Covered stent and stent delivery system

Abstract

Provided are a covered stent (100) and a stent delivery system (200). The covered stent (100) comprises a main stent (10) provided with a tubular body. Along an axial direction, the main stent (10) comprises a proximal support section (1) and a tumor cavity covered section (3). The tumor cavity covered section (3) is internally provided with a first embedded stent (4) and a second embedded stent (5) arranged radially. The distal end of the tumor cavity covered section (3) is provided with an opening (32) communicating with the exterior. Distal openings of the first embedded stent (4) and the second embedded stent (5) both communicate with the opening (32). The first embedded stent (4) has higher support strength than the second embedded stent (5). By configuring the first embedded stent (4) with relatively high support strength, patency of an external iliac artery corresponding to the first embedded stent (4) is ensured at least when the covered stent (100) is compressed. Further, extended covered configurations of the first embedded stent (4) and the second embedded stent (5) can ensure sealing integrity at an attachment gap (4021) after being sutured to the main stent (10), thereby preventing endoleaks at the embedded stents.

Description

Stent graft and stent delivery system Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a stent graft and a stent delivery system. Background Art

[0002] The iliac artery, one of the most important vascular systems in the human body, originates from the terminal segment of the abdominal aorta. It divides into two common iliac arteries, the left and right, which pass through the fourth lumbar vertebra, extend downward along the spine on the inner side of the psoas major muscle, and eventually divide into the internal iliac artery and the external iliac artery. The internal iliac artery is responsible for supplying oxygen and nutrients to the pelvis and lower limbs, while the external iliac artery supplies blood to the ilium and surrounding tissues. However, current iliac artery bifurcation stents have a series of problems, such as the internal iliac artery opening is easily closed by blood vessels, the internal iliac branches are prone to tortuosity and folding, leading to blockage, and slight movement or rotation of the stent during operation may cause blockage of the internal iliac branch opening.

[0003] To address these issues, existing technologies have specifically designed an internally branched stent, with the first branch connecting to the external iliac artery and the second branch connecting to the internal iliac artery. This innovative structural design is widely applicable to patients and can be extended to the proximal iliac bifurcation without being limited by the length of the common iliac artery, making it suitable for treating internal and external iliac arteries of various diameters. This innovative structure also facilitates stent alignment during implantation, avoiding the problems associated with iliac bifurcation stents and allowing for more convenient access to both internal and external iliac stents.

[0004] However, there are still some challenges in the design of the embedded branch stent, especially the possibility of internal leakage at the embedded stent. Summary of the Invention

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

[0006] A coated stent comprises a main stent with a tubular body, the main stent comprising a proximal support segment and a tumor cavity coated segment, the distal end of the proximal support segment is connected to the proximal end of the tumor cavity coated segment; the proximal segment comprises a support wave ring, the tumor cavity coated segment is provided with a first embedded stent and a second embedded stent arranged radially, the distal end of the tumor cavity coated segment is provided with an opening connected to the outside world, the distal ports of the first embedded stent and the second embedded stent are both connected to the opening; the support strength of the first embedded stent is greater than the support strength of the second embedded stent.

[0007] In one embodiment, the first embedded stent and the second embedded stent comprise a mesh body, on which the wire diameter of the first embedded stent is greater than the wire diameter of the second embedded stent, and / or the mesh density of the first embedded stent is greater than the mesh density of the second embedded stent.

[0008] In one embodiment, the distal ends of the first embedded bracket and the second embedded bracket are respectively provided with a first distal oblique opening and a second distal oblique opening, and the first distal oblique opening and the second distal oblique opening are arranged to face away from each other.

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

[0010] In one embodiment, the stent graft further includes a transition section connected between the proximal support section and the tumor cavity graft section, and the transition section is provided with a transition stent.

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

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

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

[0014] In one embodiment, the first distal bevel and the second distal bevel both include a long axis side wall and a short axis side wall in the circumferential direction, the axial extension length of the long axis side wall is greater than the axial extension length of the short axis side wall, the long axis side walls of the first embedded bracket and the second embedded bracket are arranged closely to each other, and the distal end of at least one of the long axis side walls is provided with a hooking portion for hooking.

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

[0016] A stent delivery system comprises the stent graft.

[0017] The benefit of the present invention lies in that it provides a coated stent and a stent delivery system, the coated stent includes a main stent with a tubular body, the main stent includes a proximal support section and a tumor cavity coated section along the axial direction, the tumor cavity coated section is provided with a first embedded stent and a second embedded stent arranged radially, the distal end of the tumor cavity coated section is provided with an opening connected to the outside world, and the distal ports of the first embedded stent and the second embedded stent are both connected to the opening; the support strength of the first embedded stent is greater than the support strength of the second embedded stent; by providing a first embedded stent with a larger support strength, at least the passability of the external iliac channel opposite to the first embedded stent is ensured when the coated stent is under pressure; further, the extended coating of the first embedded stent and the second embedded stent can ensure the sealing of the fitting gap position after suturing with the main stent, thereby avoiding internal leakage at the embedded stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic diagram of the structure of a stent graft in Example 1 of the present invention;

[0019] FIG2 is a schematic diagram of the internal structure of the stent graft in Example 1 of the present invention;

[0020] FIG3 is a schematic diagram of the wire diameter distribution of the first embedded stent and the second embedded stent in Example 1 of the present invention;

