomosis of the artificial blood vessel with the autologous artery and vein) (first incision), and a second incision (about 2 cm) is made at the intended position at the top of the artificial vascular loop. A tunnel device is used to penetrate through the first incision, move along the pre-designed tunnel route with a certain arc to the second incision for exit, and the artificial blood vessel is placed in the tunnel device. At this time, 50% of the artificial blood vessel placement is completed; second, the tunnel device is inserted through the second incision, and then move along the pre-designed tunnel route with a certain arc to the first incision for exit, completing the construction of the other 50% of the subcutaneous tunnel, and the remaining 50% of the artificial blood vessel is partially placed in the tunnel; finally, the two ends of the artificial blood vessel are anastomosed with the autologous artery and vein at the first incision and subsequent operations are performed.

[0004] It can be seen from this that if a conventional tunnel device is used to establish a U-shaped subcutaneous tunnel with a large degree of curvature, a second incision must be made at the top of the U-shaped tunnel path (the planned position of the top of the artificial vascular loop), which causes great surgical damage and is prone to postoperative infection; the artificial blood vessel needs to be tied to the tunnel device, which is relatively complicated and inefficient; the established subcutaneous tunnel is discontinuous, and the artificial blood vessel is easily twisted, folded or angled during insertion, and is easy to contact the skin, increasing the risk of infection; the tunnel device consists of a handle, inner rod, outer sheath and bullet, etc., and has many accessories.

[0005] Summary of the Invention

[0006] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and thereby provide a subcutaneous tunnel assembly for artificial vascular arteriovenous fistula. The use of the subcutaneous tunnel assembly can reduce surgical incisions when establishing a subcutaneous tunnel, facilitate the patient's postoperative recovery, and avoid infection at the second incision at the top of the artificial vascular loop. Moreover, the established subcutaneous tunnel is continuous, facilitating the placement of the artificial blood vessel.

[0007] In order to solve the above technical problems, the technical solution of the present invention is:

[0008] The present invention provides a subcutaneous tunnel device assembly for artificial blood vessel arteriovenous fistula, comprising a dilator, a guide wire and a cannula, wherein:

[0009] The dilators are provided in pairs, each of which is a cylindrical structure with openings at both ends, and each independently has a bendable section. The bendable section bends and deforms so that the curved shape of each dilator adapts to the preset path of the subcutaneous tunnel. After the two dilators are respectively placed subcutaneously, the ends abut against each other to establish a continuously curved U-shaped subcutaneous tunnel.

[0010] The guide wire is placed in the communicating inner cavity formed by the two dilators to guide the cannula into the U-shaped subcutaneous tunnel;

[0011] The sleeve has a sleeve cavity adapted to the artificial blood vessel to be placed therein, so as to accommodate the artificial blood vessel.

[0012] Preferably, in the subcutaneous tunneler assembly provided by the present invention, both of the two expanders include an expansion head section with a conical structure, and the rear end of the expansion head section and the front end of the bendable section are integrally formed.

[0013] Further preferably, in the subcutaneous tunneler assembly provided by the present invention, the abutting ends of the two expansion head sections are respectively provided with matching protrusions and recesses.

[0014] Further preferably, in the subcutaneous tunnel assembly provided by the present invention, the outer wall surface of the outlet of one expansion head section gradually shrinks toward the central axis to form the protrusion, and the inner wall surface of the outlet of the other expansion head section gradually expands away from the central axis to form the recessed portion.

[0015] Further preferably, in the subcutaneous tunneler assembly provided by the present invention, both of the two expanders include an expansion tail section, and the front end of the expansion tail section and the rear end of the bendable portion are integrally formed.

[0016] Preferably, in the subcutaneous tunneler assembly provided by the present invention, in each of the dilators, the connection portion between the dilator head section and the bendable section has a smooth transition, and the outer diameters of the bendable section and the dilator tail section are equal.

[0017] Preferably, in the subcutaneous tunnel assembly provided by the present invention, the expander is made of polypropylene.

