Covered stent and stent delivery system

Abstract

The application provides a covered stent and a stent delivery system. The covered stent comprises a main stent with a tubular main body, the main stent comprises an proximal support section and a tumor cavity covering section along the axial direction, the tumor cavity covering section is provided with a first embedded stent and a second embedded stent arranged along the radial direction, the distal end of the tumor cavity covering section is provided with an opening connected with the outside, and the distal end of the first embedded stent and the second embedded stent is communicated with the opening; the support strength of the first embedded stent is greater than that of the second embedded stent; the first embedded stent with greater support strength is arranged to at least ensure the passability of the external iliac passage opposite to the first embedded stent when the covered stent is compressed; further, the extension of the covered stent of the first embedded stent and the second embedded stent can ensure the sealing performance at the position of the fitting gap after the main stent is sewn, and the internal leakage at the embedded stent is avoided.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a covered stent and stent delivery system. Background Technology

[0002] The iliac arteries, an important part of the human vascular system, originate from the terminal segment of the abdominal aorta. They divide into two common iliac arteries, left and right, passing through the fourth lumbar vertebra, extending downwards along the spine medial to the psoas major muscle, and eventually branching into the internal and external iliac arteries. The internal iliac artery supplies oxygen and nutrients to the pelvis and lower limbs, while the external iliac artery supplies blood to the ilium and surrounding tissues. However, current iliac artery bifurcation stents have a series of problems, such as the internal iliac artery opening being easily compressed, the internal iliac branches being prone to tortuosity and kinking leading to blockage, and the possibility of blockage at the opening of the internal iliac branches due to slight movement or rotation of the stent during operation.

[0003] To address the aforementioned issues, existing technologies have specifically designed an embedded branched stent, where the first branch connects to the external iliac artery and the second branch connects to the internal iliac artery. This innovative structural design offers broad patient applicability, extending to the proximal side of the iliac bifurcation without being limited by the length of the common iliac artery, and is suitable for treating internal and external iliac arteries of various diameters. This innovative structure makes stent placement easier during implantation, avoiding the challenges associated with iliac bifurcation stents, thus facilitating the access of internal and external iliac stents.

[0004] However, the design of this embedded branch stent still presents some challenges, especially the possibility of internal leakage at the embedded stent site. Summary of the Invention

[0005] Therefore, it is necessary to provide a new covered stent and stent delivery system to at least solve the problem of internal leakage of embedded stents within the main stent.

[0006] A covered stent includes a main stent having a tubular body. The main stent includes a proximal support segment and a tumor cavity covered segment. The distal end of the proximal support segment is connected to the proximal end of the tumor cavity covered segment. The proximal segment includes a support coil. The tumor cavity covered segment has a first embedded stent and a second embedded stent arranged radially. The distal end of the tumor cavity covered segment has an opening communicating with the outside. The distal ends of the first embedded stent and the second embedded stent are both connected to the opening. The support strength of the first embedded stent is greater than that of the second embedded stent.

[0007] In one embodiment, the first embedded support and the second embedded support include a mesh body, wherein the wire diameter of the first embedded support is greater than that of the second embedded support, and / or the mesh density of the first embedded support is greater than that of the second embedded support.

[0008] In one embodiment, the first embedded bracket and the second embedded bracket are respectively provided with a first distal bevel and a second distal bevel at their distal ends, and the first distal bevel and the second distal bevel are arranged opposite to each other.

[0009] In one embodiment, the proximal ends of the first embedded stent and the second embedded stent are respectively provided with a first proximal flat opening and a second proximal flat opening; or the proximal ends of the first embedded stent and the second embedded stent are respectively provided with a first proximal bevel and a second proximal bevel, and the first proximal bevel and the second proximal bevel are arranged opposite to each other.

[0010] In one embodiment, the covered stent further includes a transition section connecting the proximal support segment and the tumor cavity covered segment, the transition section being provided with a transition stent.

[0011] In one embodiment, the surface of the first embedded stent is provided with a first covering film, and the surface of the second embedded stent is provided with a second covering film. The first covering film and the second covering film extend outward at least partially from the proximal port of the first embedded stent and the second embedded stent to form a connecting portion, and the connecting portion is connected to the tumor cavity covering segment.

[0012] In one embodiment, the connecting portion of the first film is connected to the connecting portion of the second film.

[0013] In one embodiment, the first coating and the second coating are integrally formed.

[0014] In one embodiment, both the first distal bevel and the second distal bevel include a long axis sidewall and a short axis sidewall in the circumferential direction. The axial extension length of the long axis sidewall is greater than the axial extension length of the short axis sidewall. The long axis sidewalls of the first embedded bracket and the second embedded bracket are closely attached to each other, and at least one of the long axis sidewalls has a hook portion for hooking at its distal end.

[0015] In one embodiment, the support wave ring includes at least one anchoring wave ring, and the outer side of the anchoring wave ring is provided with a plurality of anchoring barbs along the circumferential direction.

[0016] A stent delivery system includes the aforementioned covered stent.