[0021] FIG4 is a schematic diagram of the grid density distribution of the first embedded bracket and the second embedded bracket in Example 1 and Example 2 of the present invention;

[0022] FIG5 is a schematic diagram of the proximal flat ends of the first embedded stent and the second embedded stent in Example 2 of the present invention;

[0023] FIG6 is a schematic diagram of the development structure of the first embedded bracket and the second embedded bracket in Example 2 of the present invention;

[0024] FIG7 is a schematic structural diagram of a hook portion in a stent graft according to Example 2 of the present invention;

[0025] FIG8 is a schematic diagram of a hook portion provided with a blocking member in Example 2 of the present invention;

[0026] 9 is a schematic diagram of a developing structure of a hooking portion blocking member in Example 2 of the present invention;

[0027] FIG10 is a schematic diagram of a transition bracket as a special-shaped corrugated ring in Example 2 of the present invention;

[0028] FIG11 is a schematic diagram of the high wave at the far end of the special-shaped wave coil in Example 2 of the present invention;

[0029] FIG12 is a schematic diagram of the high wave tapering at the distal end of the special-shaped wave coil in Example 2 of the present invention;

[0030] FIG13 is a schematic diagram of a transition bracket including a corrugated bracket in Example 2 of the present invention;

[0031] FIG14 is a schematic diagram of a transition bracket including a mesh bracket in Example 2 of the present invention;

[0032] FIG15 is a schematic diagram of the structures of the first coating and the second coating in Example 3 of the present invention;

[0033] FIG16 is a schematic structural diagram of the connection portion between the first coating and the second coating in Example 3 of the present invention;

[0034] FIG17 is a top view of the stent graft when the connecting portion of the first and second grafts is connected to the graft segment of the tumor cavity in Example 3 of the present invention;

[0035] FIG18 is a schematic diagram of a structure in which a first covering film and a second covering film are connected via a connecting portion in Example 3 of the present invention;

[0036] FIG19 is a top view of the stent graft in Example 3 of the present invention when the first and second grafts are connected to the tumor cavity graft segment via a connecting portion;

[0037] FIG20 is a schematic diagram of the integrally formed structure of the first and second covering films in Example 3 of the present invention;

[0038] FIG21 is a top view of the stent graft when the integrally formed first and second coverings are connected to the tumor cavity covering segment in Example 3 of the present invention;

[0039] FIG22 is a schematic diagram of the structure of the middle anchoring wave ring in Example 4 of the present invention;

[0040] FIG23 is a schematic diagram of the hooking structure of the stent graft in the conveyor in Example 5 of the present invention. DETAILED DESCRIPTION

[0041] In order to better understand the concept of the present application, the following detailed description of the implementation methods of the present application is given in conjunction with the accompanying drawings. The following specific embodiments are only some embodiments of the present application and are not limitations of the present application.

[0042] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "below" another element or feature would then be oriented as "above" or "above" another element or feature. Thus, the example term "below" can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein are interpreted accordingly.

[0043] Although the terms first, second, third, etc. can 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 can only be used to distinguish an 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 order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0044] To more clearly describe the structure of this application, the terms "proximal" and "distal" are defined here as commonly used in the field of interventional medicine. Specifically, "distal" refers to the end of a blood vessel away from the heart, and "proximal" refers to the end of a blood vessel closer to the heart; "axial" refers to its length, and "radial" refers to the direction perpendicular to the "axial" direction; "upper end" and "lower end" are two ends that are relatively far apart. When one end is defined as the "upper end," the other end that is farther away is the "lower end."

[0045] Example 1

[0046] Please refer to Figure 1 and Figure 2. The present invention provides a covered stent 100. The covered stent 100 is generally composed of a metal skeleton and a covering material. As shown in Figure 3, the metal skeleton can adopt a Z-shaped wave or woven mesh design. The covering material has a certain blood flow isolation ability and is combined with the metal skeleton through 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 aorta stent, and the lumen diameter generally matches the diameter of the common iliac artery. In this embodiment, the coated stent 100 includes a main body stent 10 with a tubular body, and the surface of the main body stent 10 is provided with a surface coating 31. The main body stent 10 includes a proximal support segment 1 and a tumor cavity coating segment 3 along the axial direction. The distal end of the proximal support segment 1 is connected to the proximal end of the tumor cavity coating segment 3. The surface coating 31 of the proximal support segment 1 and the surface coating 31 of the tumor cavity coating segment 3 can be integrally formed in the form of a single coating, or can be formed by splicing multiple coatings by suturing or bonding; the proximal segment includes a support wave ring 11, and the tumor cavity coating segment 3 is only provided with a surface coating 31, and the tumor cavity coating segment 3 is provided with a There are a first embedded stent 4 and a second embedded stent 5 arranged radially, so that the main stent 10 reduces the support wave ring 11 at the position of the tumor cavity coating section 3 to improve the flexibility of the coated stent 100 at the tumor cavity section; the tumor cavity coating section 3 provides support performance through the first embedded stent 4 and the second embedded stent 5, and at the same time, when the blood flows through the tumor cavity coating section 3, the blood is diverted into the external iliac channel and the internal iliac channel. The first embedded stent 4 and the second embedded stent 5 are used to intervene in the external iliac stent and the internal iliac stent respectively, draining the blood to the external iliac artery and the internal iliac artery, isolating the blood, and preventing the blood from continuing to flow into the aneurysm.

