A double-layer drainage tube

Abstract

The present invention provides a double-layer drainage tube, which is composed of a tightly fitting inner layer and an outer layer, wherein the inner layer is made of a hydrophobic material and the outer layer is made of a human biocompatible material. It can ensure that the inner wall is free of liquid, and bile adhesion can be avoided to cause blockage of the drainage tube. The outer wall is soft, elastic and has a smooth surface, and has good compatibility with body tissues and will not cause inflammation. In addition, in the absence of a stainless steel wire middle layer, the diameter and cost of the outer tube are reduced, the difficulty of insertion is reduced, and the inner diameter of the drainage tube is increased, thereby improving the effective drainage cross-sectional area of ​​the drainage tube.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, in particular to a double-layer drainage tube. Background Art

[0002] With the continuous development of endoscopic technology and the continuous improvement of its accessories, duodenoscope technology has become an important measure for the treatment of hepatobiliary and pancreatic diseases, including common bile duct stones, bile duct injury, bile duct stenosis, and biliary complications after liver transplantation. The content of duodenoscope technology mainly includes: diagnostic endoscopic retrograde cholangiopancreatography (ERCP) and therapeutic ERCP. Therapeutic ERCP includes endoscopic sphincterotomy (EST), endoscopic biliary drainage (EBD), endoscopic nose biliaty drainage (ENBD), endoscopic retrograde pancreatodrainage (ERPD) and corresponding endoscopic fistula. With the development of therapeutic ERCP (endoscopic retrograde cholangiopancreatography), compared with traditional techniques, endoscopic biliary drainage has been recognized by most clinicians as the first choice for biliary drainage due to its advantages such as minimal trauma, fewer complications, and repeatability.

[0003] "Bile duct drainage tube", also known as "bile duct drainage tube", is mainly used for bile drainage after endoscopic biliary stone surgery and endoscopic cholecystectomy. It is used in conjunction with a duodenoscope to insert an indwelling drainage tube for temporary bile drainage. It is a simple and effective method to relieve obstruction. It is mainly used for postoperative jaundice reduction of benign and malignant bile duct obstruction, diagnosis and treatment of suppurative cholangitis and other diseases that require bile duct drainage. There are already a variety of plastic drainage tubes and metal drainage tubes in the prior art for bile duct drainage. Compared with metal drainage tubes, plastic drainage tubes are cheaper, more twistable, and easier to insert. However, both plastic drainage tubes and metal drainage tubes have problems such as easy blockage, poor biocompatibility, insufficient strength to insert into the bile duct, or easy to cause inflammation.

[0004] The above-mentioned problem has been studied in the prior art. Reference 1 (CN2531802Y) discloses a T-shaped combined biliary drainage tube, the main part of which is a T-shaped three-way tube made of polyvinyl chloride, latex or silicone material. The special feature of the T-shaped three-way tube is that the long arm of the T-shaped three-way tube is covered with a thin film made of natural red rubber material. During the operation, the two short arms of the drainage tube are left in the abdominal cavity. Polyvinyl chloride, latex or silicone materials have weak reactivity to the tissues in the bile duct, which can avoid adverse effects on the bile duct and will not cause excessive inflammatory reactions. At the same time, the natural red rubber film with strong tissue reactivity on the surface of the long arm of the drainage tube can cause the early formation of the abdominal sinus in the abdominal cavity and achieve early removal of the tube.

[0005] Reference 2 (CN1843516A) has made further improvements on the basis of reference 1. It only needs to set a composite layer different from the stent body or the stent body outer layer material on the outer layer of one arm of the T-shaped drainage tube stent body, so that the outer layers of the two arms of the T-shaped drainage tube stent body retained in the body during surgery have both good compatibility with the body's tissues and little damage to the bile duct, and relatively poor compatibility with the body's tissues and can quickly stimulate the drainage tube to form a sinus around the good effect.

[0006] However, the above references all involve T-type drainage tubes, which are mainly used in biliary incision surgery. It is necessary to promote the formation and stability of sinus tracts as much as possible on the basis of ensuring the biocompatibility of T-type tubes with the body, so as to achieve early removal of the tube. However, the drainage tubes used in ERCP surgery do not need to consider the problem of sinus tract formation, and the biocompatibility of the polyvinyl chloride material used is poor, which will cause damage to the body and cause complications such as inflammation and hyperplasia.

