A double-layer drainage tube

Abstract

The present invention provides a double-layer drainage tube, which is composed of a tightly fitted inner layer and outer layer, wherein the inner layer is made of a hydrophobic material, and the outer layer is made of a human biocompatible material, and one or more grooves extending along the axial direction of the drainage tube are provided on the outer wall of the drainage tube. It can ensure that the inner wall does not adhere to pus, blood, grease or other foreign matter in the human body, and the tube will not be blocked by crusting, and the use time is long; the outer wall is soft, elastic and has a smooth surface, has good compatibility with body tissues, and will not cause inflammation; while providing better radial expandability, the drainage tube can achieve external drainage while draining on the inside, thereby increasing the drainage effect of the drainage tube; and in the absence of an intermediate metal braided mesh, the structure of the drainage tube is simplified, and the production cost is reduced.

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] At present, there are many types of surgical drainage tubes used in clinical practice, which are used for drainage of the urethra, wounds, chest cavity, ventricle, gastrointestinal tract, bile duct, etc. After surgery, patients often need to leave drainage tubes to drain fluid from the cavity, such as peritoneal or retroperitoneal drainage tubes, which can be used to monitor whether there is active bleeding in the peritoneal cavity or retroperitoneum or anastomotic leakage in the stomach, intestines, gallbladder, pancreas, urinary tract, etc. The purpose of surgical drainage is to guide the pus, blood, and fluid accumulated between human tissues or in the body cavity to the outside of the body to prevent postoperative infection and affect wound healing, and to observe the progression of the patient's condition.

[0003] At present, the commonly used drainage tubes are mostly tubular structures made of metal or polymer materials, with side holes at the top. During the retention period, the drainage tubes made of polymer materials may cross-link with various hydrophilic or lipophilic groups contained in the pus, blood, and liquid in the body to form lumps, such as crusts, which will gradually reduce the effective drainage area of ​​the drainage tubes, or even block them. New drainage tubes need to be replaced again, which increases the burden on patients. In addition, polymer materials are often relatively soft and difficult to provide sufficient radial expandability, and cannot play a good supporting role. The outer surface of the drainage tubes made of metal materials has poor human affinity, which will stimulate the surrounding tissues and produce inflammatory reactions. In severe cases, they may even adhere to the surrounding tissues and cause hyperplasia, which is not conducive to the removal of the drainage tubes, and narrow the cavity at the insertion site, affecting the treatment effect. These complications seriously affect the treatment effect and quality of life of patients.

[0004] In order to solve the above problems, the prior art 1 (CN106924864) discloses a super hydrophobic and oleophobic anti-reflux ureteral stent, wherein the ureteral stent is a tubular body with a diameter of 1-3 mm, and is provided with a renal end portion, a ureteral portion and a bladder end portion in sequence; the renal end portion is curled, and the distal end face is open; the bladder end portion is also curled, and the proximal end face is closed; the interior of the renal end portion and the ureteral portion are both hollow, and the outer wall is provided with a plurality of staggered drainage holes; the distance between the nearest drainage hole and the bladder end portion is 3-10 cm; the inner and outer surfaces of the ureteral stent are provided with a hydrophobic and oleophobic layer, and the thickness of the hydrophobic and oleophobic layer is 50-200 nm. In this technical solution, by providing a hydrophobic and oleophobic layer on the inner and outer surfaces of the ureteral stent, body fluids and urine can be isolated from the ureteral stent, thereby preventing the occurrence of blockage, adhesion, inflammation and bacterial infection. However, since the surface of the ureteral stent in this technical solution is also coated with a hydrophobic and oleophobic layer, the ureteral stent has poor biocompatibility with the human body and is easy to irritate the inner wall of the human body, still causing inflammation and hyperplasia. In addition, the radial expandability of the drainage tube made of polymer materials in this technical solution cannot be guaranteed.