[0018] Preferably, in the subcutaneous tunnel assembly provided by the present invention, the sleeve is a cylindrical structure with two ends open, so as to be sleeved on the guide wire and inserted into the U-shaped subcutaneous tunnel under the guidance of the guide wire.

[0019] Further preferably, in the subcutaneous tunnel assembly provided by the present invention, the outer diameter of the sleeve gradually expands from the front end to the rear end, and is respectively adapted to the inner diameters of the two dilators;

[0020] The inner diameter of the sleeve is gradually expanded from the front end to the rear end, and the sleeve cavity is located at the rear end of the sleeve.

[0021] Further preferably, in the subcutaneous tunnel assembly provided by the present invention, the sleeve is a silicone tube.

[0022] The technical solution of the present invention has the following advantages:

[0023] 1. The present invention provides a subcutaneous tunneling device assembly for an artificial arteriovenous fistula, comprising a dilator, a guidewire, and a cannula. The dilators are provided in pairs, each of which is a cylindrical structure with two open ends and a bendable portion. The guidewire is placed in the connecting lumen formed by the two dilators. The cannula has a sheath cavity adapted to accommodate the artificial blood vessel to be inserted.

[0024] This subcutaneous tunneling device utilizes a flexible segment that bends and deforms, allowing the two dilators to bend to match the pre-defined path of the subcutaneous tunnel (e.g., both dilators form a J-shape). After insertion through a skin incision (a first incision), the two dilators abut their ends, creating a continuous, curved, U-shaped subcutaneous tunnel. Compared to existing tunneling devices, this invention avoids the need for a second incision at the top of the U-shaped tunnel path (the intended location of the artificial vascular loop tip), resulting in minimal surgical trauma and the prevention of infection.

[0025] Moreover, the sheath can protect the artificial blood vessel from contacting the skin, reducing the risk of infection during surgery. At the same time, after the artificial blood vessel is placed in the sheath, there is no need to adjust the position in the middle, which can avoid bending, folding or angulation during the placement of the artificial blood vessel.

[0026] 2. In the subcutaneous tunneler assembly provided by the present invention, each expansion head has a conical structure, which can minimize damage to subcutaneous tissue when the expansion head passes through the subcutaneous tissue.

[0027] 3. In the subcutaneous tunnel assembly provided by the present invention, the outer diameters of the expansion tail section and the bendable portion of each expander are equal, which can reduce subcutaneous traction damage and alleviate patient pain. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] FIG1 is a schematic structural diagram of a subcutaneous tunnel assembly provided by an embodiment of the present invention;

[0030] FIG2 is a schematic diagram of the J-shaped structure of the expander in FIG1 ;

[0031] Figure 3 is a schematic diagram of the structure of the protruding portion and the recessed portion;

[0032] FIG4 is a schematic diagram of the structure of the protruding portion and the recessed portion in abutment state;

[0033] Figure 5 is a schematic diagram of the mantle structure;

[0034] Description of reference numerals:

[0035] 1-dilator; 11-first dilator; 111-first bendable section; 112-first dilator head section; 1121-protrusion; 113-first dilator tail section; 12-second dilator; 121-second bendable section; 122-second dilator head section; 1221-recess; 123-second dilator tail section;

[0036] 2-cannula; 21-cannula cavity;

[0037] 3-Guide wire. DETAILED DESCRIPTION

[0038] The present invention is described in further detail below in conjunction with the accompanying drawings. The above-mentioned and other purposes, features, aspects and advantages of the present invention will become more apparent so that those skilled in the art can implement them with reference to the text of the specification. In the accompanying drawings, for the sake of clarity, shapes and sizes may be exaggerated, and the same reference numerals will be used in all figures to indicate the same or similar parts. In the following description, words such as center, thickness, height, length, front, back, rear, left, right, top, bottom, top, bottom, etc. are based on the orientation or positional relationship shown in the accompanying drawings. In particular, "height" is equivalent to the size from top to bottom, "width" is equivalent to the size from left to right, and "depth" is equivalent to the size from front to back. These relative terms are for the sake of convenience of explanation and are generally not intended to require a specific orientation. Terms related to attachment, connection, etc. (e.g., "connection" and "attachment") refer to the relationship between these structures that are directly or indirectly fixed or attached to each other through an intermediate structure, as well as movable or rigid attachment or relationship, unless otherwise explicitly stated.