[0047] In some embodiments, please continue to refer to Figure 2. The first embedded stent 4 and the second embedded stent 5 both adopt a mesh main body structure, the purpose of which is to emphasize better morphological support; the mesh main body structure can have better coating tension, so that even when providing a smaller braiding wire diameter, it can still provide better coating tension to maintain the shape of the blood pathway; and the mesh main body can enable the external iliac stent and the internal iliac stent to be respectively intervened in the first embedded stent 4 and the second embedded stent 5, so that there are more contact positions between the embedded stent and the intervened stent, thereby providing greater friction, which can effectively enhance the anchoring force and adhesion force between the stents and provide the stent anti-slip performance.

[0048] The distal end of the tumor cavity covered section 3 is provided with an opening 32 communicating with the outside world, and the distal ends of the first embedded stent 4 and the second embedded stent 5 are both in communication with the opening 32. In order to give priority to maintaining the morphology of the passage to the external iliac blood vessels when the covered stent 100 provided by the present application is subjected to pressure, in this embodiment, the support strength of the first embedded stent 4 is greater than the support strength of the second embedded stent 5. Here, the support strength is manifested as the overall deformation of the first embedded stent 4 is less than the overall deformation of the second embedded stent 5 when the first embedded stent 4 and the second embedded stent 5 are subjected to equal pressure, so as to maintain a better passage morphology.

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

[0050] In one embodiment, please refer to Figure 3, so that the grid density of the first embedded stent 4 and the second embedded stent 5 is uniform, and the wire diameter of the mesh body of the first embedded stent 4 is larger than the wire diameter of the mesh body of the second embedded stent 5 so that the support strength of the first embedded stent 4 is greater than the support strength of the second embedded stent 5; here, the larger stent wire diameter has a smaller deformation ability and can provide a higher support force when under pressure, so by making the wire diameter of the first embedded stent 4 larger than the wire diameter of the second embedded stent 5, when the first embedded stent 4 and the second embedded stent 5 are under pressure at the same time, due to the large wire diameter of the first embedded stent 4, its ability to resist deformation is stronger, and the resulting deformation is small, while the second embedded stent 5 has a relatively small wire diameter, and its ability to resist deformation is smaller than the first embedded stent 4, and the resulting deformation is large, then the shape of the first embedded stent 4 can be better maintained to ensure that the coated stent 100 better maintains the shape of the external iliac channel, thereby ensuring the blood flow to the external iliac artery after the blood flows through the coated stent 100.

[0051] In another embodiment, please refer to Figure 4, the wire diameters of the first embedded bracket 4 and the second embedded bracket 5 are made uniform, and the grid density of the mesh body of the first embedded bracket 4 is greater than the grid density of the mesh body of the second embedded bracket 5 so that the support strength of the first embedded bracket 4 is greater than the support strength of the second embedded bracket 5; here, the first embedded bracket 4 and the second embedded bracket 5 include a mesh body, and the mesh body has a plurality of grid structures; wherein, the higher the grid density, the more support wires are required, and the smaller the area of ​​a single grid, the greater the pressure it can withstand, and the greater the support strength that can be provided by a larger grid density. In this embodiment, the first embedded bracket 4 and the second embedded bracket 5 have a diamond grid structure, and the first embedded bracket 4 has a first diamond grid, and the second embedded bracket 5 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 spacing between the upper vertex and the lower vertex of the first diamond grid is D1, and the spacing between the left vertex and the right vertex is L1; the spacing between the upper vertex and the lower vertex of the second diamond grid is D2, and the spacing between the left vertex and the right vertex is L2; ​​preferably, D1 and L1 can 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. Therefore, under the same bracket deployment area, the first embedded bracket 4 has a higher grid density, providing stronger support strength than the second embedded bracket 5.

[0052] In some embodiments, please further refer to Figure 4, at least the L1 of the first diamond grid is made smaller than the L2 of the second diamond grid, so that the density of the first diamond grid is changed only in the circumferential direction of the first embedded bracket 4. In this way, the density of the first diamond grid can be increased at least in the radial direction, thereby achieving the effect of enhancing the support strength in the radial direction.

[0053] In one embodiment, the wire diameter of the first embedded stent 4 can be made larger than the wire diameter of the second embedded stent 5 and the grid density of the first embedded stent 4 can be made larger than the grid density of the second embedded stent 5. In this way, by setting the wire diameter and grid density of the first embedded stent 4 and the second embedded stent 5 at the same time, the first embedded stent 4 and the second embedded stent 5 can form a difference in support strength while forming a more reasonable wire diameter size and grid density distribution, avoiding excessively large or small wire diameter settings and grid density settings that result in the first embedded stent 4 and the second embedded stent 5 having too small or too large flexibility, affecting the folding and unfolding performance of the coated stent 100, and causing the coated stent 100 to be difficult to assemble and release in the sheath.

