Lumen stent and delivery system

Abstract

The application provides a lumen stent, which comprises a covered stent and a bare stent connected to the proximal end of the covered stent during transportation, characterized in that the bare stent comprises a first wave coil connected to the covered stent at one end, and the first wave coil is reversely connected to the covered stent through a folding rod structure, so that when the bare stent is released from the delivery device, the bare stent is automatically reversed into the covered stent under the driving of the folding rod structure. The lumen stent provided by the application can avoid affecting blood supply and causing branch vessel dissection. After being automatically reversed into the covered stent without increasing the assembly volume of the lumen stent, the sealing effect at the proximal end of the lumen stent can be enhanced, internal leakage and stent displacement can be reduced, and the risk of displacement or shortening of the lumen stent due to external force can be reduced compared with passive reversal.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and in particular to a lumen stent and delivery system. Background Technology

[0002] Aortic aneurysm is a common aortic disease. The main existing treatments for aortic aneurysms include traditional open surgery and endovascular repair. Endovascular repair is widely used due to its advantages such as minimal trauma, short operation and hospitalization time, rapid postoperative recovery, and low complication rate. The surgical principle is to compress a covered stent and pre-load it into the sheath of a delivery device. The delivery device sheath is then delivered to the lesion site in the blood vessel, and the stent is released from the delivery device sheath. The stent unfolds and adheres to the blood vessel through its own radial support force. The covered stent isolates the healthy blood vessel from the aneurysm, thus curing the aneurysm.

[0003] During endovascular repair, the luminal stent 50 has a post-release structure to ensure stable deployment, such as... Figure 1 As shown, the post-release structure refers to the hook structure 71 at the front end of the delivery device, and the exposed corrugated coil (bare stent corrugated coil 51) at the proximal end of the stent 50. The bare stent corrugated coil 51 can be hooked onto the hook structure 71 for post-release. When the stent 50 is delivered to the release position using the delivery device, the sheath is withdrawn, and the stent 50 unfolds and adheres to the blood vessel. Because the front end of the stent 50 is fixed to the hook structure 71 by the bare stent corrugated coil 51, the stent 50 will not shift during the deployment of the covered stent. Then, the hook structure 71 of the delivery device is opened, the bare stent corrugated coil 51 detaches from the hook structure 71 and fully unfolds, and the delivery device system is withdrawn. The release effect is as follows: Figure 2 As shown, for some special locations of the aorta, the aorta has branch vessels 53, such as the coronary arteries in the ascending aorta, the upper limb arteries in the aortic arch, and the visceral and renal arteries of the abdominal aorta. When the aneurysm 54 expands close to the branch vessel 53, and the aneurysm neck (the length of the proximal anchorage of the stent 50) is short, the proximal end of the stent 50 needs to be as close as possible to the branch vessel 53 to obtain more anchorage length. At this time, the bare stent coil 51 may block the entrance of the branch vessel 53, affecting blood supply. In more serious cases, the bare stent coil 51 may push against the inside of the branch vessel 53, leading to branch vessel dissection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a lumen stent and delivery system to address the problem in the prior art where the bare stent coil obstructs the branch artery entrance after the release of the luminal stent for aortic aneurysm, thereby affecting blood supply, or even the bare stent coil reaching into the branch vessel, thereby causing branch vessel dissection.

[0005] The technical scheme adopted by the present application to solve its technical problems is:

[0006] An embodiment of the present application provides a lumen stent, which comprises a covered stent and a bare stent connected to the proximal end of the covered stent during transportation, the bare stent comprises a first wave coil, and the first wave coil is reversely connected to the covered stent through a folding rod structure, so that the bare stent is automatically reversed into the covered stent under the driving of the folding rod structure after the bare stent is released from the delivery device.

[0007] In an embodiment of the present application, the bare stent is in a compressed state when the lumen stent is transported, and the process of reversing the bare stent from the compressed state into the covered stent comprises a compressed state, a released state and a natural state in sequence.

[0008] In an embodiment of the present application, one end of the folding rod structure is connected to the first wave coil, the other end is connected to the covered stent, and the folding point of the folding rod is located in the covered stent.

[0009] In an embodiment of the present application, the folding rod structure comprises a folding part, a fixed part and an elastically foldable connecting part, and the folding part of the folding rod structure in the reversed state has a rebound force of folding towards the fixed part with the connecting part as the folding point.

[0010] In an embodiment of the present application, the folding rod structure is integrally formed.

[0011] In an embodiment of the present application, the folding rod structure is provided with an even number, and each two of the folding rod structures are circularly symmetrical with respect to the axial direction of the covered stent.

[0012] In an embodiment of the present application, the covered stent comprises a main stent and a covering film covering the main stent, the main stent comprises a plurality of wave coils arranged and spaced along the axial direction, and the wave coil close to the bare stent is a second wave coil, the first wave coil and the second wave coil are axially spaced apart when the bare stent is in the compressed state.

[0013] In an embodiment of the present application, the covered stent is a hollow tube in the natural state, the radius of the tube of the covered stent is defined as R, and the wave height of the first wave coil is defined as H, and H satisfies: H≤R.

[0014] In an embodiment of the present application, the axial distance D between the wave trough of the first wave coil and the wave peak of the second wave coil satisfies: 0<D≤3mm.

[0015] In an embodiment of the present application, the wave trough of the first wave coil and the wave peak of the second wave coil are fixedly connected through a polymer line.

[0016] In an embodiment of the present application, the wave trough of the first wave ring is not in the same axial line with the wave peak of the second wave ring.

[0017] In an embodiment of the present application, the wave trough of the first wave ring is in the same axial line with the wave trough of the second wave ring.

[0018] In an embodiment of the present application, the wave height of the first wave ring and the second wave ring is the same, and the wave period is the same.

