Covered stent and covered stent conveying system

Abstract

The invention provides a covered stent and a covered stent conveying system, and relates to the field of medical instruments.The covered stent comprises a skeleton, a plurality of limiting pieces and a covering film, the inflection point, close to one end of the other stent ring, of each waveform unit of one stent ring in every two adjacent stent rings of the skeleton is bent to be in a W shape, and the limiting pieces are arranged on the covering film; inflection points at the ends, close to each other, of the waveform units of every two adjacent sections of support rings are in one-to-one correspondence and internally and externally staggered and mutually hung to form hanging parts; the limiting pieces are clamped and installed on the hanging parts in a one-to-one correspondence mode in the mode that the middle portions of the limiting pieces penetrate through the hanging holes, located in the middle, of the hanging parts, and the two ends of the limiting pieces are limited on the inner side and the outer side of the framework. The covering film is fixedly connected to the part, except the hanging part, of the framework and is not connected with the hanging part. The covered stent conveying system comprises a conveyor and the covered stent. The technical problems that in the prior art, a covered stent cannot meet the requirements for flexibility and shortening resistance at the same time, and the release precision is low when the covered stent is released after a covered stent conveying system is adopted are solved.

Description

Technical Field

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

[0002] For the treatment of vascular lesions, the prior art implants a covered stent at the location of the vascular lesion, uses the covered stent to support the inner wall of the blood vessel, block the blood vessel rupture or isolate the blood supply to the inner wall of the hemangioma blood vessel, and establish a new blood flow channel.

[0003] In the prior art, most covered stents adopt a structure in which a multi-section Z-shaped wire-wound stent (or a wavy stent ring formed by connecting multiple V-shaped stent units end to end) is used as a framework and a covering film is connected inside or outside the framework. There are also some double-layer covered stents that adopt a structure in which the framework is pressed in the middle by a double-layer covering film.

[0004] In order to promote accurate positioning of the covered stent during the in-vivo release process, most existing stent delivery systems adopt a post-release method, that is, during the release process of the covered stent, a part of the covered stent is temporarily not opened, so that there is still room for adjusting the position before the covered stent is fully opened, and after positioning, post-release is performed to fully release the covered stent. In the prior art, the post-release methods of the stent delivery system are mainly divided into two categories: one category restrains the head end of the covered stent through a restraint device, and the restraint device is removed after post-release to fully release the covered stent; the other category uses a compression membrane sleeve to restrain the outer wall of the stent, and when post-releasing, the membrane sleeve is opened by means of a pull wire to fully release the covered stent.

[0005] The covered stents and their delivery systems in the prior art have the following problems: Regarding the covered stent: The existing covered stents are mainly two types: Z-shaped wire-wound stents and spiral stents; For the Z-shaped wire-wound stent, in order to improve the flexibility of the stent, multiple sections of the stent need to be arranged at intervals (only the membrane, no stent at the interval position). The defect of this kind of stent is that the interval position of the stent is prone to folding, which affects the blood flow in the stent lumen, and the stent will be shortened during the release process. In order to prevent the stent from shortening during the release process, the prior art is to add longitudinal beams between two sections of the stent. Although this method can avoid the shortening of the stent, it will reduce the flexibility of the stent, that is, the Z-shaped wire-wound stent cannot meet the requirements of flexibility and anti-shortening at the same time; For the spiral stent, although it can meet the requirements of flexibility and anti-shortening to a certain extent, its supporting force is not as good as that of the Z-shaped stent.

[0006] In terms of the delivery system: The post-release devices of existing covered stent delivery systems often can only achieve the overall post-release of the stent or the post-release of either the front end or the rear end. The defect of the overall post-release is that when the post-release occurs, the wire causes the covered stent to bounce open as a whole. During this process, the covered stent will bounce, and the release position error of the covered stent is large. The defect of the post-release of either the front end or the rear end is that when the post-release occurs, the remaining parts of the covered stent except the selected post-released end have already opened and occupied the space in the blood vessel, and the adjustable range of the covered stent in the blood vessel is small. Summary of the Invention

[0007] The purpose of the present invention is to provide a covered stent and a covered stent delivery system to alleviate at least one of the above technical problems existing in the prior art.

