Covered stent

Abstract

This invention provides a covered stent, comprising a main stent and a restraint assembly. The main stent sequentially includes a proximal segment, a middle segment, and a distal segment along the axial direction. The side of the middle segment is recessed towards the inner cavity of the main stent to form a groove. The middle segment includes at least one intermediate wavelet, which includes multiple first low waves and at least one first high wavelet, wherein at least one first high wavelet crosses both sides of one of the width directions of the groove edge. The restraint assembly is disposed on the main stent and has a restrained state and a released state. When in the restrained state, the restraint assembly radially restrains at least one region of the middle segment. When in the released state, the restraint assembly releases the restraint on the middle segment. The covered stent provided by this invention can reduce the risk of branch port obstruction and better maintain the morphology of the groove edge.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more particularly to a covered stent. Background Technology

[0002] Aortic aneurysm and aortic dissection are serious diseases that threaten human life. If left untreated, the aortic aneurysm and dissection will continue to grow and eventually rupture, causing serious complications and death. With the increasing number of patients with hypertension, hyperlipidemia and hyperglycemia, the incidence of aortic aneurysm and aortic dissection is also increasing significantly.

[0003] Traditional open surgery for aortic aneurysms and aortic dissections is highly invasive, has a high mortality rate, long operation time, high postoperative complication rate, and is very difficult. Endovascular surgery, on the other hand, is less invasive, has fewer postoperative complications, shorter operation time, and is less difficult, and has gradually become the main method for treating aortic aneurysms and aortic dissections. Endovascular surgery involves implanting a stent into the aorta using a delivery device, isolating the vascular lesion outside the stent and restricting blood flow through the stent, thereby protecting the blood vessel.

[0004] When an aneurysm or arterial dissection is located on the aorta near a branch vessel, the implanted stent may obstruct the opening of the branch vessel, thus hindering blood flow. One current solution is to create grooves in the stent, with branch openings on the inner wall of these grooves communicating with the stent's lumen. These grooves correspond to the branch vessels, ensuring that blood from the aorta flows through them to the branch vessels. However, after stent implantation, if the vessel lumen is narrow, it can compress the space in the grooves, obstructing the entry of guidewires or external branch stents into the branch openings. Summary of the Invention

[0005] To address the aforementioned shortcomings, this invention provides a film-coated stent.

[0006] This invention provides a covered stent, comprising: a main stent, the main stent comprising a proximal segment, a middle segment and a distal segment in sequence along the axial direction, the side of the middle segment being recessed toward the inner cavity of the main stent to form a groove, the middle segment comprising at least one middle wave ring, the middle wave ring comprising a plurality of first low waves and at least one first high wave, wherein at least one of the first high waves crosses both sides of the edge of one of the width directions of the groove;

[0007] A restraint assembly is provided on the main support and has a restrained state and a released state. When in the restrained state, the restraint assembly radially restrains at least one area of ​​the intermediate segment. When in the released state, the restraint assembly releases the restraint on the intermediate segment.

[0008] This invention provides a covered stent, comprising:

[0009] The main support has a groove, and the bottom of the groove includes a bottom covering film;

[0010] A support structure, including a bottom support member, the bottom support member being used to support the bottom covering film;

[0011] The bottom support includes two support portions arranged radially spaced apart, and the bottom film includes a blank bottom film segment located radially between the two support portions; the two support portions are movable relative to each other so that the bottom film segment can deform.

[0012] This invention also provides a covered stent, comprising:

[0013] The main support frame has grooves;

[0014] The limiting structure includes a limiting member and a constraint member, wherein the limiting member and the constraint member are detachably connected; when the covered support is in a first state, the limiting member can, under the constraint of the constraint member, limit a target segment of the sheath core in the radial direction, the target segment being an axial segment of the sheath core, the target segment being located in the axial region between the proximal and distal ends of the groove in the first state; when the covered support is in a second state, the constraint member can disengage from the limiting member, thereby releasing the limiting member from restricting the target segment.

[0015] This invention also provides a covered stent, comprising:

[0016] The main support frame has grooves;

[0017] Two inner branch supports are arranged radially side by side within the main support. Each inner branch support has a branch opening facing the groove, and the branch opening communicates with the groove.

[0018] A limiting channel, formed between the two inner branch supports, is used to limit the sheath core radially.

[0019] The covered stent provided in this embodiment of the invention, due to the inclusion of a restraint component, remains restrained after the covered stent is released from the sheath during implantation. This component maintains radial restraint on at least one region of the intermediate segment, creating a gap between the vessel wall and at least a portion of the intermediate segment. This reduces the risk of branch orifice blockage and allows the guidewire and external branch stent to smoothly enter the branch orifice through this gap. Furthermore, since at least one first high wave crosses both sides of one of the width directions of the groove, it helps to better maintain the shape of the groove's width direction edge and its two sides. This reduces the uniformity of stress on both sides of the groove's width direction edge, making it less prone to wrinkling and thrombosis after implantation.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of the present invention. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the implantation state of the covered stent provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention;

[0024] Figure 3 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0025] Figure 4 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention;

[0027] Figure 6 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention, wherein the sheath core passes through the film-coated stent;

[0030] Figure 9 This is a partial structural schematic diagram of a film-coated support provided in an embodiment of the present invention, showing the bottom film and support structure;

[0031] Figure 10 This is a cross-sectional schematic diagram of a film-coated support provided in an embodiment of the present invention, which shows the limiting groove;

[0032] Figure 11 This is a partial structural schematic diagram of a film-coated support provided in an embodiment of the present invention, showing the bottom film and support structure;

[0033] Figure 12(A) is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0034] Figure 12(B) is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0035] Figure 13 This is a partial structural schematic diagram of a support structure provided in an embodiment of the present invention;

[0036] Figure 14 This is a partial structural schematic diagram of the bottom support member provided in an embodiment of the present invention;

[0037] Figure 15 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention, wherein the sheath core passes through the film-coated stent;

[0038] Figure 16 yes Figure 15 A partial structural diagram;

[0039] Figure 17(A) is Figure 15 A partial structural diagram;

[0040] Figure 17(B) is a schematic diagram of the connection between the limiting member and the outer sheath of the conveyor according to an embodiment of the present invention;

[0041] Figure 18 This is a schematic diagram of the structure of a limiting member provided in an embodiment of the present invention;

[0042] Figure 19 This is a schematic diagram of the structure of the first limiting part provided in an embodiment of the present invention;

[0043] Figure 20(A) is a schematic diagram of the structure of the second limiting part provided in an embodiment of the present invention;

[0044] Figure 20(B) is a schematic diagram of the structure of the second limiting part provided in an embodiment of the present invention;

[0045] Figure 21 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention, wherein the sheath core passes through the film-coated stent;

[0046] Figure 22 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0047] Figure 23 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0048] Figure 24 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0049] Figure 25 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0050] Figure 26 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0051] Figure 27 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0052] Figure 28 This is a partial structural schematic diagram of a film-covered stent provided in an embodiment of the present invention, which shows the limiting channel and the end support member;

[0053] Figure 29 This is a partial structural schematic diagram of a film-covered stent provided in an embodiment of the present invention, which shows the limiting channel and the end support member;

[0054] Figure 30 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0055] Figure 31 This is a partial structural side view of a film-coated stent provided in an embodiment of the present invention;

[0056] Figure 32 This is a planar unfolded schematic diagram of an intermediate wave loop provided in an embodiment of the present invention;

[0057] Figure 33 This is a planar unfolded schematic diagram of the main wave loop provided in an embodiment of the present invention;

[0058] Figure 34 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0059] Figure 35 This is a schematic diagram of the planar unfolding of a non-closed wave loop provided in an embodiment of the present invention;

[0060] Figure 36 This is a partial structural diagram of the film-coated stent provided in an embodiment of the present invention when the restraint component is in a restrained state;

[0061] Figure 37 This is a schematic diagram of the radially limiting sheath core of the easy-to-retract portion provided in an embodiment of the present invention;

[0062] Figure 38 This is a schematic diagram of the planar unfolding of a closed wave loop provided in an embodiment of the present invention. Detailed Implementation

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0065] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0066] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0067] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0068] For ease of description, the terms "proximal" and "distal" are used here as conventional terms in the field of interventional medicine. Specifically, "distal" refers to the end from which blood flows out, and "proximal" refers to the end from which blood flows in. For example, after a stent is implanted into the lumen, blood flows from the proximal end of the stent toward the distal end. "Axial" refers to its length direction, or the direction in which the interventional device is advanced and de-escalated. "Radial" refers to the direction perpendicular to the "axial" direction.

[0069] Taking blood vessels as an example to illustrate the lumen, the blood vessel may include at least one of the following: aortic arch, thoracic aorta, abdominal aorta, etc. Those skilled in the art should understand that the use of blood vessels as an example is merely illustrative and not intended to limit the invention. The solutions of the present invention are applicable to various human lumens or other biological lumens. Human lumens may include, for example, the lumen of the digestive tract or blood vessels. Various improvements and modifications based on the teachings of this invention are within the protection scope of this invention.

[0070] In this embodiment of the invention, the "wave loop" includes multiple waves, and the "waveform unit" includes at least one wave. The "wave loop" (also referred to as a wave-shaped ring structure) is a closed or open wave-shaped ring structure. Both the wave loop and the waveform unit can be disposed on the inner and / or outer wall of the membrane of the covered stent. The wave loop or waveform unit can be connected to the membrane by at least one of the following connection methods: suturing, bonding, heat fusion, etc. The "wave loop" and "waveform unit" are woven or cut from metallic elastic materials, polymer materials, or other biocompatible elastic materials. The metallic elastic material includes known materials used in implanted medical devices or combinations of various biocompatible materials, such as alloys of two or more single metals selected from cobalt, chromium, nickel, titanium, magnesium, and iron, as well as 316L stainless steel, nickel-titanium-tantalum alloys, etc., or other biocompatible metallic elastic materials. The polymer material includes biocompatible materials such as polylactic acid. Both the "wave loop" and "waveform unit" possess radial expansion capability, allowing them to radially contract under external force. After the external force is removed, they self-expand or mechanically expand (e.g., through balloon inflation) to return to and maintain their initial shape. Thus, once implanted into a lumen, they can adhere tightly to the inner wall of the lumen through their radial support force. The waveform of the wave in the "wave loop" and "waveform unit" is unrestricted, including Z-shaped waves, M-shaped waves, V-shaped waves, sine waves, etc. Both the "wave loop" and "waveform unit" include wave crests, wave troughs, and wave rods connecting adjacent crests and troughs. A single vertex (wave crest or trough) and the two wave rods connected to that vertex form a wave.

[0071] In one embodiment of the present invention, the "support structure" can be connected to the bottom membrane via at least one of the following connection methods: suturing, bonding, heat fusion, etc. The support structure can be disposed on the inner wall and / or outer wall of the bottom membrane of the membrane-covered stent. The support structure may include wave-shaped units and / or mesh structures, etc. The support structure is woven or cut from a metallic elastic material, a polymer material, or other biocompatible elastic materials. The metallic elastic material includes known materials used in implanted medical devices or combinations of various biocompatible materials, such as alloys of two or more single metals selected from cobalt, chromium, nickel, titanium, magnesium, and iron, as well as 316L stainless steel, nickel-titanium-tantalum alloys, etc., or other biocompatible metallic elastic materials. The polymer material includes biocompatible materials such as polylactic acid.

[0072] The "coating" in this embodiment of the invention can isolate liquids to a certain extent, and it can be made of at least one of the following polymer materials with good biocompatibility: polytetrafluoroethylene (PTFE) and polyethylene terephthalate (PET).

[0073] Please see Figure 1 This invention provides a covered stent 100 for implantation into a target cavity. The target cavity can be any cavity within a living organism, and this invention does not limit the type of target cavity. For ease of understanding, the aortic arch 300 is used as an example of the target cavity. (Refer to...) Figure 1 The aortic arch 300 is connected to three branch vessels 200, which are located on the greater curvature side of the aortic arch 300. Blood flows from the aortic arch 300 to the branch vessels 200. An aneurysm 400 is formed on the lesser curvature side of the aortic arch 300 (this is for illustrative purposes only; in other embodiments, the aneurysm 400 may be located at other locations within the aortic arch 300). By implanting the covered stent 100 into the aortic arch 300 to isolate the aneurysm 400, the blood flowing within the covered stent 100 cannot come into contact with the aneurysm 400, ultimately achieving the goal of treating the aneurysm 400. An external branch stent 500 can also be implanted into the three branch vessels 200. This external branch stent 500 can be connected to the covered stent 100, allowing blood from the covered stent 100 to enter the branch vessels 200 through the external branch stent 500.