[0019] The lumen stent can prevent the interference of the bare stent to the blood vessel branch after the release of the bare stent, that is, the bare stent can avoid blocking the entrance of the branch artery, thereby avoiding affecting the blood supply; and the bare stent can also avoid the wave ring of the bare stent being on the inside of the branch blood vessel, thereby avoiding causing the branch blood vessel to be sandwiched. While not increasing the assembly volume of the lumen stent, the lumen stent can also be automatically turned back into the covered stent after the release, thereby enhancing the sealing effect of the proximal end of the lumen stent, reducing internal leakage and stent displacement. The bare stent is automatically turned back into the covered stent, and no external force is needed in the state of the release, and compared with the passive turning back, the lumen stent can also reduce the risk of displacement or shortening of the lumen stent due to the need for external force.

[0020] The present application also provides a delivery system, comprising a delivery device and a lumen stent as described above, wherein the delivery device comprises a sheath tube and a sheath core assembly, and a receiving cavity for receiving the lumen stent is formed between the sheath tube and the sheath core assembly. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 is a structural schematic diagram of a lumen stent in a release state in the prior art;

[0023] Figure 2 is a structural schematic diagram of a lumen stent in a complete release state in the prior art;

[0024] Figure 3 is a structural schematic diagram of a regular octagonal ring structure in a natural state;

[0025] Figure 4 is Figure 3 a structural schematic diagram of a regular octagonal ring structure after turning back;

[0026] Figure 5 is a structural schematic diagram of a wave-shaped ring in a natural state;

[0027] Figure 6 is a structural schematic diagram of a lumen stent in a natural state in an embodiment of the present application;

[0028] Figure 7Figure 1 is a structural schematic diagram of a bare stent and a covered stent flip-over connection in an embodiment of the present application;

[0029] Figure 8 Figure 2 is a structural schematic diagram of a bare stent flip-over to 90° in an embodiment of the present application;

[0030] Figure 9 Figure 3 is a structural schematic diagram of a bare stent in a compressed state in an embodiment of the present application;

[0031] Figure 10 Figure 4 is a structural schematic diagram of a bare stent in a first release state in an embodiment of the present application;

[0032] Figure 11 Figure 5 is a structural schematic diagram of a bare stent in a later release state in an embodiment of the present application;

[0033] Figure 12 Figure 6 is a structural schematic diagram of a bare stent in a completely released natural state in an embodiment of the present application;

[0034] Figure 13 Figure 7 is a structural schematic diagram of a lumen stent in a natural state in an embodiment of the present application;

[0035] Figure 14 Figure 8 is a structural schematic diagram of a lumen stent in a natural state in another embodiment of the present application;

[0036] Figure 15 Figure 9 is a structural schematic diagram of a bare stent and a covered stent flip-over connection in another embodiment of the present application;

[0037] Figure 16 Figure 10 is a structural schematic diagram of a bare stent in a later release state in another embodiment of the present application;

[0038] Figure 17 Figure 11 is a structural schematic diagram of a bare stent in a completely released natural state in another embodiment of the present application;

[0039] Figure 18 Figure 12 is a structural schematic diagram of a flip-over wave and a fixed wave flip-over connection in yet another embodiment of the present application;

[0040] Figure 19 Figure 13 is a structural schematic diagram of a flip-over wave in a later release state in yet another embodiment of the present application;

[0041] Figure 20 Figure 14 is a structural schematic diagram of a bending wave in a natural state in still another embodiment of the present application;

[0042] Figure 21 Figure 15 is a structural schematic diagram of a bending wave in a later release state in still another embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways beyond the specific embodiments described herein without departing from the scope of the present application, and it is understood that similar improvements can be made by those skilled in the art without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0044] It should be noted that when an element is referred to as being "on" or "connected to" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the terms "vertical", "horizontal", "left", "right", and the like are merely used for the purpose of illustration and are not intended to limit the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. For the convenience of description, a blood vessel is taken as an example to illustrate the lumen, which can be an aortic arch, a thoracic aorta, an abdominal aorta, etc. It should be understood by those skilled in the art that the blood vessel is taken as an example and is not intended to limit the present application, and the solutions of the present application are applicable to various human body lumens, such as digestive tract lumens, etc. Various modifications and variations based on the teachings of the present application are within the scope of the present application. In addition, in the description of the blood vessel, the orientation can be defined according to the direction of blood flow, and the blood flow is defined as flowing from the proximal end to the distal end in the present application.

[0046] In the present application, the "covered stent" refers to a structure in which a film is covered on the surface of a bare stent, and the bare stent refers to a structure including at least one undulating film. The bare stent is generally used for hooking to the hooking structure of a delivery device during post-release.

[0047] In order to facilitate understanding of the technical solutions of the present application, "turnover connection", "passive turnover" and "automatic turnover" are described as follows:

[0048] Flip connection: refers to the inner side of the ring or cylindrical structure (the ring or cylindrical structure is made of elastic material) is turned outwards in its natural state and connected with other structures (such as a tubular object), or after being connected with other structures (such as a tubular object), the non-connection end is turned over with the connection end as the fulcrum. Or the wave-shaped ring is fixed with part of the single wave, and the other part of the single wave (the flipped wave) is flipped relative to the fixed wave. At this time, the wave-shaped ring has a torsional force inside the flipped wave to return to the natural state of the wave-shaped ring. Or the elastic material of the non-ring structure is pre-bent with a certain point as the boundary, including the fixed part and the flipped part. Under the action of external force, the flipped part can unfold relative to the fixed part. After the external force is removed, the flipped part has a tendency to return to the pre-bent natural state with the point as the fulcrum. Among them, the unfolded state under the action of external force is the flip connection of the flipped part and the fixed part of the structure.

[0049] Taking the wave-shaped ring as an example, if the entire structure is completely flipped 180°, the inner side and the outer side can be exchanged (the initial inner side is flipped 180° to become the outer side, and the initial outer side becomes the inner side). If the flipping angle of the non-fixed elastic body is in the range of (0°, 180°) under the action of external force, due to the elasticity of the elastic body itself and the torsional effect caused by flipping, the wave-shaped ring has a tendency to move from the flipped state to the stable state or the metastable state without external intervention. If part of the wave of the wave-shaped ring is fixed in the natural state, and the other part of the wave is flipped (0°, 180°] under the action of external force, when the external force is removed, the flipped part of the wave-shaped ring has a tendency to return to the natural state from the flipped state.

