Degradable drainage pipeline, preparation method and use method

Abstract

The invention discloses a degradable drainage pipeline, a preparation method and a use method, and relates to the technical field of medical instruments. One end of the drainage pipeline is connected with the nasobiliary duct body, the other end of the drainage pipeline is connected with the biliary stent, the drainage pipeline has the characteristic of controllable self-dissolution, and the drainage pipeline comprises a first branch part, a second branch part and a pipeline connecting body; the first branch part and the second branch part are of an integrally-formed net-shaped hollow structure, and the outer diameter of the first branch part and the outer diameter of the second branch part are kept consistent with the inner diameter of the donor biliary tract and the inner diameter of the receptor biliary tract respectively. The beneficial conveying assembly is arranged on the outer surface of the joint of the first branch part and the second branch part, and the inner surface of the first branch part and the inner surface of the second branch part are provided with covering films; one end of the drainage pipeline is a biliary stent, the other end of the drainage pipeline is a nasobiliary duct, connecting parts are connected through a dissoluble material which can be controlled manually and has certain supporting strength, and the dissoluble material is harmless to the human body after being dissolved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a degradable drainage conduit, a preparation method and a use method thereof. Background Art

[0002] Placing a bile duct stent or nasobiliary stent in the bile duct can relieve bile duct stenosis or blockage caused by tumor infiltration, stone obstruction, acute cholangitis, etc., drain bile in time, and prevent jaundice, acute aggravation of infection, secondary infectious shock, and even death.

[0003] For patients with long-term cholestatic jaundice caused by various causes, bile viscosity and bile thrombosis may cause stent obstruction after placing a biliary stent alone. Placing a nasobiliary duct alone can better drain bile and flush the bile duct, and is less likely to cause duct obstruction. However, after the condition improves, a biliary stent may need to be placed again, which increases medical expenses and aggravates the patient's pain. Placing a biliary stent and a nasobiliary duct at the same time can solve the problems of bile duct patency and bile obstruction, but there is a problem that the biliary stent may be removed when the nasobiliary duct is removed, and there are the following disadvantages:

[0004] 1. Traditional metal stents are commonly nickel-titanium alloy biliary stents. In addition to being non-cytotoxic and having good biocompatibility, corrosion resistance, and superelasticity, nickel-titanium alloy biliary stents also have a special memory function, that is, they are in a contracted state at the martensite phase temperature and return to an extended state at the austenite phase temperature, which makes the nickel-titanium memory alloy have good self-expansion. However, the long-term placement of nickel-titanium alloy biliary stents may increase the difficulty of stent removal due to the hyperplasia of biliary epithelial tissue, and local abnormal bile duct wall tissue (mainly biliary malignant tumors) may grow into the lumen through the mesh of the nickel-titanium alloy biliary stent and cause obstruction again.

[0005] 2. Plastic stents are relatively cheap, easy to replace, and have certain wear resistance, fatigue resistance, elasticity, anticoagulant and biocompatibility. However, the incidence of bile duct re-obstruction is high in a short period of time after the use of plastic stents. This is mainly due to the deposition of bacteria (aerobic and anaerobic bacteria) and cell biofilm formed by sticky protein-like substances on the surface of the stent, as well as the bile sludge formed by the aggregation of calcium bilirubin and calcium palmitate. It is also related to the shape design of the stent and the material of the stent. Usually, the obstruction rate of plastic stents is 30% after 3 months of implantation, and the obstruction rate is about 70% after 6 months. The main reason for the re-obstruction of plastic stents is that the plastic stent itself can only maintain its mechanical properties if it maintains a smaller caliber.

[0006] Therefore, it is necessary to invent a degradable drainage tube, a preparation method and a use method to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a degradable drainage tube, a preparation method and a use method to solve the problem proposed in the above background technology that placing a biliary stent and a nasobiliary duct at the same time can solve the problem of bile duct patency and bile obstruction, but there is a problem that the biliary stent may be removed when the nasobiliary duct is removed.

