Covered stent system and covered stent thereof

Abstract

The application provides a covered stent, which comprises a tubular framework, a covering and a connecting piece, wherein the connecting piece is arranged on the tubular framework or the covering, and the connecting piece is used for controlling a guide wire to pass through, so as to control the tubular framework to radially contract or expand. The application solves the technical problem that the covered stent cannot be accurately released on the inner wall of a lumen at a proper position at one time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a covered stent system and a covered stent thereof. BACKGROUND

[0002] Endoluminal repair of the thoraco-abdominal aorta is an effective treatment option that has gained significant popularity over the past decade. However, for some challenging anatomies, such as those with a high number of branch vessels and highly curved or tortuous anatomies, there is no suitable stent system for surgeons to use. Therefore, the surgeon often needs to adjust the position of the released stent when manipulating the deployed stent so that the stent is at the optimal release point, which can allow normal blood flow and normal operation of the stent.

[0003] Most aortic aneurysms occur in the abdominal aorta, mainly due to atherosclerosis. In China, according to incomplete statistics, the incidence of abdominal aortic aneurysm in 2005 was 3‰-6.6‰, and the incidence has increased by 3 times in the past 30 years. The normal diameter of the abdominal aorta is about 1 inch. Once the diameter of the aortic aneurysm reaches 5 cm, it is generally considered necessary to treat it to prevent it from bursting. The aneurysm region of the aorta can be treated by using a tubular exclusion device delivered endoluminally, such as by placing a stent within the blood vessel across the aneurysm portion of the blood vessel to occlude the aneurysm. The specific operation is to pre-install the covered stent into the delivery device, access the abdominal aortic lesion site through the femoral artery, and accurately release the stent at the lesion site under the monitoring of an X-ray fluoroscopy device.

[0004] The pathological characteristics of abdominal aortic aneurysm are that the abdominal aortic wall has less elasticity, the diameter of the abdominal aorta gradually increases and exceeds 1.5 times the normal diameter, the blood flow volume is large, and the stent anchoring is unstable, which is prone to displacement. The abdominal aorta provides two side blood vessels to the kidneys, i.e., the renal arteries. Below the level of the renal arteries, the abdominal aorta reaches the level of about the fourth lumbar vertebra (or the navel) and is divided into the ileal arteries, which in turn provide blood to the lower limbs and the perineal region. Such a physiological structure with many branches is prone to stent occlusion. Therefore, when treating abdominal aortic aneurysm, if the stent cannot be stabilized, it will cause the covered stent to block blood flow, and even block the blood flow through the abdominal aortic side branch renal artery, causing serious consequences. SUMMARY

[0005] The purpose of the present application is to provide a covered stent system and a covered stent thereof, to solve the technical problem that the covered stent cannot be accurately released at the appropriate position on the lumen wall at one time, which will cause the covered stent to block blood flow.

[0006] The application provides a covered stent, which comprises a tubular framework, a covering fixed to the tubular framework, and a connecting piece provided on the tubular framework or the covering, the connecting piece being used for controlling a guide wire to pass through, so as to control the tubular framework to radially contract or expand.

[0007] The connecting piece is fixedly connected with the covering and / or the tubular framework in a mode of sewing, heat sealing or welding.

[0008] The connecting piece is a through-hole structure on the tubular framework and / or the covering.

[0009] The connecting piece is arranged at least one circle in a circumferential direction of the covered stent.

[0010] The tubular framework comprises a plurality of annular support frames arranged in an axial direction, the annular support frame is a wave-shaped annular support frame formed by a metal rod with a head-to-tail connection, the annular support frame comprises a wave crest, a wave trough and a wave rod, the annular support frame comprises a first layer of annular support frames, at least one wave trough of the first layer of annular support frames is provided with a barb, and an included angle α between the barb and the wave trough satisfies 0° < α < 90°.

[0011] The first layer of annular support frames is located at a proximal end starting section of the tubular framework, is partially sewn on an inner surface of the covering, and the barb is exposed outside the covering by penetrating the covering.

