Extendable gastrointestinal stent and its use

Abstract

The application provides an extendable digestive tract cannula and application thereof, and relates to the technical field of medical devices. The application comprises a first cannula, a second cannula and a degradable material. Opposite ends of the first cannula are a proximal end and a distal end, respectively. The first cannula is sleeved with the second cannula, and a double-layer structure is formed at the distal end of the first cannula. The double-layer structure is fixed by the degradable material. When the degradable material degrades, the second cannula moves towards the end face of the distal end of the first cannula. By setting the movable second cannula, the second cannula moves backward after the degradable material degrades, so that the length of the digestive tract cannula is extended. Since the length of the digestive tract cannula is increased, the area of intestinal absorption is also increased, the compensatory absorption function of the intestine at the distal end of the digestive tract cannula is weakened, the isolation effect of chyme and the intestine is improved, and the digestion and absorption effect of the intestine can be reduced for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to an extendable digestive tract cannula and application thereof. BACKGROUND

[0002] With the improvement of people's living standards, the probability of obesity is also increasing year by year. At present, the annual expenditure for obesity accounts for about 2.8% of the global gross product, which also proves the fact that the population of obesity is increasing year by year. According to statistics, about 80-90% of patients in the obese population have type II diabetes, and type II diabetes is the most common type of diabetes, accounting for about 90% of all diabetes in the world. At present, diabetes has become the third largest non-communicable disease after cardiovascular disease and cancer, and the number of patients is increasing year by year, which has become a global public health problem threatening human health.

[0003] At present, the pathogenesis of type II diabetes is still not completely clear. Through the existing oral drugs and insulin treatment, the blood glucose control of some patients is still not good, and there are cases of complications and development. Weight loss surgery has good effect on the above diseases, but there is irreversible physiological trauma change and certain mortality and postoperative complications, such as digestive tract leakage, anastomotic stenosis, dumping syndrome, etc. At present, by referring to the principle of gastric bypass surgery, a duodenojejunal endoprosthesis is developed, which isolates the contact of chyme and intestinal wall by placing a cannula in the duodenum and the proximal jejunum. After the intake of nutrients enters the stomach, it enters the proximal jejunum through the cannula; pancreatic juice and bile are naturally secreted and flow downward between the cannula and the intestinal wall, and mix with chyme in the distal end of the duodenojejunal endoprosthesis (i.e. jejunum) to reduce absorption to treat obesity and type II diabetes.

[0004] However, as the research gradually deepens, we find that the placement of the digestive tract cannula can reduce the absorption of the intestinal tract to food in the short term, but with the extension of time, the absorption of the intestinal tract to food increases again, and it is unable to achieve a more lasting reduction in the digestive absorption of the intestinal tract.

[0005] In view of this, the present application is proposed. SUMMARY

[0006] The purpose of the present application is to provide an extendable digestive tract cannula and application thereof, which can realize the controllable extension of the digestive tract cannula, weaken the compensatory absorption function of the intestinal tract at the distal end of the digestive tract cannula, and improve the isolation effect of chyme and the intestinal tract.

[0007] The embodiments of the present application are implemented as follows:

[0008] In a first aspect, the present application provides an extendable gastrointestinal tube, comprising a first tube, a second tube and a degradable material, the first tube having a proximal end and a distal end at opposite ends, the first tube being sleeved with the second tube, and forming a double-layer structure at the distal end of the first tube, the double-layer structure being fixed by the degradable material, and the second tube moving towards the end face of the distal end of the first tube after the degradable material degrades.

[0009] In an optional embodiment, the degradation time of the degradable material is ≥ 30 days.

[0010] Preferably, the degradation time of the degradable material is 60-90 days.

[0011] Preferably, the connection force between the degradable material and the first tube is ≥ 2.5 N; more preferably, the connection force between the degradable material and the first tube is ≥ 10 N.

[0012] Preferably, the degradable material is an annular film, and the thickness of the annular film is 0.01-0.06 mm.

[0013] In an optional embodiment, the degradable material comprises at least one of polylactide and polyglycolide.

[0014] Preferably, the degradable material comprises one or more of poly(DL-lactide-glycolide), polyglycolide-polycaprolactone, poly(L-lactide-co-ε-caprolactone), poly-L-lactic acid, and poly-L-lactic acid-trimethyl chitosan.

