Composite membrane tube for gastrointestinal stent and preparation method and application thereof

Abstract

This invention provides a composite membrane tube for a digestive tract stent, its preparation method, and its application, relating to the field of medical device technology. By using two different materials to prepare the composite membrane tube, with a first material membrane tube and a second material membrane tube nested together and the second material membrane tube located between the first material membrane tube and the first material connecting section, the wall of the composite membrane tube is thickened in the connection area of ​​the first and second material membrane tubes, preventing the second material membrane tube from turning inward and improving the safety of the composite membrane tube in use. Furthermore, by setting multiple through holes in the second material membrane tube and using a heat-pressing connection between the first material membrane tube and the first material connecting section on both sides of the second material membrane tube, the two materials are combined, ensuring the reliability of the composite membrane tube connection. Simultaneously, the different materials of the first and second material membrane tubes allow for more targeted material selection for the composite membrane tube, thereby improving its overall performance.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a composite membrane tube for a digestive tract stent, its preparation method, and its application. Background Technology

[0002] Health problems caused by overweight or obesity, such as fatty liver and diabetes, pose a serious threat to human life. Reducing gastrointestinal absorption by using digestive tract stents has become one of the important methods in the field of weight loss.

[0003] The membrane tube of existing digestive tract stents moves with the peristalsis of the gastrointestinal tract after implantation. During this process, the membrane tube is prone to inward inversion, or even turning back into the stomach. Once the membrane tube inverts, food cannot flow smoothly from the stomach to the duodenum and small intestine, causing obstruction and endangering the patient's life.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a composite membrane tube for a digestive tract stent, its preparation method, and its application, which can prevent the membrane tube of the digestive tract stent from turning inward and improve the reliability of the membrane tube in use.

[0006] The embodiments of the present invention are implemented as follows:

[0007] In a first aspect, the present invention provides a composite membrane tube for a digestive tract stent, comprising a first material membrane tube, a second material membrane tube, and a first material connecting segment, wherein the first material membrane tube and the first material connecting segment are made of the same material.

[0008] The two opposite ends of the first material membrane tube are a first connecting end and a second connecting end, respectively. The first connecting end is configured to be fixedly connected to the bracket, and the second connecting end is sleeved with the second material membrane tube. A first material connecting segment is also provided at the sleeved position. The second material membrane tube is accommodated between the first material membrane tube and the first material connecting segment. Multiple through holes are opened on the second material membrane tube corresponding to the sleeved position. The first material membrane tube and the first material connecting segment are heat-pressed together through the through holes of the second material membrane tube.

[0009] In an optional embodiment, the total area of ​​all through-holes on the second material membrane tube is ≥15mm². 2 .

[0010] Preferably, the number of through holes is 4 to 60, the diameter of each through hole is 1.5 to 4.5 mm, and the distance between two adjacent through holes is 4 to 9 mm.

[0011] Preferably, multiple through holes are evenly spaced and distributed on the wall of the second material membrane tube.

[0012] Preferably, the multiple through holes are arranged in columns on the second material membrane tube, and the number of columns of the multiple through holes on the second material membrane tube is 1 to 5.

[0013] Preferably, the number of through holes in each row is any one of 6, 8, 10 or 12.

[0014] Preferably, the through holes in adjacent columns are staggered.

[0015] Preferably, the distance between the through hole and the end face of the end sleeved with the second material membrane tube is 10-15 mm.

[0016] In an optional embodiment, the first material membrane tube includes a large-diameter section, a small-diameter section, and a variable-diameter section, the variable-diameter section connecting the large-diameter section and the small-diameter section, the large-diameter section being configured to be fixedly connected to the support, and the small-diameter section being sleeved with the second material membrane tube.

[0017] Preferably, the inner diameter of the large-diameter portion is 50-55 mm, and the inner diameter of the small-diameter portion is 19-21 mm.

[0018] Preferably, the variable diameter section is a straight variable diameter section in the shape of a "V", and the angle of the "V" shape is 50 to 60°.