[0007] Reference 3 (CN1250382A) discloses a bonding layer for the surface coating of a medical device, wherein the surface of a medical device such as a drainage tube is coated with a thin polymer layer of appropriate composition so that the thin layer is well bonded to the substrate surface, so that the subsequent coating can be firmly bonded to the thin polymer layer, and then the device is coated with other layers intended to improve the performance and biocompatibility of the medical device. The coating may include: a drug coating that can serve as a surface reservoir of physiologically active ingredients so as to release an effective concentration of the agent near the surface of the device; a hydrogel coating for producing surface smoothness; a colored coating; an anti-corrosion coating; one or more combinations of the above coatings, and other coatings for improving the performance of the device. This satisfies the long-standing need for a thin, firmly bonded, smooth coating for indwelling medical devices. However, according to feedback in practice, for a biliary drainage tube, since it needs to be indwelled in the digestive system for a long time, even if the bonding layer of the above coating is used, there is a problem of easy detachment, which is difficult to meet the needs of long-term use.

[0008] Reference 4 (see "Indications and Technical Methods of Endoscopic Biliary Stenting Using the Doublelayer Stent", Igarashi Y, Miki K, New Challenges in Gastrointestinal Endoscopy, Springer Japan, 2008: 417-422) discloses a double-layer drainage tube used in ERCP surgery. The double-layer drainage tube is actually composed of three layers. The inner layer is a Teflon that has been specially treated and chemically smoothed. The inner surface is very smooth to prevent bile or protein from adhering; the outer layer is a polyamide elastomer to provide the necessary strength to the drainage tube; a layer of stainless steel mesh is also provided between the two to ensure that the drainage tube has a certain degree of expansibility. In this way, the inner wall of the drainage tube does not adhere to bile, and the outer wall has good biocompatibility with body tissues, while maintaining the expansibility of the drainage tube. However, in addition to increasing costs, such a three-layer structure also increases the thickness of the drainage tube wall due to the stainless steel mesh in the middle, which will actually reduce the effective drainage cross-sectional area inside the drainage tube, or expand the overall diameter of the drainage tube, causing difficulties in insertion and removal of the tube, and increased pain for the patient.

[0009] Therefore, it is urgently needed in the medical field to provide a double-layer drainage tube with a simpler structure, which can prevent bile from adhering to the inner wall and has good biocompatibility with body tissue on the outside. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a double-layer drainage tube which has a simple structure and can prevent bile from adhering to the inner wall and has good biocompatibility with body tissue on the outside.

[0011] In order to solve the above technical problems, the double-layer drainage tube provided by the present invention is composed of a tightly fitting inner layer and an outer layer, the inner layer is made of a hydrophobic material, and the outer layer is made of a human biocompatible material. The inner layer is made of a hydrophobic material to ensure that the inner wall is free of liquid, and bile adhesion can be avoided to prevent the drainage tube from being blocked. The outer wall is made of a human biocompatible material, and can be left in the human body for a long time, has good compatibility with body tissues, and will not cause inflammation; the smoothness and safety of the drainage tube are ensured.

[0012] Furthermore, the human biocompatible material is selected from one or more of polyurethane, polyethylene, silicone rubber or polyamide.

[0013] Furthermore, the human biocompatible material is preferably polyurethane.

[0014] Furthermore, the thickness ratio of the outer layer to the inner layer is 10 to 1000:1; preferably 50 to 500:1; most preferably 100 to 200:1.

[0015] Furthermore, the hydrophobic material is preferably a fluorine-containing polymer.

[0016] Furthermore, the fluorine-containing polymer is preferably polytetrafluoroethylene or fluorinated ethylene propylene copolymer.

[0017] Furthermore, the hardness of the human biocompatible material is preferably 85A to 70D, more preferably 95A to 60D.

[0018] Furthermore, the outer layer is also coated with a functional coating, which is a hydrophilic coating and / or a bioactive coating.

[0019] Furthermore, the drainage tube is one of a straight type, a 1 / 3 curved type, a middle curved type, a trumpet type or a pig tail type.

[0020] Furthermore, a development mark is provided on the drainage tube.

