Covered stent

Abstract

The present application relates to a kind of film-covered stents, including stent and the film covering on the stent, the film has the opposite first end and second end in axial direction, the first end of the film is formed with the passage with opening state and closed state, the passage is in opening state when being impacted by fluid, in closed state when no fluid impact.This film-covered stent can avoid affecting the blood supply of branch vessels.

Description

Technical Field

[0001] This invention relates to the field of interventional medical devices, and in particular to a covered stent. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Aneurysm is a common vascular disease in clinical practice, mostly occurring in the elderly. This disease can easily lead to aneurysm rupture, posing a great threat to the patient's life.

[0004] With the continuous development of modern medical technology, minimally invasive surgery has been used to implant covered stents into the body for the treatment of aortic aneurysms and dissecting aneurysms. Due to its minimal trauma and rapid recovery, it has gained widespread application. This treatment involves compressing the covered stent into a delivery device, guiding it along a pre-implanted guidewire into the body. Once it reaches the lesion site, the covered stent is released to isolate the lesion and reconstruct the blood flow channel. After the aneurysm and dissection lose their blood supply, the remaining blood in the aneurysm cavity gradually thrombus and myovascular tissue forms. The dilated aneurysm wall contracts under pressure, gradually returning to a near-original state, thereby achieving the goal of treating aortic aneurysms and dissecting aneurysms.

[0005] If the covered stent is implanted too close to the branch, the proximal cover may obstruct the opening of the branch vessel, affecting the blood supply to the branch vessel and causing harm to the patient. Summary of the Invention

[0006] Therefore, it is necessary to provide a covered stent that can avoid affecting the blood supply of branch vessels.

[0007] A covered stent includes a stent and a covering film on the stent. The covering film has an axially opposite first end and a second end. A channel with an open state and a closed state is formed on the first end of the covering film. The channel is in the open state when subjected to fluid impact and in the closed state when there is no fluid impact.

[0008] In one embodiment, there are multiple channels, which are spaced apart circumferentially along the coating.

[0009] In one embodiment, the channel is an opening formed at the first end, the opening extending axially from the end of the first end toward the second end.

[0010] In one embodiment, the channel includes a first edge line and a second edge line, which coincide or align in a closed state; one of the first edge line and the second edge line is covered.

[0011] In one of the embodiments, the channel comprises a first edge line, a second edge line, a third edge line and a fourth edge line, in the natural state, the first edge line and the third edge line coincide or align, the second edge line and the fourth edge line coincide or align; or, the third edge line and the fourth edge line are in the covered state.

[0012] In one of the embodiments, in the natural state, the first edge line and the third edge line coincide or align, the second edge line and the fourth edge line coincide or align, and the first edge line extends from the middle of the second edge line in a direction perpendicular to the second edge line.

[0013] In one of the embodiments, the covered stent further comprises a sealing member, and a window is formed on the first end of the covering film, the sealing member is arranged on the covering film and covers the window to form the channel.

[0014] In one of the embodiments, the window has an edge line, in the closed state, the sealing member covers the edge line; in the open state, at least part of the edge line is not covered by the sealing member.

[0015] In one of the embodiments, the sealing member covers the window, and opposite ends of the sealing member are connected with the covering film respectively, and the part between the opposite ends of the sealing member is overlapped on the covering film so that the sealing member can cover the window to form the channel.

[0016] In one of the embodiments, the sealing member covers the window, and one end of the sealing member is connected with the covering film so that the sealing member can cover the window to form the channel.

[0017] In one of the embodiments, the covered stent further comprises a marking structure, the marking structure is located on the first end of the covering film, and the marking structure and the channel are staggered with each other.

[0018] The first end of the covering film of the above covered stent forms a channel, when the covered stent is implanted into a blood vessel, due to the channel being in the open state when being impacted by the blood flow, even if the first end of the covering film is located at the branch part, the blood supply of the branch blood vessel will not be affected by the blockage of the blood flow of the branch blood vessel. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The structure diagram of the covered stent of one of the embodiments;

[0020] Figure 2 The structure diagram of the covered stent of one of the embodiments; Figure 1 The schematic diagram of the channel of the covered stent shown in the open state;

[0021] Figure 3 is a partial enlarged view of Figure 2 ;

[0022] Figure 4 is a schematic view of a covered stent implanted in a blood vessel as shown in Figure 1 ;

[0023] Figure 5 is a schematic view of another state of a covered stent implanted in a blood vessel as shown in Figure 1 ;

[0024] Figure 6 is a schematic view of a structure of a covered stent of another embodiment;

[0025] Figure 7 is a schematic view of a covered stent as shown in Figure 6 , with a channel in an open state;