[0074] Please see Figure 1 and Figure 2In some embodiments, the covered stent 100 is generally a hollow tubular structure with openings at both ends, and the covered stent 100 includes a main stent 10. Exemplarily, the main stent 10 includes a main cover 11 and a stent body 12. The stent body 12 may be disposed on the inner surface and / or outer surface of the main cover 11. The main cover 11 may completely cover the stent body 12 or partially cover the stent body 12. Exemplarily, the stent body 12 includes at least one supporting corrugated coil for supporting the main cover 11.

[0075] Exemplarily, the main body covering 11 can be a single-layer structure or a multi-layer structure, without limitation. The main body covering 11 may be made of at least one of the following materials: polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), or other polymeric materials with good biocompatibility. The main body covering 11 can be fixed to the inner and / or outer surface of the stent body 12 by means of suturing, bonding, heat fusion, etc., to achieve functions such as reconstructing fluid channels and isolating diseased areas of blood vessels.

[0076] Please see Figure 1 and Figure 2 In some embodiments, the main support 10 can be divided axially into a distal segment 1, a proximal segment 2, and an intermediate segment 3, with the intermediate segment 3 located between the proximal segment 2 and the distal segment 1. The proximal segment 2 includes a tubular proximal support 2a and a proximal main body covering 11a, which can be applied to the inner and / or outer surfaces of the proximal support 2a by methods such as sewing, bonding, or heat fusion. The proximal support 2a includes a plurality of axially spaced main body corrugations 101. The distal segment 1 includes a tubular distal support 1a and a distal main body covering 11b, which can also be applied to the inner and / or outer surfaces of the distal support 1a by methods such as sewing, bonding, or heat fusion. The intermediate segment 3 includes an intermediate main body covering 11c and an intermediate support 3a. The intermediate support 3a includes multiple axially spaced arc-shaped wave units. The intermediate main body covering 11c can be applied to the inner and / or outer surfaces of the intermediate support 3a by methods such as sewing, bonding, or heat fusion. The inner cavity formed by the intermediate main body covering 11c is connected to the inner cavity formed by the proximal main body covering 11a and the inner cavity formed by the distal main body covering 11b.

[0077] Please also refer to Figure 2 and Figure 3In some embodiments, the main support 10 is provided with a groove 5. Exemplarily, the main support 10 has a groove 5 recessed on the side of the intermediate section 3 towards its inner cavity. The groove 5 includes a groove bottom 51 and a groove opening 52, wherein the groove opening 52 and the groove bottom 51 are radially opposite to each other on the film-coated support 100, and the groove opening 52 faces radially outward from the film-coated support 100, while the groove bottom 51 is generally closer to the inner cavity of the main support 10 than the groove opening 52. In some embodiments, the edge of the groove 5 formed on the main film 11 is approximately rectangular, that is, when the main film 11 is unfolded along a generatrix that does not pass through the groove 5, the groove 5 is approximately rectangular. The groove 5 includes a first edge 531, a second edge 532, a third edge 533, and a fourth edge 534. In this design, the first edge 531 and the second edge 532 are radially opposite to each other (or, opposite to each other in the width direction of the groove 5) and are aligned with the length extension direction of the coating support 100. The third edge 533 and the fourth edge 534 are axially opposite to each other and are closer to the end of the coating support 100 than the first edge 531 and the second edge 532. It is understood that in other embodiments, the groove 5 can also be of other shapes, as long as the first edge 531 and the second edge 532 extend approximately along the length extension direction of the coating support 100, for example, at a certain angle to the length extension direction of the coating support 100 (e.g., the groove 5 is trapezoidal), or the first edge 531 and the second edge 532 are arc-shaped (e.g., the groove 5 is similar to an ellipse). The present invention does not limit the specific shape of the groove 5. In other embodiments, the groove 5 can also be an annular recessed structure surrounding the main support 10. It is also understood that the groove 5 is located between the proximal and distal ends of the covered stent 100. The groove 5 can be closer to the proximal end of the covered stent 100, or closer to the distal end of the covered stent 100, or the distance from the proximal end of the covered stent 100 and the distance from the distal end of the covered stent 100 can be equal.

[0078] Please refer to Figure 2 and Figure 3In some embodiments, the covered stent 100 further includes an inner branch stent 8, which comprises a tubular branched covering 801. The number of inner branch stents 8 can be designed according to actual needs, such as one, two, three, or more. At least one inner branch stent 8 is located on one axial side of the groove 5. In some embodiments, multiple inner branch stents 8 are provided, located in the inner cavity of the main stent 10, and respectively located on the proximal side and the distal side of the groove 5. For example, the inner branch stent 8 is located within the main stent 10, connected to the inner wall of the main stent 10, and extends along the length of the main stent 10. The inner cavity of the inner branch stent 8 communicates with the inner cavity of the main stent 10 and the groove 5. When an outer branch stent 500 needs to be implanted in the branch vessel 200, one end of the outer branch stent 500 can be sleeved with the inner branch stent 8, and the other end can extend through the groove 5 to the corresponding branch vessel 200, thereby forming a channel for blood to flow from the main stent 10 to the branch vessel 200. In this embodiment, branch support members may also be provided on the branch cover 801 of the inner branch support 8 to better maintain the shape of the inner branch support 8.

[0079] Please see Figure 2 In some embodiments, a mesh cover 61 is also provided on the outer side of the groove 5. The two sides of the mesh cover 61 in the circumferential direction are fixedly connected to the intermediate main body covering film 11c by means of stitching, bonding, heat fusion, etc., and at least a portion of the mesh cover 61 forms a gap (or void, cavity, interval) with the bottom 51 of the groove in the radial direction of the covering support 100. This gap can communicate with the inner cavity of the inner branch support 8. Exemplarily, the mesh cover 61 has an arc-shaped structure in the circumferential direction and is integrally woven into a mesh structure by braiding threads; the central angle corresponding to the projection of the mesh cover 61 on the radial plane is less than or equal to 120 degrees, so that the mesh cover 61 has good radial support force and ensures that there is sufficient space within the main support 10 for blood flow. In other embodiments, the above-mentioned mesh cover 61 may be omitted.

[0080] Please see Figure 3 and Figure 4For example, the bottom 51 of the groove includes a bottom covering 51a, which radially isolates the inner cavity of the main support 10 from the groove 5. For example, the first edge 531 and the second edge 532 of the groove 5 are respectively connected to the radial sides (also referred to as the sides in the width direction or the lateral sides) of the bottom covering 51a, and the third edge 533 and the fourth edge 534 of the groove 5 are respectively connected to the two axial ends of the bottom covering 51a. Each inner branch support 8 includes two branch openings, one of which is closer to the groove 5 than the other. The branch opening closer to the groove 5 is connected to the bottom 51 of the groove. The branch opening closer to the groove 5 includes an upper edge and a lower edge. Its upper edge is connected to the inner wall of the main support 10, and its lower edge can be sewn, bonded, or integrally formed with the bottom covering 51a.

[0081] Please see Figure 4 For example, the inner cavity of the proximal segment 2 of the main support 10 is provided with two inner branch supports 8, referred to as the first branch support 81 and the second branch support 82, respectively. The first branch support 81 and the second branch support 82 are arranged side by side in the radial direction on the proximal side of the groove 5. The first branch support 81 has a first branch opening 811 at the end closer to the groove 5 (i.e., the distal end of the first branch support 81), and the second branch support 82 has a second branch opening 821 at the end closer to the groove 5 (i.e., the distal end of the second branch support 82). Both the first branch opening 811 and the second branch opening 821 face the groove 5. The proximal ends of the first branch support 81 and the second branch support 82 are also provided with branch openings, and these branch openings all face the proximal end of the main support 10. The inner cavity of the distal segment 1 of the main support 10 is provided with one inner branch support 8, referred to as the third branch support 83, which is arranged on the distal side of the groove 5. The third branch bracket 83 has a third branch opening 831 at one end closer to the groove 5 (i.e., the proximal end of the third branch bracket 83), which faces the groove 5. The third branch bracket 83 also has a branch opening at its distal end, which faces the distal end of the main bracket 10.

[0082] Please see Figure 5In some embodiments, the covered stent 100 includes a first branch stent 81 and a second branch stent 82. The first branch stent 81 is disposed within the main stent 10 and communicates with the groove 5. The second branch stent 82 is connected to the main stent 10. One end of the second branch stent 82 is fixedly connected to and communicates with the main stent 10, while the other end is a free end with a branch opening. The free end of the second branch stent 82 is located outside the main stent 10 and is used for implantation into the branch vessel 200 or connection with other stents. The length extension direction of the second branch stent 82 intersects the axial direction; both the second branch stent 82 and the first branch stent 81 communicate with the inner lumen of the main stent 10. After the second branch stent 82 connects with the corresponding branch vessel 200, the groove 5 of the covered stent 100 aligns with the opening of the other branch vessels 200. This reduces the likelihood of the groove 5 being difficult to align with the corresponding branch vessel 200 due to deflection after the covered stent 100 is released. Furthermore, by placing the free end of the second branch stent 82 outside the main stent 10, the second branch stent 82 can be implanted into the branch vessel 200 without occupying space within the main stent 10's lumen, thus reducing the branch stent's encroachment on the main stent 10's lumen and increasing blood flow within the main stent 10's lumen. Compared to the first branch stent 81 and the second branch stent 82 being arranged radially side-by-side within the main stent 10, this embodiment places the free end of the second branch stent 82 outside the main stent 10, allowing the guidewire or external branch stent 500 to more accurately enter the corresponding branch stent, reducing the risk of the guidewire accidentally entering another branch stent. For example, the length extension direction of the second branch stent 82 is perpendicular to the axial direction.

[0083] Please see Figure 5 and Figure 6 In some embodiments, a first branch stent 81 is disposed within the main body stent 10 and communicates with the groove 5; a second branch stent 82 and the first branch stent 81 are disposed on one side of the axial direction of the groove 5. For example, the second branch stent 82 and the first branch stent 81 are disposed on the proximal end side of the groove 5, that is, both the second branch stent 82 and the first branch stent 81 are disposed on the proximal segment 2 of the main body stent 10. If the first branch stent 81 and the second branch stent 82 are arranged radially side-by-side on the proximal end side of the groove 5, the portion of the first branch stent 81 adjacent to the second branch stent 82, the portion of the second branch stent 82 adjacent to the first branch stent 81, and the inner wall of the main body stent 10 enclose a triangular region. This triangular region, when impacted by blood flow, will generate eddies, thereby affecting the flow direction of blood in the lumen of the main body stent 10. In this embodiment, the second branch support 82 is disposed outside the main support 10. The first branch support 81 and the second branch support 82 on the axial side of the groove 5 will not form a triangular region with the main support 10, thus reducing the impact on the blood flow direction in the inner cavity of the main support 10.

[0084] Please see Figure 5 In some embodiments, a guide segment 812 is formed at the distal end of the first branch stent 81, and the cross-sectional area of ​​the guide segment 812 extends from the proximal end to the distal end in a gradually increasing manner. The distal end of the first branch stent 81 is designed as a funnel-shaped guide segment 812, which can guide the insertion of the guide wire or the external branch stent 500.

[0085] Please see Figure 7 For example, the proximal end of the covered stent 100 is superior, and the distal end of the covered stent 100 is inferior. The second branch stent 82 is located to the right of the first branch stent 81 to better accommodate the three branch vessels 200 near the aortic arch 300. The second branch stent 82 is used for implantation. Figure 1 The leftmost branch vessel 200, after the second branch stent 82 is implanted, can play a certain role in positioning the covered stent 100, so that the groove 5 is aligned with the other two branch vessels 200. After the second branch stent 82 is implanted, it will not interfere with the implantation of the corresponding external branch stent 500 in the other two branch vessels 200, nor will it interfere with the connection between the external branch stent 500 and the corresponding internal branch stent 8.

[0086] In some embodiments, the first branch bracket 81 may also be disposed outside the main body bracket 10. For example, one end of the first branch bracket 81 is fixedly connected to and communicates with the main body bracket 10, and the other end is a free end with a branch opening. The free end of the first branch bracket 81 is disposed outside the main body bracket 10. The length extension direction of the first branch bracket 81 intersects with the axial direction. The first branch bracket 81 and the second branch bracket 82 are arranged along the axial direction of the groove bracket 100 and disposed on the proximal section 2. Specifically, the first branch stent 81 and the second branch stent 82 are used to connect two branch vessels 200, respectively. After the first branch stent 81 and the second branch stent 82 connect the corresponding branch vessels 200, the groove 5 of the covered stent 100 is aligned with the opening of the other branch vessels 200. This effectively reduces the possibility that the groove 5 is difficult to align with the corresponding branch vessel 200 due to the easy deflection of the covered stent 100 during release. In addition, by placing the branch openings of the free ends of the first branch stent 81 and the second branch stent 82 outside the main stent 10, the first branch stent 81 and the second branch stent 82 can be implanted into the branch vessels 200 without occupying the space of the inner cavity of the main stent 10, thereby further reducing the occupation of the inner cavity of the main stent by the branch stents and further increasing the blood flow in the inner cavity of the main stent 10. In other embodiments, the covered stent 100 also includes a third branch stent 83, which is disposed on the distal side of the groove 5. The third branch stent 83 is disposed outside the main stent 10; or, the third branch stent 83 is disposed inside the inner cavity of the main stent 10.