[0050] Passive flipping: refers to the ring or cylindrical structure being in a non-stable state flipped to (90°, 180°). At this time, when the external force is removed, the ring or cylindrical structure has a tendency to return to the metastable state from the non-stable state. With the help of external force, the partially flipped structure is brought to a non-stable state in the range of (0°, 90°), and then the external force is removed. Then, the ring or cylindrical structure has a tendency to return to the natural state.

[0051] Active flipping: refers to the ring, wave-shaped or cylindrical structure being in a non-stable state flipped to (0°, 180°). At this time, when the external force is directly removed, the ring or cylindrical structure has a tendency to return to the natural state from the non-stable state. For example, part of the wave of the wave-shaped ring is fixed in the natural state, and the other part of the wave is flipped (0°, 180°] under the action of external force. When the external force is removed, the flipped part of the wave can return to the natural state. Or there is other elastic force that can cause the wave-shaped ring to return to the natural state from the flipped state.

[0052] The principle of the ring or cylindrical structure being able to automatically return to the natural state is simply explained as follows:

[0053] Please see Figure 3 Taking a regular octagonal ring structure 60 (made of elastic material) as an example to illustrate the principle, the ring structure 60 made of elastic material includes an inner surface 61 and an outer surface 62. The ring structure 60 has an interior angle θ1 in its natural state. Taking one end (the axial end) of the ring structure 60 as a fulcrum, a torque is applied to the other end of the ring structure 60, causing the ring structure 60 to rotate... Figure 3 The arrow shown points outwards in the direction W, with the outward angle ranging from 0° to 180°.

[0054] When the annular structure 60 is completely rotated 180° under the action of torque, a sub-stable state is achieved where the inner surface 61 and the outer surface 62 are interchanged (the inner surface 61 in its natural state is rotated 180° to become the outer surface 62, the inner angle θ1 in its natural state is turned outward to become θ2, and the outer surface 62 in its natural state becomes the inner surface 61). Figure 4 As shown. Since the flipping of the ring structure 60 is essentially due to the elastic deformation of the elastic body, the elastic body of the ring structure 60 in the substable state can easily flip back to the natural state under a very small torque force; conversely, a larger torque is required for the elastic body of the ring structure 60 to undergo elastic deformation from the natural state to the unstable state.

[0055] For the waveform ring-shaped material 80 commonly used in vascular stents, such as Figure 5 The wave-shaped ring 80 shown includes crests 81 and troughs 82. Because it is made of an elastic material, the wave-shaped ring 80, in its natural state, will change direction under the action of an applied torque. Figure 5 The peak 81 is the fulcrum. Figure 5 The trough 82 shown in the diagram flips inward or outward around the crest 81, undergoing elastic deformation. When the non-fixed wave-shaped ring 80 flips from its natural state (0°, 180°) to an unstable flipping state, it tends to flip back due to the elasticity of the wave-shaped ring 80 itself and the resisting torque caused by the flipping. When the applied torque is removed, the wave-shaped ring 80 tends to move from the flipping state to a stable or substable state.

[0056] Specifically, if the wave-shaped ring 80 is in a non-stable state of turning to a range of (0°, 90°) under the action of an external force (torque), when the external force is removed, the wave-shaped ring 80 has a tendency to return to the natural state from the non-stable state; if the wave-shaped ring 80 is in a non-stable state of turning to a range of (90°, 180°) under the action of an external force (torque), when the external force is removed, the wave-shaped ring 80 has a tendency to return to the sub-stable state from the non-stable state, if a small external force is applied to the partially turned structure to bring it to a non-stable state in the range of (0°, 90°) and then the external force is removed, the wave-shaped ring 80 has a tendency to return to the natural state.

[0057] If a part of the wave of the wave-shaped ring 80 is fixed in the natural state, and the other part of the wave is turned (0°, 180°) under the action of an external force (torque), due to the fact that a part of the wave is fixed and the other part of the wave is turned under the influence of its own elastic deformation and the resistance torque generated by the wave ring itself, when the external force is removed, the turned part of the wave has a tendency to return to the natural state from the turned state.

[0058] Embodiment 1

[0059] As shown in Figures 6-11 , the delivery system 100 provided by the embodiment includes a lumen stent 10 and a delivery device 70, the lumen stent 10 is delivered to the implantation site (for example, the aortic arch close to the upper limb artery) by the delivery device 70, as shown in Figures 9-11 .

[0060] During delivery, as shown in Figures 6-7 in combination with Figures 9-11 , the lumen stent 10 includes a covered stent 12 and a bare stent 11 connected to the proximal end of the covered stent 12, the covered stent 12 includes a main stent 121 and a covering 122 covering the main stent 121. The main stent 121 is used to support the covering 122 so that the covered stent 12 as a whole forms a hollow tube structure, and the main stent 121 includes a plurality of annular Z-shaped wave rings arranged and spaced apart along the axial direction, each wave ring is made of a metal elastic material (for example, nickel-titanium alloy), so that when the lumen stent 10 is compressed and loaded into the sheath 73 of the delivery device 70, radial deformation can occur, and the delivery device 70 can be loaded with the lumen stent 10 (in the state shown in Figure 7 ). At the same time, after the delivery device 70 is preliminarily released to the implantation site, the covered stent 12 can be expanded in the blood vessel, and then the hook structure 71 of the delivery device 70 is used for the subsequent release of the bare stent 11. The lumen stent 10 provided by the embodiment has a turned connection between the bare stent 11 and the covered stent 12 during delivery, so that after the delivery device 70 releases the bare stent 11, the bare stent 11 will return to the covered stent 12, as shown inFigure 6 Combination Figures 9-12 The covering 122 is made of PTFE or PET film, which is used to isolate blood flow.