[0017] The advantages of this invention are that it provides a covered stent and a stent delivery system. The covered stent includes a main stent with a tubular body, and the main stent includes a proximal support segment and a lumbar covered segment along the axial direction. The lumbar covered segment is provided with a first embedded stent and a second embedded stent arranged radially. The distal end of the lumbar covered segment is provided with an opening communicating with the outside. The distal ends of the first and second embedded stents are both connected to the opening. The support strength of the first embedded stent is greater than that of the second embedded stent. By providing a first embedded stent with greater support strength, the passability of the external iliac passage corresponding to the first embedded stent is at least ensured when the covered stent is compressed. Furthermore, the extended covered stent of the first and second embedded stents can ensure the sealing at the joint after suturing with the main stent, avoiding internal leakage at the embedded stent. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the membrane-covered scaffold structure in Embodiment 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the internal structure of the film-coated stent in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the wire diameter distribution of the first embedded support and the second embedded support in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram of the grid density distribution of the first embedded bracket and the second embedded bracket in Embodiments 1 and 2 of the present invention;

[0022] Figure 5 This is a schematic diagram of the proximal flat openings of the first and second embedded stents in Embodiment 2 of the present invention;

[0023] Figure 6 This is a schematic diagram of the imaging structure of the first embedded stent and the second embedded stent in Embodiment 2 of the present invention;

[0024] Figure 7 This is a schematic diagram of the hook portion in the film-coated support structure in Embodiment 2 of the present invention;

[0025] Figure 8 This is a schematic diagram of the hook part having a blocking component in Embodiment 2 of the present invention;

[0026] Figure 9 This is a schematic diagram of the developing structure of the hook-and-hold blocking member in Embodiment 2 of the present invention;

[0027] Figure 10 This is a schematic diagram of the transition support being an irregularly shaped waveguide in Embodiment 2 of the present invention;

[0028] Figure 11 This is a schematic diagram of the high wave at the far end of the irregular wave loop in Embodiment 2 of the present invention;

[0029] Figure 12 This is a schematic diagram of the high wave taper at the far end of the irregular wave loop in Embodiment 2 of the present invention;

[0030] Figure 13 This is a schematic diagram of the transition support including the wave coil support in Embodiment 2 of the present invention;

[0031] Figure 14 This is a schematic diagram of the transition support including the mesh support in Embodiment 2 of the present invention;

[0032] Figure 15 This is a schematic diagram of the first and second coating structures in Embodiment 3 of the present invention;

[0033] Figure 16 This is a schematic diagram of the connection structure between the first coating and the second coating in Embodiment 3 of the present invention;

[0034] Figure 17 This is a top view of the membrane-covering stent when the connection between the first and second membranes is connected to the tumor cavity membrane segment in Embodiment 3 of the present invention;

[0035] Figure 18 This is a schematic diagram of the connection structure between the first coating and the second coating in Embodiment 3 of the present invention via a connecting part;

[0036] Figure 19 This is a top view of the membrane-covering stent when the first and second membranes are connected to the tumor cavity membrane segment after being connected by the connecting part in Embodiment 3 of the present invention;

[0037] Figure 20 This is a schematic diagram of the integrated molding structure of the first and second coatings in Embodiment 3 of the present invention;

[0038] Figure 21 This is a top view of the membrane-covering stent when the integrally formed first and second membranes are connected to the tumor cavity membrane segment in Embodiment 3 of the present invention;

[0039] Figure 22 This is a schematic diagram of the intermediate anchoring wave ring structure in Embodiment 4 of the present invention;

[0040] Figure 23 This is a schematic diagram of the hook structure of the film-coated support inside the conveyor in Embodiment 5 of the present invention. Detailed Implementation

[0041] To better understand the concept of this application, the implementation methods of this application will be described in detail below with reference to the accompanying drawings. The following specific embodiments are only some embodiments of this application and are not intended to limit this application.

[0042] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0043] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0044] To more clearly describe the structure of this application, the terms "proximal" and "distal" are used here as conventional terms in the field of interventional medicine. Specifically, "distal" refers to the end of the blood vessel furthest from the heart, and "proximal" refers to the end of the blood vessel closest to the heart; "axial" refers to its length direction, and "radial" refers to the direction perpendicular to the "axial" direction; "upper end" and "lower end" refer to two relatively distant ends, and when one end is defined as "upper end", the other distant end is "lower end".

[0045] Example 1

[0046] Please see 1 and Figure 2 The present invention provides a coated stent 100, which is typically composed of a metal frame and a coating material, such as... Figure 3As shown, the metal skeleton can adopt a Z-shaped wave or woven mesh design. The covering material has a certain blood flow isolation capability and is combined with the metal skeleton through pressure heating, suturing, etc. to form a complete covered stent 100. The proximal end of the covered stent 100 is generally placed in the common iliac artery or connected to the abdominal aortic stent, and the lumen diameter is generally matched with the diameter of the common iliac artery. In this embodiment, the covered stent 100 includes a main stent 10 with a tubular body. The surface of the main stent 10 is provided with a surface covering 31. The main stent 10 includes a proximal support segment 1 and an aneurysm cavity covering segment 3 along the axial direction. The distal end of the proximal support segment 1 is connected to the proximal end of the aneurysm cavity covering segment 3. The surface covering 31 of the proximal support segment 1 and the surface covering 31 of the aneurysm cavity covering segment 3 can be integrally formed by a single covering or by splicing multiple coverings by suturing or bonding. The proximal segment includes a support wave coil 11, while the aneurysm cavity covering segment 3 only has a surface covering 31, and the aneurysm cavity covering segment 3 contains There are a first embedded stent 4 and a second embedded stent 5 arranged radially. In this way, the main stent 10 reduces the support wave 11 at the position of the aneurysm cavity covered segment 3 to improve the flexibility of the covered stent 100 at the position of the aneurysm cavity segment. The aneurysm cavity covered segment 3 provides support through the first embedded stent 4 and the second embedded stent 5. At the same time, when the blood flows through the aneurysm cavity covered segment 3, the blood is diverted into the external iliac channel and the internal iliac channel. The first embedded stent 4 and the second embedded stent 5 are used to insert the external iliac stent and the internal iliac stent respectively to drain the blood to the external iliac artery and the internal iliac artery, isolate the blood, and prevent the blood from continuing to flow to the aneurysm.

