Film-covered structure, film-covered tube, film-covered tube preparation method, and film-covered stent

Abstract

The present invention discloses a coating structure, a coating tube, a method for preparing a coating tube, and a coating stent. The coating structure includes a first braided structure and a second braided structure, the second braided structure and the first braided structure together form the coating structure, the second braided structure is interspersed with the first braided structure and connected to the first braided structure, and the density of the second braided structure is lower than the density of the first braided structure. The coating tube includes a tube body formed by the coating structure. An embodiment of the present invention also provides a method for preparing a coating tube. The coating structure, coating tube, and coating tube preparation method provided by the embodiment of the present invention can effectively solve the occurrence of braiding defects in the prior art, improve the qualified rate, and reduce the cost of the coating tube.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a coated structure, a coated tube, a method for preparing a coated tube, and a coated stent that can be used to treat intravascular diseases. Background Art

[0002] In the medical field, stent grafts have become a mainstream vascular prosthesis in recent years, primarily used to treat conditions such as aneurysms and arterial dissections. A stent graft consists of a membrane and a metal stent, with the membrane primarily acting as a blood blocker. The membrane is typically constructed by sewing a flat membrane into a tubular structure, which is then wrapped around the metal stent.

[0003] At present, coated tubes usually adopt a woven plain weave structure. In order to achieve good low blood seepage, in addition to the morphology of the tissue structure, it is also related to the density of the warp and weft densities. Generally, the warp density is required to reach 150-300 threads / inch, and the weft density is required to reach 150-300 threads / inch. It is very difficult to weave a plain weave with this density because the warp yarns themselves are arranged densely. After the weft yarns are interspersed with the warp yarns, the reed of the loom needs to apply a large beating force to the weft yarns to ensure that the weft yarns and the warp yarns are tightly woven together to achieve the required density of the warp yarns and weft yarns. However, under a large beating force, it is easy to cause the warp yarns or weft yarns to break inside the fabric, forming defects (burrs, holes, and skipped yarns, etc.). Especially when making a coated structure with a changing tube diameter, since the density of each warp yarn in the weft direction increases, the defect generation rate also increases. The defects directly affect the blood seepage and strength of the coated stent, resulting in an increased probability of high-risk medical accidents.

[0004] With the advancement of textile technology, one-piece tubular membranes are increasingly recognized by the medical device industry. Their performance advantages are reflected in the following: one-piece tubular membranes avoid the existence of sutures, saving labor hours for the production of coated stents, and the one-piece coated tubes have uniform water seepage and stable strength; the one-piece coated tubes have no sutures, which reduces the thickness of the coated tubes, makes the sheath size of the coated stent smaller, and improves the patency rate of the surgical process. As for the existing one-piece coated tube weaving technology, since it needs to be woven as one, if the radial dimension of the tube body becomes smaller, such as the tube body is a vertebral canal, a bifurcated tube or an irregular tube, it is more likely that the warp yarn density will increase instantly, which will directly lead to an increase in the warp yarn tension and / or weft yarn tension. As the tension increases, the risk of yarn breakage will increase. Once the yarn breaks, defects that affect the coating performance will form on the fabric surface, which directly affects the strength and water seepage of the tube body. Therefore, the weaving qualification rate of the one-piece coated tubes in the existing technology is low, the cost is high, and it is difficult to popularize and use, which has become a bottleneck in the development of this technology. Summary of the Invention

[0005] Based on this, it is necessary to provide a coating structure, a coating tube structure, a coating tube preparation method and a coating bracket to effectively solve one or more technical problems in the existing technology, improve the coating tube weaving qualification rate and reduce the manufacturing cost of the coating tube.

[0006] The present invention provides a coating structure, including a first woven structure, which also includes a second woven structure. The second woven structure and the first woven structure together form the coating structure. The second woven structure is interspersed with the first woven structure and connected to the first woven structure. The density of the second woven structure is lower than that of the first woven structure.

[0007] In one embodiment, the membrane structure is woven from warp yarns and weft yarns, and the second woven structure extends along the warp yarn direction.

[0008] In one embodiment, the number of the second braided structures is two or more, and adjacent second braided structures are spaced apart and arranged in parallel.

[0009] In one embodiment, the interval between adjacent second braided structures is 3 mm to 6 mm.