[0054] In this embodiment, the support strength is specifically manifested as the deformation of the overall tubular inner cavity after the first embedded bracket 4 and the second embedded bracket 5 are compressed, that is, under the same force conditions, the radial force tester is used to apply the same force (this force needs to make the first embedded bracket 4 and the second embedded bracket 5 produce a certain amount of deformation) to the outer walls of the first embedded bracket 4 and the second embedded bracket 5, and the radial cross-sectional area of ​​the first embedded bracket 4 and the second embedded bracket 5 after the compression is measured and calculated. Here, the bracket with a larger total cross-sectional area measured after the compression has a greater support strength, and the bracket with a smaller total cross-sectional area has a smaller support strength; in some embodiments, the first embedded bracket 4 and the second embedded bracket 5 can be compressed respectively by a flat-plate dynamometer, and the force required when compressed to the same deformation amount is measured; the larger the measured force, the greater the support strength, and the smaller the measured force, the smaller the support strength. In this embodiment, the force measured by the first embedded bracket 4 is always greater than the force measured by the second embedded bracket 5.

[0055] Example 2

[0056] In this embodiment, please continue to refer to Figure 4. The structures of the main support 10 and the first embedded support 4 and the second embedded support 5 of the coated support 100 are substantially the same as those in Example 1. The difference is that the opening 32 at the distal end of the coated support 100 is set as an oblique opening. Specifically, the distal ends of the first embedded support 4 and the second embedded support 5 are respectively provided with a first distal oblique opening 41 and a second distal oblique opening 51, and the first distal oblique opening 41 and the second distal oblique opening 51 are set away from each other; here, the distal ports of the first embedded support 4 and the second embedded support 5 are the entrances for the intervention of the external iliac support and the internal iliac support, and the two The distal ends of the embedded stents are all set as oblique openings, firstly to increase the size of the opening 32 for the insertion of the external iliac stent and the internal iliac stent, thereby reducing the difficulty of stent insertion; secondly, since in the present application, the connection with the external iliac artery and the internal iliac artery is achieved by additional intervention of the external iliac stent and the internal iliac stent, the first distal oblique opening 41 and the second distal oblique opening 51 are set away from each other so that the two stents can be less constrained by the coated stent 100 in opposite directions after intervention, thereby making it easier to separate the external iliac stent and the internal iliac stent after connection, avoiding mutual influence between the two stents.

[0057] Among them, please refer to Figures 4 and 5. The proximal port positions of the first embedded stent 4 and the second embedded stent 5 can be set to a flat port or an oblique port. Specifically, the proximal ends of the first embedded stent 4 and the second embedded stent 5 can be provided with a first proximal flat port 43 and a second proximal flat port 53 respectively. Here, in order to form a double-layer stent when setting the first embedded stent 4 and the second embedded stent 5 while reducing the overall volume of the stent after compression and sheathing, the first proximal flat port 43 and the second proximal flat port 53 can be staggered in the axial direction so as to be in different axial positions after compression, so as to avoid accumulation at one axial position resulting in excessive volume and difficulty in sheathing.

[0058] In another embodiment, please further refer to Figure 4. The proximal ends of the first embedded bracket 4 and the second embedded bracket 5 can be respectively provided with a first proximal bevel 42 and a second proximal bevel 52, and the first proximal bevel 42 and the second proximal bevel 52 are arranged relative to each other; here, the two bevels form a V-shaped cross-section on the axial section, and the first proximal bevel 42 and the second proximal bevel 52 are blood flow entrances in the tumor cavity covering segment 3. The inclined bevel structure can increase the area of ​​the entrance to receive blood, thereby ensuring the patency of blood flow; further, the first proximal bevel 42 and the second proximal bevel 52 are arranged relative to each other, so that the higher side wall of the bevel is in close contact with the side wall of the tumor cavity covering segment 3, avoiding vibration or or swing, thereby reducing the patency of blood flow; in some embodiments, the first proximal bevel 42 and the first distal bevel 41, the second proximal bevel 52 and the second distal bevel 51 can have the same inclination angle, thereby forming a parallel opening structure to increase the versatility of the first embedded stent 4 and the second embedded stent 5; in other embodiments, the setting of the first proximal bevel 42 and the second proximal bevel 52 can cause the long axis side wall and the short axis side wall of the first embedded stent 4 and the second embedded stent 5 to be misaligned, so that when the coated stent 100 of the present application is compressed and placed into the delivery sheath, the long axis side wall and the short axis side wall of the misaligned structure can make the first embedded stent 4 and the second embedded stent 5 smaller in size after folding, and easier to deliver into the delivery sheath.

[0059] Here, the provision of the first proximal oblique opening 42 and the second proximal oblique opening 52 can also provide other stents with a larger selection entrance when implanted, thereby reducing the difficulty of implantation and improving surgical efficiency.

[0060] Wherein, please refer to Figure 6. In order to facilitate identification of the positions of the first embedded stent 4 and the second embedded stent 5 in the blood vessel after the coated stent 100 is inserted into the human body, the proximal port and the distal port of the first embedded stent 4 and the second embedded stent 5 are respectively provided with a developing structure 6. Here, the developing structure 6 can be a single developing ring that is adapted to the shape of the proximal port and the distal port of the first embedded stent 4 and the second embedded stent 5, and is connected to the edges of the proximal port and the distal port by weaving or winding; wherein, the developing ring can be made of platinum wire or tantalum metal.

