Covered stent and covered stent delivery system

Abstract

The present invention provides a covered stent and a covered stent delivery system, relating to the field of medical devices. The covered stent includes a framework, a plurality of limiting members, and a covering film. For each adjacent two stent rings of the framework, the inflection points of each waveform unit of one stent ring near one end of the other stent ring are all bent in a "W" shape, and the inflection points of each waveform unit of each adjacent two stent rings near the ends close to each other are in one-to-one correspondence and are internally and externally staggered and hooked to form a hooking portion; each of the limiting members is clamped and installed on each hooking portion in a manner that its middle portion passes through the hooking hole in the middle of the hooking portion and its two end portions are limited inside and outside the framework; the covering film is fixedly connected to the portion of the framework other than the hooking portion and is not connected to the hooking portion. The covered stent delivery system includes a delivery device and the aforementioned covered stent. The present invention alleviates the technical problems in the prior art that the covered stent cannot meet the requirements of flexibility and anti-shortening property, and the low release accuracy when the covered stent is released by the covered stent delivery system after deployment.

Description

Technical Field

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

[0002] For the treatment of vascular lesions, in the prior art, a covered stent is implanted at the location of the vascular lesion, and the covered stent is used to support the inner wall of the blood vessel, block the vascular rupture or isolate the blood supply to the inner wall of the blood vessel of the hemangioma, 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 skeleton and a covering film is connected inside or outside the skeleton. There are also some double-layer covered stents that adopt a structure in which the skeleton 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 is to restrain the head end of the covered stent through a restraining device, and the restraining device is removed after post-release to fully release the covered stent; the other category uses a compression film sleeve to restrain the outer wall of the stent, and when post-releasing, the film sleeve is opened by means of a wire to fully release the covered stent.

[0005] The covered stents and their delivery systems in the prior art have the following problems:

[0006] Regarding the covered stent: The existing covered stents are mainly two types: Z-shaped wire-wound stents and spiral stents;

[0007] 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 film exists at the interval position, without a stent). 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 being shortened 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 simultaneously meet the requirements of flexibility and anti-shortening;

[0008] 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.

[0009] 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 back end. The defect of the overall post-release is that when the post-release occurs, the wire makes the covered stent bounce open as a whole, and during this process, the covered stent will bounce, resulting in a large error in the release position of the covered stent. The defect of the post-release of either the front end or the back end is that when the post-release occurs, the rest of the covered stent except the selected post-release end has 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

[0010] 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.

[0011] To achieve the above purpose, the embodiments of the present invention adopt the following technical solutions:

[0012] In the first aspect, the present invention provides a covered stent, including:

[0013] A skeleton, including a plurality of wave-shaped stent rings arranged along the axis; for each adjacent two stent rings, the inflection points of each waveform unit of one stent ring near 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 near each other form an inner and outer staggered interlocking to form a hanging portion with three hanging holes;

[0014] A plurality of limit members, each of which is clamped and installed on each hanging portion of the skeleton in a one-to-one correspondence manner by passing through the middle hanging hole of the hanging portion with its middle part and limiting its two end parts inside and outside the skeleton;

[0015] And a film, fixedly connected to the part of the skeleton except the hanging portion and not connected to the hanging portion.

[0016] In an optional embodiment, the 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 portion, and the inner film covers the inside of the hanging portion.

[0017] In an optional embodiment, the film includes an outer film, the outer film is arranged in sections along the axis of the skeleton to avoid the hanging portion, so that the hanging portion is exposed outside the outer film.

[0018] In an optional embodiment, in the skeleton, the proximal region of the stent ring at the nearest axial end and the distal region of the stent ring at the farthest axial end are both exposed outside the film.

[0019] In an optional embodiment, the limiting member includes a middle connecting rod and a head end structure fixed 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.

[0020] In an optional embodiment, the middle connecting rod and the head end structure are both cylindrical, and the diameter of the head end structure is larger than the diameter of the middle connecting rod.