[0039] The present invention provides a subcutaneous tunnel device assembly for artificial blood vessel arteriovenous fistula, as shown in FIG1 , comprising a dilator 1, a cannula 2 and a guide wire 3.

[0040] The dilator 1 is a slender structure, and its function is to penetrate the subcutaneous tissue from the skin incision and expand the subcutaneous tissue along a preset path to form a subcutaneous tunnel, wherein the subcutaneous tunnel path can be linear or curved (such as U-shaped, etc.).

[0041] In the case where the subcutaneous tunnel path is U-shaped, when a conventional tunnel device is used to establish a subcutaneous tunnel, two skin incisions are usually required: a first incision (i.e., cutting the skin at the intended anastomosis between the artificial blood vessel and the autologous artery and vein) and a second incision (i.e., cutting the skin at the intended position at the top of the artificial blood vessel loop (the curved top of the U-shaped path)). The conventional tunnel device penetrates the subcutaneous tissue from the first incision and exits through the second incision, and then penetrates the subcutaneous tissue from the second incision and moves to the first incision to exit, so that the artificial blood vessel can be placed in the tunnel in sections. Therefore, there are at least the following defects when using a conventional tunnel device to establish a U-shaped subcutaneous tunnel: 1. An additional skin incision is added (the second incision, about 2 cm), resulting in large surgical losses and prone to infection; 2. The established subcutaneous tunnel is discontinuous, especially there is a dead angle at the second incision, and the artificial blood vessel is prone to twisting, folding or angulation during the placement process.

[0042] To solve this technical problem, the dilator 1 of the present invention is provided in two parts: a first dilator 11 and a second dilator 12. Moreover, the first dilator 11 and the second dilator 12 are each independently provided with a bendable section: the first dilator 11 includes a first bendable section 111, and the second dilator 12 includes a second bendable section 121. Under the action of an external force, the curvature of the first bendable section 111 and the second bendable section 121 can be adjusted arbitrarily, causing the first dilator 11 and the second dilator 12 to bend and deform respectively to adapt to the preset path of the subcutaneous tunnel, such as the first dilator 11 and the second dilator 12 to bend and deform simultaneously to form a J-shape, as shown in FIG2 . Therefore, when the first dilator 11 and the second dilator 12, both of which are J-shaped, are respectively inserted into the subcutaneous tissue through the first incision, a continuously curved U-shaped subcutaneous tunnel can be established by abutting the ends of the two, without the need for a second incision.

[0043] To facilitate the subcutaneous passage of the first dilator 11 and the second dilator 12, the two dilators each independently include a dilator head section. In the passage direction, the first dilator head section 112 is arranged at the front end of the first bendable section 111, and the second dilator head section 122 is arranged at the front end of the second bendable section 121.

[0044] In a specific embodiment of the present invention, the first expansion head section 112 and the second expansion head section 122 are both conical structures.

[0045] Because the subcutaneous tunnel is U-shaped, softer artificial blood vessels cannot pass through it on their own. Therefore, the present invention utilizes a cannula 2 to guide the artificial blood vessel through the U-shaped tunnel. Specifically, the cannula 2 is hollow and has a sheath cavity 21 for accommodating the artificial blood vessel to be inserted. The shape of this cavity matches the shape of the artificial blood vessel, thus securing the artificial blood vessel. Furthermore, when the artificial blood vessel is inserted into the established U-shaped subcutaneous tunnel, the cannula 2 prevents the artificial blood vessel from bending, kinking, or angling within the tunnel.