[0047] In some embodiments, please continue reading Figure 2 Both the first embedded stent 4 and the second embedded stent 5 adopt a mesh-like main structure to emphasize better morphological support. The mesh-like main structure can provide better covering tension, thus maintaining the shape of the blood passage even with a small braided wire diameter. Furthermore, the mesh-like main structure allows for more contact points between the embedded stent and the inserted stent when the external iliac stent and the internal iliac stent are respectively inserted into the first embedded stent 4 and the second embedded stent 5, thereby providing greater friction and effectively enhancing the anchoring and adhesion forces between the stents, providing stent anti-slip performance.

[0048] The distal end of the aneurysm cavity covered segment 3 is provided with an opening 32 that communicates with the outside. The distal ends of the first embedded stent 4 and the second embedded stent 5 are both connected to the opening 32. In order to make the covered stent 100 provided in this application prioritize maintaining the shape of the passage to the external iliac vessels when subjected to pressure, in this embodiment, the support strength of the first embedded stent 4 is greater than the support strength of the second embedded stent 5. Here, the support strength is manifested in that when the first embedded stent 4 and the second embedded stent 5 are subjected to the same pressure, the overall deformation of the first embedded stent 4 is less than the overall deformation of the second embedded stent 5, so as to maintain a better passage shape.

[0049] In this embodiment, please refer to Figure 3 and Figure 4 In order to make the external iliac channel and the internal iliac channel separated by the first embedded stent 4 and the second embedded stent 5 have the support strength distribution effect as described above, the wire diameter of the mesh body of the first embedded stent 4 can be greater than the wire diameter of the mesh body of the second embedded stent 5, and / or the mesh density of the first embedded stent 4 can be greater than the mesh density of the second embedded stent 5.

[0050] In one embodiment, see Figure 3 This design ensures that the mesh density of the first embedded stent 4 and the second embedded stent 5 is uniform, and that the wire diameter of the mesh body of the first embedded stent 4 is greater than that of the mesh body of the second embedded stent 5, so that the support strength of the first embedded stent 4 is greater than that of the second embedded stent 5. Here, a larger stent wire diameter has less deformation capacity and can provide higher support force under pressure. Therefore, by making the wire diameter of the first embedded stent 4 greater than that of the second embedded stent 5, when the first embedded stent 4 and the second embedded stent 5 are simultaneously compressed, the first embedded stent 4, with its larger wire diameter, has a stronger resistance to deformation and produces less deformation. In contrast, the second embedded stent 5, with its relatively smaller wire diameter, has less resistance to deformation than the first embedded stent 4 and produces more deformation. This allows the shape of the first embedded stent 4 to be maintained better, ensuring that the covered stent 100 maintains its shape in the external iliac channel, thereby ensuring the blood flow to the external iliac artery after passing through the covered stent 100.

[0051] In another embodiment, please refer to Figure 4This ensures that the wire diameters of the first embedded support 4 and the second embedded support 5 are uniform, and that the mesh density of the mesh body of the first embedded support 4 is greater than that of the mesh body of the second embedded support 5, so that the support strength of the first embedded support 4 is greater than that of the second embedded support 5. Here, the first embedded support 4 and the second embedded support 5 include a mesh body with multiple mesh structures. A higher mesh density means an increase in the number of support wires required, and a smaller area of ​​a single mesh allows for greater pressure resistance. A higher mesh density provides greater support strength. In this embodiment, the first embedded support 4 and the second embedded support 5 have a rhomboid mesh structure, with the first embedded support 4 having a first rhomboid shape. The second embedded support 5 has a second rhombic grid. Both the first and second rhombic grids have an upper and lower vertex in the axial direction and a left and right vertex in the radial direction. The distance between the upper and lower vertices of the first rhombic grid is D1, and the distance between the left and right vertices is L1. The distance between the upper and lower vertices of the second rhombic grid is D2, and the distance between the left and right vertices is L2. Preferably, D1 and L1 can be smaller than D2 and L2, so that the area occupied by a single first rhombic grid is smaller than the area occupied by a single second rhombic grid. Thus, under the same support unfolded area, the first embedded support 4 has a higher grid density and provides stronger support strength than the second embedded support 5.

[0052] In some embodiments, please refer to further information. Figure 4 This allows the density of the first rhombus mesh to be changed only in the circumferential direction of the first embedded support 4, thereby increasing the density of the first rhombus mesh at least in the radial direction and thus enhancing the support strength in the radial direction.

[0053] In one embodiment, the wire diameter of the first embedded support 4 can be made larger than that of the second embedded support 5, and the mesh density of the first embedded support 4 can be made larger than that of the second embedded support 5. In this way, by setting the wire diameter and mesh density of the first embedded support 4 and the second embedded support 5 at the same time, the first embedded support 4 and the second embedded support 5 can form a difference in support strength, while forming a more reasonable distribution of wire diameter and mesh density. This avoids the first embedded support 4 and the second embedded support 5 being too flexible or too small due to excessively large or small wire diameter and mesh density settings, which would affect the folding and unfolding performance of the covered support 100 and make it difficult to assemble and release the covered support 100 in the sheath.