[0019] Preferably, the length of the first material membrane tube is 80-120 mm, and the length ratio of the large diameter section, the small diameter section and the variable diameter section is 10.5-11.5: 5.5-6.5: 8.5-9.5.

[0020] Preferably, the wall thickness of the first material membrane tube is 0.015 to 0.025 mm.

[0021] In an optional embodiment, the inner diameter of the second material membrane tube is 21-23 mm, the wall thickness is 0.015-0.025 mm, and the length is 800-1200 mm.

[0022] In an optional embodiment, the first material membrane tube, the second material membrane tube, and the first material connecting segment are sequentially sleeved from the inside to the outside.

[0023] In an optional embodiment, the first material membrane tube and the first material connecting section are made of polyethylene.

[0024] Preferably, the material of the second material membrane tube is expanded polytetrafluoroethylene.

[0025] Preferably, the first material membrane tube and the first material connecting section are made of polyethylene, and the second material membrane tube is made of expanded polytetrafluoroethylene.

[0026] In a second aspect, the present invention provides a method for preparing a composite membrane tube of a digestive tract stent as described in any of the foregoing embodiments, comprising sleevedly connecting a first material membrane tube, a second material membrane tube, and a first material connecting segment to each other, such that the first material membrane tube and the first material connecting segment respectively cover the two ends of the through hole of the second material membrane tube, and then heating the first material membrane tube and the first material connecting segment and pressing them together through the through hole.

[0027] In an optional embodiment, the heating and pressing process is a planar pressing process, and during the heating and pressing process, a high-temperature heat insulation component is provided on the inner wall surface of the composite membrane tube.

[0028] Preferably, after one surface of the composite membrane tube is crimped, the other surface is crimped.

[0029] In an optional embodiment, during the heating and pressing process, the heating temperature is 120-130°C, the gas pressure in the reaction chamber is 0.2-0.25 MPa, and the time for the mold to be heated and pressed down is 4-6 seconds.

[0030] Thirdly, the present invention provides the application of a composite membrane tube of a digestive tract stent as described in any of the foregoing embodiments, or a composite membrane tube of a digestive tract stent obtained by any of the foregoing embodiments, in the preparation of a digestive tract stent that avoids inversion of the membrane tube.

[0031] The beneficial effects of the embodiments of the present invention are:

[0032] This invention provides a composite membrane tube for a digestive tract stent, its preparation method, and its application. By using two different materials to prepare the composite membrane tube, a first material membrane tube and a second material membrane tube are nested together, with the second material membrane tube located between the first material membrane tube and the first material connecting segment. Therefore, in the connection area between the first and second material membrane tubes, the wall of the composite membrane tube is thickened, hindering the tendency of the second material membrane tube to invert, preventing it from returning to the stomach and improving the safety of the composite membrane tube. Furthermore, by setting multiple through holes in the second material membrane tube and using a heat-pressing connection between the first material membrane tube and the first material connecting segment on both sides of the second material membrane tube, the two materials are combined, ensuring the reliability of the composite membrane tube connection. Simultaneously, the different materials of the first and second material membrane tubes allow for more targeted material selection for the composite membrane tube. For example, the first material membrane tube connected to the stent can be made of a material with good compatibility or connectivity with the stent, while the second material membrane tube, which is accommodated in the intestine, can be made of a material with less friction with the intestine and more conducive to food passage, thereby improving the overall performance of the composite membrane tube. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the composite membrane tube of the digestive tract stent provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the connection process of the composite membrane tube of the digestive tract stent provided in Embodiment 1 of the present invention;

[0036] Figure 3 This is a cross-sectional view of the sleeve of the composite membrane tube of the digestive tract stent provided in Embodiment 1 of the present invention;

[0037] Figure 4 This is a schematic diagram of the structure of the second material membrane tube provided in Embodiment 1 of the present invention;

[0038] Figure 5 This is a schematic diagram of the structure of the first material membrane tube provided in Embodiment 1 of the present invention;

[0039] Figure 6 The relationship between the through-hole arrangement of the composite membrane tube provided in the embodiments of the present invention and the force-displacement relationship;