[0046] The U-shaped subcutaneous tunnel is established by abutting the expansion tips (first expansion tip section 112 and second expansion tip section 122) of two J-shaped dilators 1 (first dilator 11 and second dilator 12), with the diameter of the tubes at the two expansion tips becoming smaller. The present invention utilizes a guide wire 3 as a medium, first inserting it into the two J-shaped dilators 1, and then guiding the cannula 2 into the U-shaped subcutaneous tunnel. To this end, the first dilator 11 and the second dilator 12 are both cylindrical structures with open ends, and the guide wire 3 can be extended into the connecting inner lumens of the two to guide the cannula 2 into the U-shaped subcutaneous tunnel.

[0047] In the present invention, the dilator 1, the cannula 2 and the guide wire 3 cooperate with each other, and the respective bendable sections of the two dilators 1 are bent and deformed to adapt to the preset path of the subcutaneous tunnel, thereby establishing a continuously curved U-shaped subcutaneous tunnel. The guide wire 3 is placed in the connecting inner cavity formed by the above-mentioned two dilators 1 to guide the cannula 2 into the U-shaped subcutaneous tunnel. The cannula 2 has a sheath cavity 21 adapted to the artificial blood vessel to be inserted, which can accommodate the artificial blood vessel. During the process of inserting the artificial blood vessel into the U-shaped subcutaneous tunnel, the artificial blood vessel is protected from contacting the skin, reducing the risk of infection; and it can also adjust the position of the artificial blood vessel to prevent the artificial blood vessel from twisting, folding or angled in the U-shaped subcutaneous tunnel.

[0048] <Expander 1>

[0049] Bendable segment

[0050] The present invention does not particularly limit the structure of the bendable segment, and those skilled in the art may select a bendable segment according to actual needs, such as a circular or elliptical cross-section. In some preferred embodiments of the present invention, the first bendable segment 111 and the second bendable segment 121 both have circular cross-sections and smooth outer surfaces, thereby reducing damage to subcutaneous tissue.

[0051] The present invention does not impose any particular limitation on the material of the bendable segment, and those skilled in the art may select materials according to actual needs, such as medical metal materials, medical polymer materials (such as polypropylene), etc. In some preferred embodiments of the present invention, both of the above-mentioned bendable segments are made of polypropylene.

[0052] The present invention does not impose any special limitation on the length of the bendable segment, and those skilled in the art may select the length according to actual needs. The present invention does not impose any special limitation on the length of the bendable segment.

[0053] The present invention does not impose any particular limitation on the diameter of the bendable segment; those skilled in the art may select the diameter 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 between 8.9 and 9.1 mm. For example, the diameters of both segments are 8.9 mm, 9.0 mm, 9.1 mm, etc.

[0054] Expansion head

[0055] The present invention does not specifically limit the specific structure of the expansion tip segment. Those skilled in the art may select a conical structure or a polygonal pyramid structure according to actual needs. In some preferred embodiments of the present invention, both the first expansion tip segment 112 and the second expansion tip segment 122 are conical structures, which can reduce damage to subcutaneous tissue compared to a polygonal pyramid structure.

[0056] In some more preferred embodiments of the present invention, the first expansion head segment 112 and the second expansion head segment 122 are both blunt-ended conical structures, such as truncated cone structures, which can further reduce damage to subcutaneous tissue.

[0057] In some specific embodiments of the present invention, according to the direction of travel, the front end outer diameter of the first expansion head segment 112 is 4 to 6 mm. For example, the front end outer diameter can be 4 mm, 5 mm, 6 mm, etc.; the front end outer diameter of the second expansion head segment 122 is 4 to 6 mm. For example, the front end outer diameter can be 4 mm, 5 mm, 6 mm, etc.