[0061] The bare stent 11 includes a first wave coil 111 connected with the covering stent 12 but not fixed. In the embodiment, the bare stent and the covering stent are movably connected through the covering and the polymer thread, so that the bare stent 11 can be flipped relative to the covering stent with the connecting point as the flipping point. The first wave coil 111 is a wave-shaped ring as shown in the figure. In other embodiments, the first wave coil can also include a single wave that can be flipped or a single wave with a flipping part, as long as the first wave coil and the covering stent can be connected by flipping (or the flipping part and the fixed part of the first wave coil are connected by flipping) so that the bare stent can be flipped back into the covering stent after being released from the delivery device 70. The main stent 121 includes a plurality of annular Z-shaped wave coils arranged and spaced along the axial direction, and the wave coil of the main stent 121 close to the first wave coil 111 is a second wave coil 1211. The lumen stent 10 is in a natural state as shown in the figure (in the embodiment, the bare stent 11 in the natural state is attached to the covering 122, and the angle between the bare stent 11 and the bare stent in the natural state is 0°), and the first wave coil 111 and the second wave coil 1211 are both arranged in the region at the proximal end of the lumen stent 10. The difference is that one end of the first wave coil 111 (the proximal end in the flipped state as shown in the figure) is connected with the covering 122, and the other part of the first wave coil 111 is attached to the covering 122 in the natural state but not connected with the covering 122, so as to facilitate the lumen stent 10 to be compressed and loaded into the sheath 73 in the form of the first wave coil 111 flipped out of the covering stent 12 (i.e., the bare stent 11 and the covering stent 12 are in the expanded state of the flipped connection as shown in the figure, and the angle between the bare stent 11 and the bare stent in the natural state is approximately 180 degrees, which can have a deviation of plus or minus 5 degrees). Figure 5 Figure 6 Figure 7 Figure 7

[0062] Figure 7 ​​​​​As shown, when the bare stent 11 and the covered stent 12 are in the unfolded state of the reverse connection but not compressed, the first wave 111 and the second wave 1211 are arranged axially spaced apart, and the axial distance D between the wave trough of the first wave 111 and the wave crest of the second wave 1211 satisfies: 0mm < D≤ 3mm, and in other embodiments, D satisfies: 1mm≤ D≤ 3mm, so that a gap is left between the first wave 111 and the second wave 1211, and the gap is connected by the soft covering 122, and the first wave 111 and the covered stent 12 are reversely connected and compressed into the sheath tube 73 of the delivery device 70, in combination with Figure 9 As shown, when the rear release structure of the delivery device 70 releases the first wave 111 in the rear release state, the soft covering 122 facilitates the free reverse rotation of the first wave 111 into the lumen of the covered stent 12, as shown in Figure 6 In combination with Figures 9-11 As shown, the first wave 111 and the second wave 1211 are prevented from interfering with each other in the axial direction, which causes difficulty in reverse rotation.

[0063] In this embodiment, the covered stent 12 is in a hollow tube in a natural state, as shown in Figures 7-8 As shown, the radius of the tube of the covered stent 12 is defined as R, and the wave height of the first wave 111 is defined as H, and H satisfies: H≤ R. The wave height can be prevented from interfering with each other during the reverse rotation of the first wave 111 into the covered stent 12 (natural state), which causes reverse rotation failure. After the stent is reversed into the covered stent 12, it is tightly attached to the proximal covering segment of the covered stent 12, which can make the proximal covering segment more closely fit the blood vessel and reduce I-type endoleak. In order to achieve the best effect of reducing I-type endoleak, the wave heights of the first wave 111 and the second wave 1211 are high and the wave periods are the same, and the wave trough of the first wave 111 and the wave trough of the second wave 1211 are on the same straight line in the axial direction, which is beneficial to the intersection of the wave bars of the first wave 111 and the second wave 1211 after the reverse rotation of the first wave 111, and the first wave 111 can support the covering 122 in the gap of the second wave 1211 (the covering not supported by the second wave 1211), so that the covering 122 at the proximal end of the lumen stent 10 is more closely fit to the blood vessel, and the double-layer intersecting wave structure makes the covering 122 at the proximal end of the lumen stent 10 better sealed after being fit to the blood vessel, reducing endoleak and stent migration, as shown in Figure 6 and Figure 12 As shown. At the same time, during the compression and loading of the lumen stent 10 into the sheath tube 73, the first wave 111 is in a reverse connection state in a non-natural state (as shown in Figure 7 and Figure 9As shown), the area where the second wave ring 1211 is located will not increase its compression area. Therefore, after the lumen stent 10 provided in this embodiment is fully released, the first wave ring 111 (in this embodiment, the annular wave ring of the bare stent 11) will flip back into the covered stent 12 (the lumen stent 10 is in its natural state, such as...). Figure 6 As shown, this design prevents interference with vascular branches after the bare stent 11 is fully deployed. This avoids the bare stent 11 blocking the entrance to the branch artery, thus preventing impaired blood supply; it also prevents the bare stent 11 coil from reaching the interior of the branch vessel 53, thus avoiding branch vessel dissection. Without increasing the assembly volume of the stent 10, it also enhances the sealing effect at the proximal end of the stent 10, reducing endoleak and stent displacement.

[0064] In other embodiments, when the individual waves of the first wave loop 111 and the second wave loop 1211 are of equal height, and the wave heights and wave periods of the first wave loop 111 and the second wave loop 1211 are equal, the troughs of the first wave loop 111 and the crests of the second wave loop 1211 are not on the same straight line along the axial direction, such as... Figure 6 As shown, after the first wave coil 111 is flipped, the wave rod of the first wave coil 111 and the wave rod of the second wave coil 1211 can cross.

[0065] The process of flipping and connecting the bare stent 11 to the covered stent 12 includes: flipping the bare stent 11 to its natural state (e.g., ... Figure 6 The bare stent 11 of the lumen stent 10 (as shown) is flipped to the position as follows: Figure 7 After reaching the state shown, it is compressed radially and then loaded into the sheath 73 of the conveyor 70, as... Figure 9 As shown, the angle between the bare stent 11 at this time and the bare stent 11 in its natural state is approximately 180°. When the lumen stent 10 is transported using the conveyor 70, both the bare stent 11 and the covered stent 12 are in a compressed state. The complete release process of the lumen stent 10 provided in this embodiment includes, in sequence: compressed state, first release state, post-release state, and natural state.

