Covered stent

Abstract

The invention provides a covered stent which comprises a main stent body with a tubular main body and an embedded stent body, and the main stent body comprises a near-end section, a tumor cavity section and a far-end section in the axial direction; the tumor cavity section comprises an internal iliac channel and an external iliac channel which are arranged in the radial direction, the external iliac channel is communicated with the far-end section, an opening is formed in the far end of the internal iliac channel, an embedded support is arranged in the internal iliac channel, and the embedded support is arranged to provide an implantation channel of the internal iliac support, so that the internal iliac support has better anchoring property; wherein the total supporting strength of the internal iliac channel and the embedded stent is smaller than the supporting strength of the external iliac channel, and the external iliac channel has higher supporting strength, so that when the covered stent is pressed, the internal iliac channel part deforms prior to the external iliac channel part, and the external iliac channel part can keep a better channel form and is prevented from being pressed and blocked; and it is ensured that blood smoothly passes through the external iliac channel part.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a covered stent. Background Art

[0002] The iliac artery includes the common iliac artery, the external iliac artery, and the internal iliac artery. In the prior art for treating iliac artery aneurysm diseases, an iliac artery bifurcation stent and an internal iliac covered stent can be implanted through endovascular treatment to reconstruct the arterial blood vessels. The conventional iliac artery bifurcation stent in the prior art usually has two branch channels, which are respectively used to reconstruct the internal iliac artery and the external iliac artery. In order to ensure that the internal iliac artery channel is not blocked due to vascular compression, the waveform design of the internal iliac artery channel provides a certain support strength. In fact, the blood flow patency of the external iliac artery channel is far more important than that of the internal iliac artery channel. Therefore, generally, a larger lumen is designed for the external iliac artery to ensure blood flow patency. However, if the lumen of the external iliac artery channel is too large, it will have higher requirements for the patient's vascular anatomy and is not conducive to expanding the applicable range of the device. Summary of the Invention

[0003] Based on this, it is necessary to provide a new covered stent that can provide an implantation channel for the internal iliac stent and can make the external iliac passage have better support strength to maintain the overall shape of the external iliac passage when the stent is compressed.

[0004] A covered stent includes a main stent with a tubular main body and an embedded stent. The main stent includes a proximal section, a aneurysm section, and a distal section along the axial direction. The proximal section is connected to the distal section through the aneurysm section. The aneurysm section includes an internal iliac channel and an external iliac channel arranged radially. The external iliac channel is connected to the distal section, and the distal end of the internal iliac channel is provided with an opening communicating with the outside. The embedded stent is arranged in the internal iliac channel, at least part of the embedded stent is connected to the side wall of the internal iliac channel, and the distal end of the embedded stent is communicated with the opening. The total support strength of the internal iliac channel and the embedded stent is less than the support strength of the external iliac channel.

[0005] In one embodiment, the aneurysm section includes a plurality of first wave loops arranged at intervals along the axial direction. The number of waves of the plurality of first wave loops is the same, and the wave peaks and / or wave valleys of adjacent first wave loops are arranged opposite to each other.

[0006] In one embodiment, at least a part of the first wave loop located in the internal iliac channel is provided with a break.

[0007] In one embodiment, the wave angle of the first wave loop located in the external iliac channel part is greater than the wave angle of the same first wave loop located in the internal iliac channel part, or the wire diameter of the first wave loop located in the external iliac channel part is greater than the wire diameter of the same first wave loop located in the internal iliac channel part.

[0008] In one embodiment, the first wave loop includes a plurality of first wave rods, and a support is provided between adjacent first wave rods. The plurality of supports are configured such that the compressible distance between the first wave rods at the external iliac artery channel portion is smaller than the compressible distance between the first wave rods at the internal iliac artery channel portion.

[0009] In one embodiment, there is a gap between the support and the adjacent first wave rod, and the gap at the external iliac artery channel portion is smaller than the gap at the internal iliac artery channel portion.

[0010] In one embodiment, the support is an elastic support. The two sides of the elastic support are respectively connected to two adjacent first wave rods, and the elastic modulus of the elastic support at the external iliac artery channel portion is greater than the elastic modulus of the elastic support at the internal iliac artery channel portion.

[0011] In one embodiment, the proximal segment includes a plurality of proximal support wave loops arranged at intervals along the axis, the distal segment includes a plurality of distal support wave loops arranged at intervals along the axis, and the embedded stent includes a mesh body.

[0012] In one embodiment, the surface of the main stent is covered with a first film, and the surface of the embedded stent is covered with a second film. The support strength of the first film is greater than the support strength of the second film.

[0013] In one embodiment, the support strength at the proximal and distal positions of the aneurysm cavity segment is greater than the support strength at the middle position.

[0014] In one embodiment, the support strength at the proximal or distal position of the aneurysm cavity segment is greater than the support strength at the middle position.

[0015] The beneficial effects of the present invention are as follows: Compared with the prior art, the present invention provides a covered stent, which includes a main stent having a tubular body and an embedded stent. The main stent includes a proximal segment, an aneurysm cavity segment, and a distal segment along the axis. The aneurysm cavity segment includes an internal iliac artery channel and an external iliac artery channel arranged radially. The external iliac artery channel communicates with the distal segment. The distal end of the internal iliac artery channel is provided with an opening and an embedded stent is arranged inside. By providing the embedded stent to provide an implantation channel for the internal iliac stent, the internal iliac stent has better anchoring. Among them, the total support strength of the internal iliac artery channel and the embedded stent is less than the support strength of the external iliac artery channel. The external iliac artery channel has higher support strength so that when the covered stent is compressed, the internal iliac artery channel portion deforms prior to the external iliac artery channel portion, enabling the external iliac artery channel portion to maintain a better channel shape, avoiding compression and occlusion, and ensuring smooth blood flow through the external iliac artery channel portion. Description of the Drawings

[0016] Figure 1Schematic diagram of the overall structure of the covered stent in Embodiment 1 of the present invention;

[0017] Figure 2 Schematic diagram of the main stent structure in Embodiment 1 of the present invention;

[0018] Figure 3 Schematic diagram of the embedded stent structure in Embodiment 1 of the present invention;

[0019] Figure 4 Schematic diagram of the angular distribution structure of the first wave ring in Embodiment 1 of the present invention;

[0020] Figure 5 Schematic diagram of the tapered angular structure of the first wave ring in Embodiment 1 of the present invention;

[0021] Figure 6 Schematic diagram of the wire diameter distribution structure of the first wave ring in Embodiment 1 of the present invention;

[0022] Figure 7 Schematic diagram of the different length support members of the first wave ring in Embodiment 2 of the present invention;

[0023] Figure 8 Schematic diagram of the different height support members of the first wave ring in Embodiment 2 of the present invention;

[0024] Figure 9 Schematic diagram of the structure when the support member is an elastic support member in Embodiment 2 of the present invention;

[0025] Figure 10 Schematic diagram of the structure of the covered stent in other embodiments in Embodiment 2 of the present invention;

[0026] Figure 11 Schematic diagram of the main stent structure in Embodiment 3 of the present invention;

[0027] Figure 12 Schematic diagram of the structure with a break in the first wave ring in Embodiment 3 of the present invention;

[0028] Figure 13 Schematic diagram of the overall structure of the covered stent in Embodiment 4 of the present invention;

[0029] Figure 14 Schematic diagram of the different wire diameters of the first embedded stent and the second embedded stent in Embodiment 4 of the present invention;

[0030] Figure 15 For the present invention Figure 14 Partial enlarged view of position A;

[0031] Figure 16 Schematic diagram of the different mesh densities of the first embedded stent and the second embedded stent in Embodiment 5 of the present invention;

[0032] Figure 17 Schematic diagram of different axial lengths of the internal iliac artery channel and external iliac artery channel in the tumor cavity segment in the sixth embodiment of the present invention.

[0033] Figure 18 Schematic diagram of the flat mouth structure of the exposed section of the second embedded stent in the sixth embodiment of the present invention;

[0034] Figure 19 Schematic diagram of the beveled mouth structure of the exposed section of the second embedded stent in the sixth embodiment of the present invention;

[0035] Figure 20 Schematic diagram of the variable-diameter proximal wave ring structure provided at the proximal position of the tumor cavity segment in the sixth embodiment of the present invention;

[0036] Figure 21 Schematic diagram of other covered stents in the sixth embodiment of the present invention;

[0037] Figure 22 Schematic diagram of the covered stent in the seventh embodiment of the present invention;

[0038] Figure 23 Schematic diagram of the main stent in the seventh embodiment of the present invention;

[0039] Figure 24 Schematic diagram of different axial lengths of the first embedded stent and the second embedded stent in the seventh embodiment of the present invention;

[0040] Figure 25 Schematic diagram of the triangular wave ring stent in the seventh embodiment of the present invention;

[0041] Figure 26 Schematic diagram of the structure with a visualization element provided at both ends of the first embedded stent and the second embedded stent in the seventh embodiment of the present invention;

[0042] Figure 27 Schematic diagram of the transition stent adopting a wave ring stent structure in the seventh embodiment of the present invention;

[0043] Figure 28 Schematic diagram of the transition stent adopting a mesh woven stent structure in the seventh embodiment of the present invention;

[0044] Figure 29 Schematic diagram of the special-shaped wave ring in the eighth embodiment of the present invention;

[0045] Figure 30 Schematic diagram of the structure with a gradually decreasing high wave at the distal end of the special-shaped wave ring in the eighth embodiment of the present invention;

[0046] Figure 31 Schematic diagram of the hook hanger and hanging rod in the ninth and tenth embodiments of the present invention;

[0047] Figure 32Schematic structural diagram of the stent delivery system in Embodiment 10 of the present invention;

[0048] Figure 33 Schematic structural diagram of the covered stent disposed in the delivery device in Embodiment 10 of the present invention. Detailed implementation manners

[0049] In order to better understand the concept of the present application, the following specifically describes the implementation manners of the present application with reference to the accompanying drawings. The following specific embodiments are only partial embodiments of the present application and do not limit the present application.