[0058] In some specific embodiments of the present invention, according to the direction of travel, the minimum diameter of the front end of the first expansion head segment 112 is 2 to 4 mm. Exemplarily, the minimum diameter of the front end can be 2 mm, 3 mm, 4 mm, etc., preferably 2 mm; the minimum outer diameter of the front end of the second expansion head segment 122 is 2 to 4 mm. Exemplarily, the minimum outer diameter of the front end can be 2 mm, 3 mm, 4 mm, etc., preferably 4 mm.

[0059] In some specific embodiments of the present invention, as shown in Figures 3 and 4, the ends of the two expansion head sections for abutment are respectively provided with matching protrusions and recesses, and the matching of the protrusions and the recesses facilitates the abutment of the ends of the first expander 11 and the second expander 12.

[0060] In some specific embodiments of the present invention, the outer wall surface of the outlet of one expansion head section gradually shrinks toward the central axis of the inner cavity to form a bulge, and the inner wall surface of the outlet of another expansion head section gradually expands away from the central axis of the inner cavity to form a recess.

[0061] Specifically, as shown in Figures 3 and 4, along the direction of travel, the outer wall surface of the outlet of the first expansion head section 112 gradually shrinks toward the central axis of the inner cavity to form a protrusion 1121, and the outer wall surface of the outlet of the second expansion head section 122 gradually expands away from the central axis of the inner cavity to form a recessed portion 1221. The protrusion 1121 can extend into the recessed portion 1221, thereby realizing the abutment of the ends of the first expander 11 and the second expander 12.

[0062] In some specific embodiments of the present invention, as shown in Figures 3 and 4, relative to the central axis of the inner cavity, the tapering angle of the outer wall surface of the outlet of the first expansion head section 112 is complementary to the gradually expanding angle of the outer wall surface of the outlet of the second expansion head section 122 away from the central axis of the inner cavity (the sum of the angles is 180°), which can achieve a smooth transition of the outer wall surface after the two are abutted.

[0063] In some specific embodiments of the present invention, in the direction of travel, the rear end outer diameter of the first expansion head section 112 is equal to the outer diameter of the first bendable section 111, and a smooth transition is made at the connection between the two to avoid damage to the subcutaneous tissue; similarly, the second expansion head section 122 also adopts the same setting method, and the technical effect produced is also the same, which will not be repeated here.

[0064] In some specific embodiments of the present invention, the lengths of the first expansion head section 112 and the second expansion head section are independently 5 to 7 mm in the direction of travel, and are preferably equal in length. For example, the lengths may be 5 mm, 6 mm, 7 mm, etc.

[0065] The present invention does not impose any particular restrictions on the material of the first expansion tip section 112 and the second expansion tip section 122. Those skilled in the art may select materials according to actual needs, such as medical metal materials, medical polymer materials (e.g., polypropylene), etc. In some specific embodiments of the present invention, the first expansion tip section 112 and the second expansion tip section 122 are both made of polypropylene and are integrally formed with the first and second flexible portions 11 and 21 at their respective rear ends.

[0066] Expansion tail

[0067] In some specific embodiments of the present invention, as shown in Figure 1 , the two dilators each independently include an expansion tail segment: First dilator 1 includes a first expansion tail segment 113, which is positioned at the rear end of first bendable segment 111 in the direction of passage, and the two dilators have equal outer diameters. Similarly, second dilator 2 includes a second expansion tail segment 123, which is positioned at the rear end of second bendable segment 121, and the two dilators have equal outer diameters. First expansion tail segment 113 and second expansion tail segment 123 can be handheld by medical personnel to propel both dilators subcutaneously.

[0068] The present invention does not impose any particular limitations on the specific structures of the two expansion tail sections, and those skilled in the art may select a suitable structure based on practical needs. In some specific embodiments of the present invention, the first expansion tail section 113 is a cylindrical structure with an outer diameter equal to that of the first bendable section 111; similarly, the second expansion tail section 123 is a cylindrical structure with an outer diameter equal to that of the second bendable section 121. For each expander, the rear end outer diameter of the expansion head section, the outer diameter of the bendable section, and the outer diameter of the expansion tail section are all equal, and the cross-sections are all circular, which can reduce damage to subcutaneous tissue.