[0010] In one embodiment, the first weaving structure is a plain weave structure; the second weaving structure is a warp-weight plain weave structure and / or a twill weave structure.

[0011] The present invention also provides a film-coated tube, comprising a tube body formed by any one of the above-mentioned film-coated structures.

[0012] In one embodiment, the membrane structure is sewn into a tubular shape to form the tubular body.

[0013] In one embodiment, the membrane structure is made into a tubular shape through an integral weaving process, thereby forming the tube body.

[0014] In one embodiment, the tube body has at least a first tube segment and a second tube segment connected to each other, the diameter of the first tube segment is larger than the diameter of the second tube segment, and at least a portion of the second braided structure is disposed in the second tube segment.

[0015] In one embodiment, the second tube segment has a connecting end connected to the first tube segment and a free end opposite to the connecting end, and a portion of the second braided structure disposed on the second tube segment extends from the connecting end to the free end.

[0016] In one embodiment, the first pipe segment is cylindrical, and the second braided structure is entirely arranged in the second pipe segment; or, the first pipe segment includes a frusto-conical transition pipe segment, and another part of the second braided structure is arranged in the frusto-conical transition pipe segment and extends to the connecting end of the second pipe segment, and is connected to the part of the second braided structure arranged in the second pipe segment.

[0017] In one embodiment, the pipe body includes a main pipe section and at least two branch pipe sections, each of the branch pipe sections is connected to one end of the main pipe section to form an integrated structure and is communicated with the main pipe section, at least one of the branch pipe sections is the second pipe section, and the main pipe section includes the first pipe body.

[0018] In one embodiment, the second braided structure extends along the axial direction of the branch pipe segment.

[0019] In one embodiment, the pipe body has at least two second pipe sections, and at least two of the branch pipe sections are the second pipe sections.

[0020] The present invention provides a method for preparing a film-coated tube, comprising the following steps:

[0021] A first woven structure and a second woven structure are woven using weft yarns and warp yarns to form the body of the coated tube, and the second woven structure is inserted into and connected to the first woven structure, and the density of the second woven structure is lower than that of the first woven structure.

[0022] In one embodiment, when weaving the second weaving structure, the second weaving structure is extended along the direction of the warp yarns.

[0023] In one embodiment, the steps include:

[0024] The step of using weft yarns and warp yarns to weave the first woven structure and the second woven structure to jointly form the tube body of the coated tube also includes: using the weft yarns and the warp yarns to weave a part of the first woven structure and a part of the second woven structure to form a first tube segment of the coated tube, and continuing to use the weft yarns and the warp yarns to weave another part of the first woven structure and the second woven structure to form at least one second tube segment of the coated tube, wherein the diameter of the first tube segment is greater than the diameter of the second tube segment.

[0025] In one embodiment, the step of using the weft yarn and the warp yarn to weave a part of the first woven structure and a part of the second woven structure to form the first tube segment of the coated tube also includes: using the weft yarn and the warp yarn to weave a part of the first woven structure to form a part of the first tube segment, and continuing to use the weft yarn and the warp yarn to weave another part of the first woven structure and the second woven structure to form a conical transition tube segment of the first tube segment.

[0026] In one embodiment, the step of using weft yarns and warp yarns to weave the first woven structure and the second woven structure to jointly form the tube body of the coated tube also includes: using the weft yarns and the warp yarns to weave a part of the first woven structure to form a cylindrical first tube segment of the coated tube, and continuing to use the weft yarns and the warp yarns to weave another part of the first woven structure and the second woven structure to form at least one second tube segment of the coated tube, wherein the diameter of the first tube segment is greater than the diameter of the second tube segment.

[0027] In one embodiment, the first braided structure and the second braided structure are woven using weft yarns and warp yarns through an integrated braiding process to directly form the tube body of the coated tube.

[0028] The present invention provides a coated stent, characterized in that it comprises any one of the above-mentioned coated tubes and a stent body, wherein the coated tube is coated on the outer surface of the stent body.

[0029] The coated tube structure of the present invention can effectively solve the problem that defects are easily caused by excessive warp yarn density during the weaving process of existing coated tubes, and improve the finished product rate of the coated tube structure. Furthermore, the coated tube of the present invention can effectively solve the problem that defects are caused by changes in fabric density as radial dimensions change during the weaving process of existing coated tubes. In particular, it solves the inevitable technical bottleneck of increased defects caused by sudden changes in the radial dimensions of the tube body when weaving the coated tube as a whole, thereby improving the qualified rate of the coated tube weaving and reducing the cost of the coated tube.