[0050] For ease of description, spatially relative relationship terms may be used in the text to describe the relationship of one element or feature shown in the figure relative to another element or feature. These relative relationship terms such as "inner", "outer", "inner side", "outer side", "below", "beneath", "above", "upper" etc. are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is flipped, then an element described as "below" or "beneath" another element or feature will then be oriented as "above" or "upper" another element or feature. Therefore, the exemplary term "below" can include both the upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatially relative relationship descriptors used in the text are correspondingly interpreted.

[0051] Although terms such as first, second, third etc. may be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply an order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below may be referred to as the second element, component, region, layer or section without departing from the teachings of the exemplary embodiments.

[0052] To more clearly describe the structure of the present application, the terms "proximal end" and "distal end" are defined herein as commonly used terms in the field of interventional medicine. Specifically, the "distal end" represents the end of the blood vessel away from the heart, and the "proximal end" represents the end of the blood vessel close to the heart; the "axial direction" represents its length direction, and the "radial direction" represents the direction perpendicular to the "axial direction"; the "upper end" and the "lower end" are two relatively distant ends. When one end is defined as the "upper end", the other relatively distant end is the "lower end".

[0053] Embodiment 1:

[0054] Please refer to Figure 1 - Figure 2 , the present invention provides a covered stent 100, which is generally composed of a metal skeleton and a covering material. The metal skeleton can adopt a Z-shaped wave or a braided mesh design. The covering material has a certain blood flow isolation ability and is combined with the metal skeleton by means of pressurization, 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 generally matches the diameter of the common iliac artery. In this embodiment, refer to Figure 1 and Figure 3, the covered stent 100 has a main stent 10 with a tubular body and an embedded stent 20. The main stent 10 is directly placed in the blood vessel in contact with the blood vessel wall. The embedded stent 20 is arranged in the inner cavity of the main stent 10 for blood flow shunting. The surface of the main stent 10 is covered with a first film 104, and the surface of the embedded stent 20 is covered with a second film 202; wherein, the main stent 10 includes a proximal section 101, a aneurysmal section 102 and a distal section 103 along the axial direction; the proximal section 101 is connected to the proximal side of the aneurysmal section 102, the distal section 103 is connected to the distal side of the aneurysmal section 102, and the proximal section 101 is connected to the distal section 103 through the aneurysmal section 102; when the covered stent 100 is installed in the diseased blood vessel, the aneurysmal section 102 is generally placed at the aneurysmal position of the blood vessel. The aneurysmal section 102 is jointly composed of an external iliac channel 1022 and an internal iliac channel 1021 arranged along the radial direction. Usually, the radial width of the aneurysmal section 102 is set to be greater than the diameters of the distal section 103 and the proximal section 101, so that both the internal iliac channel 1021 and the external iliac channel 1022 in the aneurysmal section 102 have sufficient flow space to avoid complete occlusion due to the extrusion of the aneurysm after implantation; the external iliac channel 1022 and the internal iliac channel 1021 are isolated to form two relatively independent blood flow channels. In use, the internal iliac channel 1021 is used to introduce an internal iliac stent, and the external iliac channel 1022 is used to connect the extended distal section 103 to establish communication with the external iliac artery; in this embodiment, by arranging the embedded stent 20 in the internal iliac channel 1021, the internal iliac channel 1021 and the external iliac channel 1022 are relatively independently isolated. Moreover, an opening 1024 for communicating with the outside is provided at the distal end of the internal iliac channel 1021, and the distal end of the embedded stent 20 is communicated with the opening 1024. The arrangement of the embedded stent 20 can make the shape of the formed internal iliac channel 1021 match the shape of the internal iliac stent to be implanted, so as to ensure better adaptability of the stent during and after implantation; when the embedded stent 20 is arranged in the internal iliac channel 1021, at least part of it is connected to the side wall of the internal iliac channel 1021 part of the aneurysmal section 102. Preferably, the connection between the embedded stent 20 and the aneurysmal section 102 is a surface contact connection by multi-point bonding or suturing. Such an arrangement can ensure that at least the part of the embedded stent 20 connected to the aneurysmal section 102 always remains in contact with the aneurysmal section 102 of the main stent 10. When the aneurysmal section 102 is squeezed, the contacting part can deform simultaneously with the deformation of the aneurysmal section 102, so as to effectively avoid that when the aneurysmal section 102 deforms, the embedded stent 20 does not deform but only displaces in the inner cavity of the aneurysmal section 102, affecting the width and passability of the external iliac channel 1022.

[0055] In this embodiment, please refer to Figure 1 and Figure 2, in order to ensure that when the aneurysm cavity section 102 of the covered stent 100 is squeezed, while the internal iliac artery channel 1021 obtains a certain degree of support through the embedded stent 20, it is ensured that the external iliac artery channel 1022 can maintain a good shape and avoid occlusion due to excessive squeezing. The total support strength of the internal iliac artery channel 1021 of the aneurysm cavity section 102 of the covered stent 100 of the present application and the embedded stent 20 is set to be less than the support strength of the external iliac artery channel 1022; in this way, when the part with a small support strength is subjected to a squeezing force, it will preferentially deform and the deformation amount is large, while the part with a large support strength will slowly deform and the deformation amount is limited; thus, the external iliac artery channel 1022 with a greater support strength can ensure that under the same squeezing force as the internal iliac artery channel 1021, the deformation amount is smaller, so as to maintain the shape of the external iliac artery channel 1022. And because the support strength of the internal iliac artery channel 1021 is small, it will preferentially deform and the deformation amount is larger, so that more deformation of the aneurysm cavity section 102 falls on the part of the internal iliac artery channel 1021, maintaining the shape of the external iliac artery channel 1022; and because of the setting of the embedded stent 20 in the internal iliac artery channel 1021, the part of the embedded stent 20 that is not connected to the aneurysm cavity section 102 in the cavity basically does not deform and can still maintain a good channel shape.

[0056] In this embodiment, please refer to Figure 3 , the embedded stent 20 has a mesh main body 201 and a second film 202. Among them, the mesh main body 201 adopts a mesh woven stent structure. The mesh support structure can provide better tension, so as to provide better shape retention. And, when the internal iliac artery stent is implanted, the mesh main body 201 can provide more contact sites, so that there is a greater frictional force between the internal iliac artery stent and the embedded stent 20, which can effectively enhance the adhesion force and the anti-slip performance of the stent; please refer to Figure 2 , the proximal section 101 is provided with a plurality of proximal support wave rings 1011 along the axial direction, and the distal section 103 is provided with a plurality of distal support wave rings 1031 along the axial direction. Both the proximal support wave rings 1011 and the distal support wave rings 1031 adopt Z-shaped ring wave rings to provide support force. The Z-shaped ring wave rings can provide support force while leaving a film gap between the wave rings, so that the stent can deform at the film gap position and has good flexibility. Among them, the diameter of the proximal support wave rings 1011 is larger than the diameter of the distal support wave rings 1031 to adapt to different blood vessel diameters. In other embodiments, the mesh main body can also be formed by cutting a tubular metal, such as a nickel-titanium tube, a stainless steel tube, etc. to form a cut mesh main body.

[0057] Among them, the support strength of the first film 104 is set to be greater than that of the second film 202. In this embodiment, the first film 104 is made of a PET film, and the second film 202 is made of an ePTFE film. The PET film has the characteristic of high tensile strength, while the ePTFE film has a relatively weak tensile strength, a smooth surface, is not prone to thrombus formation, has good long-term patency for small-sized blood vessels, and small pores. Combining the PET film and the ePTFE film can not only ensure the overall strength of the stent film, but also enable the covered stent 100 to have a better effect of isolating blood flow, ensure the long-term patency of branches, and have a good occlusion effect. And the support strength of the first film 104 being greater than that of the second film 202 can make the support strength of the partially covered part of the external iliac channel 1022 greater than the support strength of the embedded stent 20 in the internal iliac channel 1021 part, so that the embedded stent 20 is more prone to deformation compared with the external iliac channel 1022 part, and thus is more likely to deform along with the deformation of the internal iliac channel 1021 part.

[0058] In this embodiment, in order to make the covered stent 100 easier to be compressed and have a smaller compressed folding volume when installed on the delivery device, the proximal support wave ring 1011, the distal support wave ring 1031, and the first wave ring 1023 can be sutured to the surface of the first film by suture. Specifically, when suturing, at least the wave peaks of the proximal support wave ring 1011, the distal support wave ring 1031, and the first wave ring 1023 facing the proximal direction are not sutured to the first film. In this way, when the covered stent 100 is folded and compressed, since the wave peak positions are not restricted by sutures, other suture points can undergo slight displacements to adapt to the folding of the film and the deformation of the stent wave rings, so that the covered stent can be better folded. Further, the unsutured wave peaks can reduce the suture ratio of the film, so the film can have better flexibility to adapt to blood vessels with a more complex bending degree.