[0054] In this embodiment, the support strength is specifically manifested as the deformation of the overall tubular inner cavity after the first embedded bracket 4 and the second embedded bracket 5 are compressed. That is, under the same stress conditions, the same force (which needs to cause a certain amount of deformation in both the first embedded bracket 4 and the second embedded bracket 5) is applied to the outer walls of the first embedded bracket 4 and the second embedded bracket 5 using a radial force tester, and the radial cross-sectional area of ​​the first embedded bracket 4 and the second embedded bracket 5 after compression is measured and calculated. Here, the bracket with a larger total cross-sectional area after compression has a greater support strength, and the bracket with a smaller total cross-sectional area has a smaller support strength. In some embodiments, the first embedded bracket 4 and the second embedded bracket 5 can be compressed separately using a flat plate force gauge. When the same amount of deformation is compressed, the force required is measured. The larger the measured force, the greater the support strength, and the smaller the measured force, the smaller the support strength. In this embodiment, the force measured in the first embedded bracket 4 is always greater than the force measured in the second embedded bracket 5.

[0055] Example 2

[0056] In this embodiment, please continue to refer to Figure 4 The structure of the main stent 10, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 is largely the same as in Embodiment 1. The difference is that the opening 32 at the distal end of the covered stent 100 is set as an oblique opening. Specifically, the distal ends of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a first distal oblique opening 41 and a second distal oblique opening 51, and the first distal oblique opening 41 and the second distal oblique opening 51 are arranged opposite to each other. Here, the distal ends of the first embedded stent 4 and the second embedded stent 5 serve as the access points when the external iliac stent and the internal iliac stent are inserted. The openings are all set at an angle. First, this increases the size of the opening 32 when the external iliac stent and internal iliac stent are inserted, thereby reducing the difficulty of stent insertion. Second, since the connection with the external iliac artery and internal iliac artery is established by additional intervention with external iliac stents and internal iliac stents in this application, setting the first distal oblique opening 41 and the second distal oblique opening 51 opposite to each other can reduce the restraint of the two stents on the covered stent 100 in opposite directions after intervention, thereby making it easier for the external iliac stent and internal iliac stent to separate after connection, and avoiding mutual influence between the two stents.

[0057] Please refer to Figure 4 and Figure 5At the proximal end positions of the first embedded bracket 4 and the second embedded bracket 5, the openings can be set as flat or oblique. Specifically, the proximal ends of the first embedded bracket 4 and the second embedded bracket 5 can be respectively provided with a first proximal flat opening 43 and a second proximal flat opening 53. Here, in order to form a double-layer bracket when setting the first embedded bracket 4 and the second embedded bracket 5, while reducing the overall volume of the bracket after compression and sheathing, the first proximal flat opening 43 and the second proximal flat opening 53 can be axially offset so that they are in different axial positions after compression, avoiding excessive volume due to accumulation in one axial position and difficulty in sheathing.

[0058] In another embodiment, please refer to further details. Figure 4 The first embedded stent 4 and the second embedded stent 5 can be respectively provided with a first proximal bevel 42 and a second proximal bevel 52 at their proximal ends, and the first proximal bevel 42 and the second proximal bevel 52 are arranged opposite to each other. Here, the two bevels form a V-shaped cross-section in the axial section. The first proximal bevel 42 and the second proximal bevel 52 are the blood flow inlets within the tumor cavity covered segment 3. The inclined bevel structure can increase the area of ​​the inlet for receiving blood, thereby ensuring the patency of blood flow. Furthermore, the first proximal bevel 42 and the second proximal bevel 52 are arranged opposite to each other so that the higher side wall of the bevel is in close contact with the side wall of the tumor cavity covered segment 3, avoiding vibration or swinging during blood flushing and reducing blood flow. Smoothness; In some embodiments, the first proximal bevel 42 and the first distal bevel 41, the second proximal bevel 52 and the second distal bevel 51 may have the same tilt angle, thereby forming a parallel opening structure to increase the versatility of the first embedded stent 4 and the second embedded stent 5; In other embodiments, the arrangement of the first proximal bevel 42 and the second proximal bevel 52 can cause the long axis sidewall and the short axis sidewall of the first embedded stent 4 and the second embedded stent 5 to be misaligned, so that when the covered stent 100 of this application is compressed and placed into the delivery sheath, the misaligned long axis sidewall and short axis sidewall can make the folded volume of the first embedded stent 4 and the second embedded stent 5 smaller and easier to put into the delivery sheath.

[0059] Here, the design of the first proximal oblique opening 42 and the second proximal oblique opening 52 also allows other stents to have a larger selection of entry points during implantation, thereby reducing the difficulty of implantation and improving surgical efficiency.

[0060] Please refer to Figure 6To facilitate the identification of the positions of the first embedded stent 4 and the second embedded stent 5 within the blood vessel after the covered stent 100 is inserted into the human body, both the proximal and distal ends of the first embedded stent 4 and the second embedded stent 5 are provided with a radiopaque structure 6. Here, the radiopaque structure 6 can be a single radiopaque ring adapted to the shape of the proximal and distal ends of the first embedded stent 4 and the second embedded stent 5, and connected to the edges of the proximal and distal ends by weaving or wrapping. The radiopaque ring can be made of platinum wire or tantalum metal.