[0030] In order to solve the problem of fabric defects during the weaving process, the present invention sets a second weaving structure design for the local position of the woven fabric, locally reduces the yarn density, and prevents the occurrence of defects; the above design can not only ensure smooth weaving and avoid fabric defects, but also ensure the effective thickness and water permeability of the fabric, while effectively avoiding the occurrence of weaving defects, improving the qualified rate of finished product weaving, and reducing the cost of the coated tube structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a film-coated tube according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic structural diagram of a film-coated tube according to another embodiment of the present invention;

[0033] Figure 3 This is a schematic structural diagram of a film-coated tube according to another embodiment of the present invention;

[0034] Figure 4 Schematic diagram of plain weave structure;

[0035] Figure 5 This is a schematic diagram of Chongping’s organizational structure.

[0036] Description of Reference Numerals

[0037] 10: Film-coated tube structure;

[0038] 100: Pipe body;

[0039] 200: Supervisor section;

[0040] 210: first braided structure;

[0041] 300: branch pipe section;

[0042] 310: second braided structure;

[0043] 400: bifurcation position;

[0044] 500: Transition pipe section. DETAILED DESCRIPTION

[0045] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0046] It should be noted that when an element is referred to as being "wrapped around" another element, it may be directly wrapped around the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intervening element. When an element is referred to as being "woven into" another element, it may be directly woven into the other element or there may be an intervening element.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0048] The first embodiment of the present invention provides a coating structure, including a first woven structure and a second woven structure. The second woven structure and the first woven structure together form a coating structure. The second woven structure is interspersed with the first woven structure and connected to the first woven structure. The density of the second woven structure is lower than that of the first woven structure.

[0049] Furthermore, the membrane structure provided in this embodiment is woven from warp and weft yarns, with a second woven structure interspersed with the first woven structure and extending along the warp direction, thereby forming the membrane structure of this embodiment. Preferably, there are two or more second woven structures, with adjacent second woven structures spaced apart and arranged parallel to each other, and the spacing between adjacent second woven structures is 3mm-6mm. In this embodiment, the first woven structure is a plain weave structure; the second woven structure is a warp-heavy plain weave structure and / or a twill weave structure.

[0050] The second embodiment of the present invention provides a coated tube, comprising a tube body formed by the coated structure of the first embodiment. The coated tube provided in this embodiment is suitable for coating the outer surface of a stent body to form a coated stent.

[0051] like Figures 1 to 3 As shown, the body of the coated tube in the embodiment of the present invention is formed by a tubular coated structure made by an integral braiding process. In another embodiment, the body of the coated tube 10 can also be made by first forming a sheet-like coated structure, and then connecting the sheet-like coated structure to form the tube body, for example, by sewing the coated structure to form the tube body of the coated tube 10.

[0052] In this embodiment, a tube body formed by integrally braiding a membrane structure is used as an example. Specifically, the membrane-coated tube 10 includes a tube body 100 woven from a first braided structure 210 and a second braided structure 310. The second braided structure 310 is interspersed within and connected to the first braided structure 210. The density of the second braided structure 310 is lower than that of the first braided structure 210. Preferably, the second braided structure 310 extends along the axial direction of the tube body 100, i.e., the warp direction.

[0053] Furthermore, the number of the second woven structures 310 is two or more. There is a gap between two adjacent second woven structures 310. Preferably, the gap between two adjacent second woven structures 310 is 3mm-6mm. For example, the gap between two adjacent second woven structures 310 is 3mm, 4mm, 5mm, 6mm or other non-integer values. The gap between two adjacent second woven structures 310 can also be designed according to the fabric performance requirements during actual weaving. In the actual weaving process, the gap between two adjacent second woven structures 310 can be set according to the number of warp yarns in the first woven structure 210; for example, one or more warp yarns used to weave the first woven structure 210 can be spaced between two adjacent second woven structures 310.

[0054] Preferably, if Figure 1 or Figure 2 As shown, multiple second braided structures 310 are arranged parallel to the axial direction of the tube body 100 and are evenly distributed on the circumferential surface of the tube body 100. The intervals between each two adjacent second braided structures 310 are equal. This design can evenly reduce the density of the tube body 100 and reduce the braiding difficulty of the tube body 100.