[0015] Preferably, the mass ratio of DL-lactide to glycolide in poly(DL-lactide-glycolide) is 0.8-1.2:0.8-1.2, the mass ratio of polyglycolide to polycaprolactone in polyglycolide-polycaprolactone is 7-8:2-3, the mass ratio of L-lactide to ε-caprolactone in poly(L-lactide-co-ε-caprolactone) is 6.5-7.5:2.5-3.5, and the mass ratio of poly-L-lactic acid to trimethyl chitosan in poly-L-lactic acid-trimethyl chitosan is 6.5-7.5:2.5-3.5.

[0016] In an optional embodiment, the degradable material is connected to the first tube by calendering or RF welding.

[0017] In an optional embodiment, the first tube and the second tube are formed by folding one tube or welding two tubes, and the welding point of the two tubes welded is the distal end of the first tube.

[0018] Preferably, the second tube is located in the first tube.

[0019] In an optional embodiment, the length of the second tube extending out of the first tube after the degradable material degrades is 10-30 cm.

[0020] In an optional embodiment, the length of the first sleeve is > 30 cm and the length of the second sleeve is 15-80 cm.

[0021] In an optional embodiment, the thickness of the first sleeve and the second sleeve is 0.01-0.03 mm.

[0022] In an optional embodiment, the material of the first sleeve and the second sleeve comprises at least one of polytetrafluoroethylene, fluorinated ethylene propylene copolymer, expanded polytetrafluoroethylene, polyurethane, low-density polyethylene or linear low-density polyethylene.

[0023] In a second aspect, the present application provides use of an extendable gastrointestinal tube according to any one of the preceding embodiments in reducing absorption of the gastrointestinal tract.

[0024] The beneficial effects of the embodiments of the present application are:

[0025] The present application provides an extendable gastrointestinal tube and its use, by setting the second sleeve which can move, so that after the degradation of the degradation material, the second sleeve moves backward, to achieve the purpose of extending the gastrointestinal tube. Due to the increase of the length of the gastrointestinal tube, the area of the intestinal absorption is also increased, the compensatory absorption function of the intestine at the distal end of the gastrointestinal tube is weakened, the isolation effect of chyme and the intestine is improved, and the effect of intestinal digestion and absorption can be reduced for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0027] Figure 1 The structural schematic diagram of the extendable gastrointestinal tube provided by the embodiments of the present application is shown in the figure.

[0028] Figure 2 The structural schematic diagram of the extendable gastrointestinal tube provided by the embodiments of the present application is shown in the figure.

[0029] Figure: 100-extendable gastrointestinal tube; 110-first sleeve; 120-second sleeve; 130-degradation material. DETAILED DESCRIPTION

[0030] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Generally, the components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] It should be noted that: similar reference numerals and letters indicate similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0033] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed, and are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set", "mount", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] Please refer to Figure 1 and Figure 2In the first aspect, the application provides an extendable digestive tract cannula 100, which comprises a first cannula 110, a second cannula 120 and a degradable material 130. The first cannula 110 has a proximal end and a distal end at opposite ends. The first cannula 110 is sleeved with the second cannula 120, and a double-layer structure is formed at the distal end of the first cannula 110. The double-layer structure is fixed by the degradable material 130. The degradable material 130 has a degradation performance after the digestive tract cannula is used for a period of time. When the degradable material 130 degrades, the second cannula 120 moves towards the end face of the distal end of the first cannula 110.

[0036] At present, the method of placing a digestive tract cannula can reduce the absorption of food by the intestinal wall, thereby achieving the effect of weight loss or reducing blood sugar. However, as the time of placing the digestive tract cannula increases, the jejunum part at the distal end of the cannula will gradually form compensation, such as the lengthening of intestinal mucosal villi, the increase of folds, the deepening of intestinal glands, the thickening of the intestinal wall, and the like. The generation of these compensation phenomena increases the absorption capacity of the intestinal tract to food, thereby affecting the changes in body weight and metabolism. Therefore, the inventors creatively propose an extendable digestive tract cannula. By arranging the second cannula 120, when the degradable material 130 degrades, the second cannula 120 will move in the direction away from the stomach along with the peristalsis of the intestinal tract, thereby achieving the purpose of extending the digestive tract cannula. The lengthening of the digestive tract cannula weakens the compensatory absorption function of the intestinal tract at the distal end of the digestive tract cannula, improves the isolation effect of chyme and the intestinal tract, and further reduces the digestive absorption of food by the intestinal tract.