[0026] Figure 8 is a partial enlarged view of Figure 7 ;

[0027] Figure 9 is a schematic view of a covered stent of another embodiment, with a channel in an open state;

[0028] Figure 10 is a partial enlarged view of Figure 9 ;

[0029] Figure 11 is a schematic view of a structure of a covered stent of another embodiment;

[0030] Figure 12 is a partial enlarged view of Figure 11 ;

[0031] Figure 13 is a schematic view of a structure of a channel of a covered stent as shown in Figure 11 ;

[0032] Figure 14 is a schematic view of a structure of a covered stent of another embodiment;

[0033] Figure 15 is a partial enlarged view of Figure 14 ;

[0034] Figure 16 is a schematic view of a structure of a covered stent of another embodiment;

[0035] Figure 17 is a partial enlarged view of Figure 16 ;

[0036] Figure 18 is a schematic view of a structure of a channel of another embodiment;

[0037] Figure 19 A partial structure diagram of a covered stent according to an embodiment;

[0038] Figure 20 A structure diagram of a covered stent according to another embodiment. DETAILED DESCRIPTION

[0039] In order to make the above objectives, features and advantages of the present application more obvious and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0041] In this document, "proximal" refers to the end closer to the heart, and "distal" refers to the end further from the heart. "Axial" refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device, and "radial" refers to the direction perpendicular to the above-mentioned axial direction.

[0042] Please refer to Figure 1 A covered stent 100 according to an embodiment includes a stent 10 and a covering 20 covering the stent 10.

[0043] The stent 10 serves as a support for supporting the covering 20. The stent 10 is a hollow tube structure with open ends. The stent 10 includes a plurality of wave-shaped rings 110 arranged at intervals in the axial direction. Each wave-shaped ring 110 is a closed structure with wave crests and wave troughs formed by a plurality of wave bars 112 connected end to end. The material of the wave-shaped ring 110 is a material with good biocompatibility and good elasticity. For example, nickel-titanium alloy, stainless steel, etc.

[0044] In an embodiment, two adjacent wave-shaped rings 110 are connected by an axial connecting piece (not shown in the figure). The shape of the axial connecting piece is not limited and can be a straight rod, a special-shaped rod, etc.

[0045] In another embodiment, no axial connecting piece is provided between two adjacent wave-shaped rings 110, and a plurality of wave-shaped rings 110 are connected together by the covering 20, so that the overall flexibility of the covered stent 100 is better.

[0046] The covering 20 is used to isolate the lesion site and blood flow. The covering 20 is wrapped on the stent 10 to form a lumen structure with both ends open. The material of the covering 20 is a biocompatible material, such as e-PTFE, PET, etc.

[0047] The covering 20 has an axially opposite first end 210 and a second end 220. The first end 210 is formed with a passage 230 having an open state and a closed state. The passage 230 is in the open state when impacted by fluid (e.g. blood flow) and in the closed state when not impacted by fluid. In the natural state, the passage 230 is in the closed state.

[0048] For the convenience of description, among the plurality of wave-shaped rings 110, the wave-shaped ring closest to the end of the first end 210 of the covering 20 is marked as wave-shaped ring 110A, and the remaining wave-shaped rings are marked as wave-shaped rings 110 for distinction.

[0049] When the covering stent 100 is implanted in the blood vessel, since the passage 230 is in the open state when impacted by blood flow, even if the first end 210 of the covering 20 is located at the branch site, it will not affect the blood supply of the branch blood vessel due to the blockage of the blood flow of the branch blood vessel.

[0050] In an embodiment, as shown in Figure 1 The passage 230 is an opening formed in the first end 210 (the passage 230 can be multiple). The opening extends axially (in the direction of the longitudinal central axis I-I of the covering stent 100) from the end of the first end 210 towards the second end 220. It can be understood that the length of the passage 230 is approximately equal to or slightly greater than the axial length of the covered area of the covering stent 100 at the branch blood vessel site, so as to ensure smooth blood flow and avoid affecting the blocking effect of the remaining part of the covering stent 100 due to being too long.

[0051] In an embodiment, the opening is an elongated slit extending axially from the end of the first end 210 towards the second end 220. When the covering stent 100 is in the natural state (natural expansion state, state not compressed and not impacted by fluid), the passage 230 includes a first edge line and a second edge line (not shown in the figure), and the first edge line and the second edge line coincide (or one of the first edge line and the second edge line is blocked or covered), so that the opening appears as a line, which is also the state when the passage 230 is closed. Please refer to Figure 2 and Figure 3When the first end 210 of the membrane 20 is impacted by fluid, the membranes 20 on both sides of the channel 230 are folded open or tend to fold, thus opening the channel 230. The folded membranes 20 on both sides of the channel 230 form folded portions 230A and 230B, making the channel 230 triangular after opening to facilitate fluid passage. In its natural state, the edges of the folded portions 230A and 230B are aligned or overlapped, closing the channel 230.