[0059] In this embodiment, please refer to Figure 2 , the aneurysm cavity segment 102 includes a plurality of first wave rings 1023 arranged at intervals along the axis. The first wave rings 1023 are also Z-shaped ring wave rings. In order to make the aneurysm cavity segment 102 maintain good flexibility, the number of waves of the plurality of first wave rings 1023 is set to be the same, and the wave peaks and / or wave valleys of adjacent first wave rings 1023 are arranged opposite to each other. Here, setting the same number of waves and the wave peaks and / or wave valleys opposite means that adjacent first wave rings 1023 are almost parallel to each other, so that there is a uniform spacing distance between adjacent first wave rings 1023, and they are only connected by the film, so the flexibility is better, which is beneficial for the aneurysm cavity segment 102 to better conform to the bending shape of the blood vessel. Preferably, the number of waves of the first wave rings 1023 can also be equal to the number of waves of the proximal support wave ring 1011, and the wave peaks and / or wave valleys are arranged opposite to each other, so that the connection between the aneurysm cavity segment 102 and the proximal segment 101 and the connection between the aneurysm cavity segment 102 and the proximal segment 101 also maintain good flexibility.

[0060] In this embodiment, please refer to Figure 4 and Figure 5 , in order to make the total support strength of the internal iliac channel 1021 and the embedded stent 20 less than the support strength of the external iliac channel 1022, the wave angle (angle a in the figure) of the same first wave loop 1023 located in the external iliac channel 1022 part of the aneurysm cavity segment 102 is greater than the wave angle (angle b in the figure) of the same first wave loop 1023 located in the internal iliac channel 1021 part; this is because when the wave loop with a larger wave angle deforms, the force required for deformation is greater than that of the wave form with a smaller wave angle, so the support strength is also greater than that of the wave form with a smaller wave angle; in some embodiments, in order to make the wave angles different, the wave numbers of adjacent first wave loops 1023 are the same and the wave peaks and / or wave valleys are arranged opposite to each other. The wave height of the wave form located in the external iliac channel 1022 part can be made less than the wave height of the wave form located in the internal iliac channel 1021 part, and the wave angle (angle d in the figure) of the wave form located in the external iliac channel 1022 part is greater than the wave angle (angle c in the figure) of the wave form located in the internal iliac channel 1021 part. In another embodiment, the wave height of all the wave forms of the first wave loop 1023 can be gradually increased from the external iliac channel 1022 part to the internal iliac channel 1021 part, and the wave angle is gradually decreased, forming a structure with a gradually decreasing support strength; in this way, the gradual decrease of the support strength can avoid a sudden large difference in support strength at the junction of the external iliac channel 1022 part and the internal iliac channel 1021 part of the aneurysm cavity segment 102, thereby causing unpredictable and undesirable deformation of the aneurysm cavity segment 102 at this position.

[0061] In other embodiments, please refer to Figure 6 , in order to make the total support strength of the internal iliac channel 1021 and the embedded stent 20 less than the support strength of the external iliac channel 1022, the wire diameter R1 of the first wave loop 1023 located in the external iliac channel 1022 part can be made greater than the wire diameter R2 of the first wave loop 1023 located in the internal iliac channel 1021 part. When a larger wire diameter deforms, more force is required to resist the stiffness of the material itself. Therefore, under the same force, the deformation amount of the wave loop with a larger wire diameter is less than that of the wave loop with a smaller wire diameter, so it has a stronger support strength; in some embodiments, the braided wire with a small wire diameter and the braided wire with a wire diameter can be connected together by means of a connecting piece or a fastening piece, and after connection, they are respectively placed in the internal iliac channel 1021 part and the external iliac channel 1022 part of the aneurysm cavity segment 102; it is also possible to integrally cut and form the first wave loop 1023, and then reduce its wire diameter in the internal iliac channel 1021 part by means of chemical corrosion, physical polishing, etc., or make the wire diameter of the first wave loop 1023 have a gradually decreasing structure from the external iliac channel 1022 part to the internal iliac channel 1021 part.

[0062] In order to make the support strength of the embedded stent 20 and the part of the internal iliac artery channel 1021 in the aneurysm cavity segment 102 less than that of the external iliac artery channel 1022 part, the embedded stent 20 is woven with metal braided wires of a smaller wire diameter. In this embodiment, the wire diameter d of the embedded stent 20 is less than one-half of the wire diameter D of the first wave coil 1023 in the external iliac artery channel 1022 part, that is to say, d is less than one-half of D, and the wire diameter M of the first wave coil 1023 in the internal iliac artery channel 1021 part is also less than one-half of the wire diameter D of the first wave coil 1023 in the external iliac artery channel 1022 part. In this way, it can be ensured that the sum of the support strength of the embedded stent 20 and the internal iliac artery channel 1021 part is always less than that of the external iliac artery channel 1022 part. However, the wire diameters of the embedded stent 20 and the first wave coil 1023 in the internal iliac artery channel 1021 part of this application are not only limited to the above settings. Technicians can adjust the wire diameter of the embedded stent 20 and the wire diameter of the first wave coil 1023 in the internal iliac artery channel 1021 part according to the actual stent requirements, as long as it is ensured that the sum of their support strengths is less than that of the external iliac artery channel 1022 part.

[0063] Among them, the support strength of the aneurysm cavity segment 102 at the proximal end and / or the distal end can also be greater than that at the middle position. In one embodiment, the support strength of the first wave coil 1023 at the proximal end and the distal end of the aneurysm cavity segment 102 is greater than that of the first wave coil 1023 at the middle position. Such a setting is because when a blood vessel forms an aneurysm cavity, the junction between the aneurysm cavity and the normal blood vessel is usually a position where the extrusion is relatively severe. Setting the first wave coils 1023 at the proximal end and the distal end of the aneurysm cavity segment 102 to have a higher support strength can better resist the extrusion from the junction position of the blood vessel and the aneurysm cavity. Further, setting the middle position to have a lower support strength can make the aneurysm cavity segment 102 have a certain flexibility and better adapt to the shape of the blood vessel. In other embodiments, only the support strength of the first wave coil 1023 at the proximal end of the aneurysm cavity segment 102 can be set to be greater than that of the first wave coil 1023 at the middle position. In this way, at least the support strength of the stent at the blood inflow position can be ensured. In order to achieve the change of the above support strength, the wire diameter or the wave angle of the first wave coil 1023 at the proximal end of the aneurysm cavity segment 102 can be made greater than the wire diameter or the wave angle of the first wave coil 1023 at the middle position.

[0064] In this embodiment, the support strength is specifically manifested as the deformation amount of the overall tubular inner cavity (the internal iliac channel 1021 part and the external iliac channel 1022 part) of the covered stent 100 after being compressed in the aneurysm cavity section 102. That is, under the same force application conditions, the same force (this force needs to cause deformation in both the internal iliac channel 1021 part and the external iliac channel 1022 part) is used to press on the outer walls of the internal iliac channel 1021 part and the external iliac channel 1022 part, and then the radial cross-sectional areas of the internal iliac channel 1021 part and the external iliac channel 1022 part after pressing are measured and calculated. Here, the stent with a larger total cross-sectional area measured after pressing has a greater support strength, and the stent with a smaller total cross-sectional area has a smaller support strength; in some embodiments, the independently separated internal iliac channel 1021 part and external iliac channel 1022 part can be compressed respectively by a flat dynamometer. When the same deformation amount is compressed, the force required is measured. The stent with a larger measured force has a greater support strength, and the stent with a smaller measured force has a smaller support strength. In this embodiment, the force measured for the external iliac channel 1022 part is always greater than the force measured for the internal iliac channel 1021 part.

[0065] Embodiment Two:

[0066] In this embodiment, please refer to Figure 7 - Figure 9 , the structures of the main stent 10 and the embedded stent 20 are generally the same as those in Embodiment One. The difference is that the first wave loop 1023 includes a plurality of first wave rods 10232, and the plurality of first wave rods 10232 are connected end to end at an angle to form a Z-shaped or M-shaped ring wave loop. Among them, a support member 10233 is provided between adjacent first wave rods 10232. The support member 10233 is connected to the first film 104 between adjacent two first wave rods 10232 by sewing or bonding. When adjacent two first wave rods 10232 are deformed by extrusion force, the two first wave rods 10232 make a compression movement of approaching each other around their wave angles. When moving to the position of the support member 10233, both sides of the support member 10233 abut against the two first wave rods 10232 respectively, preventing the two first wave rods 10232 from continuing to move and compress, restricting the deformation degree of the waveform and thus providing a support force. In order to make the support strength of the first wave loop 1023 in the external iliac channel 1022 part greater than that in the internal iliac channel 1021 part, a plurality of support members 10233 are configured such that the compressible distance between the first wave rods 10232 in the external iliac channel 1022 part is smaller than the compressible distance between the first wave rods 10232 in the internal iliac channel 1021 part; this is because when the compressible distance between adjacent two first wave rods 10232 becomes smaller, the deformable degree of the waveform is reduced, and the support performance of the first wave loop 1023 at this waveform position is better.

[0067] Please refer to Figure 7 andFigure 8 In one embodiment, to achieve the above effects, a gap 10234 may be provided between the support member 10233 and the adjacent first wave rod 10232. The purpose of providing the gap 10234 is to enable a space for movable deformation between the first wave rod 10232 and the support member 10233. The larger this space is, the larger the gap 10234 is, the greater the degree of deformation that the waveform can undergo, and the lower the support strength; conversely, the smaller the gap 10234 is, the smaller the degree of deformation that the waveform can undergo, and the higher the support strength. Therefore, by setting the gap 10234 between the support member 10233 of the external iliac channel 1022 part and the adjacent first wave rod 10232 to be smaller than the gap 10234 between the support member 10233 of the internal iliac channel 1021 part and the adjacent first wave rod 10232, the support strength obtained by the first wave ring 1023 in the external iliac channel 1022 part can be made greater than the support strength obtained in the internal iliac channel 1021 part. With such a setting, when the first wave ring 1023 is subjected to an extrusion force, the first wave rods 10232 undergo relative deformation of approaching each other. When the first wave rod 10232 located in the external iliac channel 1022 part abuts against the support member 10233, the first wave rod 10232 located in the internal iliac channel 1021 part can still continue to deform, such that the deformation amount of the aneurysm cavity segment 102 in the internal iliac channel 1021 part is greater than the deformation amount in the external iliac channel 1022 part.