[0005] In order to solve the above problems, the prior art 2 (CN205549197U) also discloses a ureteral stent with an embedded grid support, including a tube body, which is a hollow tubular structure with two ends open. The tube body is a composite multilayer structure consisting of a polyurethane outer layer, a metal braided mesh layer and a polyurethane inner layer from the outside to the inside. The two ends of the tube body are curled inward in opposite directions to form a circle to form a renal pelvis connection end and a bladder connection end. The inner side of the tube body of the circular curled part where the renal pelvis connection end and the bladder connection end are located is provided with drainage holes that pass through the inside and outside. The ureteral stent tube body in this technical solution is a composite multilayer structure consisting of a polyurethane outer layer, a metal braided mesh layer and a polyurethane inner layer from the outside to the inside. It has good biocompatibility, good radial expandability, and strong compression resistance, and can play a good role in supporting the ureter. However, such a three-layer structure not only increases production costs, but the metal braided mesh in the middle also increases the thickness of the ureteral stent wall, which actually reduces the effective drainage cross-sectional area inside the stent, or expands the overall diameter of the drainage tube, causing difficulties in insertion and removal of the tube, increasing the pain of the patient, etc. In addition, the three-layer stent is made of polyurethane material, which easily adheres to body fluids or grease or other foreign matter in urine, which will cause the effective drainage area of ​​the ureteral stent to gradually decrease, or even cause crusting and blockage.

[0006] Therefore, it is an urgent need in the medical field to provide a drainage tube with a simpler structure, good drainage effect, and good biocompatibility with body tissue. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a double-layer drainage tube with a simpler structure, good drainage effect and good biocompatibility with body tissues.

[0008] In order to solve the above technical problems, the present invention provides a double-layer drainage tube, which is composed of a tightly fitted 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. One or more grooves extending along the axial direction of the drainage tube are provided on the outer tube wall of the drainage tube.

[0009] Furthermore, the human biocompatible material is selected from one of polyurethane, polyethylene, silicone rubber or polyamide.

[0010] Furthermore, the human biocompatible material is preferably polyurethane.

[0011] 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.

[0012] Furthermore, the hydrophobic material is preferably a fluorine-containing polymer.

[0013] Furthermore, the fluorine-containing polymer is preferably polytetrafluoroethylene or fluorinated ethylene propylene copolymer.

[0014] Furthermore, the hardness of the human biocompatible material is preferably 85A to 70D, more preferably 95A to 60D.

[0015] Furthermore, the outer layer is also coated with a functional coating, which is a hydrophilic coating, a lubricating coating or a bioactive coating.

[0016] Furthermore, the drainage tube has a development function.

[0017] Furthermore, the grooves are arranged in a straight line or in a spiral.

[0018] 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 the inner wall does not adhere to pus, blood, grease or other foreign matter in the human body, the tube will not be blocked by crusting, and the use time is long. The outer layer is soft, elastic and has a smooth surface, has good compatibility with body tissues, and will not cause inflammation and hyperplasia; and by providing a groove on the outer tube wall, the contact area between the drainage tube and the cavity can be reduced, reducing the possibility of inflammation and hyperplasia. In addition, compared with the three-layer drainage tube in the prior art, the double-layer drainage tube in the present invention does not contain an intermediate metal woven mesh layer and is entirely made of polymer materials, which simplifies the structure of the drainage tube and reduces the production cost. When the tube wall thickness is the same as that of the three-layer drainage tube in the prior art, the overall thickness of the inner layer and the outer layer made of polymer materials is relatively increased, thereby providing better radial expandability. Furthermore, by providing one or more grooves extending axially along the drainage tube on the outer tube wall of the drainage tube, the drainage tube can achieve outer drainage while draining on the inside without significantly reducing the radial expandability of the drainage tube, thereby increasing the drainage effect of the drainage tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0020] Figure 1 A schematic diagram of the structure of a drainage tube according to an embodiment of the present invention;

[0021] Figure 2 A schematic structural diagram of a drainage tube according to another embodiment of the present invention;

[0022] Figure 3 for Figure 1 Schematic diagram of the cross-section structure along the AA plane;

[0023] Figure 4 A schematic cross-sectional structure diagram of a drainage tube provided by another embodiment of the present invention;

[0024] Figure 5 The present invention is a schematic diagram of a cross-sectional structure of a drainage tube provided in yet another embodiment of the present invention.