[0066] In compressed state, such as Figure 9 As shown (in combination) Figure 7 The compressed lumen support 10 is loaded into the sheath 73 of the delivery unit 70. Because the bare support 11 and the coated support 12 are connected by an inverted connection, and the crest of the first wave 111 (as shown in the image)... Figure 7 The wave crest shown is hooked onto the hook structure 71 of the conveyor 70. The hook structure 71 maintains the first wave 111 of the bare support 11 in a flipped state relative to the coated support 12. Due to the spatial constraint of the sheath 73, the lumen support 10 in the compressed state (such as...) Figure 9 (As shown) relative to the lumen stent 10 in its natural state (e.g.) Figure 6As shown), the bare stent 11 will remain in a flipped connection with the covered stent 12. The covered stent 12 is compressed radially. After the lumen stent 10 is delivered to the implantation site in this state, the sheath 73 is withdrawn to release the covered stent 12.

[0067] like Figures 9-12 Combination Figures 6-7 As shown, the process from the compressed state to the first release state also includes retracting the sheath 73 to release the covered stent 12. This process involves retracting the sheath 73 in the opposite direction to the insertion direction (i.e., along the direction of blood flow), gradually releasing the luminal stent 10 from its proximal end to its distal end until the covered stent 12 is completely released, leaving only the bare stent 11 hooked onto the hook structure 71 of the delivery device 70. Figure 10 As shown. During the process of releasing the covered stent 12 by retracting the sheath 73, due to the backward frictional force between the sheath 73 and the covered stent 12 (in the direction of retracting the sheath 73), the first coil 111 of the bare stent 11 remains in a flipped state until the sheath 73 completely releases the covered stent 12. At this time, the bare stent 11 is still hooked on the hook structure 71, while the covered stent 12 expands and unfolds, adhering to the vessel wall and playing a certain role in fixation.

[0068] First release state: After the covered stent 12 is fully released from the sheath of the delivery device, it expands and adheres to the vessel wall (e.g., Figure 10 As shown, the first wave ring 111 of the bare stent is still hooked to the hook structure 71. The expanded stent 12 has a certain fixing effect on the wall. At this time, the sheath core assembly 72 can be moved backward, thereby driving the hook structure 71 on the sheath core assembly 72 to move towards the distal end of the lumen stent 10. Under the action of the hook structure 71, the first wave ring 111 of the bare stent can be flipped inward to the inside of the covered stent 12.

[0069] Post-release state: The state in which the hook assembly disengages the first wave coil 111 is the post-release state. In this embodiment, the first wave coil 111, driven by the hook structure 71, flips to an angle less than 90° with the first wave coil 111 in its natural state (in this embodiment, the bare support 11 in its natural state is in contact with the film 122). If the first wave coil 111 is not subjected to external force at this time, it has a tendency to flip back to its natural state (e.g., Figure 11 (As shown). Opening the anchor 712 allows the first wave ring 111 to disengage from the hook structure 71. Since it has a tendency to flip back to its natural state, the first wave ring 111 will flip back to its natural state.

[0070] Natural state: After the first wave 111 detaches from the hook structure 71 and flips back into the covered stent 12, the bare stent 11 is in its natural state. Both the covered stent 12 and the bare stent 11 adhere to the vessel wall. Figure 12as shown.

[0071] That is, the turning over of the bare stent 11 in the present embodiment is passive turning over from the first release state to the post-release state, and then disengaging from the hooking structure 71 and automatically turning over to the natural state.

[0072] In other embodiments, since the first wave coil 111 is connected to the film 122 segment near the proximal end of the covered stent 12 only in a small amount, so that the first wave coil 111 is mostly exposed outside the film 122, in order to enhance the connection strength of the first wave coil 111 and the covered stent 12, a polymer wire 13 can be arranged in the film 122, and the two ends of the polymer wire 13 are connected to the first wave coil 111 and the second wave coil 1211 respectively. In one embodiment, two layers of films are attached to cover the main stent 121, the polymer wire 13 is arranged in the two layers of films 122, and one end is connected to the wave valley of the first wave coil 111 (as shown in Figure 13 as shown), and the other end is connected to the wave peak of the second wave coil 1211 as shown in Figure 13 as shown. The number of polymer wires 13 can be the same as the number of wave periods.

[0073] The delivery system 100 provided in the present embodiment includes a delivery device 70 and a lumen stent 10 as described above, as shown in Figures 9-12 as shown. The delivery device 70 includes a sheath tube 73, a sheath core assembly 72, and a hooking structure 71, wherein the hooking function is formed by the cooperation of a guide head 711 and an anchor 712, and a receiving cavity for accommodating the lumen stent 10 is formed between the sheath tube 73 and the sheath core assembly 72. The sheath core assembly 72 includes an inner sheath core (not shown in the figure) and an outer sheath core 721, the inner sheath core is connected to the guide head 711, the outer sheath core 721 is connected to the anchor 712, and the outer sheath core 721 can move axially relative to the inner sheath core under the control of the handle, thereby driving the anchor 712 to close or move away from the bottom of the guide head 711, so as to realize the hooking or disengaging of the first wave coil 111 of the bare stent 11 from the hooking structure 71. Compared with the prior art delivery system, the interference of the bare stent 11 on the blood vessel branch after complete release can be prevented, that is, the bare stent 11 can be prevented from blocking the entrance of the branch artery, so as to avoid affecting the blood supply; and the bare stent 11 can also be prevented from being pressed against the inside of the branch blood vessel 53, so as to avoid causing the branch blood vessel to be sandwiched. While not increasing the assembly volume of the lumen stent 10, the sealing effect at the proximal end of the lumen stent 10 can also be enhanced, and the internal leakage and stent displacement can be reduced.