[0061] In some other embodiments, please refer to Figure 7 The inclination angles of the first distal bevel 41 and the second distal bevel 51 can be greater than those of the first proximal bevel 42 and the second proximal bevel 52. Here, since the first distal bevel 41 and the second distal bevel 51 are arranged opposite to each other, the two supports form a V-shaped tip protruding towards the distal end at their mating position. This V-shaped tip can be used to hook and connect with the conveyor when the covered support 100 of this application is conveyed in the conveyor for easy pushing and control. Specifically, the first distal bevel 41 and the second distal bevel 51 both include a long axis sidewall 501 and a short axis sidewall 502 in the circumferential direction to form a bevel structure. The axial length of the long axis sidewall 501 is greater than the axial length of the short axis sidewall 502. The long axis sidewalls 501 of the first embedded support 4 and the second embedded support 5 are arranged closely to each other, forming a V-shaped tip at the distal end. The axial length of this V-shaped tip is longer than any other position at the distal end of the covered support 100. Therefore, at the distal end of the long axis sidewall 501... The stent is provided with a hook portion 503 for hooking, which can be better hooked by the hook member 2001, while avoiding the hook member 2001 from affecting or contacting other parts of the covered stent 100 after hooking. The tilt angle of the first distal bevel 41 and the second distal bevel 51 can be set to 30° to 60°. Considering the matching requirements of the distal clamping and release structure of the delivery device, a tilt angle of less than 30° may cause the delivery device to be unable to effectively clamp the covered stent 100, thus affecting the operation. Conversely, a tilt angle of more than 60° will result in an excessive angle, which may cause unnecessary extension of the stent to the position of the external iliac artery. Considering that the diameter of the external iliac artery is small, this may be obstructed when implanting the external iliac stent, which will have a negative impact on the long-term patency rate of the stent. In addition, unnecessary stent length extension will increase the difficulty of the operation, which may make it difficult to release the covered stent 100, thus affecting the smooth operation.

[0062] Please see Figure 8 and Figure 9Here, the hook portion 503 may be provided only on the long axis sidewall 501 of the first distal bevel 41 of the mesh body of the first embedded bracket 4; or only on the long axis sidewall 501 of the second distal bevel 51 of the mesh body of the second embedded bracket 5; at least one embedded bracket has a hook portion 503 at its distal bevel to form a hooking position for hooking the member; wherein, in some embodiments, the hook portion 503 may also be formed by the mesh structure at the farthest end of the long axis sidewall 501 of the first distal bevel 41 and the long axis sidewall 501 of the mesh body of the first embedded bracket 4 and the second embedded bracket 5, and the distal side of the hook portion 503 includes at least one blocking member 5031 for hooking, wherein the blocking member 503 is provided only on the first distal bevel 41 of the mesh body of the first embedded bracket 4 and the second embedded bracket 5. The stop 5031 can be a mesh structure of wire or a developing ring at the first distal bevel 41 and the second distal bevel 51. The blocking effect provided by the developing ring alone can reduce the number of supports at this position, making it easier for the supports to be released at this position. Furthermore, in order to make the hooking effect between the hook part 503 and the hook 2001 better and less likely to fall off, the mesh structure at the farthest end of the long axis sidewall 501 of the first distal bevel 41 and the long axis sidewall 501 of the second distal bevel 51 is set as a hollow structure, that is, without the first coating 401 and the second coating 504, so that the hook 2001 can completely pass through the mesh structure of the hook part 503 to form a hook, so as to avoid accidental detachment after the hook is connected.

[0063] In this embodiment, please refer to further details. Figure 1 and Figure 10Because the proximal support segment 1 and the first embedded stent 4 and the second embedded stent 5 in the aneurysm cavity covering segment 3 use different stent structures, structural abrupt changes and discontinuities may occur at the connection points of different segments, which is not conducive to the long-term use of the stent. In order to make the connection and transition between the proximal support segment 1 and the aneurysm cavity covering segment 3 of the covered stent 100 smoother, a transition segment 2 is provided between the proximal support segment 1 and the aneurysm cavity covering segment 3 of the main stent 100. The transition segment 2 is provided with a transition stent 21. The transition segment 2 and the transition stent 21 are set between the proximal support segment 1 and the aneurysm cavity covering segment 3 to transition between the two parts of the main stent 10. Among them, when the proximal ports of the first embedded stent 4 and the second embedded stent 5 are the first proximal flat opening 43 and the second proximal flat opening 53, respectively, the transition stent 21 can... It is one of the support wave coils 11 of the proximal support segment 1. The proximal end of the transition stent 21 is flush with the distal end of the proximal segment. The distal end of the transition stent 21 is flush with the proximal end of the first embedded stent 4 and the second embedded stent 5. Here, since the surface covering 31 of the aneurysm cavity covering segment 3 is sutured to the first embedded stent 4 and the second embedded stent 5 and closely adheres to the outer surface of the first embedded stent 4 and the second embedded stent 5, the first embedded stent 4 and the second embedded stent 5 have a longer length direction and a shorter width direction after being arranged side by side. In the width direction, the width of the aneurysm cavity covering segment 3 is smaller than the diameter of the proximal support segment 1. Therefore, the transition stent 21 has a circular cross section at the proximal end and a flat strip cross section with a reduced width on one side at the distal end. The transition stent 21 has a tapered structure from the proximal end to the distal end.