[0061] In some other embodiments, please refer to Figure 7, the inclination angle of the first distal bevel 41 and the second distal bevel 51 may be greater than the first proximal bevel 42 and the second proximal bevel 52. Here, since the first distal bevel 41 and the second distal bevel 51 are arranged to deviate from each other, the two stents form a V-shaped tip protruding toward the distal direction when they are in contact with each other. The V-shaped tip can be used to hook and connect with the conveyor when the coated stent 100 of the present application is transported in the conveyor to facilitate pushing and control; specifically, the first distal bevel 41 and the second distal bevel 51 both include a major axis side wall 501 and a minor axis side wall 502 in the circumferential direction to form an oblique structure, and the axial length of the major axis side wall 501 is greater than the axial length of the minor axis side wall 502. The major axis side walls 501 of the first embedded stent 4 and the second embedded stent 5 are arranged in close contact with each other to form a V-shaped tip at the distal end. The axial length of the V-shaped tip is longer than any other position at the distal end of the coated stent 100, so The distal end of the long axis side wall 501 is provided with a hooking portion 503 for hooking, and the hooking portion 503 can be better hooked by the hooking member 2001, while avoiding the hooking member 2001 from affecting or contacting other positions of the coated stent 100 after hooking; wherein, the inclination angle of the first distal bevel 41 and the second distal bevel 51 can be set to 30°~60°. Considering the matching requirements of the distal clamping and release structure of the conveyor, an angle less than 30° may cause the conveyor to be unable to effectively clamp the coated stent 100, thereby affecting the progress of the operation; on the contrary, if it is greater than 60°, the angle will be too large, which may cause unnecessary extension of the stent to the position of the external iliac artery. Considering the small blood vessel diameter of the external iliac artery, this may be hindered when implanting the external iliac stent, which has a negative impact on the long-term patency rate of the stent; in addition, unnecessary extension of the stent length will increase the difficulty of the operation, which may cause difficulty in releasing the coated stent 100, thereby affecting the smooth progress of the operation.

[0062] Please refer to Figures 8 and 9. Here, the hooking portion 503 can be provided only on the long-axis side wall 501 of the first distal oblique opening 41 of the mesh body of the first embedded stent 4; or only on the long-axis side wall 501 of the second distal oblique opening 51 of the mesh body of the second embedded stent 5; the distal oblique opening of at least one embedded stent is provided with a hooking portion 503 to form a hooking position for a hooking member; wherein, in some embodiments, the hooking portion 503 can also be formed by the farthest end grid structure of the long-axis side wall 501 of the first distal oblique opening 41 and the second distal oblique opening 51 of the mesh body of the first embedded stent 4 and the second embedded stent 5, and the distal side of the hooking portion 503 includes at least one blocking member 5031 for hooking, The blocking member 5031 can be a wire of a mesh structure, or a developing ring at the first distal bevel 41 and the second distal bevel 51. The blocking effect provided by the developing ring alone can reduce the number of brackets at this position, thereby making it easier to release the bracket at this position; further, in order to make the hooking effect of the hooking portion 503 and the hooking member 2001 better and not easy to fall off, the mesh structure at the farthest end of the long axis side wall 501 of the first distal bevel 41 and the second distal bevel 51 is set to a hollow structure, that is, the first coating 401 and the second coating 504 are not provided, so that the hooking member 2001 can completely pass through the mesh structure of the hooking portion 503 to form a hook, so as to avoid accidental detachment after the hook connection.

[0063] In this embodiment, please further refer to Figures 1 and 10. Since the proximal support segment 1 and the first embedded stent 4 and the second embedded stent 5 in the tumor cavity coating segment 3 adopt different stent structures, structural mutations and faults will appear at the connection positions of different segments, which is not conducive to the long-term use of the stent. In order to make the connection transition between the proximal support segment 1 and the tumor cavity coating segment 3 of the coated stent 100 smoother, a transition segment 2 is provided between the proximal support segment 1 and the tumor cavity coating segment 3 of the main stent 100, and the transition segment 2 is provided with a transition stent 21. The transition segment 2 and the transition stent 21 are arranged between the proximal support segment 1 and the tumor cavity coating segment 3 to transition the two parts of the main stent 10; wherein, when the proximal ends of the first embedded stent 4 and the second embedded stent 5 are the first proximal flat end 43 and the second proximal flat end 53 respectively. When the transition bracket 21 is in the shape of a circle, the transition bracket 21 can be one of the supporting wave rings 11 of the proximal supporting segment 1, the proximal end of the transition bracket 21 is flush with the distal flat end of the proximal segment, and the distal end of the transition bracket 21 is flush with the proximal flat end of the first embedded bracket 4 and the second embedded bracket 5; here, since the surface coating 31 of the tumor cavity coating segment 3 is sutured with the first embedded bracket 4 and the second embedded bracket 5, it is tightly attached to the outer surface of the first embedded bracket 4 and the second embedded bracket 5. Then, after the first embedded bracket 4 and the second embedded bracket 5 are arranged side by side, they have a longer length direction and a shorter width direction. In the width direction, the width of the tumor cavity coating segment 3 is smaller than the diameter of the proximal supporting segment 1, so the transition bracket 21 has a circular cross-section at the proximal end, and a flat strip cross-section with a reduced width on at least one side at the distal end, and the transition bracket 21 has a tapered structure from the proximal end to the distal end.