[0021] In an optional embodiment, in the skeleton, in the structures of the section of the support ring located at the axially nearest end and the section of the support ring located at the axially farthest end, each of the waveform units is bent into a "W" shape at the inflection point near one end of each adjacent support ring, and the inflection point at the other end is in a "V" shape.

[0022] In a second aspect, the present invention provides a stent graft delivery system, comprising a conveyor and the stent graft described in any one of the aforementioned embodiments; the conveyor comprises an outer tube, an inner tube, a push-pull tube, and a rear release structure at the end of the stent;

[0023] The inner tube is installed inside the outer tube, and the push-pull tube is installed inside the inner tube;

[0024] The rear release structure of the bracket end includes a plurality of windows spaced apart along the circumference of the inner tube on the circumferential wall of the inner tube, a pin fixed or integrally connected to the inside of each of the windows, a hanging pin installed on each of the pins, and a plurality of limiting grooves arranged on the outer wall of the push-pull tube along the axial direction of the push-pull tube;

[0025] 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 near the small diameter end to be sleeved and rotatably installed on the outside of each pin shaft. The large diameter end is located inside the inner tube, and the small diameter end is exposed outside the inner tube; the large diameter end of each hanging pin is limited inside any of the limiting grooves, and pushing and pulling the push-pull tube can move the large diameter end of each hanging pin in the proximal or distal direction, so as to rotate the hanging pin relative to the pin shaft, thereby changing the direction of the small diameter end of the hanging pin.

[0026] In an optional embodiment, the rear release structure of the bracket end includes a proximal rear release structure and a distal rear release structure, and the small diameter ends of each hanging pin of the proximal rear release structure are opposite to the small diameter ends of each hanging pin of the distal rear release structure.

[0027] In an optional embodiment, the inner surface of the limiting groove is a symmetrical inclined surface with a diameter gradually decreasing from both ends to the middle along the axial direction of the push-pull tube.

[0028] The embodiments of the present invention can achieve at least the following beneficial effects:

[0029] 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, the hanging part and the limiter can ensure that each two adjacent wavy stent rings can perform relative bending movement with the limiter as the connection point, and can also avoid axial shortening between the two adjacent stent rings when the stent graft is bent. In addition, the coating is fixedly connected to the part of the skeleton other than 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.

[0030] For the coated stent delivery system provided in an embodiment of the present invention, the coated stent can be delivered and released later using its conveyor. When in use, the hollowed-out area at the end of the coated stent or a separately provided 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 through 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 being released as a whole and causing jumping.

[0031] 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

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 A schematic diagram of the overall structure of the stent graft provided by an embodiment of the present invention when the graft comprises an inner membrane and an outer membrane;

[0034] 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;

[0035] Figure 3 A schematic diagram of the skeleton structure of a stent graft provided in an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of the overall structure of a stent ring at the axially most proximal or axially most distal end of the skeleton in a stent graft provided by an embodiment of the present invention;

[0037] Figure 5 Schematic diagram of the overall structure of any stent ring axially located between the proximalmost stent ring and the distalmost stent ring in the covered stent provided by the embodiment of the present invention;

[0038] Figure 6 Schematic diagram of the structure of the hanging part formed between adjacent stent rings in the covered stent provided by the embodiment of the present invention;

[0039] Figure 7 Schematic diagram of the structure of the limiting member in the covered stent provided by the embodiment of the present invention;

[0040] Figure 8 is Figure 3 Axonometric view of the local structure of area A in

[0041] Figure 9 Partial cross-sectional view of the covered stent delivery device provided by the embodiment of the present invention;

[0042] Figure 10 is Figure 9 Enlarged view of the local structure of area B in

[0043] Figure 11 is Figure 9 Enlarged view of the local structure of area C in

[0044] Figure 12 Partial cross-sectional view of the inner tube of the covered stent delivery device provided by the embodiment of the present invention;

[0045] Figure 13 Schematic diagram of the overall structure of the hanging pin in the embodiment of the present invention;

[0046] Figure 14 Schematic diagram of the overall structure of the push-pull tube in the covered stent delivery device provided by the embodiment of the present invention;

[0047] Figure 15 Overall cross-sectional view of the covered stent delivery device provided by the embodiment of the present invention;

[0048] 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.