[0012] The annular support frame further comprises a second layer of annular support frames, the wave crest and the wave trough of the second layer of annular support frames are arranged in axial one-to-one correspondence with the wave crest and the wave trough of the first layer of annular support frames respectively, and an axial distance between the wave trough of the first layer of annular support frames and a proximal end starting section of the covering is not more than 10 mm.

[0013] The tubular framework further comprises a plurality of branch annular support frames, and an axial distance between the wave trough of the second layer of annular support frames and the wave trough of the first layer of annular support frames is less than a wave height of the second layer of annular support frames.

[0014] The wire diameter of the second layer of annular support frames is 10-70% less than that of other annular support frames.

[0015] The application provides a covered stent system, which comprises the covered stent.

[0016] The stent-graft system further comprises a delivery device, the delivery device comprises a control wire and a delivery device tip, the control wire passes through the connecting piece to control radial contraction or expansion of the tubular framework; the delivery device tip proximal end comprises a fixed part towards the operating handle direction, the fixed part is provided with at least one channel, and the fixed part is located on one side of the plane formed by the connecting piece towards the delivery device tip or the proximal end of the plane formed by the connecting piece.

[0017] The control wire is detachably connected with the channel.

[0018] The fixed part is provided with two channels, and two ends of the control wire pass through the two channels respectively, the control wire is used to be pulled out from the channel after the stent-graft is released.

[0019] The fixed part comprises a fixed wire groove and a channel, the fixed wire groove is provided with a fixed wire, when one end of the fixed wire abuts against the groove wall of the fixed wire groove, one end of the control wire is fixed by the fixed wire, the other end of the control wire passes through the channel, and the control wire and the fixed wire are used to be pulled out from the fixed wire groove after the stent-graft is released.

[0020] When the control wire controls the radial expansion of the tubular framework, the stent-graft can be released step by step multiple times under the control of the control wire, so that the stent-graft can be repeatedly tightened and expanded to seal the aortic wall and be stable on the aorta, the stent-graft after expansion does not cover or occlude the key branch artery, and the space in the stent-graft after expansion provides a flow channel for blood flowing through the aneurysm site. When the control wire controls the contraction of the tubular framework, the stent-graft can be tightened step by step multiple times under the control of the control wire, and then the stent-graft after tightening can smoothly enter the aortic cavity under the transportation of the delivery device. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is a structural schematic view of the stent-graft system provided by the present application.

[0023] Figure 2 is Figure 1 is an enlarged structural schematic view of part A in

[0024] Figure 3 is a top view structural schematic diagram of the A part in Figure 1

[0025] Figure 4 is a structural schematic diagram of the tubular skeleton in Figure 1

[0026] Figure 5 is a magnified structural schematic diagram of the A1 part in Figure 2

[0027] Figure 6 is another magnified structural schematic diagram of the A part in Figure 1

[0028] Figure 7 is a magnified structural schematic diagram of the A1 part in Figure 6 DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0030] It should be noted that for a vascular stent, the end close to the heart after being implanted into a blood vessel is called the "proximal end" of the stent, and the end away from the heart after being implanted into a blood vessel is called the "distal end" of the stent, and the "proximal end" and the "distal end" of any component of the stent are defined according to this principle. For a delivery device, the end close to the operator on the delivery device is called the "proximal end", and the end away from the operator on the delivery device is called the "distal end", and the "proximal end" and the "distal end" of any component of the delivery system are defined according to this principle. The "axial direction" generally refers to the length direction of the stent when being delivered, and the "radial direction" generally refers to the direction perpendicular to the "axial direction" of the stent, and the "axial direction" and the "radial direction" of any component of the covered stent are defined according to this principle.

[0031] Referring to Figure 1 , the present application provides a covered stent system, which comprises a covered stent 100 and a delivery device 200. The delivery device 200 is used to deliver the covered stent 100 to a lesion site, and can adjust the implantation position of the covered stent 100 by repeatedly tightening and expanding the covered stent 100, so as to accurately release the covered stent 100 at a proper position in the blood vessel lumen, and realize the treatment function of the covered stent 100 in the lumen. The covered stent 100 will be described in detail as follows.