[0008] To achieve the above object, the present invention provides the following technical solution: a degradable drainage tube, one end of which is connected to the nasobiliary body, and the other end of which is connected to the biliary stent, and the drainage tube has the characteristic of controllable self-dissolution, and the drainage tube comprises:

[0009] A first branch, a second branch, and a pipeline connector; the first branch and the second branch are an integrally formed mesh hollow structure, and the outer diameters of the first branch and the second branch are respectively consistent with the inner diameters of the donor bile duct and the recipient bile duct;

[0010] The conveying component is arranged on the outer surface of the connection between the first branch and the second branch, and the inner surfaces of the first branch and the second branch are provided with a coating; the conveying component includes a fixed ring body, the fixed ring body is in a circular ring shape, the fixed ring body is fixedly connected to the connection between the first branch and the second branch, and the outer ring of the fixed ring body is a smooth surface.

[0011] Preferably, one end of the first branch away from the fixed ring body is fixedly connected to an arc-shaped circle, and the outer circle of the arc-shaped circle is chamfered.

[0012] Preferably, the top of the fixed ring body is fixedly connected to a circular arc guide rail, the outside of the circular arc guide rail is connected to a rotating ring body, and the outer ring of the rotating ring body is fixedly connected to a plurality of connecting rods;

[0013] The bottom of the connecting rod is fixedly connected with a connecting column, the bottom of the connecting column is fixedly connected with an arc-shaped force-bearing baffle, and the arc-shaped force-baffle and the fixed ring body are mutually fitted; and a guide fin is arranged on the outer side of the arc-shaped force-baffle.

[0014] Preferably, the second branch and the nasobiliary body are in contact with each other, and the second branch and the nasobiliary body are fixedly connected via a pipe connector.

[0015] Preferably, the pipe connector is in a ring shape, is fixedly connected between the second branch and the nasobiliary duct body, and is made of aluminum metal material.

[0016] Preferably, the first branch, the second branch, the arc-shaped circle, and the interior of the nasobiliary duct body are interconnected.

[0017] Preferably, the thickness of the coating is 0.1 mm; the surface of the coating is coated with a layer of drug coating, and the drug coating includes: rapamycin, everolimus, tacrolimus, and paclitaxel.

[0018] Preferably, the side length of the grid unit of the net-like hollow structure on the first branch and the second branch is 0.1 mm; the length of the first branch and the second branch are both 20 mm, the thickness of the first branch and the second branch are both 0.3 mm, and the coating covers the area within 10 mm above and below the connection.

[0019] A preparation method, comprising the above-mentioned degradable drainage tube; and also comprising the following preparation method:

[0020] (1) preparing a medical polyurethane into an electrospinning solution; dissolving the medical polyurethane in a solvent, stirring at room temperature for 5 to 8 hours, and obtaining a uniform solution with a concentration of 3% to 15%, wherein the solvent is any one of dioxane, dimethylformamide, tetrahydrofuran and dimethylformamide;

[0021] (2) The electrospinning solution obtained in the above step is sucked into the spinning solution tube for electrospinning, and a mold rod with a smooth surface and the same diameter as the inner diameter of the mesh bile duct stent is fixed on a speed-adjustable rotating body, the rotating speed of the rotating body is 50 rpm-2000 rpm, the high-voltage power supply of the electrospinning outputs a voltage of 5KV-30KV, the distance between the nozzle of the spinning solution tube and the mold rod is 5cm-30cm, the electrospinning solution is pushed out at a speed of 0.04m / hour-3m / hour, and the electrospinning is performed for 1 hour-15 hours to obtain an electrospun nonwoven inner membrane with a thickness of 2um-15um;

[0022] (3) The selected mesh metal mesh bile duct stent is placed on the mold rod covered with the inner membrane, and the coating is allowed to completely set.

[0023] A method of use, comprising the above-mentioned degradable drainage tube; and also comprising the following method of use:

[0024] (1) The first and second branches of different sizes are used according to the needs, and the film covers the area within 10 mm above and below the connection. In actual use, the range of the film covering the connection can be determined according to the needs;

[0025] (2) The whole structure is inserted into the human body through the nasal cavity. During the insertion process, when the rotating ring body is subjected to forward resistance, the rotating ring body rotates inside the circular arc guide rail, thereby driving the arc-shaped force-bearing slider to rotate, converting the resistance into a rotational force, so as to facilitate the insertion, so that the whole structure is smoothly inserted into the predetermined position and placed successfully;

[0026] (3) After the drainage operation is completed, when the nasobiliary duct needs to be removed, a special substance that can dissolve the material of the connection site is injected into the nasobiliary duct. Subsequently, the drainage tube at the connection site between the nasobiliary duct and the biliary stent is broken, and the nasobiliary duct is removed. The broken drainage tube is exposed to the liquid metal of eutectic gallium indium and quickly disintegrates.