[0068] Among them, please refer to Figure 7 and Figure 8 The support member 10233 may be a straight-shaped structure with two end portions. To prevent the two end portions of the straight-shaped structure support member 10233 from piercing the membrane and scratching the blood vessel, the two ends can be bent to form a ring or form anti-injury head ends, etc., which are not shown in the figure. It can be understood that the support members 10233 of multiple straight-shaped structures can be support members 10233 with the same length, respectively arranged at different axial positions between adjacent first wave rods 10232. For example, in the external iliac channel 1022 part, the support members 10233 with the same length are arranged near the wave angle position to provide a smaller gap 10234. It can also be understood that the support members 10233 of multiple straight-shaped structures can be support members 10233 with different lengths, respectively arranged at the same axial position between adjacent first wave rods 10232. For example, the length of the support member 10233 in the external iliac channel 1022 part is greater than the length of the support member 10233 in the internal iliac channel 1021 part to provide a smaller gap 10234.

[0069] In another embodiment, please refer to Figure 9, the support member 10233 is an elastic support member 10235. The two sides of the elastic support member 10235 are respectively connected to the adjacent first wave rods 10232. With this arrangement, the degree of deformation of the adjacent first wave rods 10232 approaching each other is determined by the elastic deformation degree of the elastic support member 10235. When the elastic deformation degree of the elastic support member 10235 is large, that is, when the elastic modulus is small, the degree of deformation that the adjacent two first wave rods 10232 can approach each other is large, and the support strength provided is low; while when the elastic deformation degree of the elastic support member 10235 is small, that is, when the elastic modulus is large, the degree of deformation that the adjacent two first wave rods 10232 can approach each other is small, and the support strength provided is large; thus, by setting the elastic modulus of the elastic support member 10235 in the external iliac channel 1022 part to be greater than the elastic modulus of the elastic support member 10235 in the internal iliac channel 1021 part; the elastic support member 10235 with a large elastic modulus provides a greater support force in the external iliac channel 1022 part, and conversely, the elastic support member 10235 with a small elastic modulus provides a smaller support force in the internal iliac channel 1021 part.

[0070] In some embodiments, the elastic support member 10235 can be a spring structure. The two sides of the spring structure are respectively connected to the first wave rods 10232 on both sides. The elastic modulus of the spring structure in the external iliac channel 1022 part is set to be greater than the elastic modulus of the spring structure in the internal iliac channel 1021 part.

[0071] In some other embodiments, please refer to Figure 9 , the elastic support member 10235 can be an elastic connecting member with a spring member in the middle and connecting structures on both sides. Among them, the deformation distance of the first wave rods 10232 on both sides can be limited by setting the total length of the middle spring member; for example, the length of the spring member of the elastic connecting member in the external iliac channel 1022 part is set to be less than the length of the spring member of the elastic connecting member in the internal iliac channel 1021 part; the degree of deformation that the shorter spring member can provide is less than the degree of deformation that the longer spring member can provide. Thus, under the same force, the shorter spring member reaches the deformation limit earlier than the longer spring member and provides a stable support force.

[0072] In other embodiments, please refer to Figure 10 , by making the axial length of the aneurysm cavity segment 102 located in the internal iliac channel 1021 part and the embedded stent 20 less than the axial length of the external iliac channel 1022 part, the support position when it is compressed in the radial direction can be reduced, and the area that can bear the pressure is small; thus, the support strength of the aneurysm cavity segment 102 located in the internal iliac channel 1021 can be made less than the support strength of the external iliac channel 1022;

[0073] In some embodiments, please refer to Figure 10The distal port and the opening 1024 of the embedded stent 20 can be set to be oblique, and the direction of the oblique opening is towards the direction away from the external iliac channel 1022; and the setting of the oblique opening can also make the selection entrance of the internal iliac stent larger when the embedded stent 20 is implanted, reducing the difficulty of selection; the proximal port of the embedded stent 20 is also set to be oblique to increase the receiving area for blood to enter.

[0074] In one embodiment, the support member 10233 is at least partially provided with a developing structure (not shown in the figure). When the support member 10233 is provided with a developing structure, the shape of the support member 10233 can be set to a shape and structure with a marking identification function according to needs, such as a letter-shaped support member 10233 or a number-shaped support member 10233. The support member 10233 can also be entirely a developing structure. The preferred developing structure can be tantalum wire or gold wire.

[0075] Embodiment 3

[0076] In this example, see Figure 11 and Figure 12 The structures of the main support 10 and the embedded support 20 are substantially the same as those in the first embodiment, except that the first wave ring 1023 is provided with a break 10231 at least in a portion of the internal iliac channel 1021. It can be understood that the first wave ring 1023 is provided with a break 10231 to form a C-shaped wave ring 1026. The first wave ring 1023 does not provide a supporting force at the position of the break 10231. The break 10231 is located at the internal iliac channel 1021, so that the tumor cavity segment 102 is only covered by the membrane at the position of the internal iliac channel 1021, without the support of the first wave ring 1023. The supporting force of the internal iliac channel 1021 is provided by the embedded support 20, and the supporting strength of the embedded support 20 is lower than the supporting strength of the first wave ring 1023, so that the supporting strength of the tumor cavity segment 102 in the internal iliac channel 1021 is less than the supporting strength in the external iliac channel 1022.

[0077] In one of the embodiments, the fracture 10231 only covers the position where the embedded stent 20 is connected to the membrane of the tumor cavity segment 102, and the broken ends of the C-shaped wave ring 1026 are connected to the two sides of the connection position between the embedded stent 20 and the membrane of the tumor cavity segment 102, that is, the position where the internal iliac channel 1021 of the tumor cavity segment 102 is only connected to the embedded stent 20 does not have the first wave ring 1023 to provide support force. With this arrangement, when the tumor cavity segment 102 is subjected to extrusion pressure, the part where the internal iliac channel 1021 is connected to the embedded stent 20 is deformed first due to its smaller support strength, thereby effectively avoiding the excessive impact of the extrusion on the shape of the external iliac channel 1022.

[0078] Please read further Figure 20, the C-shaped wave loop 1026 is wound around the two ends of the fracture 10231 to form a circular ring structure 10261 or an anti-damage end head. The circular ring structure 10261 can accommodate the ends of the metal wires of the braided C-shaped wave loop 1026, thereby preventing the sharp ends from piercing the film and scratching the blood vessel.

[0079] Embodiment 4

[0080] In this embodiment, please refer to Figure 13 , the structures of the main body stent 10 and the embedded stent 20 are substantially the same as those in Embodiment 1. The difference is that the embedded stent 20 in the aneurysm cavity segment 102 includes a first embedded stent 21 and a second embedded stent 22 arranged radially, wherein the first embedded stent 21 communicates with the distal segment 103; an opening 1024 is provided at the distal end of the aneurysm cavity segment 102, and the distal port of the second embedded stent 22 communicates with the opening 1024; wherein, the aneurysm cavity segment 102 includes an internal iliac artery channel 1021 and an external iliac artery channel 1022, the external iliac artery channel 1022 houses the first embedded stent 21, and the internal iliac artery channel 1021 houses the second embedded stent 22;

[0081] The external iliac artery channel 1022 and the internal iliac artery channel 1021 are separated by embedding the first embedded stent 21 and the second embedded stent 22 to form a blood flow cavity. The first embedded stent 21 and the second embedded stent 22 can respectively provide support to maintain the channel shape and prevent compression and occlusion; by providing the first embedded stent 21 in the external iliac artery channel 1022, when extrusion occurs, the first embedded stent 21 in the external iliac artery channel 1022 has a supporting force that resists the second embedded stent 22 in the internal iliac artery channel 1021, so that the covered stent 100 of the present application can provide a better-shaped passage when the internal iliac stent is implanted into the internal iliac artery channel 1021, and at the same time can prevent the occlusion of the external iliac artery channel 1022 caused by the excessive extrusion of the internal iliac artery channel 1021 on the external iliac artery channel 1022, thereby being able to better maintain the overall shape and smoothness of the double channels; wherein, the blood flow inlets at the proximal end of the aneurysm cavity segment 102 and the blood flow outlets at the distal end are occupied by the proximal ports and distal ports of the first embedded stent 21 and the second embedded stent 22, so that when the blood flow flows from the proximal segment 101 into the aneurysm cavity segment 102, it is shunted by the first embedded stent 21 and the second embedded stent 22.

[0082] In this embodiment, please refer to Figure 14 - Figure 16In order to ensure the expanded shape of the external iliac channel 1022 and the patency of its blood flow when the tumor cavity segment 102 is squeezed or the stent is deployed, the present application sets the support strength of the part of the tumor cavity segment 102 of the coated stent 100 that is in the external iliac channel 1022 as a whole to be greater than the support strength of the part that is in the internal iliac channel 1021; that is, it can be achieved by setting the support strength of the first embedded stent 21 to be greater than the support strength of the second embedded stent 22 on the premise that the support strength of the tumor cavity segment 102 is uniform; or on the premise that the support strength of the first embedded stent 21 is equal to the support strength of the second embedded stent 22, the support strength of the external iliac channel 1022 of the tumor cavity segment 102 is greater than the support strength of the internal iliac channel 1021; or the support strength of the first embedded stent 21 is set to be greater than the support strength of the second embedded stent 22 and the support strength of the external iliac channel 1022 of the tumor cavity segment 102 is greater than the support strength of the internal iliac channel 1021.