[0032] Referring to Figures 2-3 ​​​​​The covered stent 100 comprises a tubular skeleton 10, a covering 20 fixed on the tubular skeleton 10, and a connecting member 30 provided on the tubular skeleton 10 or the covering 20, the connecting member 30 being provided for the control guide wire 40 to pass through so as to control the tubular skeleton 10 to contract or expand radially. In a specific embodiment, the covering 20 is sleeved on the tubular skeleton 10 and fixed on the tubular skeleton 10, and the connecting member 30 is a plurality of connecting members. Preferably, the plurality of connecting members 30 are arranged circumferentially, and the control guide wire 40 passes through each connecting member 30 circumferentially in sequence. The control guide wire 40 will be described later.

[0033] In a specific embodiment, the connecting member 30 is a through-hole structure 301 on the tubular skeleton 10 or / and the covering 20. The control guide wire 40 passes through the plurality of through-hole structures 301 in sequence so as to control the tubular skeleton 10 to contract or expand radially. In this embodiment, the control guide wire 40 passes through the through-hole structures 301 circumferentially in sequence.

[0034] In another specific embodiment, the connecting member 30 is a separate structure, and the connecting member 30 is fixedly connected to the tubular skeleton 10 or the covering 20, and each connecting member 30 has a through-hole structure 301. In this embodiment, the control guide wire 40 passes through the through-hole structure 301 of each connecting member 30 circumferentially in sequence.

[0035] In the present application, when the control guide wire 40 controls the tubular skeleton 10 to expand radially, the covered stent 100 can be released step by step multiple times through the control of the control guide wire 40, that is, the covered stent 100 is initially released into the blood vessel lumen in a contracted state, the covered stent 100 is slightly expanded by adjusting the control guide wire 40, the proximal end structure part of the covered stent 100 is unfolded, but the overall radial diameter of the covered stent 100 is still smaller than the diameter of the blood vessel, at this time, whether the position of the covered stent is appropriate is observed through angiography, when the position of the covered stent 100 is inappropriate, the position of the covered stent can still be adjusted in the blood vessel by tightening the covered stent 100 through the control guide wire 40, this process can be repeated multiple times until the covered stent 100 is released to the most appropriate position, ensuring that the covered stent 100 is accurately released to the position required by the patient, ensuring the safety of the covered stent after release, and better exerting the therapeutic effect of the covered stent. After expansion, the covered stent 100 does not cover or occlude the key branch arteries, and the space in the covered stent 100 after expansion well isolates the affected area to provide a flow channel for blood flow.

[0036] In a specific embodiment, in order to improve the stability of the tubular skeleton 10 in contraction and expansion, the number of connecting members 30 can be selected to be 4, and the 4 connecting members 30 are equally spaced around the tubular skeleton 10 or the covering film 20; or the number of connecting members 30 can be selected to be 8, and the 8 connecting members 30 are equally spaced around the tubular skeleton 10 or the covering film 20. The specific number of connecting members 30 and the specific position of the connecting members 30 are not limited in the present application, as long as the control wire 40 can pass through the through hole structure 301 to control the contraction or expansion of the covering stent 100.

[0037] The connecting member 30 can be a flexible pull ring fixed on the covering film 20 or / and the tubular skeleton 10; or the connecting member 30 can be a section of wire rope fixed on the covering film 20 or / and the tubular skeleton 10 at intervals in the circumferential direction, and a gap is formed between the wire rope fixed at intervals and the covering film 20 or / and the tubular skeleton 10 for the control wire 40 to pass through; or the connecting member 30 is a connecting ring provided with a through hole structure 301 on the covering film 20.

[0038] In a specific embodiment, the connecting member 30 is arranged at least one circle around the covering stent 10 in the circumferential direction. That is, the connecting member 30 is a plurality of connecting members 30, and the plurality of connecting members 30 is at least one circle, and the at least one circle of connecting members 30 circumferentially surrounds the covering stent 100. Specifically, the connecting member 30 can be a flexible connecting buckle with a limiting groove in at least one circle in the circumferential direction.