[0008] To achieve the above purpose, the embodiments of the present invention adopt the following technical solutions: In the first aspect, the present invention provides a covered stent, including: A skeleton, including a plurality of wave-shaped stent rings arranged axially; for each adjacent two stent rings, the inflection points of each waveform unit of one stent ring close to one end of the other stent ring are all bent into a "W" shape, and the inflection points of each waveform unit of each adjacent two stent rings close to each other form a hanging part with three hanging holes by being alternately and staggeredly hung inside and outside in a one-to-one correspondence; A plurality of limiting members, each of the limiting members is clamped and installed on each of the hanging parts of the skeleton in a one-to-one correspondence in such a way that the middle part thereof passes through the middle hanging hole of the hanging part and both ends thereof are limited inside and outside the skeleton; And a covering film, fixedly connected to the part of the skeleton except the hanging part and not connected to the hanging part.

[0009] In an optional embodiment, the covering film includes an inner film, the inner film is fixedly connected to the inner side surface of the part of the skeleton except the hanging part, and the inner film covers the inside of the hanging part.

[0010] In an optional embodiment, the covering film includes an outer film, the outer film is arranged in sections along the axis of the skeleton to avoid the hanging part, so that the hanging part is exposed outside the outer film.

[0011] In an optional embodiment, in the skeleton, the proximal region of the stent ring at the axially nearest end and the distal region of the stent ring at the axially farthest end are both exposed outside the covering film.

[0012] In an optional embodiment, the limiting member includes a middle connecting rod and head end structures fixedly or integrally connected to both ends of the middle connecting rod, the middle connecting rod passes through the corresponding hanging hole, and the two head end structures are respectively blocked outside the hanging hole.

[0013] In an alternative embodiment, both the middle connecting rod and the head end structure are cylindrical, and the diameter of the head end structure is greater than that of the middle connecting rod.

[0014] In an alternative embodiment, in the framework, in the structures of the stent ring at the axially nearest end and the stent ring at the axially farthest end, at the inflection point of each wave unit near one end adjacent to the respective adjacent stent ring, it is bent in a "W" shape, and at the inflection point at the other end, it is in a "V" shape.

[0015] In a second aspect, the present invention provides a covered stent delivery system, including a delivery device and the covered stent according to any one of the foregoing embodiments; the delivery device includes an outer tube, an inner tube, a push-pull tube, and a stent end post-release structure; The inner tube is inserted inside the outer tube, and the push-pull tube is inserted inside the inner tube; The stent end post-release structure includes a plurality of openings circumferentially spaced and formed in the circumferential wall of the inner tube along the inner tube, pins fixed or integrally connected inside each of the openings, hanging pins mounted on each of the pins, and multiple circumferential limit grooves arranged on the outer wall of the push-pull tube along the axial direction of the push-pull tube; The hanging pin is formed in a shape with a large-diameter end at one end and a small-diameter end at the other end. A through hole is provided at a portion near the small-diameter end to sleeved and rotatably installed outside each of the pins. Its large-diameter end is located inside the inner tube, and its small-diameter end protrudes outside the inner tube; the large-diameter ends of each of the hanging pins are limited inside any one of the limit grooves. Pushing and pulling the push-pull tube can move the large-diameter ends of each of the hanging pins in the proximal or distal direction, so as to rotate the hanging pins relative to the pins, and thus change the orientation of the small-diameter end of the hanging pin.

[0016] In an alternative embodiment, the stent end post-release structure includes a proximal end post-release structure and a distal end post-release structure, and the small-diameter ends of the hanging pins of the proximal end post-release structure are opposite in orientation to the small-diameter ends of the hanging pins of the distal end post-release structure.

[0017] In an alternative embodiment, the inner surface of the limit groove is a symmetric inclined surface with a diameter gradually decreasing from both ends to the middle along the axial direction of the push-pull tube.

[0018] The embodiments of the present invention can at least achieve the following beneficial effects: For the stent graft provided in the embodiment of the present invention, its wavy stent ring provides sufficient radial support force after the stent graft is opened. At the same time, through the hanging part and the limiter, it can ensure that each two adjacent sections of the wavy stent rings can make relative bending movements with the limiter as the connection point, and avoid axial shortening between the two adjacent sections of the stent graft rings when the stent graft is bent. In addition, the coating is fixedly connected to the part of the skeleton except the hanging part and is not connected to the hanging part, which can also ensure the flexibility of the stent graft when bending. In this way, the stent graft can achieve the function of taking into account flexibility and anti-shortening while ensuring radial support force, thereby improving the performance of the stent graft.