[0087] In other embodiments, the first branch support 81 and the second branch support 82 may also be located at the distal end of the groove 5, and the third branch support 83 may be located at the proximal end of the groove 5. In other embodiments, one or more of the first branch support 81, the second branch support 82, and the third branch support 83 may be omitted.

[0088] For example, each branch support has an annular support (not shown) at its edge to better maintain the shape of the branch opening, and the annular support can be made of a radiopaque material, which can provide support while being radiopaque during the operation to better indicate the position of the branch opening.

[0089] Please see Figure 8 In some embodiments, the covered stent 100 includes a support structure 7, which includes a bottom support 71 for supporting the bottom 51 of the groove 5. Exemplarily, the bottom 51 of the groove includes a bottom covering 51a, and the bottom support 71 supports the bottom covering 51a. The placement of the bottom support 71 helps to better maintain the shape of the inner cavity of the main stent 10 and / or the bottom 51 of the groove, reducing or avoiding excessive bulging of the bottom region of the groove where the bottom support 71 is located towards the groove opening 52, thus reducing the risk of the bottom 51 of the groove obstructing the guide wire or the outer branch stent 500 from entering the inner branch stent 8; furthermore, it can maintain sufficient inner cavity space for the main stent 10.

[0090] Please see Figure 9 and Figure 10 In some embodiments, the bottom support 71 includes two support portions 711 spaced apart along the width direction (or radial direction, the width direction of the groove 5) of the bottom of the groove 51. The bottom covering 51a includes a blank bottom covering segment 511, which means that the area only includes the covering and does not include other support structures. In the width direction of the bottom of the groove 51, the bottom covering segment 511 is located between the two support portions 711. The two support portions 711 can move relative to each other so that the bottom covering segment 511 can deform. This arrangement allows the bottom support 71 to reduce or avoid excessive bulging of the bottom area of ​​the groove where the bottom support 71 is located towards the groove opening 52, thereby reducing the risk of the bottom of the groove 51 blocking the guidewire or external branch stent 500 from entering the internal branch stent 8. At the same time, it also allows the bottom support 71 to maintain good lateral bending performance (i.e., bending performance towards the radial side of the groove 5), so that the covered stent 100 can adapt well to the curvature of the blood vessel and better fit the blood vessel wall.

[0091] In some embodiments, the two support portions 711 are movable relative to each other, so that the bottom film-coated section 511 can deform and form a limiting groove 51 for radially limiting the sheath core 600. In practical application, the film-coated bracket 100 of this embodiment can be compressed and assembled into the conveyor (e.g., compressed into the conveyor sheath). When the film-coated bracket 100 is compressed into the conveyor, since the two support portions 711 of the film-coated bracket 100 are movable relative to each other, the blank bottom film-coated section 511 can deform and form a limiting groove 512. The sheath core 600 of the conveyor can be accommodated at least partially in the limiting groove 512, so that the limiting groove 512 can impede the displacement of the sheath core 600 in the radial direction to a certain extent, for example, so that the limiting groove 512 can limit the sheath core 600 in the radial direction. If the aforementioned limiting groove 512 is not provided, when the covered stent 100 is compressed and assembled into the delivery device, the sheath core 600 of the delivery device may be radially offset outside the area where the groove 5 is located. During the implantation of the covered stent 100, after the delivery device (including the sheath core 600) enters the aortic arch 300, it will press against the arch region 301, so that the covered stent 100 can only expand away from the sheath core 600 during the release process. If the sheath core is radially offset outside the area where the groove 5 is located during assembly, the groove 5 will also be correspondingly offset from the arch region 301 after the covered stent 100 is released. The branch vessels 200 connected to the aortic arch 300 are usually located near the arch region 301. If the release position of the groove 5 is far away from the arch region 301, it may be difficult for the groove 5 to be aligned with the branch vessels 200, causing the covered stent 100 to block the opening of the branch vessels 200, thereby obstructing the blood flow of the branch vessels 200. Before release, the limiting groove 512 formed by the bottom covering segment 511 of the covered stent 100 in this embodiment can hinder the displacement of the sheath core 600 in the radial direction to a certain extent. Therefore, during the sheath retraction process of the covered stent 100, the sheath core 600 can be manually placed at the position of the limiting groove 512 to reduce the probability of the sheath core 600 deviating from the groove 5. This allows the groove 5 of the covered stent 100 to be more accurately aligned with the branch vessel 200 after release, reducing the probability of the covered stent 100 obstructing or blocking the branch vessel 200, thereby ensuring that the blood flow in the branch vessel 200 can flow normally and smoothly, and reducing complications caused by poor blood flow. After the covered stent 100 is implanted into the target cavity and released from the delivery device, the bottom covered segment 511 unfolds naturally. The bottom covered segment 511 releases the radial restriction on the sheath core 600. That is, the bottom covered segment 511 does not form a limiting groove 512 for radial restriction of the sheath core 600. Therefore, when the sheath core 600 is withdrawn from the target cavity, the sheath core 600 will not pull the bottom of the groove 51, causing damage or even breakage of the bottom covered segment 51a.

[0092] For example, when the covered support 100 is loaded in the conveyor, the sheath core 600 can pass through the inner cavity of the intermediate section 3. In this case, the bottom covered section 511 forms a limiting groove 512 that protrudes toward the groove opening 52 to limit the sheath core 600 in the radial direction. Alternatively, the sheath core 600 can also be located outside the inner cavity of the intermediate section 3, and the sheath core 600 enters the proximal section 2 through the groove 5. In this case, the bottom covered section 511 forms a limiting groove 512 that is recessed toward the direction away from the groove opening 52 (i.e., protrudes toward the inner cavity of the main support 10) to limit the sheath core 600 in the radial direction.

[0093] Understandably, the regions corresponding to the two support portions 711 in the coated support 100 are the first region 50a and the second region 50b, respectively. The first region 50a, the bottom coated section 511, and the second region 50b are arranged along the width direction of the bottom of the groove 51. The two radial sides of the bottom coated section 511 (i.e., the sides in the width direction of the bottom coated section 511) are respectively connected to the first region 50a and the second region 50b. The blank bottom coated section 511 refers to the bottom coated section 511 without any supporting structures such as wave coils, wave units, or support wires. Therefore, the radial support force of the bottom coated section 511 is less than that of the first region 50a and the second region 50b on both sides. When subjected to radial compression, the first region 50a and the second region 50b where the two support portions 711 are located can move relative to each other, such as moving closer or further apart, so that the bottom coated section 511 can deform and form a limiting groove 512 for radially limiting the sheath core 600. For example, two support portions 711 arranged radially (that is, along the width direction of the bottom 51 of the groove) are respectively referred to as the first support portion 711a and the second support portion 711b.

[0094] The number of bottom support components 71 can be set according to actual needs, such as one, two, three, or more. Please refer to [link / reference]. Figure 9In some embodiments, the covered support 100 includes three bottom supports 71 arranged sequentially in the axial direction, namely a first bottom support 71a, a second bottom support 71b, and a third bottom support 71c. In this embodiment, the first bottom support 71a is located in the proximal region of the bottom of the groove 51, the third bottom support 71c is located in the distal region of the bottom of the groove 51, and the second bottom support 71b is located between the proximal and distal regions of the bottom of the groove 51. In other embodiments, the relative positions of the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c can also be designed to other positional relationships according to actual needs, such as the third bottom support 71c being located in the proximal region of the bottom of the groove 51, and the first bottom support 71a being located in the distal region of the bottom of the groove 51. The number of the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c can all be designed according to actual needs, such as one, two, three, or more of each. For example, the number of first bottom support members 71a is one, the number of second bottom support members 71b includes at least two, and the number of third bottom support members 71c is one. One first bottom support member 71a, two second bottom support members 71b and one third bottom support member 71c are arranged axially.

[0095] Understandably, the covered stent 100 includes a plurality of bottom supports 71 arranged axially, and adjacent bottom supports 71 may or may not be connected. Exemplarily, the plurality of bottom supports 71 are arranged sequentially and spaced apart from the proximal end to the distal end, thereby allowing the groove bottom 51 to bend in segments. This gives the groove bottom 51 good bending flexibility and lateral bending performance, which helps the groove bottom 51 better conform to the lateral bending of the covered stent 100. This allows the groove bottom 51 and the covered stent 100 to adapt well to the lateral bending shape of the blood vessel, improving the apposition of the covered stent 100 and reducing the risk of blood leakage and thrombosis.

[0096] In some embodiments, at least one of the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c respectively includes two support portions 711 and a bottom coating section 511, so that the bottom coating 51a can form a limiting groove 512, thereby radially limiting the sheath core 600. For example, at least two of the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c respectively include two support portions 711 and a bottom coating section 511 to improve the radial limiting capability of the sheath core 600. For instance, the first bottom support 71a and the second bottom support 71b respectively include two support portions 711 and a bottom coating section 511, and the third bottom support 71c is an integral structure. The radial region where the third bottom support 71c is located does not have a blank bottom coating section 511, that is, the middle part of the third bottom support 71c does not have two portions spaced apart by the bottom coating section 511 along the width direction of the bottom of the groove 51. For example, the first bottom support 71a and the third bottom support 71c each include two support portions 711 and a bottom film section 511, while the second bottom support 71b is an integral structure. The radial region where the second bottom support 71b is located does not have a blank bottom film section 511; that is, the middle portion of the second bottom support 71b does not have two parts spaced apart by the bottom film section 511 along the width direction of the bottom of the groove 51. Similarly, the second bottom support 71b and the third bottom support 71c each include two support portions 711 and a bottom film section 511, while the first bottom support 71a is an integral structure. The radial region where the first bottom support 71a is located does not have a blank bottom film section 511; that is, the middle portion of the first bottom support 71a does not have two parts spaced apart by the bottom film section 511 along the width direction of the bottom of the groove 51.

[0097] In other embodiments, the bottom coating section 511 may be provided only on the second bottom support 71b, instead of on the first bottom support 71a and the third bottom support 71c located at the ends. The second bottom support 71b located in the middle region can more flexibly respond to the action of radial forces to form the limiting groove 512.

[0098] Please see Figure 11In some embodiments, the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c each include two support portions 711 spaced apart along the width direction of the bottom of the groove 51, with a bottom coating section 511 between the two support portions 711. For example, the two support portions 711 of the first bottom support 71a are spaced apart along the width direction of the bottom of the groove 51, and a bottom coating section 511, referred to as the first coating section 511a, is provided between the two support portions 711a. The two support portions 711 of the first bottom support 71a are relatively movable, allowing the first coating section 511a to deform and form a limiting groove 512 for radially limiting the sheath core 600. The two support portions 711 of the second bottom support member 71b are spaced apart along the width direction of the bottom 51 of the groove. A bottom coating section 511, denoted as the second coating section 511b, is provided between the two support portions 711 of the second bottom support member 71b. The two support portions 711 of the second bottom support member 71b are movable relative to each other, so that the second coating section 511b can deform and form a limiting groove 512 for radially limiting the sheath core 600. The two support portions 711 of the third bottom support member 71c are spaced apart along the width direction of the bottom 51 of the groove. A bottom coating section 511, denoted as the third coating section 511c, is provided between the two support portions 711 of the third bottom support member 71c. The two support portions 711 of the third bottom support member 71c are movable relative to each other, so that the bottom coating section 511c can deform and form a limiting groove 512 for radially limiting the sheath core 600. The first covered section 511a, the second covered section 511b, and the third covered section 511c are arranged along the delivery direction of the sheath core 600. The first covered section 511a, the second covered section 511b, and the third covered section 511c can each form a limiting groove 512 for radially limiting the sheath core 600, thereby improving the radial limiting ability of the sheath core 600, effectively reducing the probability of the sheath core 600 deviating from the groove 5, and reducing the probability of the covered stent 100 obstructing or blocking the branch blood vessel 200.