[0064] In another embodiment, please continue to refer to Figures 10 and 11. When the proximal ends of the first embedded stent 4 and the second embedded stent 5 are respectively the first proximal oblique opening 42 and the second proximal oblique opening 52, the two oblique openings form a V-shaped cross-section on the axial section, and the tumor cavity coating segment 3 forms an unsupported area at this position, wherein the proximal end of the transition stent 21 is flush with the distal flat opening of the proximal segment, and the distal end of the transition stent 21 is flush with the proximal V-shaped double oblique openings formed by the first embedded stent 4 and the second embedded stent 5; here, the transition stent 21 can support the surface coating 31 of the unsupported area formed between the double oblique openings, thereby avoiding collapse or poor release caused by the lack of support structure at this position of the tumor cavity coating segment 3. The transition bracket 21 can be a special-shaped wave ring 211, and the distal part of the special-shaped wave ring 211 extends into the unsupported area of ​​the tumor cavity covering section 3; specifically, the proximal end of the special-shaped wave ring 211 has a uniform proximal wave 2111 of equal height, and the distal end includes a plurality of distal high waves 2112 with unequal heights, and the distal high waves 2112 protrude toward the distal end, and the apex is aligned with the first proximal bevel 42 and the second proximal bevel 52 of the first embedded bracket 4 and the second embedded bracket 5 to support the unsupported area; wherein, there are at least two distal high waves 2112 of the special-shaped wave ring 211, and the two distal high waves 2112 are symmetrically arranged on both sides of the distal end along the diameter of the special-shaped wave ring 211, and the apex of the two distal high waves 2112 is close to the bottom of the V-shaped double bevel.

[0065] Further, please refer to Figure 12. Multiple distal high waves 2112 of the special-shaped wave ring 211 can be set to form a peak-like structure with the highest wave height in the middle and gradually lower wave heights on both sides on the opposite sides of the distal end of the special-shaped wave ring 211, so as to adapt to the shape of the unsupported area; the special-shaped wave ring 211 can avoid the lack of support structure in the unsupported area, resulting in local collapse or poor release affecting blood circulation. At the same time, the structure of the special-shaped wave ring 211 extending between the proximal support distal segment and the tumor cavity coating segment 3 can make the connection force of the coated stent 100 between the proximal support segment 1 and the tumor cavity coating segment 3 more sufficient, and the stent integrity is higher, thereby avoiding bending at the transition position between the tumor cavity segment and the proximal segment.

[0066] In some embodiments, referring to Figures 13-14, the transition bracket 21 includes a wave ring bracket 212 and / or a mesh bracket 213; wherein, when the proximal ports of the first embedded bracket 4 and the second embedded bracket 5 are respectively the first proximal flat port 43 and the second proximal flat port 53, the transition bracket 21 can be an annular wave ring bracket 212; and when the proximal ports of the first embedded bracket 4 and the second embedded bracket 5 are respectively the first proximal oblique port 42 and the second proximal oblique port 52, the transition bracket 21 can include a wave ring bracket 212, such as the aforementioned special-shaped wave ring, which will not be repeated here; it can also include a wave ring bracket 212 and The mesh stent 213 adopts the form of a wave coil stent 212, which is similar to the structure of the support wave coil 11 of the proximal support segment 1, so that it has a better connection with the proximal support segment 1 at this position, thereby improving the overall flexibility of the coated stent 100; the mesh stent 213 adopts a mesh stent 213 with a mesh woven structure or a mesh cut structure. The structure of the mesh stent 213 is similar to the structure of the first embedded stent 4 and the second embedded stent 5, so that the integrity of the tumor cavity segment is higher, and the support tension of the mesh woven stent is stronger, making the inner wall smoother, which can further ensure the patency of blood flow at this position.

[0067] Example 3

[0068] In this embodiment, please refer to Figures 15 to 17. The structures of the main support 10 and the first embedded support 4 and the second embedded support 5 of the coated support 100 are substantially the same as those in Example 1. The difference is that the surfaces of the first embedded support 4 and the second embedded support 5 are respectively provided with a first coating 401 and a second coating 504. In order to further ensure that the first embedded support 4 and the second embedded support 5 are tightly connected to the inner cavity surface of the tumor cavity coated segment 3 at the proximal port position after being connected to the tumor cavity coated segment 3, thereby avoiding internal leakage between the first embedded support 4 and the second embedded support 5 and the tumor cavity coated segment 3, the first coating 401 at least partially extends outward from the proximal port of the first embedded support 4 to form a connecting portion 402, and the second coating 504 at least partially extends outward from the proximal port of the second embedded support 5 to form a connecting portion 402. The connecting portion 402 forms an unsupported coating that exceeds the proximal ports of the first embedded support 4 and the second embedded support 5, so that the proximal ports of the first embedded support 4 and the second embedded support 5 are closely connected to the inner cavity surface of the tumor cavity coated segment 3 along the port position. After the cavity wall is connected for the first time by suturing or gluing, the connecting portion 402 of the first embedded stent 4 and the connecting portion 402 of the second embedded stent 5 are connected to the tumor cavity covering segment 3 for the second time, thereby ensuring that the proximal ends of the connected first embedded stent 4 and the second embedded stent 5 completely cover the internal cavity of the tumor cavity covering segment 3 without any gaps; wherein, the first embedded stent 4 and the second embedded stent 5 are arranged side by side in close contact within the tumor cavity covering segment 3, and two fitting gaps 40 are formed at the close tangent positions of the two embedded stents. 21. At this gap, it is often difficult to achieve a tight fit by suturing the gap position formed by the tumor cavity coating segment 3 and the first embedded bracket 4 and the second embedded bracket 5. Therefore, the outwardly extending connecting portion 402 is at least provided on one side of the mutually fitting position of the proximal ends of the first embedded bracket 4 and the second embedded bracket 5, so as to at least cover the closely tangent positions of the two brackets to form two fitting gaps 4021, and achieve a better gap sealing effect by covering and sealing with the coating instead of directly connecting and sealing with the tumor cavity coating segment 3.