[0040] Figure 7 The relationship between the through-hole arrangement of the composite membrane tube provided in the embodiments of the present invention and the maximum principal stress of the membrane tube;

[0041] Figure 8 The relationship between the through-hole spacing and force-displacement of the composite membrane tube provided in the embodiments of the present invention;

[0042] Figure 9 The relationship between the through-hole spacing and the maximum principal stress of the composite membrane tube provided in the embodiments of the present invention;

[0043] Figure 10 This is a diagram showing the anti-rebound state of the composite membrane tube provided in Embodiment 1 of the present invention;

[0044] Figure 11 This is a diagram showing the flip-back state of the composite membrane tube provided in Comparative Example 1 of the present invention;

[0045] Figure 12 This is a side leakage diagram of the composite membrane tube provided in Comparative Example 1 of the present invention;

[0046] Figure 13 The diagrams show the flip-back state of the composite membrane tubes provided in Comparative Examples 2, 5, and 6 of this invention.

[0047] Icons: 100 - Composite membrane tube; 110 - First material membrane tube; 111 - Large diameter section; 112 - Small diameter section; 113 - Variable diameter section; 120 - Second material membrane tube; 121 - Through hole; 130 - First material connecting section. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0052] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0053] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] Example 1

[0055] Please refer to Figure 1 This embodiment provides a composite membrane tube 100 for a digestive tract stent, including a first material membrane tube 110, a second material membrane tube 120 and a first material connecting section 130. The first material membrane tube 110 and the first material connecting section 130 are made of the same material, polyethylene (PE); the second material membrane tube 120 is made of expanded polytetrafluoroethylene (EPTFE).

[0056] In other embodiments, the materials of the first material membrane tube 110 and the first material connecting section 130 may also be at least one of other materials with properties such as softness, good ductility, or good self-melting adhesion.

[0057] The first material membrane tube 110 is a structure used to connect the support and the second material membrane tube 120. Therefore, in some embodiments of the present invention, it is sufficient to ensure that the material of the first material membrane tube 110 can better cover the support.

[0058] In other embodiments, the material of the second material membrane tube 120 may also be other materials with properties such as smooth surface and / or low coefficient of friction, such as perfluoroethylene propylene (FEP) or polyvinylidene fluoride (PVDF).

[0059] The second material membrane tube 120 is contained in the intestine during use and moves with the peristalsis of the intestine. Therefore, the material of the second material membrane tube 120 is required to have a low coefficient of friction and not be too soft. If it is too soft, the second material membrane tube 120 will turn inward, endangering the patient's life.

[0060] However, since the first material membrane tube 110 needs to be stably connected to the support, the first material membrane tube 110 has high requirements for material flexibility. The more flexible the material of the first material membrane tube 110, the more conducive it is to its stable connection with the support.

[0061] Therefore, it can be observed that the performance requirements for the membrane tube of a digestive tract stent vary significantly depending on its location. When the membrane tube material of the digestive tract stent is more flexible, it can form a good and stable bond with the stent, but the portion inside the intestine is prone to inversion, endangering the patient's life. When the membrane tube material of the digestive tract stent has poor extensibility, although it is less likely to invert inside the intestine, its bonding ability with the stent is insufficient, which can also lead to the overall failure of the digestive tract stent. At the same time, when the membrane tube material has poor extensibility, there is also a possibility that the membrane tube may scratch the intestine during the implantation process.

[0062] The applicant designed a composite membrane tube 100 made of composite materials to address the different performance requirements at different locations of the membrane tube. This not only enables the composite membrane tube 100 to be stably integrated with the stent, but also prevents the composite membrane tube 100 from turning inside out in the intestine, thereby improving the overall performance of the composite membrane tube 100.

[0063] The two opposite ends of the first material membrane tube 110 are a first connecting end and a second connecting end, respectively. The first connecting end is configured to be fixedly connected to the support, and the second connecting end is first sleeved onto the second material membrane tube 120 (e.g., Figure 2 As shown), a first material connection section 130 is also provided at the socket position (as shown). Figure 1 (As shown).