[0027] Technical effects and advantages of the present invention:

[0028] 1. In order to solve the above clinical problems, the present invention designs an integral structure having both bile duct stent and nasobiliary drainage and flushing functions. One end of the device is a bile duct stent and the other end is a nasobiliary duct. The connection parts are connected by a soluble material that can be controlled artificially and has a certain supporting strength. The material is harmless to the human body after dissolution.

[0029] 2. The present invention inserts the bile duct and retains the nasobiliary duct. When the clinical condition is stable and the nasobiliary duct needs to be removed, the eutectic gallium indium liquid metal is injected into the nasobiliary duct into a special soluble connection material. Subsequently, the connection between the nasobiliary duct and the biliary stent is broken and the nasobiliary duct is removed. The connection between the nasobiliary duct and the biliary stent is a drainage duct made of special materials such as aluminum, which can be quickly disintegrated when exposed to the eutectic gallium indium liquid metal; the problems of difficult removal and re-obstruction of traditional stents are solved.

[0030] 3. The preparation method proposed in the present invention is a method for preparing a coated metal stent, which is to coat the surface of the original stent with a layer of organic film (complete coverage and partial coverage) with good compatibility and anti-bacterial adhesion, so that the coated stent has the characteristics of being able to be removed and replaced and effectively preventing tumors from growing into the stent. The incidence of postoperative pancreatitis in the non-membrane group and the coated group was 13.6% and 1.5%, and the incidence of postoperative cholecystitis was 11.9% and 1.5%, respectively. The median survival time was 389 days, and the median stent patency time was 368 days. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 It is an exploded schematic diagram of the overall structure of the present invention and the nasobiliary body and biliary stent structure.

[0033] Figure 2 It is an axial schematic diagram of the overall structure of the present invention.

[0034] Figure 3 It is a schematic diagram of the fixed ring structure of the present invention.

[0035] Figure 4 It is a schematic diagram of the structure of the arc-shaped force-bearing baffle of the present invention.

[0036] In the figure: 1. first branch; 2. second branch; 3. arc-shaped circle; 4. fixed ring body; 5. biliary stent; 6. pipeline connector; 7. nasobiliary body; 8. arc guide rail; 9. rotating ring body; 10. connecting rod; 11. connecting column; 12. arc-shaped force baffle; 13. guide fin. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The present invention provides Figure 1-Figure 4 A degradable drainage duct is shown, one end of which is connected to the nasobiliary body 7, and the other end of which is connected to the biliary stent 5. The drainage duct has the characteristic of controllable self-dissolution. Specifically, the drainage duct is connected by a soluble material that can be controlled artificially and has a certain supporting strength. The material is harmless to the human body after dissolution. The products made of aluminum and other alloy elements are usually first processed into castings, forgings, foils, plates, strips, tubes, rods, profiles, etc., and then made through processes such as cold bending, sawing, drilling, assembly, and coloring. The main metal element is aluminum, and some alloy elements are added to improve the performance of the aluminum material.

[0039] The drainage conduit comprises: a first branch 1, a second branch 2, and a conduit connector 6; the first branch 1 and the second branch 2 are an integrally formed mesh hollow structure, and the outer diameters of the first branch 1 and the second branch 2 are respectively consistent with the inner diameters of the donor bile duct and the recipient bile duct;

[0040] The conveying component is convenient for conveying, and the conveying component is arranged on the outer surface of the connection between the first branch 1 and the second branch 2, and the inner surfaces of the first branch 1 and the second branch 2 are provided with a coating; the conveying component includes a fixed ring body 4, the fixed ring body 4 is in a circular ring shape, and the fixed ring body 4 is fixedly connected to the connection between the first branch 1 and the second branch 2, and the outer ring of the fixed ring body 4 is a smooth surface to facilitate sliding.