[0074] Embodiment 2

[0075] Embodiment 2 proposes another lumen stent 20 and delivery system, as shown in Figures 14-17As shown. The features of the lumen support 20 and delivery system in Embodiment 2 that are the same as or can be reused from those in Embodiment 1 will not be described again here. The main difference is that the lumen support 20 in Embodiment 2 also includes a foldable rod structure 23 that can be flipped and folded in half, through which the first wave coil 211 and the second wave coil 2211 are connected. The natural states of the foldable rod structure 23 and the bare support 21 are as follows... Figure 14 As shown, the folding rod structure 23 is in its natural folded state at this time. The first wave ring 211 and the second wave ring 2211 are both located in the region near the end of the lumen support 20. One end of the first wave ring 211 is connected to the membrane 222, and the other parts of the first wave ring 211 are attached to but not fixed to the membrane 222. This facilitates the lumen support 20 to flip out of the membrane support 22 with the first wave ring 211, and to be in the flipped-out form (i.e., when the bare support 21 and the membrane support 22 are in a flipped-out connected but uncompressed unfolded state, such as...). Figure 15 As shown, the bare support 21 at this time is at an angle of approximately 180° to the bare support 21 in its natural state, and is compressed and loaded into the sheath. The flipping fulcrum of the first wave coil 211 is the connection point between the first wave coil 211 and the coating.

[0076] One end of the folding rod structure 23 is fixedly connected to the wave rod of the first wave coil 211, and the other end is fixedly connected to the wave rod of the second wave coil 2211 that is closest to it. The folding rod structure 23 also includes a folding point F, such as... Figure 15 As shown, one end of the folding rod structure 23 is fixed to the midpoint of the wave rod of the first wave ring 211 (the midpoint of the wave rod between adjacent troughs and crests) or any position between the midpoint and the crest, so that when the folding rod structure 23 automatically folds back to its natural state from the folded state with the folding point F as the fulcrum, the torque on the first wave ring 211 is relatively large (the fulcrum of the first wave ring 211 when it flips back to its natural state is as follows). Figure 15 The trough of the first wave circle 211 shown.

[0077] The folding rod structure 23 also includes a folding part 231, a fixing part 232, and a resiliently foldable connecting point. One end of the folding part 231 is fixed to the wave rod of the first wave ring 211 via a cylinder sleeve, and the other end is connected to the fixing part 232 via the resiliently foldable connecting point, which is the folding point F, and the folding point F is inside the film-coated support 22. One end of the fixing part 232 is fixed to the wave rod of the second wave ring 2211 via a cylinder sleeve, and the fixing part 232 is fixed inside the film-coated 222, while the other end is fixed to the folding part 231. The folding rod structure 23 in its natural state is as follows... Figure 14 As shown, the folding part 231 and the fixing part 232 are folded together at the folding point F and integrally formed; in the flipped state, as Figure 15 As shown, the fold 231 folds outward toward the film support 22 with the fold point F as the fulcrum, and has a tendency to fold back to its natural state.

[0078] In this embodiment, the folding rod structure 23 is made of a metallic elastic material (e.g., nickel-titanium alloy). The folding rod structure 23 is fixed to the first wave coil 211 and the second wave coil 2211 by clamping with a cylinder liner or by welding binding wire.

[0079] One or more foldable folding rod structures 23 can be provided. The folding rod structure 23 should provide enough force to drive the first wave coil 211 back to its natural state when it folds back from its flipped state. The foldable folding rod structure 23 is S-shaped with smooth transitions at both ends for easy connection with the wave rods on the wave coil. In other embodiments, an even number of folding rod structures 23 are provided, and each pair is circumferentially symmetrical relative to the axis of the coating support 22, ensuring balanced force distribution during the process of the first wave coil 211 folding back to its natural state.

[0080] The lumen stent 20 provided in this embodiment is Figure 15 The bare stent 21 is compressed and loaded into the sheath of the delivery device in the flipped state shown. At this time, the angle between the bare stent 21 and the bare stent in its natural state is approximately 180°. When the lumen stent 20 is delivered using the delivery device 70, both the bare stent 21 and the covered stent 22 are in a compressed state. The complete release process of the lumen stent 20 provided in this embodiment includes, in sequence, a compressed state, a post-release state, and a natural state. The process from the compressed state to the post-release state also includes retracting the sheath to release the covered stent (the compressed state can be referred to...). Figure 10 ).

[0081] The compression state in this embodiment can be referred to in Embodiment 1, and will not be repeated here. The main difference between the release process of the bare support 21 and Embodiment 1 is that it does not include the process of using the external force of the hook structure 71 of the conveyor to move the first wave ring 211 of the bare support 21 from the first release state to the subsequent release state. That is, in this embodiment, when the first wave ring 211 is in the first release state as in Embodiment 1, the hook structure 71 can be controlled to make the first wave ring 211 disengage from the anchor 712 to achieve subsequent release. In other words, the subsequent release state coincides with the first release state. The flipping of the bare support 21 in this embodiment is an active flipping: after being directly released from the first release state, it automatically flips back to its natural state.

[0082] like Figure 16 As shown, the luminal stent 20 is in the post-release state. Before this, the luminal stent 20 is in the self-compressed state. The sheath 73 is retracted to release the covered stent 22, so that the covered stent 22 fits the blood vessel.

[0083] After the release state, the inner and outer sheath cores of the sheath core assembly 72 are controlled to disengage the first wave coil 211 from the anchor 712. Since both the first wave coil 211 and the folding rod structure 23 are in a flipped state, and the folding rod structure 23 is a single-rod structure, the folding rod structure 23 has a strong tendency to fold back to its natural state from its flipped state. This can cause the first wave coil 211 to flip back to its natural state (i.e., be stored inside the film-coated bracket 22 and attached to it). Figure 17 As shown. The luminal stent 20 provided in this embodiment can prevent interference with vascular branches after the bare stent 21 is fully deployed. This avoids the bare stent 21 blocking the entrance to the branch artery, thus preventing blood supply disruption; it also prevents the bare stent 21 from pressing against the inside of the branch vessel 53, thus preventing branch vessel dissection. Without increasing the assembly volume of the luminal stent 10, it can automatically flip back into the covered stent 22 after post-deployment, enhancing the sealing effect at the proximal end of the luminal stent 20 and reducing endoleak and stent displacement. The automatic flipping of the bare stent into the covered stent, without the need for external force in the post-deployment state, reduces the risk of stent displacement or shortening that might occur due to the need for external force provided by the delivery device's hook structure, compared to passive flipping.