[0039] In a specific embodiment, the plurality of connecting members 30 is at least two circles, and the at least two circles of connecting members 30 circumferentially surrounds the covering stent 100, and the connecting members 30 between the adjacent two circles have a gap. Specifically, the connecting member 30 can be a flexible connecting buckle with a limiting groove in at least two circles in the circumferential direction, and the openings of the limiting grooves in different rows are arranged in opposite directions. The gap between the adjacent two circles of connecting members 30 can make the control wire 40 not interfere with each other when the control wire 40 passes through the connecting member 30, so that the control wire 40 can orderly control the contraction and expansion of the covering stent 100. In other implementations, the plurality of connecting members 30 can also be half a circle, 3 / 4 of a circle or other forms in the circumferential direction.

[0040] In a specific embodiment, the connecting member 30 and the tubular stent or / and the covering film 20 are an integral structure. The connecting member 30 of this mode is an integral structure extended from the covering film 20 or / and the tubular skeleton 10, and the connecting member 30 does not need to be made separately, saving time and labor cost.

[0041] In one specific embodiment, the connecting member 30 is a connecting ring. The connecting ring is a closed loop structure. The inner annular space of the closed loop structure can be a through-hole structure 301 provided on the connecting member 30 for the control wire 40 to pass through, or the connecting member 30 cooperates with the covering film 20 to form a through-hole structure 301 or a gap for the control wire 40 to pass through. The connecting member 30 of the closed loop structure makes the control wire 40 not easy to be detached from the connecting member 30, the control force of the control wire 40 on the covering stent 100 is more stable, and the contraction and expansion of the covering stent 100 is more stable.

[0042] Alternatively, the connecting ring is an open loop structure. The open loop structure can be a limiting groove provided on the connecting member 30 with one side opening for the control wire 40 to pass through. The connecting member 30 of the open loop structure makes the control wire 40 more easily detached from the connecting member 30.

[0043] In one specific embodiment, the connecting member 30 can be made of biocompatible materials such as PET, PTFE and other high molecular polymer materials or metal materials such as nickel-titanium alloy wire, and is fixedly connected with the covering film 20 and / or the tubular scaffold 10 by sewing, heat sealing or welding.

[0044] In this application, as long as the covering stent 100 is provided with a through-hole structure 301, the control wire 40 passing through the through-hole structure 301 can control the contraction or expansion of the covering stent 100, and the specific position of the through-hole structure 301 is not limited. The material of the connecting member 30, the shape of the connecting ring and the forming method of the connecting member 30 are not limited in this application.

[0045] Please refer to Figure 4 , the tubular scaffold 10 comprises a plurality of annular support frames 110 arranged at intervals along the axial direction, and the annular support frame 110 is an annular support frame 110 in the form of an isometric wave or a high-low wave formed by the metal rods 105 connected end to end. The annular support frame 110 comprises a first layer annular support frame 101.

[0046] In this application, the metal rod 105 comprises a first metal rod 101a and a second metal rod 101b, as shown in Figure 2 , the first metal rod 101a and the second metal rod 101b are connected at an angle, and the first metal rod 101a and the second metal rod 101b are smoothly connected. The first metal rod 101a and the first metal rod 101a are relatively close to each other to make the tubular scaffold 10 contract, and the first metal rod 101a and the second metal rod 101b are relatively open to make the tubular scaffold 10 expand. The plurality of annular support frames 110 extend at equal diameters or non-equal diameters. The metal rod 105 is made of elastic metal material.

[0047] In one specific embodiment, when the connector 30 is a separate structure, multiple connectors 30 are fixed to the first metal rod 101a or the second metal rod 101b of the first-layer annular support frame 101. Multiple connectors 30 can all be fixed to the first metal rod 101a of the first-layer annular support frame 101, or all be fixed to the second metal rod 101b of the first-layer annular support frame 101, or partially fixed to the first metal rod 101a and partially fixed to the second metal rod 101b of the first-layer annular support frame 101. Figures 2-3 As shown, there are 8 connectors 30, and all 8 connectors 30 are fixed to the first metal rod 101a of the first layer ring support frame.