[0041] The end of the first branch 1 away from the fixed ring body 4 is fixedly connected to an arc-shaped enclosure 3, and a chamfer is provided at the outer circle of the arc-shaped enclosure 3. The top of the fixed ring body 4 is fixedly connected to an arc guide rail 8, and the outside of the arc guide rail 8 is connected to a rotating ring body 9, and the outer circle of the rotating ring body 9 is fixedly connected to a plurality of connecting rods 10; the bottom of the connecting rod 10 is fixedly connected to a connecting column 11, and the bottom of the connecting column 11 is fixedly connected to an arc-shaped force-bearing baffle 12, and the arc-shaped force-bearing baffle 12 fits with the fixed ring body 4; the outer side of the arc-shaped force-baffle 12 is provided with a guide fin 13; the conveying assembly is provided, and during the process of the overall structure being inserted into the human body, the rotating ring body 9 can generate self-rotation when subjected to forward resistance. Specifically, the rotating ring body 9 rotates inside the arc guide rail 8, thereby driving the arc-shaped force-bearing slider 12 to rotate, converting the resistance into rotational force, so as to facilitate the insertion, so that the overall structure can be smoothly inserted into the predetermined position and placed successfully;

[0042] The second branch 2 and the nasobiliary body 7 are fitted together, and the second branch 2 and the nasobiliary body 7 are fixedly connected by a pipe connector 6. The pipe connector 6 is in a circular ring shape, and the pipe connector 6 is fixedly connected between the second branch 2 and the nasobiliary body 7. The pipe connector 6 is made of aluminum metal material.

[0043] The first branch 1, the second branch 2, the arc-shaped circle 3, and the interior of the nasobiliary body 7 are interconnected. The thickness of the coating is 0.1 mm; a drug coating is coated on the surface of the coating, and the drug coating includes: rapamycin, everolimus, tacrolimus, and paclitaxel. The side length of the grid unit of the reticular hollow structure on the first branch 1 and the second branch 2 is 0.1 mm; the length of the first branch 1 and the second branch 2 is consistent with 20 mm, and the thickness of the first branch 1 and the second branch 2 is consistent with 0.3 mm, and the coating covers the area within 10 mm above and below the connection.

[0044] This embodiment also discloses a preparation method, including the above-mentioned degradable drainage tube; and also includes the following preparation method: (1) preparing medical polyurethane into an electrospinning solution; dissolving the medical polyurethane in a solvent, stirring at room temperature for 5 hours to 8 hours, and obtaining a uniform solution with a concentration percentage of 3% to 15%, wherein the solvent is any one of dioxane, dimethylformamide, tetrahydrofuran and dimethylformamide;

[0045] (2) The electrospinning solution obtained in the above step is sucked into the spinning solution tube for electrospinning, and a mold rod with a smooth surface and the same diameter as the inner diameter of the mesh bile duct stent is fixed on a speed-adjustable rotating body, the rotating speed of the rotating body is 50 rpm-2000 rpm, the high-voltage power supply of the electrospinning outputs a voltage of 5KV-30KV, the distance between the nozzle of the spinning solution tube and the mold rod is 5cm-30cm, the electrospinning solution is pushed out at a speed of 0.04m / hour-3m / hour, and the electrospinning is performed for 1 hour-15 hours to obtain an electrospun nonwoven inner membrane with a thickness of 2um-15um;

[0046] (3) The selected mesh metal mesh bile duct stent is mounted on a mold rod covered with an inner membrane, and the coating is allowed to take shape completely. The preparation method proposed in the present invention is a method for preparing a coated metal stent, which is to coat the surface of the original stent with an organic film (completely covered or partially covered) with good compatibility and preventing bacterial adhesion, so that the coated stent has the characteristics of being able to remove and replace the stent and effectively preventing tumors from growing into the stent. The incidence of postoperative pancreatitis in the non-membrane group and the coated group was 13.6% and 1.5%, and the incidence of postoperative cholecystitis was 11.9% and 1.5%, respectively. The median survival time was 389 days, and the median stent patency time was 368 days.