[0083] In this example, see Figure 14 and Figure 15 The first embedded stent 21 and the second embedded stent 22 both have a mesh body 201 and a second surface coating 202, and the tumor cavity section 102 of the main stent 10 includes a plurality of first wave rings 1023 spaced apart along the axial direction. The mesh body 201 can provide better ductility, and the second surface coating 202 of the first embedded stent 21 and the second embedded stent 22 can be opened more smoothly to prevent local positions from being squeezed and collapsed, and at the same time, more support sites can be provided to conflict with the iliac internal stent during implantation to increase friction; by adjusting the wire diameters of the first embedded stent 21 and the second embedded stent 22 , and adjusting the wire diameter of the first wave coil 1023 located in the external iliac channel 1022 and the wire diameter of the first wave coil 1023 located in the internal iliac channel 1021, the internal iliac channel 1021 part and the external iliac channel 1022 part of the stent graft 100 located in the tumor cavity section 102 can have a difference in support strength. It can be understood that a larger stent wire diameter can provide higher support performance, so by making the wire diameter of the first embedded stent 21 larger than the wire diameter of the second embedded stent 22, and / or the wire diameter of the first wave coil 1023 located in the external iliac channel 1022 larger than the wire diameter of the first wave coil 1023 located in the internal iliac channel 1021;

[0084] See also Figure 14, the wire diameter of the first inner stent 21 is made larger than that of the second inner stent 22, and the wire diameter of the first corrugated ring 1023 located in the external iliac channel 1022 is larger than the wire diameter of the first corrugated ring 1023 located in the internal iliac channel 1021; the wire diameter of the first corrugated ring 1023 in the internal iliac channel 1021 is small. When the aneurysm segment 102 is subjected to extrusion pressure, the first corrugated ring 1023 in the internal iliac channel 1021 deforms prior to the first corrugated ring 1023 in the external iliac channel 1022, thus preferentially affecting the deformation of the second inner stent 22 located in the internal iliac channel 1021. Since the wire diameter of the second inner stent 22 is smaller than that of the first inner stent 21, the deformation occurring in the second inner stent 22 is superior to that of the first inner stent 21, dispersing the support strength on the single-layer stent to the inner and outer two-layer stents for sharing, enabling the support strength on a single stent not to be too large. Moreover, simultaneously reducing the wire diameter of the first corrugated ring 1023 in the internal iliac channel 1021 of the aneurysm segment 102 and the second internal iliac stent can avoid too large a wire diameter difference on a single stent, and the wire diameters of the two stents will not be reduced too thin, thereby avoiding problems such as the stent being difficult to maintain the support effect due to too small a wire diameter setting and poor flexibility due to too large a wire diameter.

[0085] Embodiment Five

[0086] In this embodiment, please refer to Figure 16 , the structures of the main stent 10 and the inner stent 20 are substantially the same as those in Embodiment One and Embodiment Four. The difference lies in that, in this embodiment, by making the mesh density of the first inner stent 21 greater than the mesh density of the second inner stent 22, the support strength of the overall part of the aneurysm segment 102 of the covered stent 100 located in the external iliac channel 1022 is set to be greater than the support strength of the part located in the internal iliac channel 1021. Specifically, the first inner stent 21 and the second inner stent 22 include a reticular main body 201, and the reticular main body 201 has a plurality of mesh structures. The higher the mesh density, it means that the number of braided wires required increases, and the area of a single mesh is smaller, and the pressure that can be borne is greater. A larger mesh density can provide greater support strength.

[0087] In this embodiment, please continue to refer to Figure 16, the first embedded stent 21 and the second embedded stent 22 have a diamond grid structure formed by braiding. The first embedded stent 21 has a first diamond grid, and the second embedded stent 22 has a second diamond grid. The first diamond grid and the second diamond grid both have an upper vertex and a lower vertex in the axial direction, and a left vertex and a right vertex in the radial direction. The distance between the upper vertex and the lower vertex of the first diamond grid is D1, and the distance between the left vertex and the right vertex is L1. The distance between the upper vertex and the lower vertex of the second diamond grid is D2, and the distance between the left vertex and the right vertex is L2; preferably, D1 and L1 can both be made smaller than D2 and L2, so that the area occupied by a single first diamond grid is smaller than the area occupied by a single second diamond grid. Thus, under the same stent deployment area, the first embedded stent 21 has a higher grid density and provides a stronger support strength than the second embedded stent 22.

[0088] In another embodiment, please continue to refer to Figure 16 , it is possible to at least make L1 of the first diamond grid smaller than L2 of the second diamond grid, so as to change the density of the first diamond grid only in the circumferential direction of the first embedded stent 21. In this way, it is possible to at least increase the density of the first diamond grid in the radial direction, thereby achieving the effect of enhancing the support strength in the radial direction.

[0089] In one of the embodiments, the wave angle of the first wave loop 1023 of the aneurysm cavity segment 102 located in the external iliac artery passage 1022 is greater than the wave angle of the first wave loop 1023 located in the internal iliac artery passage 1021; in another embodiment, it is possible to make the wave height of all waveforms of the first wave loop 1023 gradually increase from the external iliac artery passage 1022 part to the internal iliac artery passage 1021 part, and the wave angle gradually decrease, forming a structure with a gradually decreasing support strength; in this way, the gradual decrease of the support strength can avoid a sudden large difference in support strength at the junction of the external iliac artery passage 1022 part and the internal iliac artery passage 1021 part of the aneurysm cavity segment 102, thereby causing unpredictable and undesirable deformation of the aneurysm cavity segment 102 at this position. By simultaneously making the grid density of the first embedded stent 21 greater than the grid density of the second embedded stent 22 and the wave angle of the first wave loop 1023 located in the external iliac artery passage 1022 greater than the wave angle of the first wave loop 1023 located in the internal iliac artery passage 1021, and setting changes in the support strength on the first wave loop 1023 of the aneurysm cavity segment 102, the first embedded stent 21 and the second embedded stent 22 at the same time, it is possible to avoid the problem of poor stent flexibility at some positions that may be caused by setting changes in the support strength only on the first embedded stent 21 and the second embedded stent 22 or setting changes in the strength on the first wave loop 1023 of the aneurysm cavity segment 102.

[0090] It can be understood that by making the mesh density of the first embedded stent 21 greater than that of the second embedded stent 22, and / or making the wave angle of the first wave ring 1023 located in the external iliac channel 1022 greater than the wave angle of the first wave ring 1023 located in the internal iliac channel 1021, the support strength of the overall part of the aneurysmal segment 102 of the covered stent 100 located in the external iliac channel 1022 can be set to be greater than that of the part located in the internal iliac channel 1021.

[0091] Embodiment Six

[0092] In this embodiment, please refer to Figure 17 - Figure 19 , the structures of the main stent 10 and the embedded stent 20 are substantially the same as those in Embodiment One and Embodiments Four to Five. The difference is that by providing different axial lengths ( Figure 17 H1 and H2 in Figure 18 and Figure 19 in the internal iliac channel 1021 and the external iliac channel 1022 of the aneurysmal segment 102), the support strength of the aneurysmal segment 102 located in the internal iliac channel 1021 and the external iliac channel 1022 is changed; specifically, the axial length H2 of the external iliac channel 1022 is greater than the axial length H1 of the internal iliac channel 1021. The aneurysmal segment 102 has an axial length H2 in the external iliac channel 1022 and an axial length H1 in the internal iliac channel 1021. The length of H2 being greater than the length of H1 enables the length and contact area of the aneurysmal segment 102 in the external iliac channel 1022 that can withstand pressure to be greater than the compressed length and contact area of the internal iliac channel 1021 when under pressure. Thus, the pressure can be better dispersed, providing better support performance and enhancing the support strength; please further refer to, wherein, the distal end of the second embedded stent 22 includes an exposed section 221, and the exposed section 221 passes through the opening 1024 and penetrates the internal iliac channel 1021, so that the internal iliac channel 1021 of the covered stent 100 also has a distribution of different support strengths. At the intervention end of the internal iliac stent, only the single-layer stent of the second embedded stent 22 serves as support, so that better flexibility is achieved at this position, facilitating the selection of the internal iliac stent; further, the distal port of the exposed section 221 is a flat port or an inclined port; when it is set as a flat port, the exposed section 221 can have more attachment and support positions with the intervened internal iliac stent, effectively improving the long-term stability after the internal iliac stent is intervened; when it is set as an inclined port, the opening direction of the inclined port faces away from the external iliac channel 1022. In this way, the selection port of the internal iliac stent can be enlarged without increasing the diameter of the second embedded stent 22, making the selection of the internal iliac stent faster and more convenient; and the enlarged selection port can also improve the accuracy of the selection of the internal iliac stent; in some embodiments, the exposed section 221 is attached to the adjacent external iliac channel 1022, and the exposed section 221 can be a free end and can be separated from the external iliac channel 1022 relatively. Such a setting can ensure that when the internal iliac stent is implanted and extends into the internal iliac blood vessel, it will not be under excessive pressure at this position and cause problems such as kinking and occlusion; the exposed section 221 can also be fixedly connected to the side wall of the external iliac channel 1022 by suture or bonding to avoid swinging, enabling the internal iliac stent to be selected better.

