Covered stent

Abstract

The application provides a covered stent, which comprises a main stent and a support structure, the main stent is provided with a groove; the support structure comprises a bottom support piece, the bottom support piece is used for supporting a groove bottom of the groove, and the groove comprises the groove bottom; the bottom support piece comprises a buffer part and a plurality of first wave-shaped units, the buffer part and the plurality of first wave-shaped units cooperate to form an integrated structure, and each first wave-shaped unit is arranged in an axial direction; the first wave-shaped unit comprises a first radial end part and a second radial end part, a first buffer rod of the buffer part is connected with the first radial end parts of two adjacent first wave-shaped units, the second radial end parts of the two first wave-shaped units connected with the same first buffer rod are arranged in an axial direction and form a first open structure. The covered stent provided by the application can avoid that the groove bottom area where the bottom support piece is located is excessively raised towards the opening direction of the groove and excessively occupies the space of the groove, so that the risk that the groove bottom blocks the guide wire or the outer branch stent from entering the inner branch stent can be reduced.

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 communicating with the stent's lumen. These grooves correspond to the branch vessels, allowing blood from the aorta to flow 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:

[0007] The main support frame is provided with a groove, the groove including the bottom of the groove;

[0008] A support structure includes a bottom support member, which is used to support the bottom of the groove;

[0009] The bottom support includes a buffer section and multiple first waveform units. The buffer section and the multiple first waveform units cooperate to form an integral structure. Each first waveform unit is arranged axially. The first waveform unit includes a first radial end and a second radial end. The buffer section includes a first buffer rod. The first buffer rod connects the first radial ends of two adjacent first waveform units. The second radial ends of two first waveform units connected to the same first buffer rod are spaced apart axially to form a first open structure.

[0010] In one embodiment, the buffer section further includes a second buffer rod, which connects the second radial ends of two adjacent first waveform units. The first radial ends of two first waveform units connected to the same second buffer rod are spaced apart in the axial direction to form a second open structure. The first buffer rod, the second buffer rod, and the plurality of first waveform units cooperate to form an integral structure.

[0011] In one embodiment, each of the first waveform units is spaced apart along the axial direction; except for the first waveform units located at both ends of the axial direction, one of the first radial ends and the second radial ends of each of the other first waveform units is connected to the first buffer rod, and the other is connected to the second buffer rod.

[0012] In one embodiment, the first open structure includes a first open opening, the number of the second buffer rods includes a plurality of the second buffer rods, the plurality of the second buffer rods are spaced apart along the axial direction, and the second buffer rods and the first open opening are alternately arranged along the axial direction; and / or, the second open structure includes a second open opening, the number of the first buffer rods includes a plurality of the first buffer rods, the plurality of the first buffer rods are spaced apart along the axial direction, and the first buffer rods and the second open opening are alternately arranged along the axial direction.

[0013] In one embodiment, the number of the first buffer rods is greater than the number of the second buffer rods; the number of the first open structures is greater than the number of the second open structures.

[0014] In one embodiment, the first buffer bar and / or the second buffer bar are substantially parallel to the edge of the groove in the width direction.

[0015] In one embodiment, the shape of the first buffer rod includes at least one of the following: straight, arc-shaped, serrated, wavy, S-shaped, or curved; when the shape of the first buffer rod includes an arc shape, the first buffer rod protrudes toward the side away from the second radial end; and / or, the shape of the second buffer rod includes at least one of the following: straight, arc-shaped, serrated, wavy, S-shaped, or curved.

[0016] In one embodiment, the shape of the first buffer rod includes an arc shape, and the number of the first buffer rods includes a plurality of the first buffer rods, which are spaced apart along the axial direction. The arc of the first buffer rods located at both ends of the axial direction is greater than the arc of the first buffer rod located in the middle of the axial direction.

[0017] In one embodiment, each of the first waveform units has the same phase.

[0018] In one embodiment, the support structure further includes:

[0019] An end support member, wherein the axial end of the end support member is movably connected to the axial end of the bottom support member;

[0020] The covered scaffold also includes:

[0021] An inner branch support is provided inside the main support and connects the inner cavity of the main support and the groove, and at least one inner branch support is provided on one axial side of the groove.

[0022] In this embodiment, at least one axial end of the end support is connected to the bottom of the groove, and the other axial end of the end support extends in a direction away from the bottom of the groove to at least one inner branch bracket and is connected to the inner branch bracket.

[0023] This invention also provides a covered stent, comprising:

[0024] The main support frame is provided with a groove, the groove including the bottom of the groove;

[0025] A bottom support member for supporting the bottom of the groove includes a first radial support edge and a second radial support edge spaced apart along the width direction of the bottom of the groove; in a natural expansion state, the second radial support edge protrudes and bends toward the side closer to the first radial support edge.

[0026] The covered stent provided in this embodiment of the invention includes a bottom support member, which includes a buffer portion and a plurality of first waveform units. The buffer portion and the first waveform units can support the bottom of the groove, thereby increasing the radial support force of the covered stent at the bottom of the groove. Therefore, after the covered stent is implanted into the blood vessel, it can reduce or avoid excessive bulging of the bottom area of ​​the groove where the bottom support member is located towards the groove opening, thus reducing the risk of the bottom of the groove blocking the guide wire or external branch stent from entering the internal branch stent.