[0047] This embodiment also discloses a method of use, including the above-mentioned degradable drainage tube; and further comprising the following: (1) using a first branch 1 and a second branch 2 of different sizes according to needs, and the film covers an area within 10 mm above and below the connection. In actual use, the range of the film covering the connection can be determined according to needs;

[0048] (2) The whole structure is inserted into the human body through the nasal cavity. During the insertion process, when the rotating ring body 9 is subjected to forward resistance, the rotating ring body 9 rotates inside the circular arc guide rail 8, thereby driving the arc-shaped force-bearing slider 12 to rotate, converting the resistance into a rotational force to facilitate the insertion, so that the whole structure is smoothly inserted into the predetermined position and placed successfully;

[0049] (3) After the drainage operation is completed, when the nasobiliary duct needs to be removed, a special substance that can dissolve the material of the connection site is injected into the nasobiliary duct. Subsequently, the drainage tube at the connection site between the nasobiliary duct and the biliary stent is broken, and the nasobiliary duct is removed. The broken drainage tube is exposed to the liquid metal of eutectic gallium indium and quickly disintegrates.

[0050] In order to solve the technical problems in the background technology, the present invention designs an overall structure that has both bile duct stent and nasobiliary drainage and flushing functions. One end of the device is a bile duct stent 5 and the other end is a nasobiliary duct. The connection parts are connected by a soluble material that can be controlled artificially and has a certain supporting strength. The material is harmless to the human body after dissolving. The present invention inserts the bile duct and retains the nasobiliary duct. When the clinical assessment shows that the condition is stable and the nasobiliary duct needs to be removed, the eutectic gallium indium liquid metal is injected into the nasobiliary duct body 7 into a special substance that can dissolve the material of the connection part. Then the connection part between the nasobiliary duct body 7 and the biliary stent 5 is broken, and the nasobiliary duct body 7 is removed. The connection part between the nasobiliary duct body 7 and the biliary stent 5 is a drainage pipe made of a special material such as aluminum. Hydraulic metal is an amorphous, flowable liquid metal, which can be regarded as a mixture of positive ion fluid and free electron gas. The liquid metal is a deformable body. The eutectic gallium indium liquid metal is an unconventional ultra-light material composed of hollow glass microspheres and gallium indium eutectic. When the liquid metal and water complex is controlled by an electric field, it can be converted between various forms and movement modes. The liquid metal can swallow a small amount of aluminum material. This characteristic can be used to quickly decompose the material pipeline connector 6. In the present invention, it can be quickly disintegrated when exposed to the eutectic gallium indium liquid metal; the problems of difficult removal and re-obstruction of traditional stents are solved.

[0051] Any numerical value cited herein includes all values ​​of lower and upper values ​​that increase by one unit from the lower limit to the upper limit, and there is at least a two-unit interval between any lower value and any higher value. For example, if the value of the quantity of a component or a process variable (such as temperature, pressure, time, etc.) is stated to be from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in this specification. For values ​​less than 1, one unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly stated in this specification in a similar manner.

[0052] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0053] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." to describe a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to indicate that any attribute described that "may" include is optional.

[0054] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0055] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by such claims. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the inventors did not consider the subject matter to be part of the disclosed inventive subject matter.

Claims

1. A degradable drainage duct, one end of which is connected to a nasobiliary duct body (7), and the other end of which is connected to a biliary stent (5), characterized in that: The drainage conduit has the characteristic of controllable self-dissolution, and the drainage conduit comprises: A first branch (1), a second branch (2), and a pipeline connector (6); the first branch (1) and the second branch (2) are an integrally formed reticular hollow structure, and the outer diameters of the first branch (1) and the second branch (2) are respectively consistent with the inner diameters of the donor bile duct and the recipient bile duct; The conveying component is arranged on the outer surface of the connection between the first branch (1) and the second branch (2), and the inner surfaces of the first branch (1) and the second branch (2) are provided with a coating; the conveying component comprises a fixed ring body (4), the fixed ring body (4) is in a circular ring shape, the fixed ring body (4) is fixedly connected to the connection between the first branch (1) and the second branch (2), and the outer ring of the fixed ring body (4) is a smooth surface.

2. A degradable drainage tube according to claim 1, characterized in that: An end of the first branch (1) away from the fixed ring body (4) is fixedly connected to an arc-shaped enclosure (3), and a chamfer is provided at the outer circle of the arc-shaped enclosure (3).