[0099] In some embodiments, the extension dimension (or width, radial extension dimension) of the bottom covering segment 511 in the width direction of the groove bottom 51 is greater than half the circumference of the sheath core 600. The bottom covering segment 511 can wrap more than half the circumference of the sheath core 600 in the radial direction, that is, the groove wall of the limiting groove 512 can wrap more than half the circumference of the sheath core 600 in the radial direction to ensure better restraint of the sheath core 600. If the radial extension length of the bottom covering segment 511 is exactly equal to the circumference of the sheath core 600, and it still wraps the sheath core 600 after the covered stent 100 is implanted into the target lumen, the two support portions 711 located on both sides of the bottom covering segment 511 may be difficult to remove if they abut against each other due to the radial pressure of the target lumen on the covered stent 100 (not that it cannot be removed, but the limiting groove 512 binds the sheath core 600 strongly in the radial direction, making it difficult to remove it radially, so it is recommended to remove it axially). Therefore, for example, the extension dimension of the bottom film-coated segment 511 in the width direction of the groove bottom 51 can be greater than half the circumference of the sheath core 600, but not equal to the circumference of the sheath core 600. For example, the extension dimension of the bottom film-coated segment 511 in the width direction of the groove bottom 51 can be greater than or less than the circumference of the sheath core 600, thereby ensuring a good constraint and limiting effect on the sheath core 600, and making it easier for the sheath core 600 to be removed from the limiting groove 512 after the film-coated bracket 100 is released. In other embodiments, the extension dimension of the bottom film-coated segment 511 in the width direction of the groove bottom 51 can also be equal to the circumference of the sheath core 600; or, the extension dimension of the bottom film-coated segment 511 in the width direction of the groove bottom 51 can also be less than half the circumference of the sheath core 600.

[0100] In some embodiments, the inner branch support 8 includes a branch opening facing the groove 5, and a bottom film section 511 is axially opposite to the branch opening. The extension dimension of the bottom film section 511 in the width direction of the groove bottom 51 may be smaller than the diameter of the branch opening. Since the extension dimension of the bottom film section 511 in the width direction of the groove bottom 51 is smaller than the diameter of the branch opening, even if the bottom film section 511 is relatively close to the branch opening and the bottom film section 511 deforms and forms a limiting groove 512 due to radial compression of the bottom film 51a and the support structure 7, the bottom film section 511 is not likely to bulge and completely block the branch opening or prevent the guide wire or outer branch support 500 from entering the branch opening. Under the premise of ensuring that the bottom film section 511 forms a limiting groove 512 for radially limiting the sheath core 600, the guide wire or outer branch support 500 can smoothly enter the inner branch support 8.

[0101] Referring to Figure 12(A), in some embodiments, the edges of the first branch opening 811 and the second branch opening 821 connected to the bottom of the groove 51 form an upwardly raised gap 54, and the bottom coating section 511 is axially opposite to the raised gap 54. The edges of both the first branch opening 811 and the second branch opening 821 connected to the bottom of the groove 51 (e.g., connected to the bottom coating 51a) form a slightly curved "W" shape, wherein the raised tip of the "W" shape forms the upwardly raised gap 54 (i.e., towards the upper edges of the first branch opening 811 and the second branch opening 821). When the bottom of the groove 51 is subjected to radial pressure, this upwardly raised gap 54 can cooperate with the bottom coating section 511 to achieve a better limiting effect on the sheath core 600.

[0102] In addition, please refer to Figure 9 When a bottom support member 71a located in the proximal region of the bottom of the groove 51 is provided with a bottom covering section 511, and the bottom covering section 511 penetrates the first bottom support member 71a axially, and is axially opposite to and connected to the protruding gap 54, after the covered stent 100 is implanted, it is subjected to radial compression of the target lumen. The upwardly protruding gap 54 can guide the bottom covering section 511 to bulge upward, playing a certain guiding role near the branch opening. The bottom covering sections 511 located on both radial sides of the bottom covering section 511 can maintain the shape of the bottom covering 51a in the area near the first branch opening 811 and the second branch opening 821. After the covered stent 100 is implanted into the target lumen, the bottom covering 51a in the area near the first branch opening 811 and the second branch opening 821 is not prone to bulging or irregular deformation, thus preventing blockage of the branch opening. The bottom support members 71 located at both axial ends of the groove bottom 51 can maintain a certain distance from the branch opening, the distance ranging from 1mm to 3mm. This arrangement facilitates better guidance of the bottom film section 511 to bulge upwards by the protrusion gap 54 when the groove 5 is subjected to radial compression. It also prevents the bottom support members 71 from deforming and elongating axially during radial compression due to excessively small distances, causing them to abut against the annular support member on the branch opening and making further radial contraction difficult. Understandably, in other embodiments, the annular support member can be omitted, and the distance between the bottom support members 71 located at both axial ends of the groove bottom 51 and the branch opening can be less than 1mm, or even the two can be in close contact.

[0103] Referring to Figures 12(A) and 12(B), in some embodiments, the bottom support 71 further includes a connecting portion 712, which is connected to the first support portion 711a and the second support portion 711b respectively. The first support portion 711a and the second support portion 711b are arranged along the width direction of the groove bottom 51 to form a gap space 713. The area in the bottom film 51a corresponding to the gap space 713 is the bottom film section 511. That is, the connecting portion 712 and the bottom film section 511 are arranged axially, and the connecting portion 712 is closer to the axial end of the groove bottom 51 than the bottom film section 511. The setting of the connecting portion 712 is beneficial to improving the radial support capacity of the bottom support 71 near the branch opening, and can better maintain the shape of the connection between the groove bottom 51 and the branch opening of the inner branch support 8. In addition, when subjected to radial compression, the bottom film section 511 can deform and form a limiting groove 512, so that the groove bottom 51 can limit the sheath core 600. For example, referring to FIG12(B), the connecting portion 712 includes overlapping waveform units 712a and 712b. The radial ends of waveform unit 712a are connected to the radial ends of waveform unit 712b, and the waveform units 712a and 712b are out of phase to form a plurality of support sub-units arranged sequentially in the radial direction, such as a first grid. The first grid can be a quadrilateral mesh such as a rhombus or a rhombus-like shape, or any other suitable shape. The connecting portion 712 is movably connected to the support portion 711. For example, the waveform units 712a and 712b are movably connected to the first support portion 711a and the second support portion 711b (e.g., hooked together), so that the connecting portion 712 and the support portion 711 can move relative to each other in the axial direction at the connection point. This arrangement allows the joint 712 and the support 711 to deform relatively independently. Therefore, when the bottom support 71 is located at the axial end of the groove 5, even if the support 711 is subjected to a large compressive force, it can deform relatively independently without directly causing the joint 712 to deform significantly. The joint 712 can still maintain the shape of the bottom film 51a near the branch opening.

[0104] Referring to Figure 12(B), the first support portion 711a includes multiple support sub-units arranged sequentially in the radial direction. For example, the support sub-unit of the first support portion 711a is a second grid. The second support portion 711b includes multiple support sub-units arranged sequentially in the radial direction. For example, the support sub-unit of the second support portion 711b is a third grid. The support sub-units closest to the bottom film section 511 in the first support portion 711a and the support sub-units closest to the bottom film section 511 in the second support portion 711b are not directly connected to the connecting portion 712. For example, they are not directly hooked to the connecting portion 712, but are only connected to it through the blank film. This arrangement is beneficial because when the bottom support member 71 is under pressure, the support sub-units closest to the bottom film section 511 in the first support portion 711a and the second support portion 711b can more flexibly cause the bottom film section 511 to deform and form the limiting groove 512. Understandably, in other embodiments, the mesh in the joint 712 and / or support 711 may be replaced by one or more waves bulging toward the axial ends of the groove 5, or any other suitable structure as a support sub-unit. In other embodiments, the joint 712 and support 711 may also be movably connected in other ways, for example, the joint 712 and support 711 may be connected only by a blank bottom film section, or by hinge, or by an elastic element (such as a spring, elastic wire), etc. In other embodiments, the joint 712 may be movably connected to only one support 711, which can also achieve a certain degree of relatively independent deformation between the two. In other embodiments, the joint 712 and support 711 may also not be movably connected.

[0105] Please see Figure 13In some embodiments, the support portion 711 includes a mesh structure 714 and a support unit 715. Exemplarily, the mesh structure 714 and the support unit 715 may be integrally woven from support wires made of metal or other medical materials with shape memory function. In other embodiments, the mesh structure 714 and the support unit 715 may also be integrally cut. The mesh structure 714 includes a first radial side edge and a second radial side edge spaced apart along the width direction of the bottom of the groove 51. The first radial side edge is closer to the bottom covering segment 511 than the second radial side edge. The width of the axial end of the mesh structure 714 closer to the branch opening is less than the maximum width of the mesh structure 714. In other embodiments, the width of the mesh structure 714 may be consistent. The support unit 715 extends axially and is connected to the first radial side edge of the mesh structure 714. Exemplarily, the support unit 715 includes multiple axial support wires 7151 arranged sequentially in the axial direction, with adjacent axial support wires 7151 overlapping and / or hooked together at their intersection. When subjected to radial compression, the bottom coated section 511 can form a limiting groove 512, and the support unit 715 can support the opening of the limiting groove 512, so that the bottom coated section 511 can better wrap at least part of the sheath core 600, thereby enabling the limiting groove 512 formed by the bottom coated section 511 to effectively limit the sheath core 600.

[0106] Please see Figure 14 In some embodiments, the bottom support 71 includes multiple rows of intersecting units formed by overlapping multiple segments of spaced-apart first-direction support wires 7141 and multiple segments of spaced-apart second-direction support wires 7142, and deformable mesh 7143. Each axial support wire 7151 is integrally formed with the corresponding first-direction support wire 7141 and / or second-direction support wire 7142 in the mesh structure 714 and forms an edge bending angle at the first radial edge of the mesh structure 714. The edge bending angle is an acute angle, and the supplementary angle of the edge bending angle is greater than the interior angle of the deformable mesh 7143 in the mesh structure 714. For example, please refer to Figure 13 and Figure 14The support unit 715 includes a first axial support wire 7151a and a second axial support wire 7151b. The first axial support wire 7151a and the second axial support wire 7151b extend substantially axially (extending substantially axially means that the angle between them and the axis of the covered support 100 does not exceed 10°). The proximal end of the first axial support wire 7151a is connected to a first direction support wire 7141 (denoted as the first wire 7141a), and the distal end of the first axial support wire 7151a is connected to a second direction support wire 7142 (denoted as the second wire 7142a). The first wire 7141a and the second axial support wire 7151b are connected to each other. The axial support wire 7151a and the second wire 7142a are an integral structure. The first wire 7141a and the first axial support wire 7151a form a first edge bending angle α, and the second wire 7142a and the first axial support wire 7151a form a second edge bending angle β. Both the first edge bending angle α and the second edge bending angle β are acute angles. The supplementary angle of the first edge bending angle α is equal to 180° - α, and the supplementary angle of the second edge bending angle β is equal to 180° - β. The supplementary angles of the first edge bending angle α and the second edge bending angle β are both greater than the interior angles within the deformable mesh 7143 in the mesh structure 714. The relative relationship between the second axial support wire 7151b and the corresponding first directional support wire 7141 and second directional support wire 7142 is similar and will not be elaborated further here. Without the axial support wire 7151, the radial edge of the mesh structure 714 near the bottom covered section 511 or a row of deformable mesh holes 7143 is directly opposite the bottom covered section 511. After implantation, the covered stent 100 will conform to the curvature of the blood vessel and will be affected by the impact of blood and vascular pulsation. If the angle of the radial edge of the mesh structure 714 or the deformable mesh hole 7143 towards the bottom covered section 511 is too small, it may wear or puncture the bottom covered section 511. The supplementary angle of the edge bending angle is greater than the inner angle of the deformable mesh hole 7143 in the mesh structure 714, which can reduce the risk of wear and puncture of the covered section at the sharp corner of the mesh structure 714 edge.