[0064] In another embodiment, please continue to refer to Figure 10 as well as Figure 11When the proximal ends of the first embedded stent 4 and the second embedded stent 5 are respectively the first proximal bevel 42 and the second proximal bevel 52, the two bevels form a V-shaped cross-section on the axial section, creating an unsupported area in the aneurysm cavity covering segment 3. The proximal end of the transition stent 21 is flush with the distal end of the proximal segment, and the distal end of the transition stent 21 is flush with the proximal V-shaped double bevel formed by the first embedded stent 4 and the second embedded stent 5. Here, the transition stent 21 can support the surface covering 31 of the unsupported area formed between the double bevels, thereby preventing collapse or poor release due to the lack of support structure in this position of the aneurysm cavity covering segment 3. The transition stent 21 can be irregularly shaped. Waveform 211, the distal portion of the irregular waveform 211 extends into the unsupported area of ​​the tumor cavity covering segment 3; specifically, the proximal end of the irregular waveform 211 has a uniform proximal wave 2111 of equal height, and the distal end includes multiple distal high waves 2112 of unequal height, the distal high waves 2112 protruding distally, the apex of which is aligned with the first proximal bevel 42 and the second proximal bevel 52 of the first embedded stent 4 and the second embedded stent 5 to support the unsupported area; wherein, the irregular waveform 211 has at least two distal high waves 2112, and the two distal high waves 2112 are symmetrically arranged on both sides of the distal end along the diameter of the irregular waveform 211, and the apex of the two distal high waves 2112 is close to the bottom of the V-shaped double bevel.

[0065] For further details, please refer to Figure 12 Multiple high-wavelength 2112s can be set at the distal end of the irregular wave loop 211, forming a mountain-like structure with the highest wavelength in the middle and gradually decreasing wavelength towards both sides at the distal end of the irregular wave loop 211, to adapt to the shape of the unsupported area. The irregular wave loop 211 can avoid local collapse or poor release due to lack of support structure in the unsupported area, which affects blood flow. At the same time, the structure of the irregular wave loop 211 extending between the distal segment of the proximal support and the aneurysm cavity covered segment 3 can make the connection force of the covered stent 100 between the proximal support segment 1 and the aneurysm cavity covered segment 3 stronger, and the overall integrity of the stent is higher, thereby avoiding bending at the transition position between the aneurysm cavity segment and the proximal segment.

[0066] In some embodiments, please refer to Figures 13-14The transition support 21 includes a wave coil support 212 and / or a mesh support 213; wherein, when the proximal ports of the first embedded support 4 and the second embedded support 5 are respectively a first proximal flat opening 43 and a second proximal flat opening 53, the transition support 21 can be an annular wave coil support 212; while when the proximal ports of the first embedded support 4 and the second embedded support 5 are respectively a first proximal bevel opening 42 and a second proximal bevel opening 52, the transition support 21 can include a wave coil support 212, such as the aforementioned irregular wave coil, which will not be described again here; it can also include both a wave coil support 212 and a mesh support 213, adopting... The use of a wave-shaped stent 212, similar in structure to the support wave-shaped stent 11 of the proximal support segment 1, allows for better connection with the proximal support segment 1 at this location, thereby improving the overall flexibility of the covered stent 100. The use of a mesh stent 213, which has a mesh braided structure or a mesh cut structure, is similar in structure to the first embedded stent 4 and the second embedded stent 5, thus improving the overall integrity of the aneurysm segment. Furthermore, the mesh braided stent has stronger supporting tension, making the inner wall smoother and further ensuring the patency of blood flow at this location.

[0067] Example 3

[0068] In this embodiment, please refer to Figures 15-17The structure of the main stent 10, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 is largely the same as that in Embodiment 1. The difference is that the surfaces of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a first covering 401 and a second covering 504. In order to further ensure that the first embedded stent 4 and the second embedded stent 5 are tightly connected to the inner surface of the tumor cavity covered stent 3 at the proximal port position, and to avoid internal leakage between the first embedded stent 4 and the second embedded stent 5 and the tumor cavity covered stent 3, the first covering 401 extends outward at least partially from the proximal port of the first embedded stent 4 to form a connecting portion 402, and the second covering 504 extends outward at least partially from the proximal port of the second embedded stent 5 to form a connecting portion 402. The connecting portion 402 forms an unsupported covering that extends beyond the proximal port of the first embedded stent 4 and the second embedded stent 5, so that the proximal port of the first embedded stent 4 and the second embedded stent 5 is connected to the inner wall of the tumor cavity covered stent 3 by suturing or adhesive bonding. After the first connection is completed, the connecting part 402 of the first embedded stent 4 and the connecting part 402 of the second embedded stent 5 are connected to the tumor cavity covering segment 3 for the second time. This ensures that the proximal ports of the first embedded stent 4 and the second embedded stent 5 completely cover the internal cavity of the tumor cavity covering segment 3 without gaps. The first embedded stent 4 and the second embedded stent 5 are arranged side by side in close contact within the tumor cavity covering segment 3. The close contact and tangent position of the two embedded stents forms two fitting gaps 4021. At this gap, it is often difficult to achieve a tight fit when suturing the gap position formed by the tumor cavity covering segment 3 and the first embedded stent 4 and the second embedded stent 5. Therefore, the outwardly extending connecting part 402 is provided at least on one side of the close contact position of the first embedded stent 4 and the second embedded stent 5, so as to at least cover the close contact and tangent position of the two stents to form two fitting gaps 4021. The method of covering and sealing with a membrane is used instead of directly connecting and sealing with the tumor cavity covering segment 3 to achieve a better gap sealing effect.