[0064] Please refer to Figure 3 In this embodiment, the first material connecting section 130 is an annular structure, and the first material membrane tube 110, the second material membrane tube 120 and the first material connecting section 130 are sequentially sleeved from the inside to the outside, with the second material membrane tube 120 being accommodated between the first material membrane tube 110 and the first material connecting section 130.

[0065] In other embodiments, the first material membrane tube 110, the second material membrane tube 120 and the first material connecting section 130 may be sequentially sleeved from the outside to the inside, but the sleeved connection method of this embodiment is preferred.

[0066] Please refer to Figure 4 The second material membrane tube 120 corresponding to the sleeve position has multiple through holes 121, and the first material membrane tube 110 and the first material connecting section 130 are heat-pressed together through the through holes 121 of the second material membrane tube 120.

[0067] Since the first material membrane tube 110 and the second material membrane tube 120 are made of different materials, direct connection between them may result in failure to connect or instability at the connection point. Therefore, in this embodiment, a through hole 121 is opened on the second material membrane tube 120, and a structure of the same material is provided on both the inner and outer sides of the second material membrane tube 120. By hot pressing, the first material membrane tube 110 and the first material connecting section 130 on the inner and outer sides of the second material membrane tube 120 are rapidly melted and filled into the through hole 121 on the second material membrane tube 120, ensuring a stable connection between the first material membrane tube 110 and the second material membrane tube 120.

[0068] In addition, the above method can not only connect composite membrane tubes 100 made of different materials and improve the overall performance of the membrane tube, but also increase the overall thickness and strength of the connection due to the three-layer structure of the first material membrane tube 110, the second material membrane tube 120 and the first material connecting section 130. This further avoids the second material membrane tube 120 from turning inward and ensures the safety of the composite membrane tube 100 in use.

[0069] In this embodiment, there are 24 through holes 121, each with a diameter of 3 mm and a spacing of 7 mm between adjacent through holes 121. The total area of ​​all through holes 121 on the second material membrane tube 120 is 170 mm². 2 .

[0070] Multiple through holes 121 are distributed in a ring on the tube wall of the second material membrane tube 120, and are arranged in three rows with eight holes in each row. The through holes 121 in adjacent rows are staggered.

[0071] In this embodiment, the minimum distance between the through hole 121 and the end face of the second material membrane tube 120 that is sleeved is 10mm, that is, the distance between the through hole 121 closest to the end face of the sleeved end and that end face is 12mm. In other embodiments, this distance can also be any value among 10mm, 11mm, 13mm, 14mm or 15mm.

[0072] Please refer to Figure 5 In this embodiment, the first material membrane tube 110 includes a large diameter portion 111, a small diameter portion 112, and a variable diameter portion 113. The variable diameter portion 113 connects the large diameter portion 111 and the small diameter portion 112. The large diameter portion 111 is configured to be fixedly connected to the support, and the small diameter portion 112 is sleeved with the second material membrane tube 120.

[0073] In this embodiment, the inner diameter of the large diameter portion 111 is 53 mm, and the inner diameter of the small diameter portion 112 is 20 mm; the variable diameter portion 113 is a straight "V"-shaped variable diameter portion 113, and the angle of the "V" shape is 58°.

[0074] The first material membrane tube 110 provided in this embodiment has a wall thickness of 0.02 mm, a length of 100 mm, and a length ratio of the large diameter portion 111, the small diameter portion 112, and the variable diameter portion 113 of 11:6:9.

[0075] The second material membrane tube 120 provided in this embodiment has an inner diameter of 22 mm, a wall thickness of 0.02 mm, and a length of 1000 mm.

[0076] In other embodiments, the dimensions of the first material membrane tube 110 and the second material membrane tube 120 may also be adjusted according to actual needs.

[0077] Experimental Example 1

[0078] 1) Based on the structure of Example 1, the number and arrangement of the through holes 121 were changed to two rows of 6 holes per row, two rows of 8 holes per row, two rows of 10 holes per row, and two rows of 12 holes per row. The composite membrane tube 100 of the digestive tract stent with the above arrangement of through holes 121 was subjected to performance testing, and the results were as follows: Figure 6 and Figure 7 The results are shown.