[0107] Please see Figure 13 and Figure 14In some embodiments, the bottom support 71 further includes deformable buffer units 716 at its radial edges, and the buffer units 716 are connected to the mesh structure 714. For example, in this embodiment, each of the two radial edges of the first bottom support 71a and the third bottom support 71c includes a buffer unit 716; in other embodiments, only one radial edge of the bottom support 71 includes a buffer unit 716, or each radial edge of the bottom support 71 may be provided with two or more buffer units 716; in other embodiments, the aforementioned buffer units 716 may be omitted. Since the buffer units 716 are radially close to the radial edge of the groove 5, when the groove 5 is subjected to radial pressure, the buffer units 716 are first subjected to force and deform and move, rather than immediately transmitting the force to the mesh structure 714, thereby playing a certain buffering role, which can better maintain the overall shape of the bottom support 71, prevent obstruction of the branch opening, and help maintain the shape of the bottom 51 of the groove. For example, the buffer unit 716 includes a buffer rod 7161 and a connecting rod 7162. One end of the connecting rod 7162 is connected to the mesh structure 714, and the other end of the connecting rod 7162 is connected to the buffer rod 7161. The buffer rod 7161 is located at the radial edge of the bottom support member 71, and the buffer rod 7161 is closer to the radial edge of the bottom support member 71 than the connecting rod 7162. A buffer apex 7163 is formed at the connection between the buffer rod 7161 and the connecting rod 7162. A movable gap is formed between the buffer apex 7163 and the mesh structure 714, allowing the buffer apex 7163 to move relative to the mesh structure 714, thereby improving the buffering effect of the buffer unit 716. The buffer rod 7161 can be used to connect to the bottom covering membrane 51a at this location, and can preferentially deform to buffer the radial force when subjected to radial force, and then transmit the unbuffered force to the connecting rod 7162, whereby the connecting rod 7162 moves to further buffer the radial force. In this embodiment, the buffer rod 7161 is approximately parallel to the radial edge of the groove 5, which facilitates uniform force distribution in the radial direction and enables it to provide a more sensitive and efficient buffering effect. In other embodiments, the buffer rod 7161 may be angled, for example, forming an acute angle with the radial edge of the groove 5. Figure 14 The buffer unit 716 contains one buffer rod 7161. The buffer rod 7161 and the connecting rod 7162 form a triangle or a triangular-like shape. In other embodiments, the buffer unit 716 may contain multiple buffer rods 7161. The multiple buffer rods 7161 and the connecting rod 7162 form a quadrilateral or other polygon. When there are multiple buffer rods 7161, the connection points of the interconnected buffer rods 7161 can also form buffer vertices 7163. It can be understood that the bottom support 71 in Figure 12(B) and Figure 13 , Figure 14Although the structure of the bottom support 71 in Figure 12(B) is different, the bottom support 71 in Figure 12(B) may also include a buffer unit 716.

[0108] Please see Figure 13 In some embodiments, the bottom support 71 located at the axial end of the groove bottom 51 includes a width-reducing segment X. This width-reducing segment X is located at the groove bottom 51 and its width decreases along the direction close to the inner branch stent 8, causing the region of the bottom support 71 near the branch opening to form a trapezoidal structure. For example, at least one of the first bottom support 71a and the third bottom support 71c includes the width-reducing segment X. The maximum radial dimension D2 (or width) of the first bottom support 71a is greater than the radial dimension D1 of the proximal end of the first bottom support 71a, and the maximum radial dimension of the third bottom support 71c may be greater than the radial dimension of the distal end of the third bottom support 71c. The purpose of this structure is that when the covered stent 100 is implanted and the groove bottom 51 is radially compressed by the target cavity, the region of the groove bottom 51 connected to the branch opening can follow the width-reducing segment X to form a trapezoidal guide structure, which can better guide the guide wire and the outer branch stent 500 into the branch opening.

[0109] For example, the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c have different structures; in other embodiments, at least two of the first bottom support 71a, the second bottom support 71b, and the third bottom support 71c may also have the same structure. For example, please refer to... Figure 13 , combined Figure 9 Both the first bottom support 71a and the third bottom support 71c include a mesh structure 714. The mesh structure 714 of the first bottom support 71a and the mesh structure 714 of the third bottom support 71c can be the same or different. For example, please refer to... Figure 13 The second bottom support 71b includes a first waveform unit 7101 and a second waveform unit 7102, wherein the first waveform unit 7101 and the second waveform unit 7102 are overlapped and / or hooked together. For example, the crest of the first waveform unit 7101 and the trough of the second waveform unit 7102 are arranged axially opposite each other.

[0110] Please see Figures 15 to 17(A)In some embodiments, the covered support 100 includes a main support 10 and a limiting structure 9 as described in any of the above embodiments. The limiting structure 9 includes a limiting member 91 and a constraint member 92 for constraining the position of the limiting member 91. The limiting member 91 and the constraint member 92 are detachably connected. When the covered support 100 is in a first state, the limiting member 91 can be used to radially limit the target segment 601 of the sheath core 600 under the constraint of the constraint member 92. The target segment 601 is an axial segment of the sheath core 600. In the first state, this axial region is located in the axial region between the proximal end and the distal end of the groove 5 (that is, in the axial region of the intermediate segment 3). When the covered support 100 is in a second state, the constraint member 92 can disengage from the limiting member 91 so that the limiting member 91 releases the restriction on the target segment 601.

[0111] In the above embodiment, when the film-coated support 100 is in a first state (such as a compressed state assembled in the sheath of the conveyor), the limiting member 91 of the limiting structure 9 can be used to limit the target segment 601 of the sheath core 600 in the radial direction under the constraint of the constraint member 92. When the covered stent 100 needs to be implanted into the target cavity, it is implanted into the target cavity through a delivery device. When the covered stent 100 located in the target cavity is released and deployed from the delivery device, the target segment 601 of the sheath core 600 of the delivery device rests on the arch region 301 of the aortic arch 300. The covered stent 100 expands in the direction away from the target segment 601 of the sheath core 600. Before the covered stent 100 is fully deployed, the limiting member 91 can radially limit the sheath core 600 under the constraint of the restraint member 92, thus reducing the probability of the sheath core 600 deviating from the bottom 51 of the groove (e.g., the bottom covered stent 51a). This allows the groove 5 of the covered stent 100 to be more accurately aligned with the branch vessels after implantation, reducing the probability of the covered stent 100 obstructing or blocking the branch vessels 200, thereby ensuring that the blood flow in the branch vessels 200 can flow normally and smoothly, and reducing complications caused by poor blood flow. When the coating support 100 is in the second state, the constraint member 92 can disengage from the limiting member 91, so that the limiting member 91 releases the restriction on the target segment 601, so that when the sheath core 600 is withdrawn from the target cavity, the sheath core 600 will not pull the bottom of the groove 51, causing damage or even breakage to the bottom coating.

[0112] For example, the first state is the compressed state corresponding to the covered stent 100 being compressed and assembled into the delivery device, and the second state is the fully deployed state corresponding to the covered stent 100 being implanted into the target cavity and released from the sheath of the delivery device. In other embodiments, the first state may also be a semi-deployed state between the compressed state and the fully deployed state, and the second state may be the fully deployed state; or, the first state may be the compressed state corresponding to the covered stent 100 being compressed and assembled into the delivery device, and the second state may be a semi-deployed state between the compressed state and the fully deployed state.

[0113] In some embodiments, the constraint member 92 includes a constraint wire. When the covered stent 100 is in a first state, the constraint wire can pass through the limiting member 91, so that the limiting member 91 can be used to limit the target segment 601 in the radial direction. When the covered stent 100 is in a second state, the constraint member 92 can move axially to disengage the constraint wire from the limiting member 91, thereby releasing the limiting member 91 from restricting the target segment 601. The constraint wire has a small diameter, resulting in less trauma to the organism when the covered stent 100 is implanted into the target cavity. Exemplarily, one end of the constraint wire is used to enter the target cavity together with the main stent 10, and the other end of the constraint wire can extend out of the organism having the target cavity to facilitate the outward removal of the constraint wire, allowing the constraint wire to disengage from the limiting member 91, thereby releasing the limiting member 91 from restricting the target segment 601. In other embodiments, both ends of the constraint wire can enter the target cavity together with the main support 10. The constraint wire can be connected to other components in the sheath core 600 or the conveyor besides the sheath core 600. When the sheath core 600 or the conveyor is withdrawn, the constraint wire can be withdrawn along with the sheath core 600 or the conveyor.

[0114] The number of limiting components 91 can be set according to actual needs, such as one, two, three or more. For example, the number of limiting components 91 is two, and the two limiting components 91 are set at intervals along the axial direction to improve the radial limiting effect on the target segment 601.

[0115] Please see Figure 16 As shown in Figure 17(A), in some embodiments, the limiting member 91 includes a limiting line 911, the end of which can form a hook portion 912. When the covered stent 100 is in a first state, the restraining member 92 can pass through the hook portion 912, so that the limiting line 911 can cooperate with the cavity wall of the inner cavity of the main stent to limit the target segment 601. When the covered stent 100 is in a second state, the restraining member 92 can be pulled out from the hook portion 912, so that the limiting line 911 releases the restriction on the target segment 601. The limiting member 91 with this structure is simple in structure and lightweight. Exemplarily, both the limiting line 911 and the restraining line are made of biocompatible materials that cause little damage to the organism. Exemplarily, when the covered stent 100 is in the first state, one of the target segment 601 and the hook portion 912 is located in the inner cavity of the main stent 10, and the other is located in the groove 5. For example, when the covered support 100 is in the first state, the target segment 601 is located in the inner cavity of the main support 10, and the wire buckle 912 is located in the groove 5.

[0116] Please refer to Figure 17(A). In some embodiments, the wire buckle portion 912 includes a first wire buckle 9121 and a second wire buckle 9122. The first wire buckle 9121 can be formed at one end of the limiting line 911; the second wire buckle 9122 can be formed at the other end of the limiting line 911. When the covered bracket 100 is in the first state, the constraint member 92 can pass through the first wire buckle 9121 and the second wire buckle 9122 so that the limiting line 911 can cooperate with the main bracket to limit the target segment 601. When the covered bracket 100 is in the second state, the constraint member 92 can disengage from the first wire buckle 9121 and the second wire buckle 9122 so that the limiting line 911 releases its restriction on the sheath core 600. When the covered stent 100 needs to be assembled on the conveyor, the constraint member 92 can be threaded through the first buckle 9121 and the second buckle 9122, so that the limiting line 911 can bind the target segment 601 to the preset area, thereby achieving radial limiting of the sheath core 600. After the covered stent 100 is implanted into the target cavity and released from the conveyor, the constraint member 92 can be moved in the removal direction by means of the conveyor or other tools or by direct operation, so that the constraint member 92 is released from the first buckle 9121 and the second buckle 9122. At this time, the two ends of the limiting line 911 are no longer constrained by the constraint member 92, and the constraint of the limiting line 911 on the target segment 601 is weakened or even released, which provides a guarantee for the sheath core 600 to be successfully removed from the target cavity. The first and second buckles 9121 and 9122 can constrain and limit the sheath core 600 at two different positions in the axial direction or in the conveying direction of the sheath core 600, improving the reliability and stability of radial limiting of the sheath core 600 when the covered support 100 is in the first state. For example, when the covered support 100 is in the first state, the limiting line 911 passes through the bottom covered film 51a, allowing the sheath core 600 to pass through the middle section 3 (see [reference]). Figure 2 The first thread buckle 9121 and the second thread buckle 9122 may be omitted from the inner cavity and groove 5 of the middle section 3, respectively.

[0117] Referring to Figure 17(B), exemplarily, the limiting line 911 can be connected to the sheath core 600. The sheath core 600 passes through one of the inner cavity and groove 5 of the main body support 10, and the wire buckle 912 is located in the other of the inner cavity and groove 5 of the intermediate section 3. Exemplarily, the number of limiting lines 911 includes two, each fixedly connected to the sheath core 600. For example, the limiting line 911 includes a connecting segment 9123, one end of which is fixedly connected to the sheath core 600 by adhesive or other means, and the other end can penetrate the bottom covering film 51a, forming a wire buckle 912 for the restraint member 92 to pass through. In other embodiments, the connecting segment 9123 can be detachably connected to the sheath core 600. For example, a connecting line is provided on the sheath core 600, connecting the connecting line and the limiting line 911 to each other via a slip knot. In other embodiments, the number of limit lines 911 can be designed to be other numbers according to actual needs, such as one, three or more.

[0118] Please see Figure 18 In some embodiments, the limiting member 91 includes a first limiting part 913 and a second limiting part 914. When the covered bracket 100 is in the first state, the constraint member 92 passes through the first limiting part 913 and the second limiting part 914 to constrain the first limiting part 913 and the second limiting part 914 to separate from each other, thereby enabling the first limiting part 913 and the second limiting part 914 to radially limit the target segment 601, thus achieving radial limiting of the target segment 601. When the covered bracket 100 is in the second state, the constraint member 92 can disengage from the first limiting part 913 and the second limiting part 914, thereby releasing the first limiting part 913 and the second limiting part 914 from limiting the target segment 601, ensuring that the sheath core 600 can be smoothly withdrawn from the target cavity. This type of limiting member 91 has a simple structure, and the radial limiting and releasing operations of the target segment 601 are easy and quick. In this embodiment, the limiting member 91 is located within the groove 5, and the sheath core 600 passes through the inner cavity of the main support 10. In the first state, the limiting member 91 restricts the target segment 601 through the bottom covering membrane 51a. In the second state, the limiting member 91 remains within the groove 5. Even if the limiting member 91 is not connected to the bottom 51 of the groove, the bottom 51 of the groove and the mesh cover 61 can still effectively restrict the limiting member 91 within the groove 5, preventing it from detaching from the covered support 100. In other embodiments, the limiting member 91 can be connected to the bottom 51 of the groove; it can be disposed within the groove 5 or within the inner cavity of the main support 10. In other embodiments, the limiting member 91 can be made of biodegradable materials such as polylactic acid, which can degrade in vivo and promote rapid thrombosis of the groove 5, thereby improving the endothelialization process of the covered support 100.