[0069] In some embodiments, please continue reading Figure 17 The outwardly extending connecting portions 402 are respectively arranged circumferentially along the near-port of the first embedded stent 4 and the second embedded stent 5. In this way, in addition to sealing the two fitting gaps 4021 formed by the close contact and tangent position of the first embedded stent 4 and the second embedded stent 5, any position where the first embedded stent 4 and the second embedded stent 5 are connected to the tumor cavity covering segment 3 can be further sealed through the secondary connection of the connecting portions 402, so as to avoid internal leakage.

[0070] In this embodiment, the first covering 401 and the second covering 504 are made of different materials than the surface covering 31 of the main stent 10. The surface covering 31 in this embodiment is made of PET material. Both the first covering 401 and the second covering 504 are ePTFE membranes. Here, the PET membrane has the characteristic of high strength, while the ePTFE membrane is weaker, has a smooth surface, is less prone to thrombosis, has good long-term patency for small blood vessels, and has small pores. Combining the PET membrane and the ePTFE membrane ensures the overall strength of the stent covering in the main stent 10, and also enables the first embedded stent 4 and the second embedded stent 5 to have a better effect of isolating blood flow in the aneurysm cavity covering segment 3, ensuring the long-term patency of the branch, that is, a good occlusion effect.

[0071] In this embodiment, the second covering 504 effectively isolates the first embedded stent 4 and the second embedded stent 5, so that when the guide wire is inserted into the first embedded stent 4 or the second embedded stent 5, it will not pass through the first embedded stent 4 or the second embedded stent 5, ensuring that the guide wire is accurately inserted into the corresponding intraluminal stent and avoiding the problem that the implanted branch stent cannot reach the designated embedded stent.

[0072] In another embodiment, please refer to Figure 18 and Figure 19 To ensure overall sealing after the connecting part 402 is connected to the tumor cavity covering segment 3, the connecting part 402 of the first covering segment 401 can be connected to the connecting part 402 of the second covering segment 504. After the connection, the two connecting parts 402 are then connected to the tumor cavity covering segment 3 respectively. In this way, the proximal ports of the first embedded stent 4 and the second embedded stent 5 are first connected by the connecting part 402 to become a whole. Before the first embedded stent 4 and the second embedded stent 5 enter the tumor cavity covering segment 3 and connect with the tumor cavity covering segment 3, the outer contour of the proximal port of the two embedded stents is first enclosed and sealed in the circumferential direction of the proximal port. After the first embedded stent 4 and the second embedded stent 5 are embedded in the tumor cavity covering segment 3, the first connection of the proximal port and the second connection of the connecting part 402 are performed to achieve a better edge sealing and anti-leakage effect.

[0073] In other embodiments, please refer to Figure 20 and Figure 21To further ensure the sealing of the first embedded stent 4 and the second embedded stent 5 after they are connected to the tumor cavity covering segment 3 near the port, and to prevent internal leakage from occurring in the fitting gap 4021 between the first embedded stent 4 and the second embedded stent 5, the first covering 401 and the second covering 504 of the first embedded stent 4 and the second embedded stent 5 are integrally formed. Here, integral forming means that the first covering 401 and the second covering 504 are continuously formed from a single covering, without any adhesive or stitching splicing structure; after forming, the first embedded stent 4 and the second embedded stent 5 with the first covering 401 and the second covering 504 are an integral, one-piece design. The first and second membranes 401 and 504 are formed continuously by a single membrane and connected together by a membrane on the side near their respective ports. The gap 4021 between the first and second embedded stents 4 and 5 after they are attached side by side is covered and sealed by the membrane. Therefore, no internal leakage will occur at this position after the membrane is connected to the aneurysm segment. Blood is blocked at this position by the membrane. Since the first and second membranes 401 and 504 are made of ePTFE membrane, the good blood barrier ability of the ePTFE membrane enhances the blood barrier ability to prevent internal leakage at this position.

[0074] Example 4

[0075] In this embodiment, please refer to Figure 1 and Figure 22 The structure of the aneurysm cavity covered segment 3, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 is generally the same as that in Examples 1 to 3. The difference is that, in order to enhance the anchoring force of the proximal support segment 1 in the lumen of the blood vessel or other stent, the support wave coil includes at least one anchoring wave coil. Here, the support wave coil 11 of the proximal support segment 1 may only include one anchoring wave coil 12, and the outer side of the anchoring wave coil 12 is provided with a plurality of anchoring barbs 121 along the circumferential direction to enhance the anchoring of the proximal support segment to the blood vessel wall or the inner wall of the stent.

[0076] In some embodiments, a plurality of support wave coils 11 are provided axially on the surface coating 31 of the proximal support segment 1, and at least one anchoring wave coil 12 is included among the plurality of support wave coils 11. The anchoring wave coil 12 is used to provide better anchoring force between the proximal support segment 1 and the blood vessel. The anchoring wave coil 12 is provided between the support wave coils 11 at the proximal end of the proximal support segment 1 and the support wave coils 11 at the distal end, and a plurality of anchoring barbs 121 are provided circumferentially on the outer side. Here, the anchoring barbs 121 protrude from the outer wall of the proximal support segment 1 and are inclined and extended distally. Thus, when the proximal support segment 1 is released in the blood vessel, the support wave coils 11 provide support deployment and anchoring force while the anchoring of the middle support wave coil 11 is also provided. The barbs 121 provide a more stable anchoring effect when embedded in the blood vessel wall. Furthermore, the anchoring coils 12 are located between the support coils 11 at the proximal end and the support coils 11 at the distal end of the proximal support segment 1, which can enhance the anchoring force near the middle of the proximal segment. Thus, whether from the middle to the proximal end or from the middle to the distal end, the anchoring coils 12, as receiving points, can ensure sufficient connection force between the stent and the blood vessel at both ends of the proximal support segment 1. In other embodiments, multiple anchoring coils 12 may be provided, and the support coils 11 at the proximal end and the support coils 11 at the distal end can be located near the middle of the proximal segment to further enhance the anchoring force of the proximal support segment 1.