[0052] In one embodiment, a slit is formed by directly cutting into the first end 210 of the film 20, thereby forming the channel 230. In another embodiment, a triangular notch is formed by cutting into the first end 210 of the film 20, with one side of the triangular notch located on the plane of the end face of the first end 210 of the film 20. Folded portions 230A and 230B are provided at this triangle, with the two edges of folded portions 230A and 230B respectively aligned with and connected to the other two sides of the triangle. Folded portions 230A and 230B can be provided on the first end 210 of the film 20 using methods known to those skilled in the art, including but not limited to sewing and gluing. In embodiments where one of the first edge line and the second edge line is obscured, at least partially, one of folded portions 230A and 230B is obscured or covered by the other.

[0053] like Figure 4 As shown, when the covered stent 100 is implanted into the branched blood vessel 10, the channel 230 and the branch blood vessel 101 are radially opposite or partially radially opposite, that is, the part with the channel 230 is in a suspended state and is not blocked or supported by the blood vessel wall. Under the impact of blood flow, the channel 230 is in an open state, and the blood flow flows from the open channel 230 to the branch blood vessel 101. The channel 230 extends axially from the end of the first end 210 towards the second end 220, that is, the end of the channel 230 away from the second end 220 is the open end, so that the channel 230 can be easily opened by the blood flow to ensure smooth blood flow.

[0054] The channel 230 is formed by directly cutting a slit at the first end 210 of the membrane 20. This method ensures that the channel 230 can be opened under the impact of blood flow and is simple to prepare. Forming the channel 230 by cutting a triangular notch at the first end 210 of the membrane 20 and then adding folded portions 230A and 230B makes it easier to open the channel 230 and ensures smooth blood flow.

[0055] like Figure 5As shown, after the stent graft 100 is implanted into the blood vessel 10 with a branch, the first end 210 of the covering 20 does not extend to the branch blood vessel 101, so that the passage 230 Figure 5 (not shown) is not radially opposite to the branch blood vessel 101, but the part of the covering 20 where the passage 230 is formed is close to the blood vessel wall. Moreover, when the stent graft 100 is in the implanted state, it is in a certain degree of radial compression (the diameter of the stent graft 100 in the implanted state is generally 90-95% of the diameter of the stent graft 100 in the natural state), so that the part of the covering 20 where the passage 230 is formed is radially compressed to a certain degree, and the areas of the covering 20 where the folded portions 230A and 230B are formed are partially overlapped, i.e., the first edge line and the edge line are no longer overlapped, but one of the first edge line and the second edge line is covered, so that the passage 230 is in a closed state. Therefore, the first end 210 of the covering 20 can also be placed at a position without a branch blood vessel.

[0056] Please refer again to Figure 1 , the wave-shaped ring 110A encloses an area A on the covering 20, and the passage 230 is located in the area A1. For example, the passage 230 is an opening formed at the first end 210. The opening is axially from the end of the first end 210 towards the second end 220, and the end of the opening away from the first end 210 does not exceed the wave-shaped ring 110A.

[0057] Please refer to Figure 6In one embodiment, the channel 230 is an opening formed in the first end 210. The opening is an elongated slit extending axially (in the direction of the longitudinal central axis I-I of the stent-graft 100) from the end of the first end 210 towards the second end 220. Moreover, the end of the opening close to the first end 210 of the covering 20 is not flush with the end of the first end 210 (or the proximal edge of the covering 20), but is kept at a distance from the end of the first end 210. The opening is an elongated slit, including a first edge line and a second edge line (not shown in the figure), and in the natural state, the first edge line and the second edge line coincide. Alternatively, one of the first edge line and the second edge line is covered. Alternatively, the first edge line and the second edge line are kept at a distance, i.e. a gap is formed between the first edge line and the second edge line. The distance (the width of the gap) is no more than 2 mm. In one embodiment, the distance is no more than 1 mm, so as to ensure that when the stent-graft 100 is in the state of being squeezed, the gap is closed when the stent-graft 100 is implanted in a site without branch vessels. In one embodiment, the diameter of the stent-graft 100 in the natural state is 20-46 mm, the compression rate (the difference between the diameter in the natural state and the diameter in the implanted state, as a percentage of the diameter in the natural state) is 5%, and the distance is 1-2.3 mm. Although the opening is an elongated slit, since when the stent-graft 100 is in the implanted state, the part of the covering 20 where the channel 230 is located is compressed radially to a certain extent, and since the blood flow has a certain pressure, under the impact of the blood flow, the channel 230 is opened, as shown in Figure 7 and Figure 8 The end of the opening close to the first end 210 of the covering 20 is not flush with the end of the first end 210 (or the proximal edge of the covering 20), i.e. both ends of the opening are closed ends, which ensures that the channel 230 is opened by the blood flow while not affecting the strength of the first end 210 of the covering 20.