[0084] Example 3

[0085] Example 3 proposes another type of lumen support 30 and delivery system, such as Figures 18-19 As shown. The features of the lumen stent 30 and delivery system in Embodiment 3 that are the same as or can be reused from Embodiment 1 will not be repeated here. The main difference is that the bare stent 31 of the lumen stent 30 in Embodiment 3 includes a first wave 311 located within the covered stent in its natural state. The covered area extending axially from the trough of the second wave to the proximal end of the covered stent 32 is defined as the first region M. The first wave 311 in its natural state includes a fixed wave 3111 as a fixing part and a reversible non-fixed wave. The fixing part includes at least one fixed wave, and the fixed wave 3111 is fixed within the first region. The non-fixed wave can be flipped relative to the fixed wave 3111 to form a reversible wave 3112. In the flipped state, the reversible non-fixed wave flips out of the covered stent 32 to form the reversible wave 3112. The reversible wave serves as the reversible part, and the reversible part includes at least one reversible wave. The covered area extending axially from the crest of the second wave 3211 to the proximal end of the covered stent 32 is defined as the second region N, and the fulcrum for the reversible non-fixed wave's flipping is located within the second region, as shown below. Figure 18 As shown.

[0086] In this embodiment, there are four reversible, non-fixed waves (defined as a wave of one cycle), including two adjacent waves and two other waves that are circumferentially symmetrical about the two adjacent waves along the axial direction of the covering support 32. Since four waves flip approximately 180° (e.g., Figure 18(As shown) compressed into the sheath. When the lumen support 30 is released to the post-release state, the four overturning waves are in the following position: Figure 19 In the flipped state shown, if the hooking action of the hook structure 71 is removed, with the fixed wave 3111 fixed to the membrane 322, the flipped wave 3112, due to the flipping deformation between itself and the adjacent fixed wave 3111, has a strong tendency to flip back to its natural state in the first wave ring 311. Therefore, when Figure 19 In the post-release state, the hook structure 71 is controlled to cause the flip wave 3112 to detach from the anchor 712, and the flip wave flips back into the film support 32 and attaches to the film 322.

[0087] When the flipped wave 3112 and the fixed wave 3111 are in the unfolded state of flipped connection, such as Figure 18 As shown, the flip wave 3112 and the second wave ring 3211 are spaced apart axially. The trough of the flip wave 3112 is located in the second region, and the axial distance D1 (refer to Embodiment 1) between the trough of the flip wave and the peak of the second wave ring satisfies: 0mm < D1 ≤ 3mm. The wave height of the flip wave is less than or equal to the tube radius of the covered stent, so that the flip wave can smoothly flip back into the covered stent.

[0088] In this implementation, the flipping wave 3112, which serves as the flipping part, is in a flipping state (e.g., ...). Figure 18 As shown, the trough of the wave 3112 and the crest of the second wave ring 3211 are not on the same straight line along the axial direction, while the trough of the flipped wave 3112 and the trough of the second wave ring 3211 are on the same straight line along the axial direction. The wave height of the flipped wave 3112 is equal to the wave height of the fixed wave 3111 and the wave height of the second wave ring 3211, so that the wave rod of the flipped wave 3112 can cross and support the coating when it flips back into the coating support 32.

[0089] The luminal stent 30 provided in this embodiment can prevent interference with vascular branches after the bare stent 31 is fully deployed. This avoids the bare stent 31 blocking the entrance to the branch artery, thus preventing impaired blood supply; it also prevents the bare stent 31 from pressing against the inside of the branch vessel 53, thus preventing branch vessel dissection. Furthermore, it can automatically flip back into the covered stent 32 after post-deployment, enhancing the sealing effect at the proximal end of the luminal stent 30 and reducing endoleak and stent displacement. The automatic flipping wave into the covered stent, without the need for external force in the post-deployment state, reduces the risk of stent displacement or shortening that might occur due to the need for external force provided by the delivery device's hook structure, compared to passive flipping.

[0090] The state of the first wave 311 of the bare stent 31 returning to the covered stent 32 after being released at the implantation site is similar to that of the first wave 311 of the bare stent 31. Figure 12The difference between the two states shown is that in the present embodiment, the first wave 311 has a partial number of waves fixed to the covered stent 32 to connect with the covered stent 32, instead of only the troughs of the first wave 311 connecting with the covered stent 32 in the flipped state in the first embodiment.

[0091] Embodiment 4

[0092] Embodiment 4 proposes another lumen stent 40 and delivery system, as shown in Figures 20-21 The lumen stent 40 and delivery system of the fourth embodiment are the same as or can use the features of the first embodiment, and the main difference is that the first wave 411 of the bare stent 41 of the lumen stent 40 of the fourth embodiment comprises at least one single bent wave, instead of a complete wave-shaped ring, and the bent wave is inside the covered stent 42 in the natural state.

[0093] As shown in Figure 20 The bent wave comprises a connecting portion 4112 and a bent portion 4111, the connecting portion 4112 is attached to the covered stent 42, and one end of the connecting portion 4112 is fixed to the wave rod of the second wave 4211 through a sleeve 4113 or a welding binding wire, and the other end of the connecting portion 4112 is connected to the bent portion 4111. One single bent wave comprises two connecting portions 4112 and one bent portion 4111, the bent portion 4111 comprises the peak of the bent wave, and the bent portion 4111 can be integrally formed with the connecting portion 4112. The plane where the bent portion 4111 is located is perpendicular to the plane where the two connecting portions 4112 are located, as shown in Figure 20 α = 90°.