[0025] The component numbers are as follows:

[0026] 1-Drainage tube

[0027] 11-Inner layer

[0028] 12-Outer layer

[0029] 13-Groove DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] like Figures 1 to 5 As shown, the double-layer drainage tube 1 provided by the present invention is composed of a tightly fitted inner layer 11 and an outer layer 12, the inner layer 11 is made of a hydrophobic material, the outer layer 12 is made of a human biocompatible material, and one or more grooves 13 extending along the axial direction of the drainage tube 1 are provided on the outer wall of the drainage tube 1. The inner layer 11 is a hydrophobic material, which can ensure that the inner wall does not adhere to pus, blood, grease or impurities in the liquid in the human body, and the tube will not be encrusted and blocked. The outer layer 12 is made of a human biocompatible material, which can be left in the human body for a long time, has good compatibility with body tissues, and will not cause inflammation and hyperplasia; the smoothness and safety of the drainage tube 1 are ensured. In addition, compared with the three-layer drainage tube in the prior art, the double-layer drainage tube 1 in the present invention does not contain an intermediate metal woven mesh layer, and is made entirely of polymer materials, which simplifies the structure of the drainage tube 1 and reduces the production cost. Under the condition of having the same tube wall thickness, the overall thickness of the inner layer and the outer layer made of polymer materials is increased, thereby providing better radial expandability. Furthermore, by providing one or more grooves 13 extending axially along the drainage tube 1 on the outer tube wall of the drainage tube 1, the drainage tube 1 can achieve external drainage while draining on the inside without significantly reducing the radial expandability of the drainage tube 1, thereby increasing the drainage effect of the drainage tube 1.

[0033] Furthermore, the shape of the drainage tube 1 is not particularly limited and can be Figure 1 A straight drainage tube in one embodiment shown; it may also be Figure 2 The drainage tube is a double-pigtail type drainage tube in the same direction in another embodiment shown; it can also be a drainage tube with a 1 / 3 bend type, a middle bend type, a trumpet type or a reverse pigtail type (not shown in the figure).

[0034] 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.

[0035] Furthermore, as the outer layer material, the above-mentioned human biocompatible materials each have advantages and disadvantages. For example, silicone rubber has slightly better biocompatibility, but its 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 human body. When it is in the working position, it cannot maintain the radial expansion of the drainage tube 1 well when it is squeezed by the inner wall of the cavity, so that the effective drainage cross-sectional area of ​​the drainage tube 1 cannot be guaranteed; the biocompatibility of polyethylene material is equivalent to that of silicone, and its 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 insertion or in the later use process, which may cause complications such as inflammation and hyperplasia; polyamide has better biocompatibility, but its water absorption is relatively large. Under the complex internal environment of the human body, the dimensional stability will be affected to a certain extent, and its biocompatibility, strength and radial expansion are far inferior to polyurethane. In the absence of an intermediate metal braided mesh layer, the insertion strength, radial expansion and X-ray development of the drainage tube 1 will be reduced.

[0036] 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 fluoropolymers, and has high interface bonding strength; and the polyurethane material has good twisting properties when it encounters human body temperature, and can be bent according to the cavity conditions without puncturing body tissues; polyurethane is non-toxic, can be left in the human body for a long time, has good compatibility with body tissues, and will not cause inflammation; most importantly, it has good strength and radial expansibility. In the absence of an intermediate metal braided mesh layer, it can provide comparable radial expansibility and insertion performance through a thickness comparable to that of the three-layer drainage tube in the prior art, and ensure that the drainage tube 1 will not collapse during use, ensuring the smoothness of the drainage tube 1. In addition, polyurethane has good X-ray development ability, and even if it does not contain an intermediate metal braided mesh layer, the drainage tube 1 of the present invention can be clearly observed under X-rays, which is convenient for operators to place accurately.

[0037] Common hydrophobic materials include fluorine-containing or organosilane polymers, but organosilane materials have poor chemical resistance. When used as drainage tube 1, the hydrophobic material is preferably a fluorine-containing polymer hydrophobic material 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 for many solvents, hydrocarbons, various acids and bases, they are inactive. Fluorine-containing polymer hydrophobic materials have low surface energy (neither oleophilic nor hydrophilic, i.e., hydrophobic and oleophobic) and hygroscopic properties. Moreover, the strong bond energy of the CF bond makes this type of polymer very stable to redox. The drainage tube 1 made of such material can be left in the human body for a long time, has stable physical and chemical properties, and ensures that the inside of the drainage tube 1 will not adhere to pus, blood, grease or other foreign matter in the human body through the double-phobic property (i.e., hydrophobic and oleophobic), thereby ensuring the patency of the drainage tube 1. The fluorinated 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.