[0048] Optionally, the connector 30 is fixed at 1 / 4 to 3 / 4 of the first metal rod 101a or the second metal rod 101b of the first-layer annular support frame 101. Preferably, the connector 30 is fixed at 1 / 2 of the first metal rod 101a or the second metal rod 101b of the first-layer annular support frame 101. When the connector 30 is fixed at 1 / 2 of the first metal rod 101a or the second metal rod 101b of the first-layer annular support frame 101, the control guide wire 40 controls the tightening or expansion of the first-layer annular support frame 101 through the connector 30. This results in a more uniform force distribution on the first-layer annular support frame 101, making the contraction and expansion of the first-layer annular support frame 101 more stable, and consequently, the contraction and expansion of the tubular skeleton 10 more stable.

[0049] In other implementations, the connector 30 may be at least one ring located at the proximal, middle, and distal ends of the membrane 20. Alternatively, the connector 30 may be fixed at least one ring at the middle, distal, or proximal end of the tubular skeleton 10. Of course, the connector 30 may also be located at other positions on the membrane 20 and / or the tubular skeleton 10.

[0050] In this application, the annular support frame 101 includes a crest 101c, a trough 101d, and a wave rod 101e. Specifically, a first metal rod 101a is smoothly connected to two second metal rods 101b to form a trough 101d, a crest 101c, and a wave rod 101e, with the wave rod 101e located between the trough 101d and the crest 101c. The crests 101c may be of equal or unequal height, and the troughs 101d may be of equal or unequal height.

[0051] The first-layer annular support frame 101 is located at the proximal starting segment of the tubular skeleton 10. It is a cut-type bare scaffold, with 1 / 2 of it sutured inside the covering membrane 20.

[0052] That is, the first layer of annular support frame 101 of the tubular skeleton 10 proximal end of the first metal rod 101a and the second metal rod 101b exposed outside the covering film 20. When the first layer of annular support frame 101 of the first metal rod 101a and the second metal rod 101b exposed outside the covering film 20, the tubular skeleton 10 release, the barb 90 on the trough 101d will be inserted into the aortic wall, and then the trough 101d of the first layer of annular support frame 101 and the aortic wall can be stably connected, and the covering film stent 100 is firmly fixed on the aortic wall, which improves the stability of the connection between the covering film stent 100 and the aortic wall. In one embodiment, 1 / 3-1 / 2 of the first metal rod 101a and the second metal rod 101b are covered in the covering film 20.

[0053] Please refer to Figure 4 , the diameter of the first layer of annular support frame 101 of the tubular skeleton 10 proximal end is greater than that of the remaining annular support frame 110. Specifically, the inner space of the first layer of annular support frame 101 is the entrance of blood flow, and the larger diameter of the first layer of annular support frame 101 increases its radial support force to the pipe wall, so that the stent is fixed firmly and the interference of blood flow is reduced, so that the blood flow in the lumen of the covering film stent is more smooth.

[0054] The hardness of the first layer of annular support frame 101 of the tubular skeleton 10 proximal end is greater than that of the remaining annular support frame 110. Specifically, the first layer of annular support frame 101 is a cutting type stent, which has greater width and friction force than the woven type stent, and the remaining annular support frame 110 is used to fit with the aortic wall. The first layer of annular support frame 101 with greater hardness is beneficial to be stably fixed on the aortic wall, and the remaining annular support frame 110 with smaller hardness can reduce the damage to the aortic wall.

[0055] Please continue to refer to Figure 2 , the first layer of annular support frame 101 is provided with barb 90, and the barb 90 is arranged along the axial direction of the first layer of annular support frame 101; the included angle α between the barb 90 and the first layer of annular support frame 101 is 0°<α<90°. The barb 90 pierces the covering film 20 and is exposed outside the covering film 20.