[0037] In an optional embodiment, desirably, the second cannula 120 should be extended after the first cannula 110 reduces the digestive absorption effect first, i.e., when the intestinal wall at the distal end of the originally placed digestive tract cannula starts to compensate for absorption. Therefore, the degradation time of the degradable material 130 is required to be ≥30 days to ensure that the first cannula 110 fully plays its role.

[0038] Preferably, in order to ensure that the first cannula 110 can fully play its role of reducing the digestive absorption of the intestinal tract, the degradation time of the degradable material 130 is 60-90 days.

[0039] Preferably, in order to ensure that the degradable material 130 can degrade according to the above-mentioned time to enable the second cannula 120 to smoothly extend, the connecting force between the degradable material 130 and the first cannula 110 is required to be ≥2.5 N; more preferably, the connecting force between the degradable material 130 and the first cannula 110 is ≥10 N.

[0040] Preferably, the degradable material 130 is a ring-shaped film. In order to ensure that the degradable material 130 can degrade according to the above-mentioned time to enable the second cannula 120 to smoothly extend, the thickness of the ring-shaped film is 0.01-0.06 mm.

[0041] In optional embodiments, to ensure that the second sleeve 120 can be extended out of the first sleeve 110 within a fixed time, the selection of the degradation material 130 is one of the key influencing factors.

[0042] Preferably, the degradation material 130 comprises at least one of poly-lactide and poly-glycolide.

[0043] Preferably, the degradation material 130 comprises one or more of poly(DL-lactide-glycolide), poly-glycolide-polycaprolactone, poly(L-lactide-co-ε-caprolactone), poly-L-lactic acid, and poly-L-lactic acid-trimethyl chitosan.

[0044] Preferably, to ensure the degradation characteristics of the degradation material 130, the ratio of the above-mentioned composite degradation material 130 needs to be controlled, for example, the mass ratio of DL-lactide to glycolide in poly(DL-lactide-glycolide) is 0.8-1.2:0.8-1.2; the mass ratio of polyglycolide to polycaprolactone in poly-glycolide-polycaprolactone is 7-8:2-3; the mass ratio of L-lactide to ε-caprolactone in poly(L-lactide-co-ε-caprolactone) is 6.5-7.5:2.5-3.5; and the mass ratio of poly-L-lactic acid to trimethyl chitosan in poly-L-lactic acid-trimethyl chitosan is 6.5-7.5:2.5-3.5. By controlling the ratio of the degradation material 130 within the above-mentioned range, the degradation material 130 prepared thereby can meet the connection force between the first sleeve 110 and the degradation material 130.

[0045] In some embodiments, the performance of the degradation material 130 is related to the specific selection of its raw materials, and different raw material selections, or the same raw material selection but different ratios, can result in different degradation times of the degradation material 130. For example, when the degradation time of the degradation material 130 is about 1 month, poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide) can be selected as raw materials in a mass ratio of 1-2:8-9; when the degradation time of the degradation material 130 is 1-2 months, poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide) can be selected as raw materials in a mass ratio of 3:7; when the degradation time of the degradation material 130 is about 3 months, poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide) can be selected as raw materials in a mass ratio of 1:1; and when the degradation time of the degradation material 130 is about 4 months, poly(L-lactide-co-ε-caprolactone) and poly(DL-lactide-glycolide) can be selected as raw materials in a mass ratio of 6-8:2-4, or poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide) can also be selected as raw materials in a mass ratio of 6-8:2-4.

[0046] In an alternative embodiment, the preparation method of the degradable material 130 includes solvent forming, spinning, etc.

[0047] In an alternative embodiment, the degradable material 130 is connected with the first sleeve 110 by calendering or RF welding.