[0058] Please refer to Figure 9 and Figure 10In one embodiment, the passage 230 comprises a first edge line 230a, a second edge line 230b, a third edge line 230a' and a fourth edge line 230b'. The first edge line 230a and the second edge line 230b form an acute angle (or an obtuse angle). In the natural state, the first edge line 230a and the third edge line 230a' coincide or align. The second edge line 230b and the fourth edge line 230b' coincide or align. Alternatively, the third edge line 230a' and the fourth edge line 230b' are in a covered state. In the implanted state, the stent-graft 20 provided with the passage 230 is radially compressed to a certain extent, so that the stent-graft 20 is locally misaligned, the first edge line 230a and the third edge line 230a' no longer coincide or align, and the second edge line 230b and the fourth edge line 230b' no longer coincide or align. Under the impact of blood flow, the distance between the first edge line 230a and the third edge line 230a' increases, and the distance between the second edge line 230b and the fourth edge line 230b' increases, forming a gap between the four edge lines for blood flow. Alternatively, under the impact of blood flow, the local area of the stent-graft 20 is pushed open by the blood flow to expose the third edge line 230a' and the fourth edge line 230b', and a gap is formed between the first edge line 230a and the third edge line 230a' and between the second edge line 230b and the fourth edge line 230b', thereby forming a blood flow passage.

[0059] It should be noted that when the first edge line 230a and the third edge line 230a' coincide or align and the second edge line 230b and the fourth edge line 230b' coincide or align in the natural state, the passage 230 can be formed by cutting the stent-graft 20. When the third edge line 230a' and the fourth edge line 230b' are in a covered state in the natural state, the stent-graft 20 can be formed by splicing two stent-grafts, and the passage 230 is formed when splicing, so that the third edge line 230a' and the fourth edge line 230b' are in a covered state. Alternatively, the stent-graft 20 is a one-piece stent-graft, an opening is formed at the first end 210 of the stent-graft 20, and another stent-graft with a smaller area is pasted or sewn at the opening to form the passage 230, so that the third edge line 230a' and the fourth edge line 230b' are in a covered state. It should be noted that when the passage 230 is formed by splicing, the stent-graft (which can cover the third edge line 230a' and the fourth edge line 230b') in the covered position is located on the outer surface of the stent-graft support 100, so as to ensure that when the blood flow impacts from the inside to the outside of the lumen of the stent-graft support 100, the passage 230 can be opened.

[0060] It can be understood that the above-mentioned method of forming the passage 230 is only illustrative, and any method known to those skilled in the art can be used.

[0061] Please refer to Figure 11 andFigure 12 In one embodiment, the passage 230 comprises a first edge line 230c, a second edge line 230d, a third edge line 230c' (not shown in the figure) and a fourth edge line 230d' (not shown in the figure). In the natural state, the first edge line 230c and the third edge line 230c' coincide, and the second edge line 230d and the fourth edge line 230d' coincide. Moreover, the first edge line 230c and the second edge line 230d are perpendicular, and the first edge line 230c extends from the middle of the second edge line 230d in a direction perpendicular to the second edge line 230d. Under the impact of blood flow, the first edge line 230c and the third edge line 230c' separate to form a gap, and the second edge line 230d and the fourth edge line 230d' separate to form a gap, so that the passage 230 is in the open state. Moreover, in the open state, the fourth edge line 230d' is composed of two parts. The passage 230 of the present embodiment is easier to open, so as to keep the blood flow unobstructed.