[0019] For the coated stent delivery system provided in the embodiment of the present invention, the coated stent can be delivered and released later by using its conveyor. When in use, the hollow area at the end of the coated stent or a separately arranged hanging ring structure is hung on the small diameter end of the hanging pin, so as to radially constrain the end structure of the coated stent by the small diameter end of the hanging pin before the coated stent is released later. Moreover, when the coated stent is released later, the hanging pin is rotated relative to the pin shaft by pushing and pulling the push-pull tube to change the direction of the small diameter end of the hanging pin, thereby releasing the end structure of the coated stent, thereby avoiding the problem of the coated stent jumping when being released as a whole.

[0020] Other beneficial effects that can be achieved by the embodiments of the present invention will be described in more detail in the specific implementation section of this application specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the overall structure of the stent graft provided in an embodiment of the present invention when the graft comprises an inner membrane and an outer membrane; Figure 2 A schematic diagram of the overall structure of the stent graft provided by an embodiment of the present invention when the graft includes an inner membrane but does not include an outer membrane; Figure 3 A schematic diagram of the skeleton structure of a stent graft provided in an embodiment of the present invention; Figure 4 A schematic diagram of the overall structure of a stent ring at the axially most proximal end or the axially most distal end of the skeleton in a stent graft provided by an embodiment of the present invention; Figure 5 A schematic diagram of the overall structure of any stent ring located between the most proximal stent ring and the most distal stent ring in the axial direction of the skeleton of the stent graft provided in an embodiment of the present invention; Figure 6 Schematic structural diagram of the hanging part formed between adjacent stent rings in the covered stent provided by the embodiment of the present invention; Figure 7 Schematic structural diagram of the limiting member in the covered stent provided by the embodiment of the present invention; Figure 8 For Figure 3 Isometric view of the local structure of area A in Figure 9 Partial cross-sectional view of the covered stent delivery device provided by the embodiment of the present invention; Figure 10 For Figure 9 Enlarged view of the local structure of area B in Figure 11 For Figure 9 Enlarged view of the local structure of area C in Figure 12 Partial cross-sectional view of the inner tube of the covered stent delivery device provided by the embodiment of the present invention; Figure 13 Overall structural diagram of the hanging pin in the embodiment of the present invention; Figure 14 Overall structural diagram of the push-pull tube in the covered stent delivery device provided by the embodiment of the present invention; Figure 15 Overall cross-sectional view of the covered stent delivery device provided by the embodiment of the present invention; Figure 16 Schematic diagram of the working state of the covered stent delivery device provided by the embodiment of the present invention when the end of the covered stent is not post-released.

[0023] Icon: 1 - stent ring; 11 - hanging part; 111 - hanging hole; 2 - limiting member; 21 - middle connecting rod; 22 - head end structure; 31 - inner membrane; 32 - outer membrane; 4 - outer tube; 5 - inner tube; 51 - window opening; 52 - pin shaft; 53 - hanging pin; 531 - large diameter end; 532 - small diameter end; 6 - push-pull tube; 61 - limiting groove; 110 - proximal end post-release structure; 120 - distal end post-release structure. Detailed implementation manners

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0025] Accordingly, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0026] It should be noted that like reference numerals and letters in the drawings denote like items, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0027] In the description of the present invention, it should be noted that: Unless otherwise clearly defined and limited, the terms "arranged", "installed", and "connected" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The orientation or positional relationship indicated by the terms "proximal end", "distal end", "axial direction", "radial direction", "circumferential direction", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0029] The terms "first", "second", etc. are only used for distinguishing descriptions, do not represent a total number, or a relative position in time and / or space, and cannot be understood as indicating or implying relative importance.

[0030] Hereinafter, taking the end of the medical device close to the operator during surgery as the proximal end of the medical device, and the end of the medical device entering the patient's blood vessel as the distal end of the medical device; in conjunction with the drawings, some embodiments of the present invention will be described in detail.