[0048] In an alternative embodiment, the first sleeve 110 and the second sleeve 120 are formed by folding one tube or welding two tubes, and the welding point of the two tubes is the distal end of the first sleeve 110. When the first sleeve 110 and the second sleeve 120 are formed by folding one tube, the diameters of the first sleeve 110 and the second sleeve 120 are the same; when the first sleeve 110 and the second sleeve 120 are formed by welding two tubes, the diameters are slightly different according to the positions of the first sleeve 110 and the second sleeve 120, and the diameter of the outer sleeve needs to be slightly larger than that of the inner sleeve. Preferably, in order to simplify the preparation process, the first sleeve 110 and the second sleeve 120 are formed by folding one tube.

[0049] Since the degradable material 130 is degraded, the second sleeve 120 needs to move to the distal end of the first sleeve 110. In order to facilitate the movement of the second sleeve 120, preferably, the second sleeve 120 is located in the first sleeve 110, and when the degradable material 130 fails, the second sleeve 120 can be turned over in the first sleeve 110 under the pushing action of the chyme and move to the distal end of the first sleeve 110 without being hindered by the wall of the digestive tract.

[0050] Preferably, the movement of the second sleeve 120 to the distal end can be translation or turning over, more preferably turning over, and more preferably turning over into the digestive tract sleeve.

[0051] In an alternative embodiment, when the degradable material 130 is degraded, the length of the second sleeve 120 extending out of the first sleeve 110 is 10-30 cm.

[0052] In an alternative embodiment, the length of the first sleeve 110 is ≥30 cm, and the length of the second sleeve 120 is 15-80 cm.

[0053] In an alternative embodiment, the thickness of the first sleeve 110 and the second sleeve 120 is 0.01-0.03 mm. The thickness of the first sleeve 110 and the second sleeve 120 can be the same or different, as long as they are within the above range.

[0054] Preferably, in order to better turn over the second sleeve 120, the length of the second sleeve 120 is less than the length of the first sleeve 110.

[0055] In an optional embodiment, the material of the first sleeve 110 and the second sleeve 120 comprises at least one of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), expanded polytetrafluoroethylene (ePTFE), polyurethane (PU), low-density polyethylene (LDPE), or linear low-density polyethylene (LLDPE). The first sleeve 110 and the second sleeve 120 of the above-mentioned materials are matched with the material of the degradable material 130, which can ensure the smooth extension of the second sleeve 120.

[0056] In a second aspect, the present application provides a use of the extendable digestive tract sleeve 100 according to any one of the preceding embodiments in a product for reducing absorption in the digestive tract.

[0057] Example 1

[0058] The present embodiment provides an extendable digestive tract sleeve 100, which comprises a first sleeve 110, a second sleeve 120, and a degradable material 130. The opposite ends of the first sleeve 110 are a proximal end and a distal end, respectively. The first sleeve 110 and the second sleeve 120 are fixed by the degradable material 130, and a double-layer structure is formed at the distal end of the first sleeve 110. The degradable material 130 has a degradation performance after the digestive tract sleeve is used for a period of time. When the degradable material 130 degrades, the second sleeve 120 moves towards the distal end.

[0059] In the present embodiment, the first sleeve 110 and the second sleeve 120 are formed by folding one tube, and the second sleeve 120 is located in the first sleeve 110. When the degradable material 130 fails, the second sleeve 120 folds towards the lumen of the digestive tract sleeve and moves towards the distal end of the first sleeve 110 by the pushing of chyme, thereby completing the extension of the digestive tract sleeve. Therefore, the diameters of the first sleeve 110 and the second sleeve 120 are the same, both being 25 mm.

[0060] In the present embodiment, the material of the first sleeve 110 is low-density polyethylene, the length is 30 cm, and the thickness is 0.02 mm. The material of the second sleeve 120 is low-density polyethylene, the length is 15 cm, and the thickness is 0.02 mm.

[0061] In the present embodiment, the degradable material 130 is a mixture of poly(L-lactide-co-ε-caprolactone) and poly(DL-lactide-glycolide) mixed at a ratio of 8:2. The mass ratio of lactide to caprolactone in the poly(L-lactide-co-ε-caprolactone) is 7:3, and the mass ratio of lactide to glycolide in the poly(DL-lactide-glycolide) is 1:1.

[0062] The preparation method of the degradable material 130 is solution forming, and the degradable material 130 is prepared into a ring-shaped film. The ring-shaped film is connected to the first sleeve 110 by laser welding. In the present embodiment, the thickness of the ring-shaped film is 0.03 mm.