[0021] In summary, the double-layer drainage tube involved in the present invention is composed of a tightly fitting inner layer and outer layer, the inner layer is made of a hydrophobic material, and the outer layer is made of a human biocompatible material. It can ensure that there is no liquid hanging on the inner wall, and avoid bile adhesion and blockage of the drainage tube. The outer layer is soft, elastic and has a smooth surface, has good compatibility with body tissues, and will not cause inflammation; compared with the prior art, it does not contain a stainless steel wire middle layer, reduces the diameter of the outer tube, reduces the difficulty of insertion, and at the same time increases the inner diameter of the drainage tube, improves the effective drainage cross-sectional area of ​​the drainage tube, has a simple structure, and reduces the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0023] Figure 1 A schematic diagram of the structure of the drainage tube according to an embodiment of the present invention

[0024] Figure 2 It is a partial cross-sectional enlarged structural schematic diagram of an embodiment provided by the present invention.

[0025] The component numbers are as follows:

[0026] 1-Drainage tube

[0027] 11-Inner layer

[0028] 12-Outer layer DETAILED DESCRIPTION

[0029] Now, in conjunction with the accompanying drawings, the preferred embodiments of the present invention will be described in detail. Although the description of the present invention will be introduced in conjunction with various embodiments, this does not mean that the features of this invention are limited to these several embodiments. On the contrary, the purpose of introducing the invention in conjunction with the embodiments is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the key points of the present invention, some specific details will be omitted in the description.

[0030] In addition, the terms “up”, “down”, “left”, “right”, “top” and “bottom” used in the following description are intended to better describe the preferred embodiments of the present invention and should not be construed as limitations on the present invention.

[0031] Example 1

[0032] like Figure 1 and Figure 2 As shown, the double-layer drainage tube provided by the present invention is composed of a tightly fitted inner layer 11 and an outer layer 12, wherein the inner layer 11 is made of a hydrophobic material, and the outer layer 12 is made of a human biocompatible material. The inner layer 11 is made of a hydrophobic material to ensure that the inner wall is free of liquid, and bile adhesion can be avoided to prevent the drainage tube from being blocked. The outer layer 12 is made of a human biocompatible material, and can be left in the human body for a long time, has good compatibility with body tissues, and will not cause inflammation; thus ensuring the smoothness and safety of the drainage tube.

[0033] Furthermore, there is no particular limitation on the specific types of human biocompatible materials. Taking into account the biocompatibility and cost of each material, the human biocompatible material is preferably one or more of polyurethane, polyethylene, silicone rubber and polyamide.

[0034] Furthermore, as the outer layer material, the above-mentioned human biocompatible materials each have their own advantages and disadvantages. For example, the biocompatibility of silicone is slightly better, but the insertion strength and radial expansion are relatively poor. When it is used as the outer tube material, it is not easy to insert into the bile duct; when it is in the working position, when it is squeezed by the inner wall of the cavity, it cannot maintain the radial expansion of the drainage tube well, so that the effective drainage cross-sectional area of ​​the drainage tube cannot be guaranteed; the biocompatibility of polyethylene material is equivalent to that of silicone, and the strength and expansion are slightly better, but its hardness is higher and its flexibility is poor. It cannot bend according to the needs of the cavity at human body temperature. It may pierce the inner wall during the insertion process or in the later use process, which may cause complications such as inflammation and hyperplasia; as for the polyamide used in reference 4, its biocompatibility is good, but its water absorption is large, and its dimensional stability will be affected to a certain extent under the complex internal environment of the human body; and its biocompatibility, strength and radial expansion are far inferior to polyurethane. In the absence of the middle layer of stainless steel wire, the insertion strength, radial expansion and X-ray development of the drainage tube will be reduced.

[0035] The present invention preferably uses polyurethane as the outer layer material. Compared with other biocompatible materials, polyurethane has better compatibility with hydrophobic materials such as fluorine-containing polymers and high interface bonding strength. In addition, the polyurethane material has good twistability when encountering human body temperature and can be bent according to the cavity conditions without puncturing body tissues. Polyurethane is non-toxic and can be retained in the human body for a long time. It has good compatibility with body tissues and will not cause inflammation. Most importantly, it has good strength and radial expansibility. Even in the absence of a stainless steel wire middle layer, it provides good insertion strength, ensuring that the drainage tube will not collapse during use and ensuring the smoothness of the drainage tube. In addition, polyurethane has good X-ray development ability. Even if it does not contain a stainless steel wire layer, the drainage tube of the present invention can be clearly observed under X-rays, which is convenient for operators to place it accurately.