[0056] Specifically, the barb 90 is used for inserting into the aortic wall to improve the connection stability of the covering film stent 100 and the aortic wall. When the barb 90 protrudes outside the covering film 20, the barb 90 can be directly inserted into the aortic wall to be directly inserted and fixed with the aortic wall. Thus, the barb 90 on the trough 101d of the first layer of annular support frame 101 fixed inside the covering film 20 is inserted into the aortic wall to be directly inserted and fixed with the aortic wall, which reduces the contact area between the metal and the human body and reduces the damage of the metal to the human body compared with the general stent. At the same time, the included angle between the barb 90 and the annular support frame 101 is less than 90°, which can improve the radial support force of the barb area.

[0057] Because the first-layer annular support 101 at the proximal end of the tubular skeleton 10 has greater rigidity, the fixed connection of multiple barbs 90 to the more rigid first-layer annular support 101 can improve the connection stability of the barbs 90, thereby improving the stability of the barbs 90 inserted into the aortic wall. It also improves the connection stability of the covered stent 100. Furthermore, the placement of the barbs 90 at the trough 101d position ensures sufficient space above the barbs 90 for the covered stent 20 to connect with other covered stent systems, increasing wall apposition and sealing.

[0058] The annular support frame 110 also includes a second annular support frame 103. The positions of the crests and troughs of the second annular support frame 103 are axially aligned with the positions of the crests 101c and troughs 101d of the first annular support frame 101. The first annular support frame 101 is partially sewn into the covering film 20, with the sewn portion occupying 1 / 2 to 2 / 3 of the first annular support frame 101. The axial distance between the trough 101d of the first annular support frame 101 and the proximal starting section of the covering film 20 is between 5 and 10 mm. The axial distance between the trough of the second annular support frame and the trough of the first annular support frame is less than the wave height of the second annular support frame, between 1 and 9 mm. The second annular support frame 103 is entirely sewn into the covering film 20, with the crests and troughs embedded at the distal ends of the crests 101c and troughs 101d of the first annular support frame 101. Figure 4 As shown. The wire diameter of the second-layer annular support frame is 0.15-0.3 mm, which is smaller than the wire diameter of the other annular support frames 110, making it easier to compress and assemble into the sheath. Specifically, the wire diameter of the second-layer annular support frame is 10-70% smaller than that of the other annular support frames, and more preferably, the wire diameter of the second-layer annular support frame is 20-50% smaller than that of the other annular support frames. In this application, the second-layer annular support frame 103 is used to adhere to the aortic wall. The second-layer annular support frame 103, with its smaller wire diameter and better flexibility, is located near the distal end of the first-layer annular support frame 101, which helps to support the area near the barbs 90 to stably adhere to the arterial wall, improves the wall adhesion of the proximal end of the covered stent 100, thereby enhancing the overall sealing of the covered stent 100 and preventing blood from flowing out from the gap between the stent and the vessel wall.

[0059] The annular support frame 110 also includes multiple high and low wave annular support frames half-stitched outside the covering film 20, axially arranged at the far end of the second layer annular support frame 103, which improves the radial support force and bending flexibility of the main support frame.

[0060] Please see Figure 4The tubular skeleton 10 further comprises a plurality of branch annular supports 102, which are located on one side of the main annular support 101 and are arranged side by side. In this embodiment, the branch annular supports 102 are two, which are integrally formed with the main annular support 101, and the distal end of the covered stent 100 extends out two branch supports. The proximal end of the long branch annular support is made of a smaller wire diameter to improve flexibility, and the distal end annular support is made of a larger wire diameter to improve radial support force, ensure the distal end to be in contact with the wall, and prevent type I endoleak. The most important thing in the abdominal aortic stent implantation surgery is to accurately anchor the covered stent 100 during implantation, so that the covered stent 100 can seal the aortic wall and be stable on the aorta. After expansion, the covered stent 100 does not cover or occlude the key branch arteries, and the space in the expanded covered stent 100 provides a flow channel for blood to flow through the aneurysm site.