[0063] Example 2

[0064] This example provides an extendable gastrointestinal tube 100, which has the same structure as that of Example 1. The only difference is that: 1, the length of the first tube 110 is 40 cm; and the length of the second tube 120 is 20 cm.

[0065] 2, the ratio of the degradable material is different. In this example, the mass ratio of poly(L-lactide-co-ε-caprolactone) to poly(DL-lactide-glycolide) in the degradable material is 1:1.

[0066] Example 3

[0067] This example provides an extendable gastrointestinal tube 100, which includes a first tube 110, a second tube 120, and a degradable material 130. The opposite ends of the first tube 110 are a proximal end and a distal end, respectively. The first tube 110 and the second tube 120 are fixed by the degradable material 130, and a double-layer structure is formed at the distal end of the first tube 110. The degradable material 130 has a degradation performance after the gastrointestinal tube is used for a period of time, and the second tube 120 moves towards the distal end after the degradable material 130 degrades.

[0068] In this example, the first tube 110 and the second tube 120 are two tubes welded together, and the welding point of the two tubes welded together is the distal end of the first tube 110, and the second tube 120 is located inside the first tube 110. When the degradable material 130 fails, the second tube 120 folds inward into the gastrointestinal tube and extends out of the distal end of the first tube 110 by being driven by chyme. Since the welding point fixes the first tube 110 and the second tube 120, the second tube 120 will not separate from the first tube 110 after being extended.

[0069] In this example, the thickness of the first tube 110 and the second tube 120 is 0.01-0.03 mm. Since the second tube 120 is sleeved on the surface of the first tube 110, the diameter of the second tube 120 needs to be larger than that of the first tube 110. In order to ensure that the second tube 120 extends smoothly and does not extend out of the first tube 110, the diameter of the second tube 120 is larger than that of the first tube 110.

[0070] In this example, the material of the first tube 110 is expanded polytetrafluoroethylene / polyperfluoroethylene propylene composite, the length is 50 cm, the thickness is 0.013 mm, and the diameter is 23 mm. The material of the second tube 120 is expanded polytetrafluoroethylene / polyperfluoroethylene propylene composite, the length is 25 cm, the thickness is 0.013 mm, and the diameter is 25 mm.

[0071] In the present embodiment, the degradable material 130 is poly-L-lactic acid-trimethyl chitosan, in which the mass ratio of poly-L-lactic acid and trimethyl chitosan is 7:3.

[0072] The preparation method of the degradable material 130 is solution forming, and the degradable material 130 is connected with the first sleeve 110 by RF welding.

[0073] Embodiment 4

[0074] The present embodiment provides an extendable gastrointestinal tube 100, which has the same structure as that of Embodiment 3. The only difference is that: 1, the length of the first sleeve 110 is 40 cm; the length of the second sleeve 120 is 20 cm, and the diameter of the first sleeve 110 and the second sleeve 120 is 25 mm, and the thickness is 0.03 mm. The material of the first sleeve 110 and the second sleeve 120 is the same, which is low-density polyethylene.

[0075] 2, the degradable material is different. In the present embodiment, the degradable material is a mixture of poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide), and the mixing ratio is 1:1.

[0076] Embodiment 5

[0077] The present embodiment provides an extendable gastrointestinal tube 100, which has the same structure as that of Embodiment 1. The only difference is that: 1, the length of the first sleeve 110 is 60 cm; the length of the second sleeve 120 is 20 cm, and the diameter of the second sleeve 120 is 28 mm. The material of the first sleeve 110 and the second sleeve 120 is linear low-density polyethylene, and the thickness is 0.05 mm.

[0078] 2, the ratio of the degradable material is different. In the present embodiment, the mass ratio of poly(L-lactide-co-ε-caprolactone) and poly(DL-lactide-glycolide) in the degradable material is 7:3, and the thickness of the annular film as the degradable material is 0.06 mm.

[0079] Embodiment 6

[0080] The present embodiment provides an extendable gastrointestinal tube 100, which has the same structure as that of Embodiment 3. The only difference is that: 1, the length of the first sleeve 110 is 30 cm; the length of the second sleeve 120 is 30 cm, and the diameter of the first sleeve 110 and the second sleeve 120 is 25 mm, and the thickness is 0.03 mm. The material of the first sleeve 110 and the second sleeve 120 is the same, which is polyurethane.