3. The degradable drainage tube according to claim 1, characterized in that: The top of the fixed ring body (4) is fixedly connected to a circular arc guide rail (8), the outside of the circular arc guide rail (8) is connected to a rotating ring body (9), and the outer ring of the rotating ring body (9) is fixedly connected to a plurality of connecting rods (10); The bottom of the connecting rod (10) is fixedly connected to a connecting column (11), the bottom of the connecting column (11) is fixedly connected to an arc-shaped force-bearing baffle (12), and the arc-shaped force-bearing baffle (12) and the fixed ring body (4) are mutually fitted; and a guide fin (13) is provided on the outer side of the arc-shaped force-baffle (12).

4. The degradable drainage tube according to claim 1, characterized in that: The second branch (2) and the nasobiliary main body (7) are in contact with each other, and the second branch (2) and the nasobiliary main body (7) are fixedly connected via a pipe connector (6).

5. The degradable drainage tube according to claim 1, characterized in that: The pipeline connector (6) is in the shape of a ring. The pipeline connector (6) is fixedly connected between the second branch (2) and the nasobiliary main body (7). The pipeline connector (6) is made of aluminum metal material.

6. The degradable drainage tube according to claim 1, characterized in that: The first branch (1), the second branch (2), the arc-shaped circle (3), and the interior of the nasobiliary duct body (7) are interconnected.

7. The degradable drainage tube according to claim 1, characterized in that: The thickness of the coating is 0.1 mm; a drug coating is coated on the surface of the coating, and the drug coating includes: rapamycin, everolimus, tacrolimus, and paclitaxel.

8. The degradable drainage tube according to claim 1, characterized in that: The side length of the grid unit of the net-like hollow structure on the first branch (1) and the second branch (2) is 0.1 mm; the length of the first branch (1) and the second branch (2) is the same as 20 mm, the thickness of the first branch (1) and the second branch (2) is the same as 0.3 mm, and the coating covers the area within 10 mm above and below the connection.

9. A preparation method, comprising a degradable drainage tube as claimed in claims 1 to 8; and further comprising the following preparation method: (1) preparing a medical polyurethane into an electrospinning solution; dissolving the medical polyurethane in a solvent, stirring at room temperature for 5 to 8 hours, and obtaining a uniform solution with a concentration of 3% to 15%, wherein the solvent is any one of dioxane, dimethylformamide, tetrahydrofuran and dimethylformamide; (2) The electrospinning solution obtained in the above step is sucked into the spinning solution tube for electrospinning, and a mold rod with a smooth surface and the same diameter as the inner diameter of the mesh bile duct stent is fixed on a speed-adjustable rotating body, the rotating speed of the rotating body is 50 rpm-2000 rpm, the high-voltage power supply of the electrospinning outputs a voltage of 5KV-30KV, the distance between the nozzle of the spinning solution tube and the mold rod is 5cm-30cm, the electrospinning solution is pushed out at a speed of 0.04m / hour-3m / hour, and the electrospinning is performed for 1 hour-15 hours to obtain an electrospun nonwoven inner membrane with a thickness of 2um-15um; (3) The selected mesh metal mesh bile duct stent is placed on the mold rod covered with the inner membrane, and the coating is allowed to completely set.

10. A method of use, comprising a degradable drainage tube as claimed in claims 1 to 8; and further comprising the following method of use: (1) The first support 1 and the second support 2 of different sizes are used according to the needs, and the film covers the area within 10 mm above and below the connection. In actual use, the range of the film covering the connection can be determined according to the needs; (2) The whole structure is inserted into the human body through the nasal cavity. During the insertion process, when the rotating ring body 9 is subjected to forward resistance, the rotating ring body 9 rotates inside the circular arc guide rail 8, thereby driving the arc-shaped force-bearing slider 12 to rotate, converting the resistance into a rotational force to facilitate the insertion, so that the whole structure is smoothly inserted into the predetermined position and placed successfully; (3) After the drainage operation is completed, when the nasobiliary duct needs to be removed, a special substance that can dissolve the material of the connection site is injected into the nasobiliary duct. Subsequently, the drainage tube at the connection site between the nasobiliary duct and the biliary stent is broken, and the nasobiliary duct is removed. The broken drainage tube is exposed to the liquid metal of eutectic gallium indium and quickly disintegrates.

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