[0061] Please continue to refer to Figure 1 The delivery device 200 comprises a control guide wire 40 and a delivery device tip 50. The control guide wire 40 passes through the connecting piece 30 to control the radial contraction or expansion of the tubular skeleton 10. The delivery device tip 50 comprises a fixed part 60 facing the direction of the operating handle. The fixed part 60 is provided with at least one channel 601, and the fixed part 60 is located at the proximal end of the connecting piece 30.

[0062] Please refer to Figure 5 In a specific embodiment, the fixed part 60 is provided with two channels 601, and the two ends of the control guide wire 40 pass through the two channels 601 respectively. After the release of the covered stent 100 is completed, the control guide wire 40 is withdrawn from the channel 601 and finally withdrawn from the body. In this application, the channel 601 is an open structure or a closed structure. After the two ends of the control guide wire 40 pass through the channel 601, the covered stent 100 can be controlled to be tightened and released by the axial movement of the two ends of the control guide wire 40.

[0063] Alternatively, the fixed part 60 of the delivery device tip 50 is located on the central axis of the covered stent 100, and the two channels 601 are also symmetrically arranged on both sides of the central axis. After the two ends of the control guide wire 40 pass through the two channels 601, the covered stent 100 can be controlled to be folded from the outside to the center, or the covered stent 100 can be controlled to be released from the center to the outside.

[0064] Please refer to Figures 6-7In another specific embodiment, the fixing part 60 comprises a fixing wire slot 603 and a channel 601, the fixing wire slot 603 is detachably connected with the control guide wire 40, the fixing wire slot 603 is provided with a fixing wire 80, one end of the control guide wire 40 is sleeved on the fixing wire 80, and the other end of the control guide wire 40 passes through the channel 601. In this mode, the fixing wire 80 is made of a rigid material, and is used for detachably connecting the distal end of the control guide wire 40. The distal end of the control guide wire 40 can be bent to form a guide wire ring 401, and the fixing wire 80 passes through the guide wire ring 401. When the covered stent 100 is released, the fixing wire 80 is first removed, the ring guide wire at the distal end of the control guide wire 40 is separated from the fixing, and then the proximal end of the control guide wire 40 is pulled back, so that the control guide wire 40 is completely removed. In this way, the stroke of the control guide wire 40 is halved, the distal end of the control guide wire 40 is more efficiently separated from the stent, and the risk of surgery is reduced. In this mode, the control guide wire 40 is preferably a single flexible rope, and a ring structure is left at the distal end as a guide wire ring at the proximal end of the control guide wire 40. One end (proximal end) of the control guide wire 40 passes through the channel 601 of the delivery device end head 50 and the inner cavity of the delivery device 200 to reach the handle control part. The ring structure at the other end (distal end) of the control guide wire 40 is sleeved on the control fixing wire 80, the fixing wire 80 passes through the fixing wire slot 603, and the proximal end of the control guide wire 40 is fixed on the handle control assembly of the delivery device 200.

[0065] Please continue to refer to Figures 2-3 The delivery device 200 further comprises a guide wire tube 70 connected with the fixing part of the delivery device end head. The guide wire tube 70 penetrates the internal space of the covered stent 100, and the two ends of the control guide wire 40 are respectively accommodated in the guide wire tube 70 after passing through the two channels 601. In this embodiment, the guide wire tube 70 is provided with two through grooves 701, and one through groove 701 is used for accommodating one end of the control guide wire 40.

[0066] The handle assembly is connected to the distal end of the guide wire tube 70, and the two ends of the control guide wire 40 are fixed on the handle assembly after passing through the guide wire tube 70. The handle assembly is used to exert a pulling force on the control guide wire 40.