[0081] 2, the degradable material is different. In the present embodiment, the degradable material is a mixture of poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide), and the mixing ratio is 2:8, and the thickness of the annular film as the degradable material is 0.04 mm.

[0082] Example 7

[0083] This example provides an extendable gastrointestinal tube 100, which has the same structure as that of Example 1. The only difference is that: 1, the length of the first tube 110 is 70 cm, and the diameter of the first tube 110 is 20 mm; the length of the second tube 120 is 30 cm, and the diameter of the second tube 120 is 23 mm. The material of the first tube 110 and the second tube 120 is a mixture of linear low-density polyethylene and low-density polyethylene in a mass ratio of 1:1, and the thickness is 0.015 mm.

[0084] 2, the ratio of the degradable material is different. In this example, the degradable material is a mixture of poly-L-lactic acid-trimethyl chitosan and poly(DL-lactide-glycolide), and the mass ratio of poly-L-lactic acid-trimethyl chitosan to poly(DL-lactide-glycolide) is 3:7. The thickness of the annular film as a degradable material is 0.05 mm.

[0085] Example 8

[0086] This example provides an extendable gastrointestinal tube 100, which has the same structure as that of Example 1. The only difference is that: 1, the length of the first tube 110 is 90 cm, and the diameter of the first tube 110 is 20 mm; the length of the second tube 120 is 30 cm, and the diameter of the second tube 120 is 23 mm. The material of the first tube 110 and the second tube 120 is a mixture of expanded polytetrafluoroethylene / polyperfluoroalkyl propylene composite, and the thickness is 0.018 mm.

[0087] 2, the degradable material is poly-p-dioxanone (PDO), and the thickness of the annular film as a degradable material is 0.05 mm.

[0088] Comparative Example 1

[0089] This comparative example provides a gastrointestinal tube, which has the same structure as that of Example 1. The only difference is that the connection between the second tube and the first tube has no degradable material, and is directly connected by laser welding.

[0090] Comparative Example 2

[0091] This comparative example provides a gastrointestinal tube, which has the same structure as that of Example 2. The only difference is that the connection between the second tube and the first tube has no degradable material, and is directly connected by laser welding.

[0092] Comparative Example 3

[0093] This comparative example provides a gastrointestinal tube, which has the same structure as that of Example 3. The only difference is that the connection between the second tube and the first tube has no degradable material, and is directly connected by RF welding.

[0094] Comparative Example 4

[0095] This comparative example provides a digestive tract cannula, which has the same structure as Example 4. The only difference is that the connection between the second cannula and the first cannula has no degradable material, and is directly connected by RF welding.

[0096] Comparative Example 5

[0097] This comparative example provides a digestive tract cannula, which has the same structure as Example 5. The only difference is that the connection between the second cannula and the first cannula has no degradable material, and is directly connected by laser welding.

[0098] Comparative Example 6

[0099] This comparative example provides a digestive tract cannula, which has the same structure as Example 6. The only difference is that the connection between the second cannula and the first cannula has no degradable material, and is directly connected by RF welding.

[0100] Comparative Example 7

[0101] This comparative example provides a digestive tract cannula, which has the same structure as Example 7. The only difference is that the connection between the second cannula and the first cannula has no degradable material, and is directly connected by laser welding.

[0102] Comparative Example 8

[0103] This comparative example provides a digestive tract cannula, which has the same structure as Example 8. The only difference is that the connection between the second cannula and the first cannula has no degradable material, and is directly connected by laser welding.

[0104] Test Example 1

[0105] The extendable digestive tract cannula 100 provided by Examples 1-8 and Comparative Examples 1-8 was tested, and the test method was as follows:

[0106] 1. The extendable digestive tract cannula 100 prepared by Examples 1-8 and Comparative Examples 1-8 was completely immersed in simulated intestinal fluid (the preparation method is referred to the Pharmacopoeia of the People's Republic of China 2022 edition), and was shaken at 37±2℃ in a shaking bed at 40 rpm for different times to the set time, then the cannula in the simulated intestinal fluid was taken out gently, the surface liquid was absorbed with water absorption paper, the first cannula section was fixed, the second cannula distal end was cut, and the extendable part was fixed to the computer material testing machine clamp, and the connection force before measurement was set at 20 mm / min. If the force when the second cannula and the first cannula are separated is less than 1N, it is considered to reach the degradation time.