[0031] First aspect This embodiment provides a covered stent. Refer to Figures 1 to 8The coated stent includes a skeleton, a plurality of stoppers 2 and a coating. Specifically, the skeleton includes a plurality of wave-shaped stent rings 1 arranged in the axial direction; the inflection points of each wave unit of one stent ring 1 near one end of the other stent ring 1 of each adjacent stent ring 1 are bent into a "W" shape, and the inflection points of each wave unit near one end of each adjacent stent ring 1 correspond to each other, and the inside and outside are staggered and hung to form a hanging part 11 with three hanging holes 111. Each stopper 2 is clamped and installed on each hanging part 11 of the skeleton in a one-to-one manner in such a way that the middle part thereof passes through the hanging hole 111 located in the middle of the hanging part 11, and the two ends thereof are limited on the inside and outside of the skeleton. The coating is fixedly connected to the part of the skeleton except the hanging part 11 and is not connected to the hanging part 11.

[0032] In the above-mentioned stent graft structure provided in this embodiment, the wavy stent ring 1 provides sufficient radial support force after the stent graft is opened. At the same time, through the hanging part 11 and the limiter 2, it can be ensured that each two adjacent sections of the wavy stent ring 1 can perform relative bending movement with the limiter 2 as the connection point, and the axial shortening between the two adjacent sections of the stent graft ring 1 can be avoided when the stent graft is bent. In addition, the coating is fixedly connected to the part of the skeleton other than the hanging part 11 and is not connected to the hanging part 11, which can also ensure the flexibility of the stent graft when bending. In this way, the stent graft can achieve the function of taking into account flexibility and anti-shortening while ensuring radial support force, thereby improving the performance of the stent graft.

[0033] In an optional implementation of the present embodiment, the coating of the stent graft may specifically include an inner membrane 31, which is fixedly connected to the inner side of the skeleton except the hanging portion 11, and the inner membrane 31 covers the inner side of the hanging portion 11 (but is not connected to the hanging portion 11). Optionally, the coating may include an outer membrane 32, which is segmented along the axial direction of the skeleton to avoid the hanging portion 11, so that the hanging portion 11 is exposed to the outer membrane 32. The inner membrane 31 and the outer membrane 32 may be provided simultaneously or selectively, preferably, the inner membrane 31 and the outer membrane 32 are provided simultaneously, and the method of fixedly connecting the coating to the skeleton includes but is not limited to pressing the inner membrane 31 and multiple segments of the outer membrane 32 on the surface of the skeleton except the hanging portion 11, or fixing the coating to the corresponding surface of the skeleton by suturing.

[0034] In an optional implementation of the present embodiment, in the skeleton of the coated stent, the proximal region of the stent ring 1 located at the nearest axial end and the distal region of the stent ring 1 located at the farthest axial end are both exposed to the coating, so that these regions of the corresponding stent ring 1 are bare stents, thereby increasing the anchoring ability of the coated stent after it is released into the blood vessel, and the hollow region thereof can also be used to cooperate with the post-release functional structure of the conveyor to realize the post-release function of the coated stent.

[0035] In an alternative embodiment of the present embodiment, the limiting member 2 includes a middle connecting rod 21 and head end structures 22 fixedly or integrally connected to both ends of the middle connecting rod 21. The middle connecting rod 21 passes through the corresponding hanging holes 111, and the two head end structures 22 are respectively blocked outside the hanging holes 111. In order to reduce the damage to the patient's vascular intima during the implantation process and increase the bending smoothness of the bending part during the implantation of the covered stent, in an alternative embodiment of the present embodiment, both the middle connecting rod 21 and the head end structures 22 of the limiting member 2 are cylindrical, and the diameter of the head end structures 22 is greater than the diameter of the middle connecting rod 21.

[0036] In an alternative embodiment of the present embodiment, in the framework of the covered stent, in the structures of each of the stent rings 1 at the axially proximal end and the stent rings 1 at the axially distal end, the inflection points of each waveform unit near one end adjacent to the respective adjacent stent ring 1 are bent in a "W" shape, and the inflection points at the other end are in a "V" shape.

[0037] Second aspect The present embodiment further provides a covered stent delivery system, which includes a delivery device and the covered stent provided in any alternative embodiment of the first aspect above.