[0069] The present invention does not impose any specific limitation on the length of the two expansion tail segments, and those skilled in the art may select the length based on actual needs. In some specific embodiments of the present invention, the total length of the bendable segment and the expansion tail segment of each expander is equal, and is 242 to 246 mm. For example, the total length may be 242 mm, 244 mm, 246 mm, etc.

[0070] The present invention does not impose any particular restrictions on the material of the aforementioned expansion tail segment. Materials such as medical metals and medical polymers (e.g., polypropylene) can be selected based on practical needs in the art. In some specific embodiments of the present invention, both the first expansion tail segment 113 and the second expansion tail segment 123 are made of polypropylene (i.e., the entire material of the expander 1 is polypropylene), and are integrally formed with the first bendable segment 111 and the second bendable segment 121, respectively. The surfaces are smoothed to prevent damage to the subcutaneous tissue.

[0071] <Casing 2>

[0072] The cannula 2 is used to fix the artificial blood vessel so as to introduce the artificial blood vessel into the U-shaped subcutaneous tunnel. The present invention does not particularly limit the specific structure of the cannula 2, and those skilled in the art can select it according to actual needs. In a specific embodiment of the present invention, as shown in Figures 1 and 5, the cannula 2 is a cylindrical structure with openings at both ends, which can be sleeved on the guide wire 3 and inserted into the above-mentioned U-shaped subcutaneous tunnel under the guidance of the guide wire 3. In this solution, the inner cavity of the cannula 2 serves as a mantle cavity 21, which can accommodate the artificial blood vessel. After the guide wire 3 is withdrawn, the artificial blood vessel is inserted into the mantle cavity 21, thereby achieving the insertion of the artificial blood vessel into the U-shaped subcutaneous tunnel.

[0073] In some preferred embodiments of the present invention, the outer diameter of the cannula 2 gradually expands from the front end to the rear end (e.g., gradually or evenly) in the direction of travel to match the inner diameter of the dilator 1. In this embodiment, the inner diameter of the cannula 2 also gradually expands (e.g., gradually or evenly), with the inner lumen near the rear end serving as the mantle lumen 21 for accommodating the artificial blood vessel.

[0074] In some more preferred embodiments of the present invention, the outer diameter of the sleeve 2 shows a trend of gradually expanding from the front end to the rear end in the direction of travel, such as being formed by connecting 3 to 5 sections of sub-sleeves with successively increasing outer diameters. In a specific embodiment of the present invention, the sleeve 2 is formed by connecting three sections of sub-sleeves: the outer diameter of the front section is 4 mm, the outer diameter of the middle section is 7 mm, and the outer diameter of the rear section is 11 mm. The connection between the three sections of sub-sleeves is smoothed. In this solution, the inner diameter of the sleeve 2 also shows a trend of gradually expanding, and corresponds to the setting method of gradually expanding the outer diameter, specifically: the inner diameter of the front section is 2 mm, the inner diameter of the middle section is 4 mm, and the inner diameter of the rear section is 8 mm. The inner cavity of the rear section serves as the sleeve cavity 21 for accommodating the artificial blood vessel.

[0075] The present invention does not impose any particular limitation on the length of the sleeve 2, and those skilled in the art can select the length according to actual needs.

[0076] The present invention does not impose any particular limitation on the material of the sleeve 2 , and those skilled in the art may select the material according to actual needs, with silicone being preferred.

[0077] <Guidewire 3>

[0078] The present invention does not impose any particular limitation on the length of the guide wire 3 , and those skilled in the art may select the length according to actual needs.

[0079] The present invention does not impose any particular limitation on the diameter of the guide wire 3 , and those skilled in the art may select the diameter according to actual needs.

[0080] The present invention does not specifically limit the material of the guide wire 3. Those skilled in the art can select according to actual needs, such as medical metal materials (such as stainless steel) and medical polymer materials. In a specific embodiment of the present invention, the guide wire 3 is made of stainless steel.