[0062] In one embodiment, the thickness of the covering membrane 20 at 1 mm near the first edge line 230c, the second edge line 230d (not shown in the figure), the third edge line 230c' and the fourth edge line 230d' (not shown in the figure) is greater than the thickness of other regions of the covering membrane 20. As shown in the figure, the covering membrane 20 at 1 mm near the first edge line 230c, the second edge line 230d, the third edge line 230c' (not shown in the figure) and the fourth edge line 230d' (not shown in the figure) refers to the region A2 enclosed by the dashed line in the figure, wherein D1=D2=D3=D4=1 mm. In another embodiment, the thickness of the region A2 is 2 times the thickness of other regions of the covering membrane 20. When the application site of the covering membrane stent 100 does not need to open the passage 230, the thickness of the covering membrane 20 at 1 mm near each edge line of the passage 230 is greater, so that during assembly and release, when the covering membrane stent 100 moves in the sheath, the covering membrane 20 (i.e. the region A2) of the region around each edge line can form support to prevent the passage 230 from being opened. Figure 13

[0063] Please refer to Figure 14 and Figure 15 In one embodiment, the covering membrane stent 100 further comprises a sealing member 30. The first end 210 of the covering membrane 20 is provided with a window 240. The sealing member 30 is arranged on the outer surface (the surface away from the inner cavity of the covering membrane stent 100) of the covering membrane 20 and can openably cover the window 240 to form the passage 230 having an open state and a closed state. In the natural state, the sealing member 30 covers the window 240 to make the passage 230 in the closed state. When impacted by fluid, the sealing member 30 forms a gap with the covering membrane 20 to open the passage 230.

[0064] ​In one embodiment, the window 240 has an edge line. In the closed state, the seal 30 covers the edge line to close the window 240, so that the passage 230 is in the closed state. When at least part of the edge line is not covered by the seal 30, the passage 230 is in the open state.

[0065] In one embodiment, the window 240 has four edge lines, edge line 240A, edge line 240B, edge line 240C and edge line 240D, respectively. Among them, edge line 240A and edge line 240B are opposite, and edge line 240C and edge line 240D are opposite. The seal 30 is a sheet structure, which has four edge lines, edge line 30A, edge line 30B, edge line 30C and edge line 30D, respectively. Among them, edge line 30A and edge line 30B are opposite, and edge line 30C and edge line 30D are opposite. The seal 30 covers the window 240, and the two ends of the seal 30 are fixedly connected with the film 20. For example, in position, the edge line 30A of the seal 30 corresponds to the edge line 240A of the window 240, the edge line 30B corresponds to the edge line 240B, and the edge line 30C and the edge line 30D correspond to the edge line 240C and the edge line 240D, respectively. The end where the edge line 30C of the seal 30 is located is fixedly connected with the film 20, and the end where the edge line 30D is located is fixedly connected with the film 20. The part between the end where the edge line 30C is located and the end where the edge line 30D is located is overlapped on the film 20, but is not fixedly connected with the film 20, so that the seal 30 can open to cover the edge line 240A and the edge line 240B of the window 240. When impacted by blood flow, the seal 30 is impacted to form gaps with the edge line 240A and the edge line 240B, so as to open the passage 230. In this embodiment, the edge line 30C coincides with the edge line 240C, and the edge line 30D coincides with the edge line 240D. It can be understood that in other embodiments, the edge line 30C can not coincide with the edge line 240C, and the edge line 30D can not coincide with the edge line 240D. In the natural state, the seal 30 completely blocks the edge line 240A, the edge line 240B, the edge line 240C and the edge line 240D. When impacted by blood flow, the edge line 240A, the edge line B, the edge line C and the edge line D are exposed, so as to open the passage 230.

[0066] Please refer to Figure 16 and Figure 17In another embodiment, the window 240 has four edge lines, namely the edge line 240A, the edge line 240B, the edge line 240C and the edge line 240D. The edge line 240A and the edge line 240B are opposite to each other, and the edge line 240C and the edge line 240D are opposite to each other. The sealing member 30 has a sheet structure and has four edge lines, namely the edge line 30A, the edge line 30B, the edge line 30C and the edge line 30D. The edge line 30A and the edge line 30B are opposite to each other, and the edge line 30C and the edge line 30D are opposite to each other. The edge line 30A coincides with the edge line 240A, and the sealing member 30 is located outside (or the outer surface) of the covering film 20 by being connected to the covering film 20 only at the end where the edge line 30A is located. When the covering film stent 100 is implanted in the blood vessel, if the first end 210 of the covering film 20 is located at the branch blood vessel position, when the channel 230 is not supported by the blood vessel wall, under the impact of the blood flow, the sealing member 30 is broken, the edge line 240B, the edge line 240C and the edge line 240D of the window 240 are exposed, and the channel 230 is in an open state so that the blood flow passes through. If the first end 210 of the covering film 20 is not located at the branch blood vessel position, but the sealing member 30 is supported by the blood vessel wall, so that the channel 230 is in a closed state, so that the covering film 20 plays a role of isolation.

[0067] In an embodiment, the shape of the window 240 and the shape of the sealing member 30 are matched, and both are rectangular. It can be understood that in other embodiments, the shape of the window 240 and the shape of the sealing member 30 are not limited, and can be other shapes, for example, oval, circular, square, etc.