[0069] In some embodiments, please continue to refer to Figure 17. The outwardly extending connecting portion 402 is respectively arranged along the circumference of the proximal end of the first embedded bracket 4 and the second embedded bracket 5. In this way, in addition to the two fitting gaps 4021 formed at the tangent positions of the first embedded bracket 4 and the second embedded bracket 5 to be sealed, any position where the first embedded bracket 4 and the second embedded bracket 5 are connected to the tumor cavity covering segment 3 can be further sealed through the secondary connection of the connecting portion 402 to avoid internal leakage.

[0070] In this embodiment, the first coating 401 and the second coating 504 are made of a different material than the surface coating 31 of the main stent 10. The surface coating 31 is made of PET in this embodiment. Both the first coating 401 and the second coating 504 are ePTFE membranes. PET membranes are characterized by high strength, while ePTFE membranes are weaker, have a smooth surface, are less susceptible to thrombus formation, and have good long-term patency for small blood vessels and small pores. Combining the PET and ePTFE membranes not only ensures the overall strength of the stent coating on the main stent 10, but also allows the first and second embedded stents 4 and 5 to better isolate blood flow within the aneurysm cavity coating segment 3, ensuring long-term patency of the branch, i.e., a good occlusion effect.

[0071] In this embodiment, the setting of the second coating 504 effectively isolates the first embedded stent 4 and the second embedded stent 5 so that the guide wire will not pass through the first embedded stent 4 or the second embedded stent 5 when passing into the first embedded stent 4 or the second embedded stent 5, ensuring that the guide wire is accurately passed into the corresponding inner cavity stent, avoiding the problem that the implanted branch stent cannot reach the designated embedded stent.

[0072] In another embodiment, please refer to Figures 18 and 19. In order to ensure the overall sealing after the connection part 402 is connected to the tumor cavity covering segment 3, the connection part 402 of the first covering 401 can be connected to the connection part 402 of the second covering 504, and then the two connection parts 402 are respectively connected to the tumor cavity covering segment 3; in this way, the proximal ports of the first embedded stent 4 and the second embedded stent 5 are first connected through the connection part 402 to become one, so that before the first embedded stent 4 and the second embedded stent 5 enter the tumor cavity covering segment 3 and connect with the tumor cavity covering segment 3, the outer contours of the proximal ports of the two embedded stents are first enclosed and sealed in the circumferential direction of the proximal ports, so that after the first embedded stent 4 and the second embedded stent 5 are embedded in the tumor cavity covering segment 3, the first connection of the proximal ports and the second connection of the connection part 402 are performed, and a better edge sealing and anti-internal leakage effect is achieved.

[0073] In some other embodiments, please refer to Figures 20 and 21. In order to further ensure the sealing of the first embedded stent 4 and the second embedded stent 5 after being connected to the tumor cavity covering segment 3 at the proximal port position, the fitting gap 4021 between the first embedded stent 4 and the second embedded stent 5 does not produce internal leakage, the first covering 401 and the second covering 504 of the first embedded stent 4 and the second embedded stent 5 are integrally molded. Here, integral molding refers to the first covering 401 and the second covering 504 being continuously molded by a single covering without bonding or suturing the splicing structure; after molding, the first embedded stent 4 and the second embedded stent 5 have the first covering 401 and the second covering 504. The stent 5 is arranged as an integrated body, and is connected together by a coating at least on the side where the proximal ends thereof are in contact with each other. Here, since the first coating 401 and the second coating 504 are continuously formed by a single coating, and are connected together by a coating on the side where the proximal ends thereof are in contact with each other, the bonding gap 4021 after the first embedded stent 4 and the second embedded stent 5 are bonded side by side is covered and blocked by the coating. Therefore, after being connected to the coating of the tumor cavity section, no internal leakage will occur at this position, and the blood is blocked by the coating at this position. However, since the first coating 401 and the second coating 504 adopt ePTFE film, the good blood isolation ability of the ePTFE film enhances the blood isolation ability to avoid internal leakage at this position.

[0074] Example 4

[0075] In this embodiment, referring to Figures 1 and 22, the structures of the tumor cavity coating segment 3, the first embedded stent 4 and the second embedded stent 5 of the coated stent 100 are substantially the same as those in Examples 1 to 3, with the difference being that, in order to enhance the anchoring force of the proximal support segment 1 in the lumen of the blood vessel or other stent, the support wave ring includes at least one anchoring wave ring. Here, the support wave ring 11 of the proximal support segment 1 may include only one anchoring wave ring 12, and a plurality of anchoring barbs 121 are circumferentially provided on the outer side of the anchoring wave ring 12 for enhancing the anchoring of the proximal support segment to the blood vessel wall or the inner wall of the stent.