[0081] The working principle of the subcutaneous tunnel assembly provided by the present invention is:

[0082] 1. Preset the subcutaneous tunnel path and pre-adjust the curvature of the first dilator 11 and the second dilator 12 to adapt to the preset path.

[0083] 2. Make a skin incision in front of the elbow joint, then use the first dilator 11 and the second dilator 12 to expand the subcutaneous tunnels on both sides of the skin incision respectively and abut the ends to finally form a U-shaped subcutaneous tunnel.

[0084] 3. Insert the guide wire 3 into the two dilators, and then remove the first dilator 11 and the second dilator 12 respectively.

[0085] 4. Insert cannula 2 along guide wire 3 into the U-shaped subcutaneous tunnel and remove guide wire 3.

[0086] 5. Place the artificial blood vessel into the cannula 2. The tail end of the artificial blood vessel must be exposed outside the cannula 2 and fixed. Slowly adjust the position of the cannula 2 along the U-shaped subcutaneous tunnel and slowly pull out the cannula 2 so that the artificial blood vessel is placed in the U-shaped subcutaneous tunnel to form a U-shaped loop.

[0087] The number of devices and processing scales described herein are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

[0088] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with this field, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A subcutaneous tunnel assembly for artificial blood vessel arteriovenous fistula, characterized in that: It includes a dilator, a guide wire and a cannula, wherein: The dilators are provided in two pieces, both of which are cylindrical structures with openings at both ends, and each of which has an independent bendable section, and the bendable section is bent and deformed so that the bending shape of each dilator is adapted to the preset path of the subcutaneous tunnel. After the two dilators are respectively placed subcutaneously, the ends thereof are abutted to establish a continuous curved U-shaped subcutaneous tunnel; The guide wire is placed in the communicating inner cavity formed by the two dilators to guide the cannula into the U-shaped subcutaneous tunnel; The sleeve has a sleeve cavity adapted to the artificial blood vessel to be inserted so as to accommodate the artificial blood vessel.

2. The subcutaneous tunnel assembly according to claim 1, characterized in that: The two expanders both include an expansion head section with a conical structure, and the rear end of the expansion head section is integrally formed with the front end of the bendable section.

3. The subcutaneous tunnel assembly according to claim 2, characterized in that: The ends of the two expansion head sections for abutment are respectively provided with matching protrusions and recesses.

4. The subcutaneous tunnel assembly according to claim 3, characterized in that: The outer wall surface of the outlet of one expansion head section gradually contracts toward the central axis to form the protruding portion, and the inner wall surface of the outlet of the other expansion head section gradually expands away from the central axis to form the recessed portion.

5. The subcutaneous tunnel assembly according to claim 4, characterized in that: The two expanders both include an expansion tail section, and the front end of the expansion tail section is integrally formed with the rear end of the bendable portion.

6. The subcutaneous tunnel assembly according to any one of claims 1 to 5, characterized in that: In each of the expanders, the connection portion between the expansion head section and the bendable section has a smooth transition, and the outer diameters of the bendable section and the expansion tail section are equal.

7. The subcutaneous tunnel assembly according to any one of claims 1 to 5, characterized in that: The material of the expander is polypropylene.

8. The subcutaneous tunneler assembly according to any one of claims 1 to 5, characterized in that: The sleeve is a cylindrical structure with two ends opened, so as to be sleeved on the guide wire and inserted into the U-shaped subcutaneous tunnel under the guidance of the guide wire.

9. The subcutaneous tunnel assembly according to claim 8, characterized in that: The outer diameter of the sleeve gradually expands from the front end to the rear end, and is respectively adapted to the inner diameters of the two dilators; The inner diameter of the sleeve gradually expands from the front end to the rear end, and the sleeve cavity is located at the rear section of the sleeve.

10. The subcutaneous tunneler assembly according to claim 9, characterized in that: The sleeve is a silicone tube.

Images