[0068] In an embodiment, the hardness of the sealing member 30 is greater than the hardness of the covering film 20, so that in the assembly and release process, the sealing member 30 can cover each edge line of the window 240, so that the channel 230 is in a closed state. Only when it is impacted by the blood flow, the sealing member 30 is broken to form a gap with the window 240, so that the channel 230 is opened.

[0069] In an embodiment, the material of the sealing member 30 is the same as the material of the covering film 20, but the thickness of the sealing member 30 is greater than the thickness of the covering film 20.

[0070] In an embodiment, the material of the sealing member 30 is different from the material of the covering film 20, for example, the material of the covering film 20 is e-PTFE or PET, and the material of the sealing member 30 is a metal material, such as stainless steel, etc.

[0071] In an embodiment, please refer to Figure 18, the window 240 is located between two wave poles 112, and the sealing member 30 extends from the edge line 30A to outside one wave pole 112. When the stent-graft 100 is arranged at a position where the passage 230 needs to be opened, because the blood flow has a certain pressure, even if the length of the sealing member 30 is slightly extended to outside the wave pole 112, the blood flow can also flush the sealing member 30 to open the passage 230. When the stent-graft 100 is used at a position where the passage 230 does not need to be opened, because the sealing member 30 extends to outside the wave pole 112, when the stent-graft 100 is fixed at the application position by the radial supporting force of the wave-shaped ring 110, one end of the sealing member 30 is connected with the stent-graft 20, and the other end is abutted by the wave pole 112, so that the sealing effect of this position is better, and the purpose of isolating the aneurysm and the aneurysm rupture is better achieved.

[0072] Please refer to Figure 19 The wave-shaped ring 110A closest to the end of the first end 210 of the stent-graft 20 divides the first end 210 of the stent-graft 20 into two regions, which are region A1 and region A3, wherein region A1 and region A3 each contain a plurality of triangular sub-regions, and the plurality of bottom edges of the plurality of triangular sub-regions of region A1 are coplanar with the end face of the first end 210. No matter what form the passage 230 is, the passage 230 can be arranged in the triangular sub-regions of region A1, as shown in Figure 19 , or can be arranged in the triangular sub-regions of region A3, as shown in Figure 20 .

[0073] No matter what form the passage 230 is, or whether the passage 230 is arranged in region A1 or region A3, in an embodiment, the passage 230 is a plurality of passages 230, and the plurality of passages 230 are distributed along the circumference of the stent-graft 20 at intervals, so as to ensure that the passage 230 can be opposite to the branch blood vessel after implantation.

[0074] Please refer to Figure 20 In an embodiment, the number of waves (or the number of wave crests or wave troughs, the same below) of the wave-shaped ring 110A closest to the end of the first end 210 of the stent-graft 20 is greater than the number of waves of the other wave-shaped rings 110 of the stent-graft 10, and the wave height of the wave-shaped ring 110A is less than the wave height of the other wave-shaped rings 110, so that the sealing performance of the wave-shaped ring 110A is greater than the sealing performance of the other wave-shaped rings 110, thereby achieving good anti-leakage performance at the end of the stent-graft 100.

[0075] Please continue to refer to Figure 20In an embodiment, the covered stent 100 further comprises an anchoring bare stent 40, and the number of the anchoring bare stent 40 is two or one. When the number is two, the two anchoring bare stents 40 are respectively located at two ends of the covered stent 100. When the number is one, the anchoring bare stent 40 is located at one end of the covered stent 100. The anchoring bare stent 40 is arranged to further enhance the anchoring performance of the end of the covered stent 40.

[0076] Figure 20 In the illustrated embodiment, the anchoring bare stent 40 is one, and the anchoring bare stent 40 is connected with the first end 210 of the covering 20 or connected with the wave-shaped ring 110A. Please refer back to Figure 4 When the covered stent 100 is implanted into the blood vessel 10 with a branch, the channel 230 is opposite to the branch blood vessel 101, and the anchoring bare stent 40 extends to the area radially opposite to the branch blood vessel 102. Since the part provided with the channel 230 is located at the first end 210 of the covering 20, the part provided with the channel 230 is opposite to the branch blood vessel 101, and there is no blood vessel wall support, so that the anchoring performance of the first end 210 of the covering 20 is poor. The anchoring bare stent 40 is arranged to enhance the anchoring performance of the end of the covered stent 100, and does not affect the blood supply of the branch blood vessel 102.