[0093] Among them, please refer to Figure 18 - Figure 19 , because the second embedded stent 22 passes through the opening 1024 of the aneurysm cavity section 102, there is only a single-layer stent at the opening 1024 position, and the support is weakened significantly compared with other positions. To ensure that the aneurysm cavity section 102 of the covered stent 100 of the present application is more likely to deform at the internal iliac channel 1021 position than at the external iliac channel 1022 position when being squeezed, while avoiding the selection port of the exposed section 221 from being compressed and occluded, the support of the stent at the part of the external iliac channel 1022 close to the exposed section 221 is weakened. At least the first corrugated ring 1023 of the external iliac channel 1022 at the same axial position as the exposed section 221 can be provided with a break 10231 to form a C-shaped corrugated ring 1026, and the break 10231 faces the exposed section 221. With such a setting, the support at the position where the external iliac channel 1022 contacts the exposed section 221 is effectively weakened, so that the selection port of the internal iliac stent of the exposed section 221 can undergo a certain amount of deformation at the position where it abuts against the external iliac channel 1022 when being compressed, thereby buffering the extrusion force and avoiding the further extrusion of the selection port.

[0094] Same as in Embodiment 3, the C-shaped corrugated ring 1026 forms a circular ring structure by winding at the two ends of the break 10231. The circular ring structure can accommodate the ends of the metal wires braiding the C-shaped corrugated ring 1026, thereby avoiding the sharp ends from piercing the film and scratching the blood vessels.

[0095] In this embodiment, please refer to Figure 20 , in order for the covered stent 100 to better adapt to the morphology of the diseased blood vessel, a proximal wave ring 1025 is provided at the proximal position of the aneurysm cavity segment 102. The proximal wave ring 1025 at the proximal end of the aneurysm cavity segment 102 is set such that the diameter of the proximal end is smaller than that of the distal end, so that the proximal wave ring 1025 has an inclination angle, forming a stent structure with a narrow proximal end and a wide distal end. In this way, a gradually changing transition structure from wide to narrow is formed at the position where the aneurysm cavity segment 102 of the covered stent 100 is connected to the proximal segment 101, so as to adapt to the change in diameter from the normal blood vessel to the diseased blood vessel, enhance the anchoring property between the proximal segment 101 and the blood vessel, and improve the stability of the covered stent 100 after implantation; in this embodiment, in order for both the internal iliac channel 1021 and the external iliac channel 1022 of the aneurysm cavity segment 102 to have good passability, the radial dimension of the aneurysm cavity segment 102 is made larger than that of the proximal segment 101 and the distal segment 103, and the setting of the first embedded stent 21 and the setting of the second embedded stent 22 can ensure the blood passability of the internal iliac channel 1021 and the external iliac access. Among them, the aneurysm cavity blood vessel also has a change in size from large to small compared with the proximal blood vessel. Therefore, when setting the proximal wave ring, while adapting to this structure, it can enhance the surface adhesion of the covered stent 100 of the present application, avoid the stent from swinging in the blood vessel, and at the same time avoid the stent from slipping and shifting in the blood vessel.

[0096] In other embodiments, please refer to Figure 21 , the proximal ports and distal ports of the first embedded stent 21 and the second embedded stent 22 can be respectively set as flat ports or inclined ports. For example, both the proximal port and the distal port of the second embedded stent 22 are set as parallel inclined ports, and the proximal port of the first embedded stent 21 is set as an inclined port. In this way, further, by making the second embedded stent 22 form an unstable parallelogram structure, there are staggered support points in the radial direction, and it is easy to deform under pressure to reduce the support strength. The inclined port settings of the proximal ports of the first embedded stent 21 and the second embedded stent 22 can form a larger blood inlet to smoothly receive the blood from the proximal segment.

[0097] In this embodiment, the surface of the main stent 10 is covered with a first film 104, and the surfaces of the first embedded stent 21 and the second embedded stent 22 are covered with a second film 202. The support strength of the first film 104 is greater than that of the second film 202. Among them, the first film 104 is made of a PET film, and the second film 202 is made of an ePTFE film. Here, the change in the support strength of the first film 104 and the second film 202 is mainly reflected in the characteristics of the materials themselves. The tensile strength of the PET film used for the first film 104 is usually between 50-200 MPa, and it has good impact resistance, while the tensile strength of the ePTFE film used for the second film 202 is usually between 23-30 MPa, and its impact resistance is poor. Therefore, using the first film 104 and the second film 202 with different tensile strengths can make the main stent 10, the first embedded stent 21, and the second embedded stent 22 have different support strengths at the film layer, and better cooperate with the stent itself to set different support strengths. The purpose of using the ePTFE film for the first embedded stent 21 and the second embedded stent 22 is to improve blood permeability while minimizing the impact of the film on the support strength.

[0098] In another embodiment, in order to make the covered stent 100 provided in the present application better adapt to the diseased iliac artery blood vessel, the support strengths of the distal segment 103 and the proximal segment 101 of the covered stent 100 are set to be greater than the total support strength of the aneurysm cavity segment 102, the first embedded stent 21, and the second embedded stent 22. Such a setting is because the aneurysm cavity segment 102 itself has support strength, and the support strength of the covered stent 100 at this position with the first embedded stent 21 and the second embedded stent 22 is measured by the total support strength of the aneurysm cavity segment 102, the first embedded stent 21, and the second embedded stent 22. Setting the support strengths of the distal segment 103 and the proximal segment 101 of the covered stent 100 to be greater than the total support strength of the aneurysm cavity segment 102, the first embedded stent 21, and the second embedded stent 22 can make the covered stent 100 have good support properties in the proximal blood vessel and the distal blood vessel near the iliac artery lesion position of the blood vessel, improve the anchoring force with the blood vessel, and firmly anchor the covered stent 100 of the present application at the release position. The purpose of weakening the support strength at the position of the aneurysm cavity segment 102 is to make it have better flexibility so as to improve compliance, better fit the shape of the blood vessel in the aneurysm cavity segment 102, and avoid poor adhesion. In some other embodiments, the support strength of the distal segment 103 or the proximal segment 101 of the covered stent 100 is set to be greater than the total support strength of the aneurysm cavity segment 102, the first embedded stent 21, and the second embedded stent 22. A larger support strength is set at either the proximal segment 101 or the distal segment 103 to meet the condition that the aneurysm cavity segment 102 has good flexibility, and at least one end has good support and anchoring performance to ensure the stability of the covered stent 100 when anchored in the in-vivo blood vessel.

[0099] In some embodiments, it can be achieved by simultaneously reducing the support strength of the first embedded stent 21, the second embedded stent 22, and the aneurysm cavity segment 102. For example, the overall support strength of the first embedded stent 21 and the second embedded stent 22 is less than one-half of the support strength of the proximal segment 101 or the distal segment 103, and the support strength of the aneurysm cavity segment 102 is less than one-half of the support strength of the proximal segment or the distal segment 103.

[0100] Embodiment Seven

[0101] In this embodiment, please refer to Figure 22 and Figure 23 , the structures of the main stent 10 and the embedded stent are substantially the same as those in Embodiment One and Embodiments Four to Six. The difference is that the main stent 10 is provided with support corrugated rings at the proximal segment 101 and the distal segment 103, while the aneurysm cavity covered segment 102 is not provided with the first corrugated ring 1023 and is only covered with a film. The inner cavity of the aneurysm cavity covered segment 102 is provided with the first embedded stent 21 and the second embedded stent 22 to provide support performance; among them, the proximal segment 101, the aneurysm cavity covered segment 102, and the distal segment 103 of the main stent 10 can be connected by the first film 104. The proximal segment 101 and the distal segment 103 are provided with support corrugated rings on the surface, and the aneurysm cavity covered segment 102 is only provided with a film; alternatively, the proximal segment 101 and the aneurysm cavity covered segment 102 can be connected by a single-piece film, and the distal segment 103 is connected to the distal end of the external iliac artery channel 1022 of the aneurysm cavity covered segment 102 by bonding or suturing; please refer to Figure 24 , the first embedded stent 21 and the second embedded stent 22 include a reticular main body 201. The purpose of setting the reticular main body 201 is to emphasize better morphological support; compared with the support corrugated ring, the reticular main body 201 can have better film tension, so that even when providing a smaller wire diameter of the braided wire, it can also provide better film tension to maintain the shape of the blood passage; the aneurysm cavity covered segment 102 is only covered with a film, which can make the overall support strength of the covered stent 100 in the aneurysm cavity covered segment 102 less than that of the proximal segment 101 and the distal segment 103 when the first embedded stent 21 and the second embedded stent 22 are set with a smaller wire diameter, so that the overall aneurysm cavity covered segment 102 can maintain the shape and patency of the internal iliac artery channel 1021 and the external iliac artery channel 1022 while having better flexibility.