[0077] The anchoring barbs 121 of the anchoring wave coil 12 are designed so that when the proximal support segment 1 of the covered stent 100 is implanted into a blood vessel or other stent, and an external iliac stent or an internal iliac stent is implanted into the covered stent 100 of this application, the anchoring barbs 121 enhance the anchoring force and connection force, so that the covered stent 100 itself will not shift or shake.

[0078] Example 5

[0079] In this embodiment, please refer to Figure 23The structure of the main stent 10, the first embedded stent 4, and the second embedded stent 5 of the covered stent 100 is largely the same as that in Embodiments 1 to 4. Furthermore, this embodiment also provides a stent delivery system 200, which includes the covered stent 100 as described in the preceding embodiments and a delivery device. The delivery device is used to deliver the covered stent 100 of this application to a designated vascular location and release it. The delivery device typically includes a delivery sheath and a delivery handle. The delivery handle is used to control the advance and retraction of the delivery sheath to release the stent from the delivery sheath. The delivery device also includes a push rod 2002. A hook 2001 is connected to the proximal end of the 2002. The hook portion 503 of the covered bracket 100 is used to establish a connection with the hook 2001 and then control the relative position of the covered bracket 100 in the delivery sheath of the conveyor via the push rod 2002. The hook 2001 can be switched between an unlocked state and a locked state by external force. When the hook 2001 is in the locked state, the hook portion 503 is connected to the hook 2001 and cannot be detached. When the hook 2001 is in the unlocked state, the hook portion 503 can be separated from the hook 2001 to perform the subsequent release steps of the covered bracket 100.

[0080] The above specific embodiments are only some embodiments of the present invention and are not intended to limit the present invention. This specification cannot exhaustively describe all embodiments of the present invention concept, and some features of the different embodiments described above can be substituted for or combined with each other. Those skilled in the art can also make simple substitutions according to actual needs. The concept of the present invention is subject to the claimed protection scope.

Claims

1. A covered stent, characterized in that, The device includes a main support structure with a tubular body. The main support structure comprises a proximal support segment and a tumor cavity covering segment. The distal end of the proximal support segment is connected to the proximal end of the tumor cavity covering segment. The proximal support segment includes a support wave coil. The tumor cavity covering segment has a first embedded stent and a second embedded stent arranged radially within it. The distal end of the tumor cavity covering segment has an opening communicating with the outside. The distal ends of both the first and second embedded stents communicate with the opening. The support strength of the first embedded stent is greater than that of the second embedded stent. The first and second embedded stents are arranged side-by-side and closely attached within the tumor cavity covering segment. The distal ends of the first and second embedded stents are respectively provided with a first distal bevel and a second distal bevel, and the first and second distal bevels are arranged opposite to each other.

2. The covered stent according to claim 1, characterized in that, The first embedded support and the second embedded support include a mesh body, wherein the wire diameter of the first embedded support is greater than that of the second embedded support, and / or the mesh density of the first embedded support is greater than that of the second embedded support.

3. The covered stent according to claim 1, characterized in that, The first embedded stent and the second embedded stent are respectively provided with a first proximal end flat opening and a second proximal end flat opening at their proximal ends; or the first embedded stent and the second embedded stent are respectively provided with a first proximal end bevel and a second proximal end bevel at their proximal ends, and the first proximal end bevel and the second proximal end bevel are arranged opposite to each other.

4. The covered stent according to claim 1, characterized in that, The covered stent also includes a transition section connecting the proximal support segment and the tumor cavity covered segment, and the transition section is provided with a transition stent.

5. The covered stent according to claim 1, characterized in that, The surface of the first embedded stent is provided with a first covering film, and the surface of the second embedded stent is provided with a second covering film. At least a portion of the first covering film and the second covering film extend outward from the proximal port of the first embedded stent and the second embedded stent respectively to form a connecting portion, and the connecting portion is connected to the tumor cavity covering segment.

6. The covered stent according to claim 5, characterized in that, The connecting portion of the first coating is connected to the connecting portion of the second coating.

7. The covered stent according to claim 6, characterized in that, The first coating and the second coating are integrally formed.

8. The covered stent according to claim 1, characterized in that, Both the first distal bevel and the second distal bevel include a long axis sidewall and a short axis sidewall in the circumferential direction. The axial extension length of the long axis sidewall is greater than the axial extension length of the short axis sidewall. The long axis sidewalls of the first embedded bracket and the second embedded bracket are closely attached to each other. At least one of the long axis sidewalls has a hook portion for hooking at its distal end.

9. The covered stent according to claim 1, characterized in that, The supporting wave ring includes at least one anchoring wave ring, and the outer side of the anchoring wave ring is provided with a plurality of anchoring barbs along the circumferential direction.

10. A support conveying system, characterized in that, Includes the covered stent as described in any one of claims 1-9.

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