[0055] Furthermore, the first weaving structure 210 is a plain weave structure, and the second weaving structure 310 is a warp-weight plain weave structure and / or a twill weave structure. It should be noted that the plain weave structure is an interweaving of warp yarns and weft yarns in which one floats and the other sinks (e.g. Figure 4 The warp-heavy plain weave structure is based on plain weave, and the weave points are extended along the warp direction to become a double plain weave (as shown in the figure). Figure 5 (As shown). A twill weave structure is one in which each yarn has only one warp weave point and the rest are weft weave points, or only one weft weave point and the rest are warp weave points, collectively referred to as a twill weave structure. Because the weaving density of a warp-heavy plain weave structure and / or a twill weave structure is lower than that of a plain weave structure, this embodiment utilizes a design that interweaves a plain weave structure with a warp-heavy plain weave structure and / or a twill weave structure to reduce the local density of the fabric of the coated tube structure 10, thereby reducing the probability of defects on the fabric surface of the coated tube structure 10.

[0056] Preferably, a plain weave structure and / or a twill weave structure formed by weaving 1-2 warp yarns and weft yarns can be selected to avoid an increase in water seepage while ensuring that defects are reduced.

[0057] The following are three implementations of the film-coated tube 10 provided in the embodiments of the present invention, specifically as follows:

[0058] In the first implementation, Figure 1As shown, the tube body 100 comprises at least a first tube segment 200 and a second tube segment 300 connected to each other. The diameter of the first tube segment 200 is larger than that of the second tube segment 300, and at least a portion of the second braided structure 310 is disposed in the second tube segment 300. The first tube segment 200 includes a tapered transition tube segment 500, the ends of which respectively connect the second tube segment 300 and the other cylindrical portions of the first tube segment 200.

[0059] The radial dimensions of the first pipe segment 200 change from the transition pipe segment 500. Since the change in the radial dimensions of the pipe body 100 is a gradual change in the radial dimensions of the pipe segments, it is understood that the second braided structure 310 can be installed either at the beginning of the transition pipe segment or at the end of the transition pipe segment. When the second braided structure 310 is installed at the beginning of the transition pipe segment, the second braided structure 310 is installed on both the first pipe segment and the second pipe segment. That is, at least a portion of the second braided structure 310 is installed on the second pipe segment, while another portion is installed on the first pipe segment. The portion of the second braided structure 310 installed on the second pipe segment 300 is connected to the other portion of the second braided structure 310 installed on the first pipe segment.

[0060] The location where the transition pipe section 500 ends can be considered to be the connecting end where the second pipe section 300 is connected to the first pipe section 200. The second pipe section 300 also includes a free end opposite the connecting end. The second braided structure 310 can also be provided at the location where the transition pipe section 500 ends, and the second braided structure 310 extends from the connecting end to the free end of the second pipe section 300. It is understandable that because the integrated braiding process is a computer-controlled program that controls a textile machine to automatically execute the braiding program, in practice, due to issues such as machine control accuracy, the starting position of the second braided structure 310 in an actual product may deviate from the predetermined position within a reasonable error range. For example, the second braided structure 310 extends from the area near the connecting end of the second pipe section 300 (3-5 mm above and below) to the free end of the second pipe section 300. This should also be considered as the second braided structure 310 extending from the connecting end to the free end of the second pipe section 300.

[0061] like Figure 1 As shown, in this embodiment, the second braided structure 310 extends from between the starting position and the ending position of the transition tube segment 500 to the free end of the second tube segment 300 .

[0062] During the tube body weaving process, changes in tube diameter will cause a sudden change in warp density, increasing the risk of defects. Therefore, the starting position and the ending position of the transition tube segment 500 are both positions where defects begin to occur in large numbers, and from the ending position of the transition tube segment 500 to the free end of the second tube segment 300, since the warp yarn becomes further denser, the probability of defects occurring is higher than from the starting position of the transition tube segment 500 to the ending position of the transition tube segment 500. Therefore, preferably, the second braided structure 310 extends from the starting position of the transition tube segment 500 to the free end of the second tube segment 300, which can minimize the occurrence of defects. However, it can be understood that setting the second braided structure 310 at any of the above positions can achieve the technical effect of reducing defects.