[0067] When the proximal end of the covered stent 100 is released, moving the handle assembly at the rear end of the delivery device 200 can make the control guide wire 40 relax, the proximal end of the covered stent 100 expand, and the movement amount of the handle assembly is used to control the expansion amount of the first main body ring-shaped stent 101 at the proximal end of the skeleton. When the covered stent 100 is completely released, the covered stent 100 is attached to the blood vessel; when the covered stent 100 is not completely attached to the blood vessel, the control guide wire 40 can be used to tighten the first main body ring-shaped stent 101 at the proximal end of the skeleton, the covered stent 100 is tightened, the delivery device 200 is moved again for stent positioning, and the covered stent 100 is reattached to the blood vessel until the covered stent 100 is completely attached to the blood vessel.

[0068] The above merely provides the preferred embodiment of the application, and cannot alluded the scope of the application. Those skilled in the art can understand that all or part of the flow of the above embodiment can be implemented, and equivalent variations made according to the claims of the application still belong to the scope of the application.

Claims

1. A covered stent, characterized by, The application relates to a covered stent, which comprises a tubular framework, a covering film fixed on the tubular framework and a connecting piece; the tubular framework comprises a plurality of annular support frames arranged at intervals in the axial direction, the annular support frames are wave-shaped annular frames formed by metal rods connected end to end, the annular support frames comprise wave crests, wave troughs and wave rods; the annular support frames comprise a first layer of annular support frames and a second layer of annular support frames; at least one wave trough of the first layer of annular support frames is provided with a barb; the first layer of annular support frames is located at a proximal end starting section of the tubular framework, is partially sutured to the inner surface of the covering film and is sutured to the inner surface of the covering film in a proportion of 1 / 2-2 / 3 of the first layer of annular support frames; the barb is exposed outside the covering film through the covering film; the wave crests and wave troughs of the second layer of annular support frames are arranged in axial one-to-one correspondence with the wave crests and wave troughs of the first layer of annular support frames respectively; the axial distance between the wave troughs of the second layer of annular support frames and the wave troughs of the first layer of annular support frames is smaller than the wave height of the second layer of annular support frames; the connecting piece is arranged on the tubular framework or the covering film and is used for controlling a guide wire to pass through so as to control the radial contraction or expansion of the tubular framework. The connecting piece is fixedly connected with the covering film or the tubular framework by suturing or heat sealing.

2. The stent graft of claim 1, wherein, The connecting piece is fixedly connected with the covering film or the tubular framework by welding.

3. The stent graft of claim 2, wherein, The connecting piece is a through hole structure on the tubular framework or the covering film.

4. The stent graft of claim 1, wherein, The connecting piece is arranged in at least one circle in the circumferential direction of the covering stent.

5. The stent graft of claim 1, wherein, The included angle between the barb and the wave trough is 0<alpha<90.

6. The stent graft of claim 1, wherein, The axial distance between the wave trough of the first layer of annular support frames and the proximal end starting section of the covering film is not more than 10 mm.

7. The stent graft of claim 6, wherein, The wire diameter of the second layer of annular support frames is 10-70% smaller than the wire diameter of other annular support frames except the second layer of annular support frames.

8. The stent graft of claim 7, wherein, The application further relates to a covered stent system, which comprises the covered stent and a delivery device; the delivery device comprises a control guide wire and a delivery device tip; the control guide wire passes through the connecting piece; the proximal end of the delivery device tip comprises a fixing part which is provided with at least one channel and is located on one side of the plane formed by the connecting piece or the plane formed by the connecting piece.

9. A covered stent system, characterized by, The control guide wire is detachably connected with the channel.

10. The covered stent system of claim 9, wherein, The fixing part is provided with two channels, and the two ends of the control guide wire pass through the two channels respectively; the control guide wire is used for being separated from the channels after the release of the covered stent.

11. The covered stent system of claim 10, wherein, The fixing part comprises a fixing wire groove which is provided with a fixing wire; when one end of the fixing wire abuts against the groove wall of the fixing wire groove, one end of the control guide wire is fixed by the fixing wire; the other end of the control guide wire passes through one channel; the control guide wire and the fixing wire are used for being separated from the fixing wire groove after the release of the covered stent.

12. The covered stent system of claim 10, wherein, ​

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