[0079] Depend on Figure 6 and Figure 7 It can be seen that as long as the parameters and arrangement of the through holes 121 are set within the requirements of the embodiments of the present invention, the rigidity of the obtained composite membrane tube 100 is close, and the maximum principal stress of the membrane tube is between 20 and 30 MPa.

[0080] 2) Based on the structure of Example 1, the spacing between two adjacent through holes 121 was changed to 6 mm. The resulting composite membrane tube 100 of the digestive tract stent was subjected to performance testing, and the results were as follows: Figure 8 and Figure 9 The results are shown.

[0081] Depend on Figure 8 and Figure 9 It can be seen that as long as the parameters and arrangement of the through holes 121 are set within the requirements of the embodiments of the present invention, the rigidity of the obtained composite membrane tube 100 is close, and the maximum principal stress of the membrane tube is between 20 and 30 MPa.

[0082] Example 2

[0083] This embodiment provides a method for preparing a composite membrane tube 100 for a digestive tract stent, applicable to the preparation of the composite membrane tube 100 for a digestive tract stent of Embodiment 1. The specific steps are as follows:

[0084] S01. In order to facilitate the cutting of through holes 121 on the second material membrane tube 120, the second material membrane tube 120 of EPTFE material is pressed into a flat strip. Then, at a distance of 12mm from the end face, a cutting tool is used to cut out 3 rows of holes on the second material membrane tube 120, with 8 holes in each row, and they are evenly wrapped around the surface of the second material membrane tube 120. The diameter of each through hole 121 is 3mm.

[0085] S02. The first material membrane tube 110 with a large diameter portion 111, a small diameter portion 112 and a variable diameter portion 113, as provided in Example 1, is cut using an ironing machine. Then, Teflon high-temperature insulation cloth is placed into the cut first material membrane tube 110 to prevent the inside of the first material membrane tube 110 from sticking together during the heating and pressing process.

[0086] S03. The second material membrane tube 120 of EPTFE material is sleeved on the surface of the first material membrane tube 110 of PE material, and the depth of the first material membrane tube 110 extending into the second material membrane tube 120 exceeds the position of the through hole 121 of the second material membrane tube 120, so as to ensure that the first material membrane tube 110 blocks one end of the through hole 121. Then, the first material connecting section 130 of PE material is sleeved on the surface of the second material membrane tube 120 of EPTFE material, and the first material connecting section 130 blocks the other end of the through hole 121. Then, the first material connecting section 130 and the first material membrane tube 110 are connected through the through hole 121 by means of heat pressing.

[0087] The heating and pressing process is a planar pressing process, which presses the annular composite template into a flat structure to ensure that the first material connecting section 130 and the first material membrane tube 110 are fused together. For example, after pressing one surface of the composite membrane tube 100, the other surface is pressed.

[0088] In other embodiments, a three-dimensional annular mold can be used to heat and press the entire annular surface of the first material connecting section 130.

[0089] The parameters for heating and pressing include: heating temperature of 125℃, gas pressure in the reaction chamber of 0.22MPa, and heating and pressing time of the mold of 5s.

[0090] S04. After the heating and pressing are completed, wait for the composite membrane tube 100 to cool and solidify, then remove the Teflon high-temperature insulation cloth inside to obtain the composite membrane tube 100 of the digestive tract stent.

[0091] The properties of the EPTFE used in the second material membrane tube 120 in this embodiment include: bending length 7.12cm, puncture force 4.703N, coefficient of friction 0.18, maximum breaking force 30.947N, and elongation at break 232.59%.

[0092] Comparative Example 1

[0093] This comparative example provides a composite membrane tube 100 for a digestive tract stent, whose structure is similar to that of Example 1, except that: the through holes 121 are arranged in a single row at uniform intervals on the second material membrane tube 120, with a total of 6 through holes 121, each with a diameter of 3 mm, and the total area of ​​all through holes 121 on the second material membrane tube 120 is 42 mm². 2 .