[0102] In this embodiment, please refer to Figure 23 - Figure 26The first embedded stent 21 and the second embedded stent 22 are connected to the first covering film 104 of the tumor cavity covering segment 102 at least at the distal end position of the distal end and the proximal end position of the proximal end by bonding or suturing, wherein the blood inlet at the proximal end and the blood outlet at the distal end of the tumor cavity covering segment 102 are occupied by the proximal end and the distal end of the first embedded stent 21 and the second embedded stent 22, so that when the blood flows from the proximal segment 101 into the tumor cavity covering segment 102, it is shunted by the first embedded stent 21 and the second embedded stent 22, thereby avoiding internal leakage in the tumor cavity covering segment 102; the proximal end and the distal end of the first embedded stent 21 and the second embedded stent 22 can be set to be flat or oblique;

[0103] See also Figure 24 In order to improve the permeability of blood flow and make the tumor cavity coating section 102 have better flexibility, the proximal ports of the first embedded stent 21 and the second embedded stent 22 are set to be oblique ports, wherein a first proximal oblique port 211 is provided at the proximal end of the first embedded stent 21, and a second proximal oblique port 222 is provided at the proximal end of the second embedded stent 22, the first proximal oblique port 211 and the second proximal oblique port 222 are arranged opposite to each other, and the two oblique ports form a V-shaped cross-section on the axial section; in this way, the double oblique ports of the first embedded stent 21 and the second embedded stent 22 can increase the receiving area of ​​the blood flow inlet at the blood flow inlet position of the tumor cavity coating section 102, so that the blood flow is smoother; and the oblique port setting reduces the support points of the first embedded stent 21 and the second embedded stent 22 on both sides of the radial direction, thereby reducing the support strength in the radial direction to a certain extent, so that the coated stent 100 is located in the tumor cavity coating section 1 02 has a support strength that is smaller than that of the proximal segment 101 and the distal segment 103; and, generally, when the stent is bent, the larger curved side is the extended portion, while the smaller curved side is the compressed portion. The first proximal bevel 211 and the second proximal bevel 222 are set as a double bevel design that is relatively arranged, so that when the coated stent 100 is bent, the larger curved side is on the side of the first proximal bevel 211 or the second proximal bevel 222 with a longer bevel extension length, and the smaller curved side is on the side with a shorter bevel extension length. Therefore, when bending, the bevel structure of the first proximal bevel 211 and the second proximal bevel 222 just conforms to the bending structure of the stent, the side with a longer bevel extension length is on the larger curved side, and the side with a shorter bevel extension length is on the smaller curved side, so that the coated stent 100 has better flexibility at least in the part of the tumor cavity coated section. When the coated stent 100 is bent, the bending of the embedded stent in the tumor cavity coated section 102 can be effectively prevented.

[0104] In other embodiments, the provision of the first proximal bevel 211 and the second proximal bevel 222 enables the first embedded stent 21 and the second embedded stent 22 to be misaligned on the long-axis sidewall and the short-axis sidewall. Thus, when the covered stent 100 of the present application is compressed and placed into the delivery sheath, the long-axis sidewall and the short-axis sidewall of the misaligned structure can make the volume of the first embedded stent 21 and the second embedded stent 21 smaller after folding, making it easier to be inserted into the delivery sheath.

[0105] In this embodiment, please refer to Figure 24 and Figure 26 , the distal port of the first embedded stent 21 is a bevel or a flat port, and the distal port of the second embedded stent 22 is also a bevel or a flat port. Moreover, the distal blood outlet of the aneurysm cavity covered segment 102 is flush with the distal ports of the first embedded stent 21 and the second embedded stent 22 and is fixed by bonding or suturing. Among them, the distal port of the second embedded stent 22 is provided with a second distal bevel 223, and the distal port of the first embedded stent 21 is provided with a first distal bevel 213 or a flat port. Please refer to Figure 26 , when the distal ports of the first embedded stent 21 and the second embedded stent 22 are bevels, the first distal bevel 213 and the second distal bevel 223 are respectively parallel to the first proximal bevel 211 and the second proximal bevel 222. Compared with a non-rectangular parallelogram and a rectangle, the supporting force of its opposite sides is less than that of the opposite sides of a rectangle. Thus, the bevels arranged in parallel can make the supporting positions on the radial two sides of the first embedded stent 21 and the second embedded stent 22 form a staggered structure. Therefore, when subjected to a radial squeezing force, part of the radial pressure will be converted into an axial force by the special structure of the parallelogram, effectively dispersing the radial pressure to achieve the effect of reducing the radial supporting force, enabling the first embedded stent 21 and the second embedded stent 22 to have better flexibility while providing the pipe shape maintaining force, so that the aneurysm cavity covered segment 102 of the covered stent 100 has better flexibility.

[0106] In another embodiment, please refer to Figure 24 , the distal port of the second embedded stent 22 is a second distal bevel 223, and the distal port of the first embedded stent 21 is a first distal flat port 212. With such a setting, the axial length H3 of the side of the first embedded stent 21 away from the second embedded stent 22 can be greater than the axial length H4 of the side of the second embedded stent 22 away from the first embedded stent 21, so that the first embedded stent 21 has more stent supporting positions to disperse the squeezing force from the blood vessel, and thus has better supporting strength than the second embedded stent 22;

[0107] Please refer to Figure 25, when the distal port of the first inner stent 21 is set as an inclined port, the support wave rings at the connection position between the distal segment 103 and the aneurysm cavity are of an inclined structure adapted to the first distal inclined port 213, and are set as triangular wave rings 1032, wherein the wave height on one side of the triangular wave rings 1032 is greater than that on the other side and has a gradually decreasing structure, or a break is formed on the side with the lower wave height.

[0108] In this embodiment, please refer to Figure 25 , wherein the covered stent 100 further includes a transition segment 1027 connected between the proximal segment and the aneurysm cavity covered segment 102. When the proximal ports of the first inner stent 21 and the second inner stent 22 are set as double inclined ports, the transition segment 1027 is located at the position between the proximal end of the aneurysm cavity covered segment 102 and the first proximal inclined port 211 and the second proximal inclined port 222. The transition segment 1027 is provided with a transition stent 10271, and the transition stent 10271 can support the covering film of the transition segment 1027 formed between the double inclined ports, so as to avoid the collapse or poor release caused by the lack of a support structure at this position of the aneurysm cavity covered segment 102.

[0109] In this embodiment, please refer to Figure 27 - Figure 28 , the transition stent 10271 is separately arranged on the transition segment 1027, and the shape of the transition stent 10271 is adapted to the shape of the transition segment 1027. Here, since the distal end of the support wave ring of the proximal segment 101 close to the aneurysm cavity covered segment 102 is a flat port with uniform wave height, and a V-shaped port is formed between the first proximal inclined port 211 and the second proximal inclined port 222, in order for the transition stent 10271 to be flush with the proximal end of the aneurysm cavity covered segment 102 and the first proximal inclined port 211 and the second proximal inclined port 222 at the proximal and distal ends respectively, the proximal end of the transition stent 10271 includes a flat port, while the distal end includes a protruding V-shaped protrusion.

[0110] In some embodiments, the transition stent 10271 can be an annular stent or a separate sheet stent. When the transition stent 10271 is arranged as an annular stent, at least two V-shaped protrusions are provided and symmetrically arranged on both sides of the annular stent for adapting to the V-shaped opposing opening formed by the first proximal bevel 211 and the second proximal bevel 222. The annular stent can provide better overall support performance, providing support not only in the transition section 1027 area but also at the junction of the proximal section 101 and the aneurysmal cavity covered membrane section 102, making the connection of the covered stent 100 at the transition position between the proximal section 101 and the aneurysmal cavity covered membrane section 102 more stable. When the transition stent 10271 is arranged as a separate sheet stent, at least two sheet stents are provided, which are symmetrically arranged on both sides of the V-shaped opposing opening formed by the first proximal bevel 211 and the second proximal bevel 222. The proximal side of a single sheet stent is a flat edge, and the distal side is a V-shaped edge with a middle protrusion and gradually decreasing sides on both sides. The single sheet stent directly provides support force on both sides of the transition section 1027, which can ensure the support of the transition section 1027 while making the flexibility between the proximal section 101 and the aneurysmal cavity covered membrane section 102 better.

[0111] Among them, in one embodiment, please refer to Figure 27 and Figure 28 , the transition stent 10271 is a corrugated ring stent with a Z-shaped or W-shaped braided structure. The form of the corrugated ring stent is similar to the structure of the proximal support corrugated ring 1011 of the proximal section 101, so that it has a better connection with the proximal section 101 at this position, thereby improving the overall flexibility of the covered stent 100. In another embodiment, the transition stent 10271 is a mesh braided stent with a mesh braided structure. The structure of the mesh braided stent is similar to the structures of the first embedded stent 21 and the second embedded stent 22, so that the integrity of the aneurysmal cavity covered membrane section 102 is higher. Moreover, the support tension of the mesh braided stent is stronger, making the inner wall smoother, which can further ensure the patency of blood flow at this position.

[0112] Embodiment VIII

[0113] In this embodiment, please refer to Figure 29 and Figure 30, the structures of the main body stent 10 and the embedded stent 20 are substantially the same as those in the seventh embodiment. The difference is that the transition stent 10271 is not provided separately. By providing a special-shaped wave loop 1012 at the distal end of the proximal segment 101, a part of the special-shaped wave loop 1012 extends into the aneurysm cavity film covering segment 102 to form a support structure in the transition segment 1027 to form the transition stent 10271. Specifically, the proximal end of the special-shaped wave loop 1012 has uniformly equal-height proximal waves 102711, and the distal end includes a plurality of distal high waves 102712 with unequal heights. The distal high waves 102712 protrude towards the distal end, and the vertices are flush with the first proximal bevel 211 of the first embedded stent 21 and the second proximal bevel 222 of the second embedded stent 22 to support the transition segment 1027; there are at least two distal high waves 102712 at the distal end of the special-shaped wave loop 1012, and the two distal high waves 102712 are symmetrically arranged on both sides of the distal end along the diameter of the special-shaped wave loop 1012, and the vertices of the two distal high waves 102712 are close to the bottom of the V-shaped pair opening; please refer further to Figure 29 , a plurality of distal high waves 102712 can also be provided at the distal end of the special-shaped wave loop 1012 to form a mountain-shaped structure with the highest middle wave height and gradually decreasing wave heights towards both sides on the opposite sides of the distal end of the special-shaped wave loop 1012 to adapt to the shape of the transition segment 1027; setting the support wave loop at the distal end of the proximal segment 101 as the special-shaped wave loop 1012 can avoid local collapse or poor release of the transition segment 1027 due to lack of support structure, which affects blood patency. At the same time, the structure of the special-shaped wave loop 1012 extending between the proximal segment 101 and the aneurysm cavity film covering segment 102 can make the connection force between the film-covered stent 100 between the proximal segment 101 and the aneurysm cavity film covering segment 102 stronger, and the integrity of the stent is higher, thereby avoiding the situation of bending at the transition position between the aneurysm cavity film covering segment 102 and the proximal segment 101.