[0119] Please see Figures 18 to 20(A)In some embodiments, the first limiting portion 913 includes a first connecting portion 9131 and a first limiting portion 9132 connected to the first connecting portion 9131, and the second limiting portion 914 includes a second connecting portion 9141 and a second limiting portion 9142 connected to the second connecting portion; when the covering bracket 100 is in the first state, the constraint member 92 can pass through the first connecting portion 9131 and the second connecting portion 9141, so that the first limiting portion 9132 and the second limiting portion 9142 are connected. The target segment 601 can be radially restricted, thereby achieving radial constraint on the target segment 601. When the covered support 100 is in the second state, the constraint member 92 can disengage from the first connecting part 9131 and the second connecting part 9141, so that the first connecting part 9131 and the second connecting part 9141 move away from each other, thereby releasing the restriction of the target segment 601 by the first limiting part 9132 and the second limiting part 9142, so as to ensure that the sheath core 600 can be smoothly withdrawn from the target cavity. For example, the first connecting part 9131 is provided with a first connecting hole 91311, and the second connecting part 9141 is provided with a second connecting hole 91411. When the film-covered bracket 100 is in the first state, the constraint member 92 can pass through the first connecting hole 91311 and the second connecting hole 91411, thereby constraining the first limiting part 913 and the second limiting part 914, so that the first limiting part 9132 and the second limiting part 9142 can form a limiting space 915 for limiting the target segment 601 in the radial direction. The width of the opening 9151 of the limiting space 915 is smaller than the diameter of the sheath core 600. The first connecting hole 91311 and the second connecting hole 91411 are arranged axially along the groove 5 to form a channel through which the constraint member 92 passes. The first connecting hole 91311 and the second connecting hole 91411 can be arranged coaxially or non-axially, as long as the channel formed allows the constraint member 92 to pass through, and when the constraint member 92 passes through the channel, the width of the opening 9151 of the restriction space 915 can always be less than the diameter of the sheath core 600. It can be understood that the first restriction sub-part 9132 and the second restriction sub-part 9142 can be connected to the bottom covering film 51a or not.

[0120] Please see Figure 18 In some embodiments, the first limiting part 913 and the second limiting part 914 can be used to cooperate to form a limiting space 915. At least one of the first limiting part 913 and the second limiting part 914 is provided with a limiting part 916 for limiting the enlargement of the opening 9151 of the limiting space 915; or, at least one of the first limiting part 913 and the second limiting part 914 is provided with a limiting part 916 for limiting the enlargement and reduction of the opening 9151 of the limiting space 915, so as to ensure that when the covered support 100 is in the first state, the first limiting part 913 and the second limiting part 914 can achieve radial limiting of the target segment 601 under the constraint of the constraint member 92.

[0121] In some embodiments, the limiting portion 916 can also be used to limit the reduction of the opening 9151 of the limiting space 915, so that the first limiting portion 913 and the second limiting portion 914 cooperate to form a limiting space 915 that is adapted to the diameter of the target segment 601 of the sheath core 600, thereby reducing the damage to the sheath core 600 caused by the first limiting portion 913 and / or the second limiting portion 914.

[0122] Please see Figures 18 to 20(B) In some embodiments, the limiting part 916 includes a first limiting mechanism 916a, which is used to limit the increase of the opening 9151 of the limiting space 915. For example, the first limiting mechanism 916a includes a first limiting wall 9162 (e.g., extending laterally, i.e., the first limiting sub-part 9132 points in the direction of the second limiting sub-part 9142, or the second limiting sub-part 9142 points in the direction of the first limiting sub-part 9132) and a second limiting wall 9161 (e.g., extending longitudinally, i.e., the first connecting hole 91311 or the second connecting hole 91411 points in the direction of the limiting space 915, or the limiting space 915 points in the direction of the first connecting hole 91311 or the second connecting hole). The second limiting wall 9161 and the first limiting wall 9162 are disposed on the first limiting part 913. The second limiting part 914 includes a first mating wall 9144 (e.g., extending laterally) and a second mating wall 9143 (e.g., extending longitudinally). The second limiting wall 9161 can abut against the second mating wall 9143 to limit the second limiting part. The first limiting part 914 rotates relative to the first limiting part 913 in a first rotational direction to reduce the opening 9151 of the limiting space 915. The first limiting wall 9162 can contact the first mating wall 9144 to limit the second limiting part 914 from rotating relative to the first limiting part 913 in a second rotational direction opposite to the first rotational direction to increase the opening 9151 of the limiting space 915. Thus, when the film-coated bracket 100 is in the first state, the constraint member 92 can constrain the positions of the first limiting part 913 and the second limiting part 914, and the first limiting mechanism 916a can limit the second limiting part 914 from rotating between the second limiting wall 9161 and the first limiting wall 9162 in a direction opposite to the clamping direction, thereby limiting the increase of the opening 9151 of the limiting space 915, so that the limiting structure 9 can reliably radially limit the sheath core 600. In other embodiments, the second limiting wall 9161 may be omitted.

[0123] Please see Figure 19In some embodiments, the limiting part 916 and the connecting part enclose to form a clearance space 917 for avoiding the second limiting part 914. When the constraint member 92 passes through the first limiting part 913 and the second limiting part 914, the clearance space 917 can avoid part of the second limiting part 914, which is beneficial to reduce the size of the first limiting part 913 and the second limiting part 914.

[0124] Please see Figures 18 to 20(B) In some embodiments, the limiting portion 916 includes a second limiting mechanism 916b, which is at least used to limit the movement of the first limiting portion 913 and the second limiting portion 914 along the length extension direction of the constraint member 92. Exemplarily, the second limiting mechanism 916b is also used to limit the enlargement of the opening 9151 of the limiting space 915. The second limiting mechanism 916b also includes a constraint groove 9163, which is disposed in one of the first connecting sub-portion 9131 and the second connecting sub-portion 9141. The other of the first connecting sub-portion 9131 and the second connecting sub-portion 9141 can be inserted into the constraint groove 9163 to at least limit the movement of the first limiting portion 913 and the second limiting portion 914 along the length extension direction of the constraint member 92. For example, the constraint groove 9163 is provided in the second connecting part 9141, and the first connecting part 9131 can be inserted into the constraint groove 9163, so that the two opposite groove walls of the constraint groove 9163 limit the first connecting part 9131 along the length direction of the constraint member 92, thereby limiting the first limiting part 913 and the second limiting part 914 along the length extension direction of the constraint member 92. The constraint groove 9163 is provided with a third limiting wall 9164 (e.g., extending laterally) and a fourth limiting wall 9165 (e.g., extending longitudinally). The first limiting part 913 includes a third mating wall 9145 (e.g., extending laterally) and a fourth mating wall 9146 (e.g., extending longitudinally). The fourth limiting wall 9165 can abut against the fourth mating wall 9146 to limit the second limiting part 914 from rotating relative to the first limiting part 913 in a first rotation direction, thereby limiting the reduction of the opening 9151 of the limiting space 915. The third limiting wall 9164 can abut against the third mating wall 9145 to limit the second limiting part 914 from rotating relative to the first limiting part 913 in a second rotation direction opposite to the first rotation direction, thereby limiting the increase of the opening 9151 of the limiting space 915. In other embodiments, the fourth limiting wall 9165 may be omitted. In other embodiments, one of the first limiting mechanism 916a and the second limiting mechanism 916b may be omitted. In other embodiments, the number of the first limiting mechanism 916a and the second limiting mechanism 916b may be one or more.

[0125] Please see Figure 18 , combined Figure 15In some embodiments, the first branch opening 811 of the first branch bracket 81 and the second branch opening 821 of the second branch bracket 82 form an upwardly raised gap 54 at the edge connecting with the bottom 51 of the groove. The portion of the limiting structure 9 used for connecting with the constraint member 92 is axially opposite to the raised gap 54. For example, the wire buckle portion 912 is axially opposite to the raised gap 54. Alternatively, the limiting space 915 is axially opposite to the raised gap 54, which helps to improve the radial limiting effect on the sheath core 600.

[0126] Please see Figure 21 and Figure 22 In some embodiments, the covered support 100 includes a main support 10, a limiting channel 62, and two inner branch supports 8, referred to as the first branch support 81 and the second branch support 82, respectively, according to any of the above embodiments. The first branch support 81 and the second branch support 82 are arranged side by side in the radial direction within the main support 10. The first branch support 81 has a first branch opening 811 at the end closer to the groove 5, and the second branch support 82 has a second branch opening 821 at the end closer to the groove 5. Both the first branch opening 811 and the second branch opening 821 face the groove 5 and are connected to the groove 5. The limiting channel 62 is formed between the first branch support 81 and the second branch support 82 and is used to limit the sheath core 600 in the radial direction.

[0127] In practical applications, the film-coated support 100 of the above embodiment can be compressed and assembled onto a conveyor (such as a conveying sheath). Before the film-coated support 100 is released and detached from the conveyor, the sheath core 600 passes through a limiting channel 62, which can radially limit the sheath core 600. When the covered stent 100 needs to be implanted into the target cavity, it is implanted into the target cavity via a delivery device. When the covered stent 100 located in the target cavity is released and deployed from the delivery device, the sheath core 600 of the delivery device rests against the arch region 301 of the aortic arch 300, and the covered stent 100 expands in a direction away from the sheath core 600. Before the covered stent 100 is fully deployed, the limiting channel 62 can radially limit the sheath core 600, thus reducing the probability of the sheath core 600 deviating from the groove 5. This allows the groove 5 of the covered stent 100 to be more accurately aligned with the branch vessel 200 after implantation, reducing the probability of the covered stent 100 obstructing or blocking the branch vessel 200, thereby ensuring normal and smooth blood flow in the branch vessel 200 and reducing complications caused by poor blood flow. After the covered stent 100 is implanted into the target cavity and released from the delivery device, the sheath core 600 can be withdrawn axially from the target cavity.

[0128] Please see Figure 23In some embodiments, the first branch bracket 81 and the second branch bracket 82 are arranged radially at intervals to form a limiting channel 62, which communicates with the inner cavity and groove 5 of the main bracket 10, respectively. In this embodiment, the covering bracket 100, a portion of the first branch bracket 81, a portion of the second branch bracket 82, and a portion of the main bracket 10 together enclose the limiting channel 62. The limiting channel 62, which limits the sheath core 600 in the radial direction, has a simple, reasonable, and ingenious structure, eliminating the need for additional limiting constraint structures for limiting the sheath core 600 in the radial direction, thus reducing the number of components.

[0129] Please see Figure 24 and Figure 25 In some embodiments, the first branch support 81 is provided with a blank cover (denoted as the first blank cover 813), and the second branch support 82 is provided with a blank cover (denoted as the second blank cover 822). The first blank cover 813 and the second blank cover 822 are arranged radially side by side to form a limiting channel 62 between the first branch support 81 and the second branch support 82. The first blank cover 813 and the second blank cover 822 can move in a direction away from each other so that the limiting channel 62 is in an open state, such as... Figure 24 As shown; when part of the external branch stent 500 is implanted into the first branch stent 81 and / or the second branch stent 82 and the sheath core 600 does not penetrate the limiting channel 62, the first blank covering 813 and the second blank covering 822 are attached to ensure that the limiting channel 62 is in a closed state, as shown. Figure 25 As shown. Understandably, the first blank covering 813 and the second blank covering 822 refer to coverings that are not supported by any supporting structures such as wave loops or waveform units. The radial support capacity of the first blank covering 813 and the second blank covering 822 is relatively small. The limiting channel 62 formed by the first blank covering 813 and the second blank covering 822 has good deformability. The limiting channel 62 can open when the sheath core 600 enters the limiting channel 62, and the limiting channel 62 can close when the sheath core 600 has not penetrated the limiting channel 62 and part of the external branch stent 500 is implanted into the first branch stent 81 and / or the second branch stent 82, to prevent blood in the inner cavity of the main stent 10 from leaking out through the limiting channel 62. In other embodiments, the areas corresponding to the first blank covering 813 and the areas corresponding to the second blank covering 822 can also be supported by waveform units.