[0094] Comparative Example 2

[0095] This comparative example provides a composite membrane tube 100 for a digestive tract stent, whose structure is similar to that of Example 1, except that: the through holes 121 are arranged in two evenly spaced rows on the second material membrane tube 120, with 6 holes in each row, for a total of 12 through holes 121. The diameter of each through hole 121 is 3 mm, and the total area of ​​all through holes 121 on the second material membrane tube 120 is 85 mm². 2 .

[0096] Comparative Example 3

[0097] This comparative example provides a composite membrane tube 100 for a digestive tract stent, whose structure is similar to that of Example 1, except that: the through holes 121 are arranged in a single row at uniform intervals on the second material membrane tube 120, with a total of 8 through holes 121, each with a diameter of 3 mm, and the total area of ​​all through holes 121 on the second material membrane tube 120 is 57 mm². 2 .

[0098] Comparative Example 4

[0099] This comparative example provides a composite membrane tube 100 for a digestive tract stent, whose structure is similar to that of Example 1, except that: the through holes 121 are arranged in two evenly spaced rows on the second material membrane tube 120, with 12 holes in each row, for a total of 24 through holes 121. The diameter of each through hole 121 is 2 mm, and the total area of ​​all through holes 121 on the second material membrane tube 120 is 75 mm². 2 .

[0100] Comparative Example 5

[0101] This comparative example provides a composite membrane tube 100 for a digestive tract stent, whose structure is similar to that of Example 1, except that: the through holes 121 are arranged in two evenly spaced rows on the second material membrane tube 120, with 8 holes in each row, for a total of 16 through holes 121. The diameter of each through hole 121 is 3 mm, and the total area of ​​all through holes 121 on the second material membrane tube 120 is 113 mm². 2 .

[0102] Comparative Example 6

[0103] This comparative example provides a composite membrane tube 100 for a digestive tract stent, wherein the first material membrane tube 110 and the second material membrane tube 120 are made of the same material, both being polyethylene, and neither has a through hole 121.

[0104] Experimental Example 1

[0105] The composite membrane tube 100 of the digestive tract stent provided in Example 1 and the composite membrane tubes 100 of the digestive tract stents provided in Comparative Examples 1 to 6 were subjected to performance tests, and the results were as follows: Figures 10-13 The results are shown in Table 1.

[0106] The maximum principal stress of the membrane tube was tested using finite element analysis; the resistance to rollover and side leakage were tested by filling a U-shaped tube with water to simulate the internal environment; and the connection force was tested using a universal testing machine for tensile testing.

[0107] Table 1 Performance of Composite Membrane Tube 100

[0108]

[0109] As shown in Table 1, the composite membrane tube 100 provided in the embodiments of the present invention experiences a lower maximum principal stress, which is beneficial to improving the anti-overturning ability of the composite membrane tube 100 and ensuring the safety of the digestive tract stent. In Comparative Examples 1-3, due to the small number and / or small diameter of the through holes 121, the composite membrane tube 100 has poor anti-overturning ability and / or side leakage. Simultaneously, the maximum principal stress experienced by the composite membrane tube 100 is relatively large, failing to adequately guarantee the safety of the digestive tract stent. While the composite membrane tubes 100 obtained in Comparative Examples 4 and 5 have anti-overturning ability and do not leak on the sides, the total area of ​​the through holes 121 in Comparative Example 4 is too small, resulting in a large maximum principal stress on the composite membrane tube 100, failing to adequately guarantee the safety of the digestive tract stent. Comparative Example 5 also suffers from a weak connection force between the first material membrane tube 110 and the first material connecting section 130, also failing to adequately guarantee the safety of the digestive tract stent. Comparative Example 6 does not have through holes 121, making it prone to side leakage and not resistant to overturning.