[0063] It is understandable that a second braided structure 310 may be provided in the axial direction of the entire coated tube (ie, from the free end of the first tube segment to the free end of the second tube segment) to reduce defects to a certain extent, but this embodiment is not limited thereto.

[0064] The second implementation is similar to the first implementation. For the sake of brevity, only the differences are described below. Figure 2 As shown, the tube body 100 of the coated tube provided in this embodiment includes a first tube segment 200 (i.e., the main tube segment) and two second tube segments 300 (i.e., the branch tube segments), thereby forming a bifurcated tube structure. The main tube segment and each branch tube segment are both cylindrical tubes. Each branch tube segment is connected to one end of the main tube segment to form an integral structure and communicate with the main tube segment. The second braided structure 310 extends axially along the branch tube segments, starting at the boundary between the branch tube segments and the main tube segment. The second braided structure 310 is provided on both branch tube segments.

[0065] Of course, in other embodiments, the second braided structure 310 may also be arranged only on one branch pipe segment or extend axially along the branch pipe segment starting from near the boundary position between the branch pipe segment and the main pipe segment, which can also achieve the technical effect of reducing the generation of defects. The reason has been explained in the first implementation method and will not be repeated here.

[0066] The third implementation is similar to the second implementation. For the sake of brevity, only the differences are described below. Figure 3 As shown, the first tube body 200 further includes a transition tube segment 500 having a varying radial dimension. The transition tube segment 500 is connected to and communicates with the two second tube segments 300 (i.e., branch tube segments). It is understood that the second braided structure 310 can be positioned at the beginning or end of the transition tube segment 500, or at a position between the beginning and end of the transition tube segment 500, and this embodiment does not impose any limitation on this.

[0067] In the coated tube provided by the above-described embodiment of the present invention, when the radial dimension of the tube body 100 decreases from one end to the other, a second braided structure 310 is woven at the end with the smaller radial dimension, thereby reducing the fabric density of the original first braided structure 210, thereby lowering the local yarn density and preventing the formation of defects. At the boundary where the radial dimension of the tube body 100 changes, the braided structure is changed from a single plain weave to a plain weave structure with warp-heavy plain weaves uniformly interspersed within the plain weave structure. This reduces the local fabric density of the coated tube structure 10. Lowering the density reduces yarn tension, making the fabric of the coated tube structure 10 less susceptible to defects during the weaving process.

[0068] The third embodiment of the present invention further provides a method for preparing a film-coated tube, which is used to prepare the film-coated tube in the above embodiment. The method for preparing the film-coated tube structure includes the following steps:

[0069] When the pipe body 100 is a non-bifurcated pipe structure with a transition pipe section 500 in the first implementation, the preparation method is as follows:

[0070] The weft yarns and the warp yarns are used to weave a part of the first woven structure 210 to form a part of the first tube segment, the weft yarns and the warp yarns are used to weave another part of the first woven structure 210 and the second woven structure 310 inserted into and connected to the first woven structure 210 to form a transition tube segment 500, and the weft yarns and the warp yarns are used to weave another part of the first woven structure 210 and another part of the second woven structure 310 to form a second tube segment, and the second woven structure 310 extends along the warp direction of the branch tube segment.

[0071] When the pipe body 100 is a bifurcated pipe structure without the transition pipe section 500 in the second implementation, the preparation method is as follows:

[0072] The weft yarn and the warp yarn are used to weave a part of the first woven structure 210 to form a main pipe section, and the weft yarn and the warp yarn are used to weave another part of the first woven structure 210 and a second woven structure 310 that is inserted into and connected to the first woven structure 210 to form two or more branch pipe sections that are connected and communicated with the main pipe section, and the second woven structure 310 extends along the warp yarn direction of the branch pipe section.

[0073] When the pipe body 100 is a bifurcated pipe structure with a transition pipe section 500 in the third implementation, the preparation method is as follows:

[0074] The weft yarn and the warp yarn are used to weave a part of the first woven structure 210 to form a part of the main pipe section, the weft yarn and the warp yarn are used to continue to weave another part of the first woven structure 210 and the second woven structure 310 inserted into the first woven structure 210 and connected to the first woven structure 210 to form a transition pipe section, the weft yarn and the warp yarn are used to continue to weave another part of the first woven structure 210 and another part of the second woven structure 310 to form two or more branch pipe sections connected and communicated with the main pipe section, and the second woven structure 310 extends along the warp direction of the branch pipe section.