[0076] In some embodiments, a plurality of support coils 11 are axially arranged on the surface coating 31 of the proximal support segment 1, and the plurality of support coils 11 include at least one anchoring coil 12; the anchoring coil 12 is used to provide a better anchoring force between the proximal support segment 1 and the blood vessel, wherein the anchoring coil 12 is arranged between the support coil 11 at the proximal end and the support coil 11 at the distal end of the proximal support segment 1, and a plurality of anchoring barbs 121 are circumferentially arranged on the outside, where the anchoring barbs 121 protrude from the outer wall of the proximal support segment 1, and are inclined and extended toward the distal direction, so that when the proximal support segment 1 is released in the blood vessel, the support coil 11 provides support expansion and anchoring force while the anchor of the middle support coil 11 The fixed barbs 121 penetrate into the blood vessel wall to provide a more stable anchoring effect; further, the anchoring wave ring 12 is arranged between the support wave ring 11 at the proximal end of the proximal support segment 1 and the support wave ring 11 at the distal end, which can enhance the anchoring force near the middle of the proximal segment. In this way, whether from the middle to the proximal end or from the middle to the distal end, the anchoring wave ring 12 as a connecting point can ensure that both ends of the proximal support segment 1 can ensure that the stent has sufficient connection force when connected to the blood vessel; in some other embodiments, there can also be multiple anchoring wave rings 12, and the support wave ring 11 at the proximal end and the support wave ring 11 at the distal end can be located near the middle of the proximal segment to further enhance the anchoring force of the proximal support segment 1.

[0077] Among them, the design of the anchoring barbs 121 of the anchoring wave ring 12 ensures that after the proximal support segment 1 of the coated stent 100 is implanted in a blood vessel or other stent, when an external iliac stent or an internal iliac stent is implanted in the coated stent 100 of the present application, the anchoring barbs 121 enhance the anchoring force and the connection force, so that the coated stent 100 itself will not shift or shake.

[0078] Example 5

[0079] In this embodiment, please refer to Figure 23. The structures of the main stent 10 and the first embedded stent 4 and the second embedded stent 5 of the coated stent 100 are substantially the same as those in Examples 1 to 4. In addition, a stent delivery system 200 is also provided in this embodiment, wherein the stent delivery system 200 includes the coated stent 100 as described in the above embodiment and a delivery device, the delivery device is used to deliver the coated stent 100 of the present application to a specified blood vessel position and release it, wherein the delivery device generally includes a delivery sheath and a delivery handle, the delivery handle is used to control the advance and retreat of the delivery sheath to release the stent from the delivery sheath, and the delivery device is also provided with a push rod 2002, a hook part 2001 is connected to the proximal end of the push rod 2002, and the hook part 503 of the coated stent 100 is used to establish a connection with the hook part 2001 and then control the relative position of the coated stent 100 in the delivery sheath of the conveyor through the push rod 2002; the hook part 2001 can be controlled by external force to switch between an unlocked state and a locked state, wherein, when the hook part 2001 is in a locked state, the hook part 503 is connected to the hook part 2001 and cannot be disengaged; when the hook part 2001 is in an unlocked state, the hook part 503 can be separated from the hook part 2001 to perform the subsequent release step of the coated stent 100.

[0080] The above specific embodiments are only some embodiments of the present invention and are not limitations of the present invention. This specification cannot be an exhaustive list of all embodiments of the present invention. Some features of the above different embodiments can be replaced or combined with each other. Those skilled in the art can also make simple replacements according to actual needs. The concept of the present invention shall be subject to the required scope of protection.

Claims

1. A covered stent, characterized in that, Comprising a body stent with a tubular body, the body stent includes a proximal support section and a lumen covered section, the distal end of the proximal support section is connected to the proximal end of the lumen covered section; the proximal section includes support wave rings, and the lumen covered section is provided with a first embedded stent and a second embedded stent arranged radially, the distal end of the lumen covered section is provided with an opening communicating with the outside, and the distal ports of the first embedded stent and the second embedded stent are both communicated with the opening; the support strength of the first embedded stent is greater than that of the second embedded stent.

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

3. The covered stent according to claim 1, wherein, The distal ends of the first embedded stent and the second embedded stent are respectively provided with a first distal bevel and a second distal bevel, and the first distal bevel and the second distal bevel are arranged away from each other.

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

5. The covered stent according to claim 1, characterized in that, The covered stent further includes a transition section connected between the proximal support section and the lumen covered section, and the transition section is provided with a transition stent.

6. The covered stent according to claim 1, characterized in that, The surface of the first embedded stent is provided with a first covering film, the surface of the second embedded stent is provided with a second covering film, and at least part of the first covering film and the second covering film respectively extend outward at the proximal ports of the first embedded stent and the second embedded stent to form connecting parts, and the connecting parts are connected to the lumen covered section.

7. The covered stent according to claim 6, wherein, The connecting part of the first covering film is connected to the connecting part of the second covering film.

8. The covered stent according to claim 7, wherein, The first covering film and the second covering film are integrally formed.

9. The covered stent according to claim 3, characterized in that, Both the first distal bevel and the second distal bevel include a long-axis side wall and a short-axis side wall in the circumferential direction, the axial extension length of the long-axis side wall is greater than that of the short-axis side wall, the long-axis side walls of the first embedded stent and the second embedded stent are arranged closely against each other, and a hooking part for hooking is provided at the distal end of at least one long-axis side wall.

10. The covered stent according to claim 1, characterized in that, The support wave rings include at least one anchoring wave ring, and a plurality of anchoring barbs are arranged along the circumferential direction on the outside of the anchoring wave ring.

11. A stent delivery system, characterized in that, Comprising the covered stent according to any one of claims 1-10.

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