[0077] As Figure 20 The anchoring bare stent 40 comprises a bare wave coil 410, and the bare wave coil 410 is also a closed structure with wave crests and wave troughs formed by a plurality of wave rods connected end to end. It can be understood that the bare wave coil 410 is not covered by the covering 20, so that the anchoring bare stent 40 is a hollow structure to avoid affecting the branch blood flow. The number of the bare wave coil 410 can be one or multiple. When the number of the bare wave coil 410 is multiple, the multiple bare wave coils 410 are arranged in an axial direction with or without spacing.

[0078] In an embodiment, the wave height of the bare wave coil 410 is greater than the wave height of the wave-shaped ring 110A and the wave-shaped ring 110, and the wave number of the bare wave coil 410 is less than the wave number of the wave-shaped ring 110A and the wave-shaped ring 110, that is, the hollow rate of the bare wave coil 410 is higher. Even if the anchoring bare stent 40 extends to the branch blood vessel part, it can also ensure smooth blood flow. At the same time, due to the higher hollow rate, it is also beneficial to avoid thrombosis. Moreover, the wave height of the bare wave coil 410 is larger, so that the anchoring bare stent 40 can cross the opening of the branch blood vessel and will not reach the inner wall of the branch blood vessel, thereby avoiding the risk of puncturing the blood vessel. The wave number of the bare wave coil 410 is smaller, and the contact points with the blood vessel wall are fewer, which is beneficial to reduce the damage to the blood vessel wall.

[0079] Please refer back to Figure 2In an embodiment, the covered stent 100 further comprises a marking structure 50 arranged at the first end 210 of the covering 20, for indicating the position of the end of the covered stent 100. The marking structure 50 is not arranged at the position where the channel 230 is arranged, i.e. the marking structure 50 and the channel 230 are staggered with each other, so as to avoid shielding the channel 230. The marking structure 50 is made of a material which has a relatively strong developing property under a medical imaging device (the intensity can meet the visual medical imaging device collected image, such as DSA image). For example, gold, platinum and the like. In an embodiment, the number of the marking structure 50 is three, and the three marking structures are arranged on the covering 20 in a circumferential direction. The marking structure 50 can be arranged on the inner surface of the covering 20, or can be arranged on the outer surface of the covering 20. Alternatively, when the covering 20 is a double-layer or multi-layer structure, the marking structure 50 is located inside the covering 20. The marking structure 50 can be directly pasted on the surface of the covering 20 by biological glue, or the marking structure 50 is placed on the surface of the covering 20, and then the marking structure 50 is fixed on the surface of the covering 20 by suturing.

[0080] In an embodiment, among the three marking structures 50, one is in the shape of a number "8", one is in the shape of a letter "O" or a number "0", and the other is in the shape of a letter "e". Different shapes of the marking structure 50 are used to distinguish different positions. Moreover, when the marking structure 50 is fixed on the covering 20 by suturing, the suture can reliably hook the marking structure 50 due to the structural characteristics of the marking structure 50, so that the marking structure 50 can be reliably fixed on the surface of the covering 20, effectively avoiding the risk of the marking structure 50 falling off.

[0081] In an embodiment, the covering 20 is a double-layer or multi-layer structure, the marking structure 50 is located inside the covering 20, and the marking structure 50, the covering 20 and the wave-shaped ring 110A are fixed together by suturing.

[0082] It can be seen that the covering 20 not only plays a role in isolating the lesion site and the blood flow, but also plays a role in bearing the marking structure 50 when the marking structure 50 is arranged at the first end 210. This not only makes the operation of fixing the marking structure 50 more convenient, but more importantly, reliably fixes the marking structure 50 to avoid the marking structure 50 falling off. When multiple marking structures 50 are arranged on the first end 210, the bearing role of the covering 20 is more significant, which facilitates preparation and improves the reliability of fixation.

[0083] Therefore, when the covered stent 100 is implanted in a blood vessel with a branch, and the first end 210 of the covering 20 is opposite to the branch blood vessel, the first end 210 of the covering 20 can carry the marking structure 50, so that the operator can better judge the position of the end, and at the same time, since the passage 230 located at the first end 210 can be opened under the impact of blood flow, the covering 20 will not block the opening of the branch blood vessel to block the blood flow.

[0084] In an embodiment, the number of marking structures 50 is three. Among them, the line connecting two marking structures 50 passes through the geometric center of the end face of the covered stent 100. The line connecting the other marking structure 50 and the geometric center of the end face of the covered stent 100 is perpendicular to the line connecting the above-mentioned two marking structures 50. Alternatively, two marking structures 50 are located at 3 o'clock and 9 o'clock directions respectively, and the other marking structure is located at 12 o'clock or 6 o'clock direction. For example, the "8" shaped marking structure 50 and the "O" shaped (number "0" shaped) marking structure 50 are located at 3 o'clock and 9 o'clock directions respectively, and the "e" shaped marking structure 50 is located at 12 o'clock or 6 o'clock direction.