[0075] Compared with the prior art, the method for preparing the coated tube provided in the embodiment of the present invention has a relatively small yarn density at the location of the second braided structure 310 on the branch tube segment because the density of the second braided structure 310 is lower than that of the first braided structure 210, thereby preventing the generation of defects during weaving.

[0076] The fourth embodiment of the present invention provides a stent graft, wherein the coated tube 10 prepared by the coated tube preparation method of the third embodiment is coated on the outer surface of the stent body to form the stent graft.

[0077] The coated tube provided in this embodiment has a significantly improved qualification rate while maintaining the existing tensile strength and water permeability.

[0078] When developing the film-coated tube with a bifurcated tube structure, the inventor measured the qualified rates of the film-coated tubes with and without the second braided structure 310 through batch experiments.

[0079] Then 110 coated tubes from the prior art were selected for pass rate detection. The main tube section of the coated tube had a diameter of 26 mm and a length of 120 mm. The two branch tube sections had diameters of 12 mm and lengths of 140 mm respectively. That is, the main tube section included a transition tube section between the branch tube section. The pass rate was only 22.7%, and the main reason for the failure was mainly defects. After a second weaving structure 310 (a single warp yarn and multiple weft yarns formed a flat warp) was set on the transition tube section and the branch tube section, the starting position of the second weaving structure 310 was located at the connecting end of the branch tube section (basically without error). The interval between two adjacent weaving structures was 30-60 yarns and the width was 3-6 mm. After selecting 110 tubes for testing, the applicant found that the pass rate rose to 86.67%.

[0080] Then 90 coated tubes from the prior art were selected for pass rate detection. The main tube section of the coated tube had a diameter of 24 mm and a length of 120 mm. The two branch tube sections had diameters of 12 mm and lengths of 140 mm respectively. That is, the main tube section did not include the transition tube section between the branch tube section. The pass rate was only 27.78%, and the main reason for the failure was mainly defects. After a second weaving structure 310 (a single warp yarn and multiple weft yarns formed a flat warp) was set on the transition tube section and the branch tube section, the starting position of the second weaving structure 310 was located at the connecting end of the branch tube section (basically without error), and the interval width between two adjacent weaving structures was 3-5 mm. After selecting 90 tubes for testing, the applicant found that the pass rate rose to 87.50%.

[0081] In terms of water permeability, the coated tubes in two basic embodiments were selected for pass rate testing. The diameter of the main tube section of the coated tube was 26 mm and the length was 120 mm. The diameters of the two branch tube sections were 12 mm and the lengths were 140 mm. The starting position of the second braided structure 310 (the warp weight formed by a single warp yarn and multiple weft yarns) was located at the connection end of the branch tube section (basically without error). The interval width between the two adjacent braided structures was 3-5 mm. As a result, the partial water permeability parameter of the first braided structure 210 of one coated tube was: 113 ml / cm 2 / min; the water seepage parameter of the branch pipe section 300 of the mixed portion of the first braided structure 210 and the second braided structure 310 is: 115ml / cm 2 / min, and the partial water seepage parameter of the first braided structure 210 of another coated tube is: 109ml / cm 2 / min; The water seepage parameter of the branch tube body 300 of the mixed portion of the first braided structure 210 and the second braided structure 310 is: 103ml / cm 2 / min.

[0082] The test data shows that after the second weaving structure 310 is added to the coated tube in this embodiment, not only will it not significantly affect the water permeability of the coated tube, but the water permeability parameters of the branch pipe section of the coated tube may also be smaller than the water permeability parameters of the main body. This is mainly because the warp density of the branch tube body increases after the diameter of the branch tube body is reduced, which causes the water permeability parameters of the first weaving mechanism on the branch tube body to become smaller. Although the second weaving structure 310 on the branch tube body will increase the water permeability parameters of the branch tube body, the increase in the overall warp density causes the water permeability parameters of the first weaving mechanism to become smaller. After the overall addition, the water permeability parameters of the branch tube body are slightly smaller than the water permeability parameters of the main body.