[0107] The digestive tract cannula at the end of the degradation test is placed in the U-shaped pipeline test device, and the extension of the second cannula under the instantaneous pressure difference of 30 cmH2O is observed. The extension distance ratio = actual extension distance / theoretical extension distance, and the results shown in Table 1 are obtained.

[0108] Table 1: Disintegration of the degradation material

[0109]

[0110] *Note: The connection force of the degradation material of Comparative Examples 1-8 in Table 1 and the first cannula is the connection force of the second cannula and the first cannula.

[0111] As shown in Table 1, the degradation material 130 of the extendable digestive tract cannula 100 provided by the embodiments has better disintegration ability, and can be controlled to disintegrate after 30 days, and the longest disintegration time can reach 180 days, so that the extension effect of the digestive tract cannula can be better achieved.

[0112] The above is only the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An extendable digestive tract cannula, characterized in that, It includes a first sleeve, a second sleeve, and a degradable material. The two ends of the first sleeve are a proximal end and a distal end, respectively. The first sleeve is sleeved with the second sleeve, and a double-layer structure is formed at the distal end of the first sleeve. The double-layer structure is fixed by the degradable material. When the degradable material degrades, the second sleeve moves toward the distal end face of the first sleeve. The degradation time of the degradation material is ≥30 days; The degradable materials include one or more of the following: poly(DL-lactide-glycolic acid), polyglycolic acid-polycaprolactone, poly(L-lactide-co-ε-caprolactone), poly-L-lactic acid, poly-L-lactic acid-trimethyl chitosan, and poly(p-dioxanone). The mass ratio of DL-lactide to glycolide in the poly(DL-lactide-glycolide) is 0.8~1.2:0.8~1.2; the mass ratio of polyglycolide to polycaprolactone in the polyglycolide-polycaprolactone is 7~8:2~3; the mass ratio of L-lactide to ε-caprolactone in the poly(L-lactide-co-ε-caprolactone) is 6.5~7.5:2.5~3.5; and the mass ratio of poly-L-lactic acid to trimethyl chitosan in the poly-L-lactic acid-trimethyl chitosan is 6.5~7.5:2.5~3.

5.

2. The extendable digestive tract cannula according to claim 1, characterized in that, The degradation time of the degradation material is 60 to 180 days.

3. The extendable digestive tract cannula according to claim 1, characterized in that, The connection force between the degradation material and the first sleeve is ≥2.5N.

4. The extendable digestive tract cannula according to claim 1, characterized in that, The connection force between the degradation material and the first sleeve is ≥10N.

5. The extendable digestive tract cannula according to claim 2, characterized in that, The degradation material is an annular membrane with a thickness of 0.01~0.06 mm.

6. The extendable digestive tract cannula according to claim 1, characterized in that, The degradation material is connected to the first sleeve by laser welding or RF welding.

7. The extendable digestive tract cannula according to claim 1, characterized in that, The first sleeve and the second sleeve are formed by folding a single tube or by welding two tubes together, with the welding point of the two tubes being the far end of the first sleeve; the second sleeve is located inside the first sleeve.

8. The extendable digestive tract cannula according to claim 1 or 7, characterized in that, After the degradation material degrades, the second sleeve extends 10-30 cm beyond the first sleeve.

9. The extendable digestive tract cannula according to claim 8, characterized in that, The length of the first sleeve is ≥30cm, and the length of the second sleeve is 15~80cm.

10. The extendable digestive tract cannula according to claim 8, characterized in that, The thickness of both the first sleeve and the second sleeve is 0.01~0.03mm.

11. The extendable digestive tract cannula according to claim 8, characterized in that, The materials of the first sleeve and the second sleeve include one or more composites of polytetrafluoroethylene, fluorinated ethylene propylene copolymer, expanded polytetrafluoroethylene, perfluoroethylene propylene, polyurethane, low-density polyethylene, or linear low-density polyethylene.

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