[0036] Common hydrophobic materials include fluorine-containing or silane polymers, but organic silane materials have poor chemical resistance. When used as drainage tubes, hydrophobic materials are preferably fluorine-containing polymer hydrophobic materials with more stable chemical properties and lower surface energy. Fluorine-containing polymer hydrophobic materials have high heat resistance, chemical corrosion resistance, durability and weather resistance, especially inactivity to many solvents, hydrocarbons, various acids and bases, low surface energy (neither oleophilic nor hydrophilic, i.e. hydrophobic and oleophobic) and hygroscopic properties. In addition, the strong bond energy of the CF bond makes this type of polymer very stable to redox. The prepared drainage tube can be left in the human body for a long time, has stable physical and chemical properties, and ensures that bile or other foreign matter will not adhere to the inside of the drainage tube through the ambiphobic property, thereby ensuring the patency of the drainage tube. The fluorine-containing polymer can be selected from polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), perfluoroalkoxy polymer (PFA), copolymer of tetrafluoroethylene and ethylene (ETFE), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE), etc., but is not limited to the above materials.

[0037] Furthermore, the fluorinated polymer is preferably polytetrafluoroethylene or fluorinated ethylene propylene copolymer. Polytetrafluoroethylene is resistant to acids, alkalis, and various organic solvents, and is almost insoluble in all solvents; fluorinated ethylene propylene copolymer is a soft plastic, and its tensile strength, wear resistance, and creep resistance are lower than many engineering plastics, and it has excellent chemical inertness. Compared with other fluorinated polymer hydrophobic materials, the above two materials not only have better amphiphilic properties, but also have smoother inner surfaces and less friction, further reducing the possibility of bile hanging on the wall.

[0038] In the present invention, there is no particular limitation on the relative thickness of the inner layer 11 and the outer layer 12 , and the thickness of the inner layer 11 and the outer layer 12 can be adjusted according to the needs of use and cost in the field.

[0039] Furthermore, the outer layer material needs to have a suitable hardness. If the hardness is too low, it will be difficult to provide the drainage tube with a suitable insertion strength and radial expansion performance; if the hardness is too high, it is easy to puncture the inner wall of the body, causing complications such as hyperplasia or inflammation. Therefore, the hardness of the outer layer material is preferably 85A to 70D. Furthermore, the biocompatibility of the material with the body is not only related to the structure of the material itself, but also to whether the hardness of the material matches the body tissue. Therefore, the hardness of the human biocompatible material is more preferably 95A to 60D. Within the above range, it can have better biocompatibility with the body tissue.

[0040] Generally speaking, the hydrophobic material of the inner layer 11, such as fluoropolymer, has high mechanical properties such as hardness and strength, and is also expensive. If the thickness of the inner layer is too large, the manufacturing cost of the drainage tube will increase; in addition, as the thickness of the inner layer increases, the hardness of the inner layer 11 will gradually increase. If the hardness is too high and the hardness difference with the outer layer 12 is too large, it will affect the interface bonding performance of the inner layer 11 and the biocompatible material of the outer layer 12, such as polyurethane; when the inner layer 11 is thinner, the inner layer 11 has better flexibility and bendability, and better interface bonding performance with the material of the outer layer 12, such as polyurethane. Preferably, the thickness ratio of the outer layer 12 to the inner layer 11 is 10 to 1000:1; more preferably, the thickness ratio of the outer layer 12 to the inner layer 11 is 50 to 500:1; most preferably, the thickness ratio of the outer layer 12 to the inner layer 11 is 100 to 200:1.

[0041] Further, the outer layer 12 of the drainage tube is also coated with a functional coating, which is a hydrophilic coating and / or a bioactive coating. The hydrophilic coating can attract water molecules to form a "gel-like" surface on its surface, reduce the resistance when the drainage tube is inserted, and further enhance the biocompatibility of the drainage tube with body tissues. There is no specific limitation on the hydrophilic coating material, and the coating is selected to be formed by a material with low friction resistance. For example, it is preferably made of one or more of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyacrylamide, polyacrylic acid, sodium polyacrylate, poly (2-hydroxyethyl methacrylate), maleic anhydride copolymer, ethylene-vinyl alcohol copolymer, 2-methacryloyloxyethyl phosphorylcholine or its copolymer, (2-hydroxyethyl methacrylate)-styrene block copolymer, various synthetic polypeptides, collagen, hyaluronate, and cellulose copolymer.