[0083] The coated stent provided by the embodiment of the present invention can effectively solve the problems of low qualified rate and many defects in the weaving process of existing coated tubes, especially in the one-piece weaving molding process, the problem of defects caused by changes in the fabric density due to changes in the radial size of the fabric will be solved, which solves the technical bottleneck of inevitable defects caused by changes in the radial size of the tube body, improves the qualified rate of coated tube weaving, and reduces the cost of coated tubes. In order to solve the problem of fabric defects in the weaving process, the present invention sets a second weaving structure 310 at a local position of the woven fabric to locally reduce the yarn density and prevent the generation of defects; since the second weaving structure 310 is set locally, the above design can not only ensure smooth weaving and avoid fabric defects, but also ensure the effective thickness and water seepage function of the fabric, avoid the problem of thickening of the entire fabric thickness and the resulting increase in water seepage, effectively solve the occurrence of weaving defects, improve the qualified rate of finished product weaving, and reduce the cost of the coated tube structure.

[0084] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A film-coated tube, characterized in that: It includes a tube body formed by a membrane structure, the membrane structure includes a first braided structure and a second braided structure, the second braided structure and the first braided structure together form the membrane structure, the membrane structure is woven into a tube by a one-piece braiding process of warp yarn and weft yarn to form the tube body, the second braided structure extends along the warp direction, the second braided structure is interspersed with the first braided structure and connected to the first braided structure, the density of the second braided structure is lower than the density of the first braided structure, the first braided structure is a plain weave structure; the second braided structure is a warp-heavy plain weave structure and / or a twill weave structure, The tube body has at least a first tube segment and a second tube segment connected to each other, the diameter of the first tube segment is larger than the diameter of the second tube segment, at least a portion of the second braided structure is arranged in the second tube segment, the second tube segment has a connecting end connected to the first tube segment and a free end opposite to the connecting end, the portion of the second braided structure arranged in the second tube segment extends from the connecting end to the free end, the first tube segment includes a frusto-conical transition tube segment, a portion of the second braided structure is arranged in the frusto-conical transition tube segment and extends to the connecting end of the second tube segment, and is connected to the portion of the second braided structure arranged in the second tube segment.

2. The film-coated tube according to claim 1, characterized in that: The number of the second braided structures is two or more, and adjacent second braided structures are arranged at intervals and in parallel.

3. The film-coated tube according to claim 2, characterized in that: The interval between adjacent second braided structures is 3 mm to 6 mm.

4. The film-coated tube according to any one of claims 1 to 3, characterized in that: The pipe body includes a main pipe section and at least two branch pipe sections, each of the branch pipe sections is connected to one end of the main pipe section to form an integrated structure and communicates with the main pipe section, at least one branch pipe section is the second pipe section, and the main pipe section is the first pipe section.

5. The film-coated tube according to claim 4, characterized in that: The second braided structure extends along the axial direction of the branch pipe segment.

6. The film-coated tube according to claim 4, characterized in that: The pipe body has at least two second pipe sections, and at least two of the branch pipe sections are both second pipe sections.

7. A method for preparing a film-coated tube according to any one of claims 1 to 6, characterized in that: The steps include: Use weft yarns and warp yarns to weave a part of the first woven structure and a part of the second woven structure to form the first tube segment of the coated tube, and continue to use the weft yarns and the warp yarns to weave another part of the first woven structure and the second woven structure to form at least one second tube segment of the coated tube, wherein the diameter of the first tube segment is greater than the diameter of the second tube segment, the second woven structure is interspersed with the first woven structure and connected to the first woven structure, the second woven structure extends along the direction of the warp yarn, the first woven structure is a plain weave structure; the second woven structure is a warp-weight plain weave structure and / or a twill weave structure, the density of the second woven structure is lower than the density of the first woven structure, and the first woven structure and the second woven structure together form the tube body of the coated tube.

8. The method for preparing a film-coated tube according to claim 7, wherein: The step of using the weft yarn and the warp yarn to weave a part of the first woven structure and a part of the second woven structure to form the first tube segment of the coated tube also includes: using the weft yarn and the warp yarn to weave a part of the first woven structure to form a part of the first tube segment, and continuing to use the weft yarn and the warp yarn to weave another part of the first woven structure and the second woven structure to form a conical transition tube segment of the first tube segment.

9. A stent graft, characterized in that: It comprises the coated tube according to any one of claims 1-6 or the coated tube prepared by the preparation method according to any one of claims 7-8, and a stent body, wherein the coated tube is coated on the outer surface of the stent body.

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