[0038] 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 crusting on the inner wall.

[0039] 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.

[0040] 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 1 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.

[0041] 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 1 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.

[0042] Further, the outer layer 12 of the drainage tube 1 is also coated with a functional coating, which is a hydrophilic coating, a lubricating coating 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 1 is inserted, and further enhance the biocompatibility of the drainage tube 1 with body tissues. There is no specific limitation on the hydrophilic coating material, and the coating is 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.

[0043] There is no specific limitation on the type of lubricating coating, as long as it can reduce the friction on the surface of the guide wire and improve the insertion performance of the guide wire. Specifically, a fluorine-containing polymer coating can be selected.

[0044] 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, antibiotics such as gentamicin, norfloxacin and rifamycin, etc.

[0045] Furthermore, in order to facilitate observation by the operator, the drainage tube 1 also has a developing function, which is convenient for positioning during the placement of the drainage tube 1. The developing function can be achieved by a developing portion arranged on the outer wall of the drainage tube. The shape of the developing portion is not specifically limited, as long as it is convenient for observation, and can be a ring, strip, dot, or a cross mark or other patterns. Alternatively, an additive with a developing function can be directly and evenly blended into the outer layer 12 and / or the inner layer 11, so that the drainage tube 1 directly has a developing function. The additive with a developing function can be selected from barium sulfate, antimony trioxide, tungsten powder, etc.

[0046] When the drainage tube 1 enters the patient's body, the developing unit can clearly display the position of the drainage tube 1 , so that the operator can better monitor the placement of the drainage tube 1 .

[0047] Furthermore, there is no special limitation on the number of grooves 13, and a suitable number of grooves 13 can be selected according to actual needs, for example, Figure 3 In the embodiment shown, only one groove 13 is provided. Figure 4 In another embodiment shown in the figure, four grooves 13 are provided. Similarly, there is no special limitation on the shape of the grooves 13, as long as the grooves 13 are connected in the axial direction of the drainage tube 1 and can achieve the function of external drainage. Figure 1 and Figure 4 The smaller groove 13 shown may also be Figure 5 A further embodiment is shown in which the recess 13 is larger.

[0048] Furthermore, the grooves 13 are preferably arranged in a straight line or in a spiral shape along the axial extension of the drainage tube 1. When the grooves 13 are arranged in a straight line, the distance that the liquid needs to flow through is the shortest and the drainage efficiency is the highest; when the grooves 13 are arranged in a spiral shape, the drainage tube 1 can be provided with a higher radial expandability, and the selection can be made according to the actual needs during use.

[0049] 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, the outer layer is made of a human biocompatible material, and one or more grooves extending along the axial direction of the drainage tube are provided on the outer wall of the drainage tube. It can ensure that the inner wall does not adhere to pus, blood, grease or other foreign matter in the human body, the tube will not be blocked by crusting, and the use time is long; the outer wall is soft, elastic and has a smooth surface, has good compatibility with body tissues, and will not cause inflammation; while providing better radial expandability, the drainage tube can achieve external drainage while draining on the inside, thereby increasing the drainage effect of the drainage tube; and in the absence of an intermediate metal braided mesh, the structure of the drainage tube is simplified, and the production cost is reduced.

[0050] 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: The double-layer drainage tube is composed of a tightly fitted 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 a hydrophobic material to ensure that it does not adhere to pus, blood, grease or impurities in the liquid in the human body, and the tube will not be blocked by crusting; the outer layer is made of a human biocompatible material, and one or more grooves extending along the axial direction of the drainage tube are provided on the outer wall of the drainage tube; 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, a lubricating coating or a bioactive coating.

7. The drainage tube according to claim 1, characterized in that: The drainage tube has a developing function.

8. The drainage tube according to claim 1, characterized in that: The grooves are arranged in a straight line or in a spiral shape.

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