[0038] Referring to Figures 9 to 16 , the delivery device specifically includes an outer tube 4, an inner tube 5, a push-pull tube 6, and a stent end post-release structure. The inner tube 5 is installed inside the outer tube 4, and the push-pull tube 6 is installed inside the inner tube 5. The stent end post-release structure includes a plurality of openings 51 circumferentially spaced apart on the circumferential wall of the inner tube 5, pin shafts 52 fixedly or integrally connected inside each opening 51, hanging pins 53 installed on each pin shaft 52, and multiple circumferential limit grooves 61 arranged on the outer wall of the push-pull tube 6 along the axial direction of the push-pull tube 6. The hanging pin 53 is formed in a shape with a large-diameter end 531 at one end and a small-diameter end 532 at the other end. A through hole is provided at a position near the small-diameter end 532 to sleeved and rotatably installed outside each pin shaft 52. Its large-diameter end 531 is located inside the inner tube 5, and its small-diameter end 532 is exposed outside the inner tube 5; the large-diameter ends 531 of each hanging pin 53 are limited inside any one of the limit grooves 61. Pushing and pulling the push-pull tube 6 can move the large-diameter ends 531 of each hanging pin 53 in the proximal or distal direction to rotate the hanging pin 53 relative to the pin shaft 52, thereby changing the orientation of the small-diameter end 532 of the hanging pin 53.

[0039] During use, as Figure 16As shown, the hollowed-out area at the end of the covered stent or the separately provided hanging ring structure is hung on the small-diameter end 532 of the hanging pin 53, so as to radially constrain the end structure of the covered stent through the small-diameter end 532 of the hanging pin 53 before the covered stent is released later. And when the covered stent is released later, the hanging pin 53 is rotated relative to the pin shaft 52 by pushing and pulling the push-pull tube 6, changing the orientation of the small-diameter end 532 of the hanging pin 53, thereby releasing the end structure of the covered stent and avoiding the problem that the covered stent bounces when it is released as a whole.

[0040] In an alternative embodiment of the present embodiment, the end post-release structure of the stent includes a proximal end post-release structure 110 and a distal end post-release structure 120. The small-diameter ends 532 of the respective hanging pins 53 of the proximal end post-release structure 110 are opposite in orientation to the small-diameter ends 532 of the respective hanging pins 53 of the distal end post-release structure 120. When the push-pull tube 6 is pushed or pulled in a certain axial direction, the hanging pin 53 of one of the proximal end post-release structure 110 and the distal end post-release structure 120 will rotate in the opposite direction, and the hanging pin 53 of the other will remain stationary. When the push-pull tube 6 is pushed or pulled in the other axial direction, the opposite effect can be achieved.

[0041] During loading, the two ends of the covered stent in the axial direction are respectively hung on the small-diameter ends 532 of the respective hanging pins 53 of the proximal end post-release structure 110 and the distal end post-release structure 120. When the covered stent is pushed forward from the outer tube 4, the covered stent does not open. When the push-pull tube 6 is pushed in the distal direction, the front end of the covered stent is released. When the push-pull tube 6 is pulled in the proximal direction, the rear end of the covered stent is released; conversely, if the push-pull tube 6 is first pulled in the proximal direction, the rear end of the covered stent is released first, and then the push-pull tube 6 is pushed in the distal direction, the front end of the covered stent is released. The conveyor provided in this embodiment can not only realize the function of post-releasing the two ends of the covered stent in the axial direction, but also flexibly control the release sequence of the post-release of the two ends of the covered stent in the axial direction according to the actual surgical needs. And during the release process, since both ends of the covered stent in the axial direction can be post-released, thereby increasing the adjustable range of the release position of the covered stent during the post-release process, thus significantly improving the accuracy of the post-release position of the covered stent.

[0042] In addition, in an alternative embodiment of the present embodiment, the inner surface of the limiting groove 61 is a symmetric inclined surface with a diameter gradually decreasing from both ends to the middle along the axial direction of the push-pull tube 6, that is, the part between two adjacent limiting grooves 61 forms a structure similar to an "abacus bead", so as to improve the operation smoothness of rotating the hanging pin 53 relative to the pin shaft 52 by pushing and pulling the push-pull tube 6, while improving the limiting reliability of the limiting groove 61 on the hanging pin 53 before post-release, and improving the surgical efficiency and the safety of using the instrument.

[0043] Finally, it should be noted that the above embodiments and their optional embodiments in this specification are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing optional embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. In addition, it is emphasized again that, without conflict, the features of the embodiments and the optional embodiments in the embodiments in this specification can be combined with each other.