[0049] Reference numerals: 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 Description

[0050] 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. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0051] Therefore, the detailed description of the embodiments of the present invention provided in the accompanying 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 fall within the scope of protection of the present invention.

[0052] It should be noted that: like reference numerals and letters denote like items in the accompanying drawings. Therefore, once an item is defined in one of the accompanying drawings, it does not need to be further defined and explained in the subsequent drawings.

[0053] In the description of the present invention, it should be noted that:

[0054] Unless otherwise clearly defined and limited, the terms "arrangement", "installation", and "connection" 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 a direct connection, or an indirect connection 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.

[0055] 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 accompanying drawings, or the orientation or positional relationship in which the product of the present invention 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 therefore cannot be understood as a limitation to the present invention.

[0056] 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.

[0057] Below, taking the end of the medical device closer 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; with reference to the accompanying drawings, some embodiments of the present invention will be described in detail.

[0058] First aspect

[0059] This embodiment provides a stent graft, referring to Figures 1 to 8 The stent graft comprises a skeleton, a plurality of limiting members 2 and a membrane. Specifically, the skeleton comprises a plurality of wavy stent rings 1 arranged in the axial direction; the inflection points of each wave-shaped 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-shaped unit of each adjacent stent ring 1 near one end correspond to each other, and the inward and outward staggered units are hung together to form a hanging portion 11 with three hanging holes 111. Each limiting member 2 is clamped and installed on each hanging portion 11 of the skeleton in a one-to-one manner in such a way that its middle part passes through the hanging hole 111 in the middle of the hanging portion 11, and its two ends are limited on the inside and outside of the skeleton. The membrane is fixedly connected to the skeleton except for the hanging portion 11 and is not connected to the hanging portion 11.

[0060] 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, the hanging portion 11 and the limiter 2 can ensure 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 can also avoid axial shortening between the two adjacent sections of the stent graft ring 1 when the stent graft is bent. In addition, the coating is fixedly connected to the part of the skeleton other than the hanging portion 11 and is not connected to the hanging portion 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.

[0061] In an optional implementation of this embodiment, the stent graft can 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 graft can 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 above-mentioned inner membrane 31 and outer membrane 32 can be set at the same time or selectively, preferably, the inner membrane 31 and outer membrane 32 are set at the same time, and the method of fixedly connecting the graft to the skeleton includes but is not limited to pressing the inner membrane 31 and multiple segments of outer membrane 32 on the surface of the skeleton except the hanging portion 11, or fixing the graft to the corresponding surface of the skeleton by suturing.

[0062] In an optional implementation of this embodiment, in the skeleton of the coated stent, the proximal region of the stent ring 1 located at the axially nearest end and the distal region of the stent ring 1 located at the axially farthest 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 its hollow area 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.

[0063] 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, the middle connecting rod 21 and the head end structures 22 of the limiting member 2 are both cylindrical, and the diameter of the head end structures 22 is greater than the diameter of the middle connecting rod 21.

[0064] 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 nearest end and the stent rings 1 at the axially farthest end, the inflection points of each waveform unit near one end adjacent to the respective adjacent stent rings 1 are bent in a "W" shape, and the inflection points at the other end are in a "V" shape.

[0065] Second aspect

[0066] 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.

[0067] 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 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 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.

[0068] When in 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. Moreover, 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, and then releasing the end structure of the covered stent, avoiding the problem that the covered stent bounces when it is released as a whole.

[0069] In an alternative embodiment of the present embodiment, the end part 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.