[0042] Furthermore, a bioactive coating of a drug component can also be coated on the outside of the drainage tube. There is no specific limitation on the type of biological coating, and a suitable coating can be selected according to the needs of the patient's condition. For example, antithrombotic agents such as heparin-quaternary ammonium complexes; antimicrobial agents such as various silver compounds, quaternary ammonium compounds such as benzalkonium chloride, phenol derivatives such as thymol, and antibiotics such as gentamicin, norfloxacin, and rifamycin, etc.

[0043] Furthermore, there is no particular limitation on the shape of the drainage tube, except that the shape commonly used in ERCP surgery can be selected. Figure 1 In addition to the straight type shown in the figure, a 1 / 3 curved type, a middle curved type, a trumpet type or a pig tail type can also be used. Selecting any of the above shapes and adopting the double-layer structure of the present invention can achieve the technical effect that the inner wall of the present invention does not adhere to bile, the outside has good biocompatibility with body tissues, and the structure is simple and the cost is low.

[0044] Furthermore, in order to facilitate observation by the operator, a developing part may be provided on the drainage tube to facilitate positioning during placement of the drainage tube. The shape of the developing part is not specifically limited, as long as it is convenient for observation, and may be in the form of a ring, strip, dot, or a cross mark or other patterns. When the drainage tube enters the patient's body, the developing part can clearly display the position of the drainage tube, so that the operator can better monitor the placement of the drainage tube.

[0045] In summary, the double-layer drainage tube involved in the present invention is composed of a tightly fitting inner layer and outer layer, the inner layer is made of a hydrophobic material, and the outer layer is made of a human biocompatible material. It can ensure that there is no liquid hanging on the inner wall, and bile adhesion can be avoided to cause blockage of the drainage tube. The outer wall is soft, elastic and has a smooth surface, has good compatibility with body tissues, and will not cause inflammation; and in the absence of a stainless steel wire middle layer, the diameter and cost of the outer tube are reduced, the difficulty of insertion is reduced, and the inner diameter of the drainage tube is increased, thereby improving the effective drainage cross-sectional area of ​​the drainage tube.

[0046] The above description is an example of a specific implementation of the present invention, which is used to more clearly illustrate the inventive concept of the present invention, but it is not used to limit the scope of the claims of the present invention. According to the inventive concept of the present invention, those skilled in the art can easily modify and amend the above-mentioned embodiments, and these modifications and variations within the inventive concept of the present invention are all included in the scope of the claims attached to the present invention.

Claims

1. A double-layer drainage tube, characterized in that: It is composed of a tightly fitting inner layer and an outer layer. The liquid in the human body is drained out of the human body through the inner layer. The inner layer is made of hydrophobic material to ensure that the inner wall is free of liquid and to prevent the liquid in the human body from adhering to the drainage tube and causing blockage. The outer layer is made of human biocompatible material. The human biocompatible material is polyurethane, and the polyurethane has better compatibility with the hydrophobic material, so that the interface bonding strength between the outer layer and the inner layer is high.

2. The drainage tube according to claim 1, characterized in that: The thickness ratio of the outer layer to the inner layer is 10 to 1000:

1.

3. The drainage tube according to claim 1, characterized in that: The hydrophobic material is a fluorine-containing polymer.

4. The drainage tube according to claim 3, characterized in that: The fluorine-containing polymer is polytetrafluoroethylene or fluorinated ethylene propylene copolymer.

5. The drainage tube according to claim 1, characterized in that: The hardness of the human biocompatible material is 85A to 70D.

6. The drainage tube according to claim 1, characterized in that: The outer layer is also coated with a functional coating, which is a hydrophilic coating or a bioactive coating.

7. The drainage tube according to claim 1, characterized in that: The drainage tube is one of a straight type, a 1 / 3 curved type, a middle curved type, a trumpet type or a pig tail type.

8. The drainage tube according to claim 1, characterized in that: The drainage tube is provided with a developing mark.

Images