[0094] In the present embodiment, the bent portion 4111 is parallel to the plane where the two connecting portions 4112 are located after being flipped by 90°, and is compressed in this flipped state to be loaded into the sheath of the delivery device 70. The fulcrum of the bent portion 4111 is the connection between the bent portion 4111 and the connecting portion 4112, and the connection is located in the area inside the covered stent 42, so that after the lumen stent 40 is released at the implantation site, the bent portion 4111 of the bent wave flips back to the natural state, and the bent portion 4111 does not protrude out of the covered stent 42; when the bent portion 4111 of the bent wave is flipped by 90° relative to the connecting portion 4112, most of the bent portion 4111 protrudes out of the covered stent 42, so as to be hooked on the hooking structure 71 of the delivery device 70 after being flipped by 90°, and to facilitate subsequent post-release, as shown in Figure 21 .

[0095] In the present embodiment, since the two connecting portions serve as fixed portions and the bent portion serves as a flipped portion, when entering the post-release state, as shown in Figure 21As shown, the bending part of the bending wave is in the flip state and has the resilience towards the natural state, at this time the control hooking structure 71 makes the bending part 4111 of the bending wave flip back to the natural state with the joint between the bending part 4111 and the connecting part 4112 as the fulcrum. The lumen stent 40 provided by the embodiment can prevent the interference of the bare stent 41 to the blood vessel branch after the complete release of the bare stent 41, that is, can avoid the bare stent 41 blocking the entrance of the branch artery, thereby avoiding affecting the blood supply; and can also avoid the top of the bare stent 41 wave coil reaching the inside of the branch blood vessel 53, thereby avoiding causing the branch blood vessel dissection. The bending part automatically flips into the covered stent, and in the post-release state, no external force is needed, and compared with passive flipping, the risk of displacement or shortening of the blood vessel stent caused by the need to rely on the hooking structure of the delivery device to provide external force can be reduced.

[0096] The angle α of the bending part 4111 and the connecting part 4112 of the lumen stent 40 provided by the embodiment in the natural state ranges from [0°, 90°], and the corresponding recovery force in the flip state is relatively large (corresponding to the bending part 4111 and the connecting part 4112 in the flip state, the angle relative to the natural state needs to be flipped is large); of course, in other embodiments, the angle range α of the bending part 4111 and the connecting part 4112 can also be (90°, 180°), as long as it is guaranteed that it does not expose to the covered stent 42 in the natural state and is easy to hook and post-release of the hooking structure 71. In the flip state of the compression state, the flip angle of the bending part 4111 relative to the connecting part 4112 is 180-α, and the flip angle in the post-release state is less than 180-α, that is, the larger the α angle in the natural state, the smaller the flip deformation angle in the flip state or the post-release state, and the smaller the recovery force; the smaller the α angle in the natural state, the larger the flip deformation angle in the flip state or the post-release state, and the larger the recovery force.

[0097] The lumen stent 40 provided by the embodiment includes two bending waves that are circumferentially symmetrical along the axis direction of the covered stent, and α = 90°, which can guarantee the balance and size of the recovery force, and can also guarantee the number of bending waves flipped to the natural state to be small. Although the bending wave does not adhere to the covered stent 42, it will not have a large impact on blood flow, and reducing the flip angle can prevent the unreliability caused by the deformation of the joint between the bending part 4111 and the connecting part 4112 being too large (for example, it can cause plastic deformation or fracture of the single-wave rod).

[0098] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0099] The above embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A tubular stent, comprising a covered stent and a bare stent connected to the proximal end of the covered stent, wherein during delivery, the tubular stent comprises a covered stent and a bare stent connected to the proximal end of the covered stent, characterized in that, The bare stent comprises a first wave ring, which is reversely connected with the covered stent through a folding rod structure, so that the bare stent is automatically reversed into the covered stent under the driving of the folding rod structure after the bare stent is released from the delivery device; The folding rod structure comprises a folding part, a fixed part and an elastically foldable connecting part, and the folding part of the folding rod structure in the reversed state has a rebound force for folding towards the fixed part with the connecting part as a folding point.

2. The intraluminal stent of claim 1, wherein, When the lumen stent is delivered, the bare stent is in a compressed state, and the process of reversing the bare stent from the compressed state into the covered stent comprises a compressed state, a released state and a natural state in sequence.

3. The intraluminal stent of claim 1, wherein One end of the folding rod structure is connected with the first wave ring, and the other end is connected with the covered stent, and the folding point of the folding rod is located in the covered stent.

4. The intraluminal stent of claim 1, wherein, The folding rod structure is made of a metal elastic material.

5. The intraluminal stent of claim 1, wherein, The folding rod structure is integrally formed.

6. The intraluminal stent of claim 1, wherein, The folding rod structure is provided in pairs and is circularly symmetrical with respect to the axial direction of the covered stent.

7. The intraluminal stent of claim 2, wherein, The covered stent comprises a main stent and a covering film covering the main stent, the main stent comprises a plurality of wave rings arranged and spaced along the axial direction, and the wave ring close to the bare stent is a second wave ring, and when the bare stent is in the compressed state, the first wave ring and the second wave ring are arranged and spaced along the axial direction.

8. The intraluminal stent of claim 1, wherein, The covered stent is a hollow tube in the natural state, the radius of the tube of the covered stent is defined as R, and the wave height of the first wave ring is defined as H, and H satisfies: H≤R.

9. The intraluminal stent of claim 7, wherein, The axial distance D between the wave trough of the first wave ring and the wave peak of the second wave ring satisfies: 0<D≤3mm.

10. The intraluminal stent of claim 7, wherein, The wave trough of the first wave ring and the wave peak of the second wave ring are fixedly connected by a polymer line.

11. The intraluminal stent of claim 7, wherein, The wave trough of the first wave ring and the wave peak of the second wave ring are not on the same straight line along the axial direction.

12. The intraluminal stent of claim 11, wherein, The wave trough of the first wave ring and the wave trough of the second wave ring are on the same straight line along the axial direction.

13. The intraluminal stent of claim 12, wherein, The wave height of the first wave ring and the wave height of the second wave ring are high, and the wave periods are the same.

14. A delivery system characterized by, The lumen stent comprises a delivery device and a lumen stent according to any one of claims 1-13, the delivery device comprises a sheath tube and a sheath core assembly, and a receiving cavity for receiving the lumen stent is formed between the sheath tube and the sheath core assembly.

Images