[0070] 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 is not opened. 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 the present 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. Moreover, during the release process, since both ends of the covered stent in the axial direction can be post-released, the adjustable range of the release position of the covered stent during the post-release process is increased, thereby significantly improving the accuracy of the post-release position of the covered stent.

[0071] 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 fluency 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.

[0072] Finally, it should be noted that the above embodiments and their optional implementation manners 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 implementation manners, 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 implementation manners in the embodiments in this specification can be combined with each other.

Claims

1. A covered stent, characterized in that, Comprising: A framework, including a plurality of wave-shaped support rings (1) arranged axially; in each adjacent pair of said support rings (1), the inflection points of each wave unit of one support ring (1) near one end close to the other support ring (1) are bent into a "W" shape, and the inflection points of each wave unit of each adjacent pair of said support rings (1) near the ends close to each other are in one-to-one correspondence and are interlocked inside and outside to form a hanging portion (11) having three hanging holes (111); A plurality of limit members (2), each of said limit members (2) is clamped and installed on each of said hanging portions (11) of the framework in a manner that its middle part passes through the middle hanging hole (111) of the hanging portion (11) and its two end parts are limited inside and outside the framework; And a film, fixedly connected to the parts of the framework other than the hanging portion (11) and not connected to the hanging portion (11).

2. The covered stent according to claim 1, characterized in that, Said film includes an inner film (31), the inner film (31) is fixedly connected to the inner side surface of the parts of the framework other than the hanging portion (11), and the inner film (31) covers the inside of the hanging portion (11).

3. The covered stent according to claim 1, characterized in that, Said film includes an outer film (32), the outer film (32) is arranged in sections along the axis of the framework to avoid the hanging portion (11), so that the hanging portion (11) is exposed outside the outer film (32).

4. The covered stent according to claim 1, characterized in that, In said framework, the proximal region of the support ring (1) at the nearest end in the axial direction and the distal region of the support ring (1) at the farthest end in the axial direction are exposed outside the film.

5. The covered stent according to claim 1, wherein Said limit 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 hole (111), and the two head end structures (22) are respectively blocked outside the hanging hole (111).

6. The covered stent according to claim 5, characterized in that, Both the middle connecting rod (21) and the head end structure (22) are in the shape of a cylinder, and the diameter of the head end structure (22) is larger than the diameter of the middle connecting rod (21).

7. The covered stent according to claim 1, wherein In said framework, in the structures of the support ring (1) at the nearest end in the axial direction and the support ring (1) at the farthest end in the axial direction, the inflection points of each wave unit near one end close to its adjacent support ring (1) are bent into a "W" shape, and the inflection points at the other end are in the shape of a "V".

8. A covered stent delivery system, characterized in that, Comprising a transporter and the film-covered stent according to any one of claims 1 to 7; said transporter 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); Said stent end post-release structure includes a plurality of openings (51) circumferentially spaced and opened on the circumferential wall of the inner tube (5) along the circumferential direction of the inner tube (5), pin shafts (52) fixedly or integrally connected inside each of said openings (51), hanging pins (53) installed on each of said pin shafts (52), and a plurality of circles of limit grooves (61) arranged axially on the outer wall 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 near the small-diameter end (532) to sleeved and rotatably installed outside each of the pin shafts (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 of the hanging pins (53) are limited inside any one of the limiting grooves (61). Pushing and pulling the push-pull tube (6) can move the large-diameter ends (531) of each of the hanging pins (53) in the proximal or distal direction to rotate the hanging pins (53) relative to the pin shafts (52), thereby changing the orientation of the small-diameter ends (532) of the hanging pins (53).

9. The covered stent delivery system according to claim 8, wherein The bracket end post-release structure includes a proximal end post-release structure (110) and a distal end post-release structure (120). The orientations of the small-diameter ends (532) of the hanging pins (53) of the proximal end post-release structure (110) are opposite to those of the small-diameter ends (532) of the hanging pins (53) of the distal end post-release structure (120).

10. The covered stent delivery system according to claim 8, wherein, 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).

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