Claims

1. A stent graft, characterized in that: include: The skeleton comprises a plurality of wave-shaped support rings (1) arranged in an axial direction; the inflection points of each wave-shaped unit of one support ring (1) of each two adjacent support rings (1) close to one end of the other support ring (1) are bent into a "W" shape, and the inflection points of each wave-shaped unit of each two adjacent support rings (1) close to one end correspond to each other and are staggered and hung inside and outside to form a hanging portion (11) having three hanging holes (111); A plurality of limiting members (2), each limiting member (2) being clamped and mounted on each of the hanging portions (11) of the frame in a one-to-one correspondence in such a manner that the middle portion thereof passes through a hanging hole (111) located in the middle of the hanging portion (11), and both ends thereof are limited at the inner side and the outer side of the frame; and a coating, which is fixedly connected to a portion of the frame other than the hanging portion (11) and is not connected to the hanging portion (11).

2. The stent graft according to claim 1, characterized in that: The coating comprises an inner membrane (31), wherein the inner membrane (31) is fixedly connected to the inner side surface of the frame except the hanging portion (11), and the inner membrane (31) covers the inner side of the hanging portion (11).

3. The stent graft according to claim 1, characterized in that: The coating comprises an outer membrane (32), and the outer membrane (32) is arranged in sections along the axial direction of the skeleton to avoid the hanging portion (11), so that the hanging portion (11) is exposed to the outer membrane (32).

4. The stent graft according to claim 1, characterized in that: In the skeleton, the proximal region of a stent ring (1) located at the most axial end and the distal region of a stent ring (1) located at the most axial end are exposed to the coating.

5. The stent graft according to claim 1, characterized in that: The limiting member (2) comprises a middle connecting rod (21) and head end structures (22) fixedly or integrally connected to two ends of the middle connecting rod (21); the middle connecting rod (21) passes through the corresponding hanging hole (111), and the two head end structures (22) are respectively blocked outside the hanging hole (111).

6. The stent graft according to claim 5, characterized in that: The middle connecting rod (21) and the head end structure (22) are both cylindrical, and the diameter of the head end structure (22) is greater than the diameter of the middle connecting rod (21).

7. The stent graft according to claim 1, characterized in that: In the skeleton, in the structures of the support ring (1) located at the closest axial end and the support ring (1) located at the farthest axial end, each of the waveform units is bent into a "W" shape at an inflection point at one end of each adjacent support ring (1), and the inflection point at the other end is in a "V" shape.

8. A stent graft delivery system, characterized in that: It comprises a conveyor and a coated stent according to any one of claims 1 to 7; the conveyor comprises an outer tube (4), an inner tube (5), a push-pull tube (6) and a rear release structure at the end of the stent; The inner tube (5) is installed inside the outer tube (4), and the push-pull tube (6) is installed inside the inner tube (5); The rear release structure at the end of the bracket comprises a plurality of windows (51) arranged at intervals along the circumference of the inner tube (5) on the peripheral wall of the inner tube (5), a pin (52) fixed or integrally connected inside each of the windows (51), a hanging pin (53) mounted on each of the pins (52), and a plurality of limiting grooves (61) arranged on the outer wall of the push-pull tube (6) along the axial direction of the push-pull tube (6); The hanging pin (53) is formed in a shape with a large diameter end (531) at one end and a small diameter end (532) at the other end. A through hole is provided at a portion close to the small diameter end (532) so as to be sleeved and rotatably mounted on the outside of each of the pin shafts (52). The large diameter end (531) is located inside the inner tube (5), and the small diameter end (532) is exposed outside the inner tube (5). The large diameter end (531) of each of the hanging pins (53) is limited inside any of the limiting grooves (61). Pushing and pulling the push-pull tube (6) can move the large diameter end (531) of each of the hanging pins (53) in a proximal or distal direction, so as to rotate the hanging pin (53) relative to the pin shaft (52), thereby changing the direction of the small diameter end (532) of the hanging pin (53).

9. The stent graft delivery system according to claim 8, characterized in that: The rear release structure at the end of the stent comprises a proximal rear release structure (110) and a distal rear release structure (120), wherein the small diameter ends (532) of each hanging pin (53) of the proximal rear release structure (110) and the small diameter ends (532) of each hanging pin (53) of the distal rear release structure (120) are oriented in opposite directions.

10. The stent graft delivery system according to claim 8, characterized in that: The inner surface of the limiting groove (61) is a symmetrical inclined surface whose diameter gradually decreases from both ends to the middle along the axial direction of the push-pull tube (6).

Images