[0085] It can be understood that the shape of the marking structure 50 is not limited to "8" shape, "O" shape or number "0" shape and "e" shape, and any shape that can meet the visual requirements, has a distinguishing degree and can be reliably fixed on the covering 20. The setting position of the marking structure 50 is not limited to 3 o'clock, 9 o'clock, 12 o'clock and 6 o'clock directions, and any setting method that can meet the visual requirements and has a distinguishing degree can be used. For example, a plurality of marking structures 50 are uniformly distributed along the circumferential direction.

[0086] The passage 230 is formed on the first end 210 of the covering 20 of the covered stent 100 described above. When the covered stent 100 is implanted in a blood vessel, since the passage 230 is in an open state when it is impacted by blood flow, even if the first end 210 of the covering 20 is located at the branch site, it will not affect the blood supply of the branch blood vessel due to the blockage of the blood flow of the branch blood vessel.

[0087] And since the passage 230 has an open state and a closed state, when the passage 230 is not supported by the blood vessel wall, the passage 230 can be in an open state under the impact of blood flow. When the passage 230 is supported by the blood vessel wall, the passage 230 can be in a closed state. So that the covered stent 100 can be suitable for different application sites to adapt to different individuals.

[0088] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0089] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A covered stent, characterized by, The stent includes a stent body and a covering film covering the stent body, the covering film has axially opposite first and second ends, and a channel is formed on the first end of the covering film, the channel has an open state and a closed state, and the channel is in the open state when impacted by fluid and in the closed state when not impacted by fluid. The stent body includes a plurality of wave-shaped rings arranged along the axial direction, and a wave-shaped ring closest to the end of the first end divides the first end of the covering film into region A1 and region A3, the region A1 and the region A3 each include a plurality of triangular sub-regions, the plurality of bottom edges of the plurality of triangular sub-regions of the region A1 are coplanar with the end face of the first end, and at least one of the region A1 and the region A3 is provided with the channel. The stent body further includes an anchoring bare stent, the anchoring bare stent is arranged at the end of the first end, the anchoring bare stent is a hollow structure and includes a bare wave coil. The wave height of the bare wave coil is greater than the wave height of each wave-shaped ring, and the wave height of the wave-shaped ring closest to the end of the first end is less than the wave height of the other wave-shaped rings. The wave number of the bare wave coil is less than the wave number of each wave-shaped ring, and the wave number of the wave-shaped ring closest to the end of the first end is greater than the wave number of the other wave-shaped rings.

2. The stent graft of claim 1, wherein, The channel is a plurality of channels, and the plurality of channels are arranged along the circumferential direction of the covering film.

3. The stent graft of claim 1, wherein, The channel is an opening formed on the first end, and the opening extends axially from the end of the first end to the direction close to the second end.

4. The stent graft of claim 1, wherein, The channel includes a first edge line and a second edge line, and in the closed state, the first edge line and the second edge line coincide or align; one of the first edge line and the second edge line is covered.

5. The stent graft of claim 1, wherein, The channel includes a first edge line, a second edge line, a third edge line and a fourth edge line, and in the natural state, the first edge line and the third edge line coincide or align, and the second edge line and the fourth edge line coincide or align; or, the third edge line and the fourth edge line are in a covered state.

6. The stent graft of claim 5, wherein, In the natural state, the first edge line and the third edge line coincide or align, the second edge line and the fourth edge line coincide or align, and the first edge line extends from the middle of the second edge line in a direction perpendicular to the second edge line.

7. The stent graft of claim 1, wherein, The covering film stent further includes a sealing member, and a window is formed on the first end of the covering film, the sealing member is arranged on the covering film and covers the window to form the channel.

8. The stent graft of claim 7, wherein, The window has an edge line, and in the closed state, the sealing member covers the edge line; In the open state, at least part of the edge line is not covered by the sealing member.

9. The stent graft of claim 8, wherein, The sealing member covers the window, and opposite ends of the sealing member are connected to the covering film, respectively, and a part between the opposite ends of the sealing member is overlapped on the covering film so that the sealing member can cover the window to form the channel.

10. The stent graft of claim 8, wherein, The sealing member covers the window, and one end of the sealing member is connected with the film, so that the sealing member can cover the window to form the channel.

11. The stent graft of claim 1, wherein, The film support further comprises a marking structure, which is located at the first end of the film, and the marking structure is staggered with the channel.

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