[0130] Please see Figure 22 and Figure 24In some embodiments, the first blank film 813 and the second blank film 822 respectively form the first channel wall and the second channel wall of the limiting channel 62. The first channel wall has a first wall edge 8131 and a second wall edge 8132 spaced apart circumferentially, and the second channel wall has a third wall edge 8221 and a fourth wall edge 8222 spaced apart circumferentially. The first wall edge 8131 and the third wall edge 8221 are spaced apart and can form an open opening 63. The second wall edge 8132 and the fourth wall edge 8222 are connected, and the open opening 63 communicates with the limiting channel 62. The open opening 63 facilitates the insertion of the tip 610 (or end) of the sheath core 600 into or out of the limiting channel 62. Understandably, the channel wall of the limiting channel 62 can cover more than 1 / 5 of the circumference of the sheath core 600. For example, the channel wall of the limiting channel 62 can wrap around more than half the circumference of the sheath core 600, so that the limiting channel 62 can better limit the sheath core 600 radially. Alternatively, the channel wall of the limiting channel 62 can wrap around the entire sheath core 600, to better limit the radial movement of the sheath core 600. Exemplarily, the main support 10 includes an inner wall segment 13 disposed opposite to the open opening 63. The inner wall segment 13, the open opening 63, and the second wall edge 8132 are sequentially arranged. The inner wall segment 13, the first channel wall, and the second channel wall cooperate to form the limiting channel 62. This reduces the requirements on the deformation capacity of the first and second channel walls, allowing both the first branch support 81 and the second branch support 82 to maintain a good shape, thus providing sufficient space for blood flow. In addition, the inner wall segment 13, the first channel wall and the second channel wall cooperate to form a limiting channel 62. Compared with the scheme where the first wall edge 8131 and the third wall edge 8221 are fixedly connected to each other without an open opening 63, when the sheath core 600 is withdrawn from the limiting channel 62, the sheath core 600 is withdrawn against the inner wall segment 13, making it less likely for the tip 610 of the sheath core 600 to hook onto the edge of the opening at the axial end of the limiting channel 62 that is further away from the groove 5. This makes it less likely for the corresponding areas of the first branch bracket 81 and / or the second branch bracket 82 to deform or shift.

[0131] Please see Figure 26 and 27In some embodiments, the first blank film 813 and the second blank film 822 respectively form the first channel wall and the second channel wall of the limiting channel 62. The first channel wall has a first wall edge 8131 and a second wall edge 8132 arranged radially spaced apart, and the second channel wall has a third wall edge 8221 and a fourth wall edge 8222 arranged radially spaced apart. The first wall edge 8131 is connected to the third wall edge 8221, and the second wall edge 8132 is connected to the fourth wall edge 8222, so that the channel wall of the limiting channel 62 forms a closed annular structure. The first blank film 813 and the second blank film 822 can move in a direction away from each other so that the limiting channel 62 is in an open state, allowing the sheath core 600 to enter the limiting channel 62, such as... Figure 26 As shown; when the sheath core 600 is withdrawn from the limiting channel 62, the first blank covering 813 and the second blank covering 822 adhere to each other so that the limiting channel 62 is in a closed state. When part of the external branch stent 500 is implanted into the first branch stent 81 and / or the second branch stent 82, the first blank covering 813 and the second blank covering 822 adhere even more tightly, as shown. Figure 27 As shown. When the limiting channel 62 is in the closed state, the first blank cover 813 and the second blank cover 822 can be attached together to effectively seal the limiting channel 62 and prevent blood from leaking out through the limiting channel 62.

[0132] Please see Figure 28 and Figure 29 In some embodiments, an end support 64 is provided at the axial end of the limiting channel 62 further away from the groove 5, and the end support 64 extends circumferentially along the limiting channel 62. When the inner branch stent 8 is in its natural state, the opening at the axial end of the limiting channel 62 further away from the groove 5 is open. When part of the outer branch stent 500 is implanted into the inner branch stent 8, the opening at the axial end of the limiting channel 62 further away from the groove 5 is closed, which can prevent blood flow in the main stent 10 from leaking out of the limiting channel 62. The provision of the end support 64 allows the opening at the axial end of the limiting channel 62 further away from the groove 5 to maintain a good shape and remain open when the inner branch stent 8 is in its natural state (i.e., when the outer branch stent 500 is not inserted into the inner branch stent 8 or the inner branch stent 8 is not compressed or deformed), which facilitates the retraction of the sheath core 600 and can effectively reduce the risk of the sheath core 600 hooking the edge of the opening at the axial end of the inner branch stent 8 further away from the groove 5 during the retraction process. Exemplarily, the end support 64 includes a wave loop, wave unit, or other closed or open annular support structure. Exemplarily, the radial support force of the end support 64 is less than the radial support force of the first branch bracket 81 or the second branch bracket 82. Exemplarily, the end support 64 extends at least one circumferential turn along the limiting channel 62, such as... Figure 28As shown; or, the length of the end support 64 extending circumferentially along the limiting channel 62 is less than the circumference of the limiting channel 62, such as... Figure 29 As shown. Exemplarily, the shape of the end support 64 can be designed to any suitable shape according to actual needs, such as circular, C-shaped, or crescent-shaped. Exemplarily, the end support 64 can be made of a radiopaque material, which can provide support while also being radiopaque during the operation to better indicate the position of the opening of the limiting channel 62 at the axial end further away from the groove 5.

[0133] In some embodiments, the channel wall at the opening of the limiting channel 62 further away from the axial end of the groove 5 and / or at the distal opening closer to the axial end of the groove 5 is a blank end film. In this embodiment, the opening of the limiting channel 62 further away from the axial end of the groove 5 is provided with an end support, and the channel wall at the opening of the limiting channel 62 closer to the axial end of the groove 5 is a blank end film, that is, the opening of the limiting channel 62 closer to the axial end of the groove 5 is not provided with an end support, to prevent the guide wire or external branch support 500 from accidentally entering the limiting channel 62 when the film support 100 is in its natural state.

[0134] In some embodiments, the sheath core 600 includes a tip head 610 and a core rod 620 connected to the tip. To enable the sheath core 600 to retract more smoothly and reduce the opening of the axial end of the hooked inner branch bracket 8 further away from the groove 5 during the retraction of the sheath core 600, a transition portion 630 may be provided between the tip head 610 and the core rod 620 of the sheath core 600. The maximum width of the transition portion 630 gradually decreases from the core rod 620 to the tip head 610. This arrangement facilitates a smooth transition between the tip head 610 and the core rod 620 and enables the sheath core 600 to retract more smoothly from the self-limiting channel 62.

[0135] In some embodiments, the limiting channel 62 and the bottom film section 511 are axially spaced apart, such that the limiting groove 512 formed by the limiting channel 62 and the bottom film section 511 is axially spaced apart. In this way, both the limiting channel 62 and the limiting groove 512 can radially limit the sheath core 600, thereby improving the radial limiting capability of the sheath core 600.

[0136] In some embodiments, the limiting channel 62 and the limiting structure 9 are spaced apart along the axial direction, so that the limiting channel 62 and the limiting structure 9 are spaced apart along the axial direction. In this way, both the limiting channel 62 and the limiting structure 9 can radially limit the sheath core 600, thereby improving the radial limiting capability of the sheath core 600.

[0137] In some embodiments, the limiting structure 9 and the bottom film section 511 can respectively radially limit the sheath core 600, thereby improving the radial limiting capability of the sheath core 600.

[0138] In some embodiments, the limiting channel 62 and the bottom film section 511 are axially spaced apart, so that the limiting groove 512 formed by the limiting channel 62 and the bottom film section 511 is axially spaced apart; the limiting structure 9 and the bottom film section 511 can respectively radially limit the sheath core 600; thus, the limiting channel 62, the limiting groove 512 and the limiting structure 9 can all radially limit the sheath core 600, effectively improving the radial limiting capability of the sheath core 600.

[0139] Understandably, the bottom film section 511, the limiting structure 9 and the limiting channel 62 can be provided by any one of them, any two of the three, or all three at the same time.

[0140] Reference Figure 30 In some embodiments, the mesh cover 61 may be omitted. When the mesh cover 61 is omitted, after the covered stent 100 is implanted, the narrow blood vessel lumen is easily squeezed by the middle section 3 where the groove 5 is located because the middle section 3 is not supported by the mesh cover 61. This causes the blood vessel wall to occupy the space of the groove 5 and cause the branch opening to be blocked. To reduce the probability of this phenomenon, a restraint component can be provided on the covered stent 100.

[0141] Exemplarily, a restraint assembly is disposed on the main stent 10, having a restrained state and a released state. When in the restrained state, the restraint assembly radially restrains at least one region of the intermediate segment 3. When in the released state, the restraint assembly releases the restraint on the intermediate segment 3. During implantation, after the covered stent 100 is released from the sheath, the restraint assembly remains in the restrained state, maintaining radial restraint on at least one region of the intermediate segment 3, thus forming a gap between the vessel wall and at least a portion of the intermediate segment 3. This reduces the risk of branch orifice blockage, allowing the guidewire and external branch stent 500 to smoothly enter the branch orifice through this gap. After the external branch stent 500 is implanted, the restraint on the intermediate segment 3 is released, allowing the intermediate segment 3 to be completely released.

[0142] In this embodiment, the intermediate main body film 11c includes an intermediate film 110 and a bottom film 51a. The intermediate film 110 is generally arc-shaped, and its cross-sectional profile is generally arc-shaped. Its two radial edges serve as the two edges of the groove 5 in the width direction, and are respectively fixedly connected to the two edges of the bottom film 51a in the width direction. For example, the two edges of the bottom film 51a in the width direction are respectively fixedly connected to the two edges of the groove 5 in the width direction (the first edge 531 and the second edge 532) by means of sewing, gluing, etc.

[0143] The intermediate segment 3 also includes at least one intermediate wavering coil 310 arranged at intervals along the axial direction. The intermediate wavering coil 310 is connected to the intermediate main body covering membrane 11c by means of suturing, bonding, etc. The intermediate wavering coil 310 includes multiple waves arranged sequentially along the circumferential direction. Among the multiple waves, there are at least multiple first short waves 311 and at least one first high wave 312 (the wave height of the high wave is greater than that of the short wave). At least one first high wave 312 crosses both sides of one of the width directions of the groove 5. This arrangement helps to better maintain the shape of the edge of the groove 5 in the width direction and the shape of both sides of the edge, making the force on both sides of the edge of the groove 5 in the width direction more uniform, and making it less likely to form wrinkles and cause thrombosis after implantation. In particular, when multiple first high waves 312 are arranged sequentially along the axial direction of the edge of the groove 5, the probability of edge shortening in the width direction of the groove 5 can be effectively reduced, further reducing the risk of wrinkles forming at the edge of the groove 5. In this embodiment, the intermediate segment 3 is supported only by multiple intermediate wavering coils 310. In other embodiments, one or more intermediate wavering coils 310 may be omitted, and instead, they may be supported by means of other means. Figure 1 , Figure 2 One or more arc-shaped waveform units arranged at axial intervals are used instead, and the bottom 51 of the groove can be set as follows: Figures 8 to 15 One or more bottom support members 71 shown may be configured, for example, as follows: Figure 9 One or more of the first bottom support member 71a, the second bottom support member 71b and the third bottom support member 71c shown may also be provided as shown in Figures 12(A) and 12(B), including the joint portion 712.

[0144] Reference Figure 30 and Figure 32 Furthermore, the intermediate wave loop 310 may include low-profile wave units and high-profile wave units. The low-profile wave units include a plurality of sequentially arranged first low-profile waves 311, and the high-profile wave units include a plurality of sequentially arranged first high-profile waves 312. The high-profile wave units extend from the first edge 531 of the groove 5 to the second edge 532, such that both edges of the groove 5 in the width direction are provided with first high-profile waves 312, and the first high-profile waves 312 span both sides of the edge of the groove 5 where they are located. This arrangement helps to better maintain the shape of the two edges of the groove 5 in the width direction.