[0110] Depend on Figure 10 It can be seen that, during the rollback resistance test, the composite membrane tube 100 provided in Example 1 did not exhibit rollback, while Figure 11 and Figure 13 (From left to right in the figure are Comparative Examples 2, 5, and 6) The composite membrane tubes 100 provided by Comparative Examples 1, 2, 5, and 6 are clearly flipped back, and Figure 12 The composite membrane tube 100 in Comparative Example 1 exhibits obvious side leakage. This illustrates that the structure of the composite membrane tube 100 provided in this embodiment of the invention offers superior safety in use.

[0111] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite film tube for a digestive tract stent, characterized by, The first material film tube, the second material film tube and the first material connecting section are sequentially sleeved from inside to outside. The first material film tube and the first material connecting section are made of polyethylene. The second material film tube is made of expanded polytetrafluoroethylene.

2. The composite film tube for a digestive tract stent according to claim 1, characterized by The total area of the through holes on the second material film tube is ≥ 15 mm 2 .

3. The composite film tube for a digestive tract stent according to claim 1, characterized by The first connecting end is configured to be fixedly connected with a stent.

4. The composite film tube for a digestive tract stent according to claim 1, characterized by The second connecting end is sleeved with the second material film tube.

5. The composite film tube for a digestive tract stent according to claim 1, characterized by The second material film tube is accommodated between the first material film tube and the first material connecting section.

6. The composite film tube for a digestive tract stent according to claim 1, wherein The second material film tube is provided with a plurality of through holes corresponding to the sleeving position.

7. The composite film tube for a digestive tract stent according to claim 1, characterized by The plurality of through holes are arranged in columns on the second material film tube.

8. The composite film tube for a digestive tract stent according to claim 7, characterized by The diameter of each through hole is 1.5-4.5 mm.

9. The composite film tube for a digestive tract stent according to claim 7, characterized by The distance between adjacent two through holes is 4-9 mm.

10. The composite film tube for a digestive tract stent according to claim 7, characterized by The plurality of through holes are uniformly and spacedly distributed on the tube wall of the second material film tube.

11. The composite film tube for a digestive tract stent according to claim 7, characterized by The through holes of adjacent two columns are arranged in a staggered manner.

12. The composite film tube for a digestive tract stent according to claim 1, characterized by The distance between the through hole and the end face of the end of the second material film tube is 10-15 mm.

13. The composite film tube for a digestive tract stent according to claim 1, characterized by The first material film tube includes a large diameter part, a small diameter part and a variable diameter part.

14. A method of producing a composite film tube for a digestive tract stent according to any one of claims 1 to 13, characterized by, The large diameter part is configured to be fixedly connected with a stent.

15. The preparation method according to claim 14, characterized in that, The inner diameter of the large diameter part is 50-55 mm. The inner diameter of the small diameter part is 19-21 mm. The variable diameter part is a "V"-shaped straight section variable diameter part. The angle of the "V" shape is 50-60°. The length of the first material film tube is 80-120 mm. The length ratio of the large diameter part, the small diameter part and the variable diameter part is 10.5-11.5:5.5-6.5:8.5-9.

5. The wall thickness of the first material film tube is 0.015-0.025 mm. The inner diameter of the second material film tube is 21-23 mm. The wall thickness of the second material film tube is 0.015-0.025 mm. The length of the second material film tube is 800-1200 mm. The first material film tube, the second material film tube and the first material connecting section are sequentially sleeved from inside to outside. The first material film tube and the first material connecting section are heated and crimped through the through holes. The process of heating and crimping is a process of planar pressing. The inner wall surface of the composite film tube is provided with a high-temperature heat insulation member during the process of heating and crimping. After the crimping of one surface of the composite film tube is completed, the crimping of the other surface is replaced.

16. The production method according to claim 14 or 15, characterized by, In the process of heating and pressing, the heating temperature is 120-130℃, the reaction cavity gas pressure is 0.2-0.25MPa, and the time of mold heating and pressing is 4-6s.

17. Use of a composite membrane tube of a gastrointestinal stent according to any one of claims 1 to 13 or produced according to the production method of any one of claims 14 to 16 for the production of a gastrointestinal stent which avoids inversion of the membrane tube.

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