[0114] Embodiment Nine

[0115] In this embodiment, the structures of the main body stent 10 and the embedded stent 20 are substantially the same as those in the seventh to eighth embodiments. The difference is that the distal segment 103 of the main body stent 10 and the aneurysm cavity film covering segment 102 are spliced and fixed by bonding or suturing. The surface of the main body stent 10 is provided with a first film 104, and the surface of the embedded stent 20 is provided with a second film 202. The first film 104 is a PET film, and the second film 202 is an ePTFE film. The distal segment 103 and the aneurysm cavity film covering segment 102 are arranged in a spliced manner, which can make the surface film of the distal segment 103 also use the ePTFE film to further ensure the patency of the blood flow in the external iliac artery.

[0116] In one embodiment, the first embedded stent 21 and the distal segment 103 are integrally formed. The distal segment 103 directly extends into the aneurysmal cavity covered segment 102 and is sutured to the aneurysmal cavity covered segment 102. The part of the external iliac artery channel 1022 within the aneurysmal cavity covered segment 102 forms the first embedded stent 21, and the part outside the aneurysmal cavity covered segment 102 forms the distal segment 103. Thus, the stent body integrally formed by the first embedded stent 21 and the distal segment 103 can adopt a corrugated ring stent or a mesh woven stent, and the surface coating uses an ePTFE membrane. Here, integrally formed means that the first embedded stent 21 and the distal segment 103 are formed on the same ePTFE coated membrane, and the formed integral stent does not have an adhesive structure or a suture structure. Integrally forming the first embedded stent 21 and the distal segment 103 can ensure that when blood flow enters the external iliac artery channel 1022 and flows towards the external iliac artery, there are no blocking objects or protruding parts generated by the splicing structure in the channel that affect the smoothness of its inner wall, and can effectively further improve the patency when blood flow passes through.

[0117] In this embodiment, please refer to Figure 26 , a radiopaque member 203 is provided at the proximal end port and / or the distal end port of the first embedded stent 21 and the second embedded stent 22; when radiopaque members 203 are provided at both the proximal end port and the distal end port of the first embedded stent 21 and the second embedded stent 22, the setting of the radiopaque members 203 can help the operator quickly locate the position of the aneurysmal cavity covered segment 102, the relative positions of the internal iliac artery channel 1021 and the external iliac artery channel 1022, and the morphological changes after compression through imaging equipment, and can also help the operator quickly locate the selection entrance position of the internal iliac artery stent, so as to achieve the rapid and accurate implantation of the internal iliac artery stent.

[0118] In this embodiment, please refer to Figure 31, in order to enable the covered stent 100 provided by itself to be able to fine-tune the release position when the position is inaccurate after the initial release in the blood vessel, a plurality of hook members 1013 are provided on the proximal segment 101 of the main stent 10. There are a plurality of hook members 1013, which are arranged along the axial direction of the proximal segment 101, and at least two hook members 1013 are provided at the same axial position. In this way, after the two hook members 1013 at the same axial position are pulled to the same position, they can be hooked on the hanging rod 30. After the hook members 1013 at different axial positions are all hooked on the hanging rod 30, at least a part of the proximal segment 101 of the covered stent 100 can be at least partially radially constricted and constrained, so that the stent is in a semi-constrained state after being initially released from the catheter of the delivery device and is not completely released. At this time, if the release position is inaccurate, the release position can be fine-tuned, and then the hanging rod 30 is withdrawn to achieve the complete release of the stent; among them, the hook member 1013 can be a ring-shaped hook made of a polymer material, such as a ring-shaped wire made of PET material; it can be fixed to the proximal support wave ring 1011 or the film of the proximal segment 101 by suture or bonding.

[0119] Embodiment Ten

[0120] In this embodiment, please refer to Figure 32 - Figure 33 , a stent delivery system 1000 is provided. The stent delivery system 1000 includes the covered stent 100 provided in Embodiments 1 to 9, and further includes a delivery device 200. The delivery device 200 is used to deliver the covered stent 100 of the present application to a specified blood vessel position and release it. Among them, the delivery device 200 generally includes a delivery sheath 2001 and a delivery handle 2002. The delivery handle 2002 is used to control the advancement and retraction of the delivery sheath 2001 to release the stent from the delivery sheath 2001. Please refer to Figure 31 , wherein the delivery sheath 2001 includes a hanging rod 30. The hanging rod 30 is used to hook the hook members 1013 on the proximal segment 101 of the covered stent 100. After hooking, at least the proximal segment 101 of the covered stent 100 is in a semi-constrained state.

[0121] In this embodiment, a pre-set guide wire 40 is provided in the internal iliac channel 1021 of at least the aneurysm cavity film segment 102 of the covered stent 100. The prefabricated guide wire is pre-placed in the covered stent 100 after the production of the covered stent 100 of the present application is completed. In this way, when the stent is released, there is no need to re-insert the guide wire; by providing the pre-set guide wire 40 in the internal iliac channel 1021 of the aneurysm cavity film segment 102, the operations of introducing and selecting the guide wire can be reduced, and the internal iliac stent can be quickly guided into the first embedded stent 21 of the internal iliac channel 1021 for release directly under the guidance of the pre-set guide wire 40, improving the release accuracy and reducing the operation time at the same time.

[0122] The above specific embodiments are only partial embodiments of the present invention and do not limit the present invention. This specification cannot list all embodiments of the inventive concept of the present invention. Moreover, some features of the above different embodiments can be mutually replaced or combined, and those skilled in the art can also make simple replacements according to actual needs. The inventive concept of the present invention shall be subject to the scope of protection required.

Claims

1. A covered stent, characterized in that, Comprising a main stent with a tubular body and an inlaid stent, the main stent axially includes a proximal segment, a aneurysmal cavity segment and a distal segment; the proximal segment is communicated with the distal segment through the aneurysmal cavity segment; the aneurysmal cavity segment includes an internal iliac artery channel and an external iliac artery channel arranged radially, the external iliac artery channel is communicated with the distal segment, and the distal end of the internal iliac artery channel is provided with an opening communicated with the outside; the inlaid stent is arranged in the internal iliac artery channel, at least part of the inlaid stent is connected with the side wall of the internal iliac artery channel, and the distal end of the inlaid stent is communicated with the opening; the total support strength of the internal iliac artery channel and the inlaid stent is less than the support strength of the external iliac artery channel.

2. The covered stent according to claim 1, wherein, The aneurysmal cavity segment includes a plurality of first corrugated rings arranged axially at intervals, the number of corrugations of the plurality of first corrugated rings is the same, and the peaks and / or valleys of adjacent first corrugated rings are arranged opposite to each other.

3. The covered stent according to claim 2, wherein At least a part of the first corrugated ring located in the internal iliac artery channel is provided with a break.

4. The covered stent according to claim 2, wherein The wave angle of the first corrugated ring located in the external iliac artery channel part is greater than the wave angle of the same first corrugated ring located in the internal iliac artery channel part, or the wire diameter of the first corrugated ring located in the external iliac artery channel part is greater than the wire diameter of the same first corrugated ring located in the internal iliac artery channel part.

5. The covered stent according to claim 2, characterized in that, The first corrugated ring includes a plurality of first corrugated rods, and a support member is arranged between adjacent first corrugated rods. The plurality of support members are configured such that the compressible distance between the first corrugated rods at the external iliac artery channel part is less than the compressible distance between the first corrugated rods at the internal iliac artery channel part.

6. The covered stent according to claim 5, characterized in that, There is a gap between the support member and the adjacent first corrugated rod, and the gap at the external iliac artery channel part is less than the gap at the internal iliac artery channel part.

7. The covered stent according to claim 5, wherein The support member is an elastic support member, both sides of the elastic support member are respectively connected with two adjacent first corrugated rods, and the elastic modulus of the elastic support member at the external iliac artery channel part is greater than the elastic modulus of the elastic support member at the internal iliac artery channel part.

8. The covered stent according to claim 1, characterized in that, The proximal segment includes a plurality of proximal support corrugated rings arranged axially at intervals, the distal segment includes a plurality of distal support corrugated rings arranged axially at intervals, and the inlaid stent includes a reticular body.

9. The covered stent according to claim 1, wherein The surface of the main stent is covered with a first film, the surface of the inlaid stent is covered with a second film, and the support strength of the first film is greater than the support strength of the second film.

10. The covered stent according to any one of claims 1-9, characterized in that, The support strength of the aneurysmal cavity segment at the proximal and distal ends is greater than the support strength at the middle position.

11. The covered stent according to any one of claims 1-9, characterized in that, The support strength of the aneurysmal cavity segment at the proximal or distal end is greater than the support strength at the middle position.

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