[0145] Reference Figures 30 to 33For example, the main wave loop 101 of the proximal segment 2 and the distal segment 1 includes a second high wave 112 and a second low wave 111, wherein the wave angle of the first high wave 312 is smaller than the wave angle of the second high wave 112 in the proximal segment 2 and the distal segment 1, and the first high wave 312 and the second high wave 112 are located on the same radial side of the covered stent 100, for example, both are located on the large bend side (i.e., the outer side of the bend when the covered stent 100 bends in the direction of the groove opening 52, the side that is stretched when bending), while the first low wave 311 and the second low wave 111 are located on the small bend side (i.e., the inner side of the bend when the covered stent 100 bends in the direction of the groove opening 52, the side that is compressed when bending). Because the wave angle of the first high wave 312 is smaller than that of the second high wave 112 in the proximal segment 2 and the distal segment 1, the middle segment 3 is more easily bound by the binding component, and the radial force after binding is not too large, which may cause the binding component to loosen, deform or be difficult to remove, thus improving the reliability of binding.

[0146] In some embodiments, refer to Figure 34 and Figure 36 The coating support 100 also includes a retractable portion 320, which is located at the bottom 51 of the groove. When in a restrained state, the restraining assembly restrains the retractable portion 320 so that the retractable portion 320 has a first dimension in the width direction of the groove 5. When in a released state, the restraining assembly releases the restraint on the retractable portion 320 so that the retractable portion 320 has a second dimension in the width direction of the groove 5, where the first dimension is smaller than the second dimension. In this embodiment, the bottom 51 of the groove is provided with a plurality of retractable portions 320 spaced apart axially. In other embodiments, one or more retractable portions 320 may be provided.

[0147] Reference Figure 35 For example, along the width direction of the groove 5, support portions 711 are provided on both sides of the easy-to-retract portion 320. For example, please refer to... Figure 34The easy-to-retract section 320 only includes a blank bottom film section 511. The middle wavering 310 is a non-closed wavering 310a. The non-closed wavering 310a includes a bottom section located at the bottom of the groove 51. The bottom section is connected to the bottom film 51a by stitching, gluing, or other means. The bottom section includes a wavering opening and support portions 711 located on both sides of the wavering opening. The blank bottom film section 511 in the area of ​​the bottom of the groove corresponding to the wavering opening serves as the easy-to-retract section 320. Since the bottom film section 511 has no support structure, it can be easily restrained when subjected to the restraining force of the restraining component. Moreover, the radial force after restraint is not too large, which may cause the restraining component to loosen, deform, or be difficult to remove, thus improving the reliability of the restraint. The non-closed waveguide 310a includes a first end and a second end, forming a waveguide opening 313 between the first and second ends. Support portions 711 are provided on both sides of the waveguide opening 313, and each support portion 711 includes one or more sequentially arranged and interconnected support waves 314. A support unit 715 is also provided between the waveguide opening 313 and the support portion 711 of the non-closed waveguide 310a. The support unit 715 includes a first edge wave 315a located at the first end of the non-closed waveguide 310a and a second edge wave 315b located at the second end of the non-closed waveguide 310a. The wave angles of the first edge wave 315a and the second edge wave 315b are smaller than the wave angles of the support waves 314 in the support portion 711. This arrangement makes it easier for the areas on both sides of the waveguide opening 313 to be restrained by the restraint components. Furthermore, the wave rod closer to the wave opening 313 in the first edge wave 315a is designated as the first axial support wire 7151a, and the wave rod closer to the wave opening 313 in the second edge wave 315b is designated as the second axial support wire 7151b. The first axial support wire 7151a and the second axial support wire 7151b extend approximately axially (approximately axially means that the angle between them and the axis of the covering support 100 does not exceed 10°). This arrangement helps to reduce the risk of the first and second ends of the non-closed wave 310a puncturing the bottom covering 51a.

[0148] Reference Figures 34 to 36For example, the restraint assembly includes a plurality of coils 41 and a restraint wire 42; at least some of the coils 41 are connected to at least one intermediate wave coil 310. When the restraint wire 42 passes through the plurality of coils 41, the restraint assembly is in a restrained state; when the restraint wire 42 is withdrawn from the plurality of coils 41, the restraint assembly is in a released state. For example, at least some of the coils 41 are located at the bottom 51 of the groove and connected to at least one non-closed wave coil 310a. For the same non-closed wave coil 310a, at least two coils 41 are provided thereon, and the at least two coils 41 are arranged sequentially along the circumference of the non-closed wave coil 310a and distributed on both sides of the retractable portion 320 in the width direction of the groove 5. When the restraint wire 42 passes through at least two coils 41 distributed on both sides of the retractable portion 320 and brings the coils 41 on both sides of the retractable portion 320 closer to each other, the retractable portion 320 is restrained, and its size in the width direction of the groove 5 decreases. When the binding wire 42 is pulled out of the coil 41, the binding assembly no longer binds the easy-retractable part 320. The diameter of the coil 41 can be matched with the binding wire 42, and each coil 41 is formed by a single strand of wire or by multiple strands of wire.

[0149] Understandably, the retractable part 320 in this embodiment can also achieve the function of the radially limiting sheath core 600 described above, for example, referring to... Figure 37 In the restrained state, the first and second ends of the non-closed wave coil 310a bend toward the inner cavity of the main support 10 and approach each other. The bottom coated section 511 between the first and second ends forms a limiting groove 512 recessed toward the inner cavity of the main support 10. The opening direction of the limiting groove 512 is toward the inner cavity of the main support 10. The limiting groove 512 radially restricts the sheath core 600, while the restraining assembly reduces the size of the retractable portion 320 in the width direction of the groove 5. The size of the bottom coated section 511 in the width direction of the groove 5 can be set according to its specific function; for example, when used as a seat limiting sheath core 500, it can be set as described above.

[0150] In other embodiments, refer to Figure 38The retractable section 320 includes a retractable unit, which may include one or more retractable waves 3211. Exemplarily, the intermediate wave loop 310 is a closed wave loop 310b, which includes a bottom section located at the bottom of the groove 51. The bottom section is connected to the bottom covering film 51a by stitching, adhesive, or other means. The bottom section includes a retractable unit and support portions 711 disposed on both sides of the retractable unit. The retractable unit includes multiple retractable waves 3211 arranged sequentially and interconnected, and the support portions 711 include multiple support waves 314 arranged sequentially and interconnected. The wave angle of the retractable wave 3211 is smaller than that of the support waves 314, making it easier for the retractable wave 3211 to be restrained by the restraining component. In other embodiments, the wave height of the retractable wave 3211 may also be higher than that of the support waves 314, which is beneficial for better limiting the shortening of the bottom of the groove 51. In other embodiments, the support portion 711 may include only one support wave 314.

[0151] In the above embodiments, the easy-to-receive part 320 can also be any other suitable structure, and the support part 711 can also adopt such as Figure 9 , Figure 11 Figure 12(A), Figure 12(B) Figure 13 , Figure 14 The structure of the central support portion 711 can be any suitable structure. As long as the bending strength of the retractable portion 320 is less than that of the support portion, the retractable portion 320 can be more easily bound by the binding assembly than the support portion. The bending strength can be measured by a three-point bending test. In other embodiments, the radial support force of the retractable portion 320 can be less than that of the support portion; that is, in the width direction of the groove 5, the support force of the retractable portion 320 can be less than that of the support portion.

[0152] The dimension of the retractable part 320 in the width direction of the groove 5 can be 10% to 50% of the width of the groove 5, for example, 10%, 20%, 30%, 40%, 50%. This arrangement allows the intermediate wave ring 310 to provide better support and be easily secured by the binding component.

[0153] Understandably, the aforementioned easy-to-receive part 320, limit structure 9 and limit channel 62 can be provided with only one of them, or any two of the three, or all three at the same time.

[0154] Figure 30 , Figure 31 , Figure 34 , Figure 36In this embodiment, a first branch stent 81 is disposed within the main stent 10 and communicates with the groove 5. A second branch stent 82 and the first branch stent 81 are disposed on one side of the axial direction of the groove 5, and the first branch stent 81 and the second branch stent 82 are spaced apart axially. For example, the second branch stent 82 and the first branch stent 81 are disposed on the proximal end side of the groove 5, that is, both the second branch stent 82 and the first branch stent 81 are disposed on the proximal segment 2 of the main stent 10. In this embodiment, the second branch stent 82 is disposed outside the main stent 10, and the first branch stent 81 and the second branch stent 82 on the axial side of the groove 5 do not form a triangular region with the main stent 10, thus reducing the impact on the blood flow direction within the lumen of the main stent 10. Furthermore, once the second branch stent 82 is implanted into the branch vessel 200, it facilitates the alignment of the groove 5 with the branch vessel 200. Please refer to [link to previous text]. Figure 31 In some embodiments, the distal end of the first branch support 81 may also have a guide segment 812, the cross-sectional area of ​​which extends from the proximal end to the distal end in a gradually increasing manner. Designing the distal end of the first branch support 81 as a funnel-shaped guide segment 812 allows the guide segment 812 to guide the insertion of the guide wire or the external branch support 500. Understandably, in other embodiments, the positions of the first branch support 81 and the second branch support 82 may differ. Figure 30 , Figure 31 , Figure 34 , Figure 36 As shown in the image.

[0155] In other embodiments, the covered stent 100 further includes a restraint assembly disposed on the proximal segment 2 and / or the distal segment 1, which, when in a restrained state, radially restrains at least one region of the proximal segment 2 and / or the distal segment 1, and when in the released state, releases the restraint assembly from the proximal segment 2 and / or the distal segment 1.

[0156] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "mechanical coupling," and "coupling" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and can refer to the internal communication of two components or the interaction between two components. Mechanical coupling or coupling of two components includes direct coupling and indirect coupling, such as a direct fixed connection or a connection through a transmission mechanism. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0157] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0158] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A covered stent, characterized in that, include: The main support includes a proximal section, a middle section and a distal section in sequence along the axial direction. The side of the middle section is recessed towards the inner cavity of the main support to form a groove. The middle section includes at least one middle wave loop. The middle wave loop includes a plurality of first low waves and at least one first high wave, wherein at least one of the first high waves crosses both sides of the edge of one width direction of the groove. A restraint assembly is provided on the main support and has a restraint state and a release state. When in the restraint state, the restraint assembly radially restrains at least one area of ​​the middle section. When in the release state, the restraint assembly releases the restraint on the middle section. The groove includes a bottom, and the intermediate wavering is a non-closed wavering, which includes a first end and a second end, forming a wavering opening between the first end and the second end. Support portions are provided on both sides of the wavering opening along the width direction of the groove. The wavering opening and the support portions are located at the bottom of the groove. A blank bottom film section is provided in the bottom area of ​​the groove corresponding to the wavering opening. The bottom film section is an easily retractable part. In the bound state, the first end and the second end of the non-closed wavering bend towards the inner cavity of the main support and move closer to each other. The bottom film section forms a limiting groove recessed towards the inner cavity of the main support, with the opening direction of the limiting groove facing towards the inner cavity of the main support. The limiting groove is used to limit the sheath core radially.

2. The covered stent according to claim 1, characterized in that, The intermediate wave ring includes a low-wave unit and a high-wave unit. The low-wave unit includes a plurality of first low-wave units arranged in sequence, and the high-wave unit includes a plurality of first high-wave units arranged in sequence. The high-wave units extend from a first edge spaced apart in the width direction of the groove to a second edge. A first high-wave unit in the high-wave unit crosses both sides of the first edge, and a first high-wave unit in the high-wave unit also crosses both sides of the second edge.

3. The covered stent according to claim 2, characterized in that, One or more main wave rings are provided in both the proximal and distal segments along the axial direction of the covered stent. The main wave rings include a second high wave and a second low wave. The wave angle of the first high wave is smaller than that of the second high wave, and the first high wave and the second high wave are located on the same radial side of the covered stent.

4. The covered stent according to claim 1, characterized in that, When in the constrained state, the constraining assembly constrains the retractable part so that the retractable part has a first dimension in the width direction of the groove. When in the released state, the constraining assembly releases the constraining assembly from the retractable part so that the retractable part has a second dimension in the width direction of the groove, wherein the first dimension is smaller than the second dimension.

5. The covered stent according to claim 4, characterized in that, The bottom of the groove includes a bottom covering film, and the support portion is connected to the bottom covering film.

6. The covered stent according to claim 1, characterized in that, A support unit is also provided between the support portion and the wave ring opening. The support unit includes a first edge wave and a second edge wave respectively disposed on both sides of the wave ring opening. The support portion includes one or more support waves. The wave angles of the first edge wave and the second edge wave are both smaller than the wave angle of the support wave.

7. The covered stent according to any one of claims 4 to 6, characterized in that, The bending strength of the retractable part is less than that of the support part.

8. The covered stent according to any one of claims 1 to 6, characterized in that, The restraint assembly includes multiple coils and restraint wires; at least some of the coils are connected to at least one of the intermediate wave coils; when the restraint wires are threaded through the multiple coils, the restraint assembly is in a restrained state; when the restraint wires are pulled out from the multiple coils, the restraint assembly is in a released state.

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