[0027] 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

[0028] 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.

[0029] Figure 1 This is a schematic diagram of the implantation state of the covered stent provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of a film-coated stent provided in an embodiment of the present invention;

[0031] Figure 3 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0032] Figure 4 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the support structure provided in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the support structure provided in an embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the support structure provided in an embodiment of the present invention;

[0036] Figure 8(A) is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0037] Figure 8(B) is a schematic diagram of the structure of a covered scaffold provided in an embodiment of the present invention;

[0038] Figure 8(C) is a schematic diagram of the structure of a covered scaffold provided in an embodiment of the present invention;

[0039] Figure 9(A) is a partial structural schematic diagram of a covered scaffold provided in an embodiment of the present invention;

[0040] Figure 9(B) is a schematic diagram of the structure of a covered scaffold provided in an embodiment of the present invention;

[0041] Figure 10(A) is a partial structural schematic diagram of a covered stent provided in an embodiment of the present invention, wherein two adjacent suture teeth in the toothed area of ​​the groove are not sutured;

[0042] Figure 10(B) is a partial structural schematic diagram of a covered stent provided in an embodiment of the present invention, wherein two adjacent suture teeth in the toothed region of the groove have been sutured.

[0043] Figure 11 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0044] Figure 12(A) is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0045] Figure 12(B) is an enlarged schematic diagram of region A in Figure 12(A);

[0046] Figure 12(C) is a folding diagram of the second protrusion in Figure 12(A);

[0047] Figure 13 This is a schematic diagram of the support structure provided in an embodiment of the present invention;

[0048] Figure 14 This is a partial structural schematic diagram of a support structure provided in an embodiment of the present invention;

[0049] Figure 15 This is a partial structural schematic diagram of a film-coated stent provided in an embodiment of the present invention;

[0050] Figure 16 This is a partial structural schematic diagram of a support structure provided in an embodiment of the present invention. Detailed Implementation

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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, where the radial direction of the groove and the mesh cap refers to its width direction.

[0056] 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.

[0057] 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 covered body of the covered stent. The wave loop and the covered body are connected 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 wave crests and troughs. A wave crest and two wave rods connected to it form a wave, and a wave trough and two wave rods connected to it form a wave.

[0058] Understandably, the "wave number" referred to in the embodiments of the present invention refers to the number of wave crests or wave troughs, and the number of wave crests and wave troughs is the same in the same wave loop. "Wave height" refers to the vertical distance between a wave crest and two adjacent lowest wave troughs. "Wave angle" refers to the angle between two adjacent wave rods connecting the same vertex.

[0059] The radial support strength (unit: Pa) mentioned in this embodiment of the invention can be calculated by the following formula: Radial support strength = Radial support force ÷ Maximum axial length of the measured position. It is understood that when multiple corrugations are axially arranged at the measured position, the closer the corrugations are to each other axially, the greater the radial support strength.

[0060] 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).

[0061] Please see Figure 1This 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 is connected to the covered stent 100, and blood in the covered stent 100 enters the branch vessels 200 through the external branch stent 500.

[0062] Please see Figure 1 and Figure 2 In 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.

[0063] 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.

[0064] Please see Figure 1 and Figure 2In 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.

[0065] 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 opposite each other and extend in the same direction as the length of the covered support 100. The third edge 533 and the fourth edge 534 are axially opposite each other and are closer to the end of the covered 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 of the covered support 100, for example, at a certain angle to the length of the covered 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 recess 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.

[0066] Please refer to Figure 2 and Figure 3 In 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. In some embodiments, multiple inner branch stents 8 are provided, located within the lumen of the main stent 10, and positioned at the proximal and distal ends of the groove 5. For example, the inner branch stent 8 is connected to the inner wall of the main stent 10 and extends along the length of the main stent 10. The lumen of the inner branch stent 8 communicates with the lumen of the main stent 10 and the groove 5. When an outer branch stent 500 needs to be implanted into 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.

[0067] Please see Figure 2 In some embodiments, a mesh cover 6 is also provided on the outer side of the groove 5. The two sides of the mesh cover 6 in the circumferential direction are fixedly connected to the intermediate main body covering 11c and / or the bottom covering 51a by means of stitching, bonding, heat fusion, etc., and at least a portion of the mesh cover 6 forms a gap (or void, cavity) 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 6 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 6 on the radial plane is less than or equal to 120 degrees, so that the mesh cover 6 has good radial support force and ensures that there is sufficient space within the main support 10 for blood flow. In other embodiments, the mesh cover 6 may be omitted.

[0068] Please see Figure 4 For 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.

[0069] Please see Figure 4For 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.

[0070] For example, the edges of the first branch opening 811, the second branch opening 821 and the third branch opening 831 are provided with annular support members (not shown) to better maintain the shape of the branch openings, and the annular support members can be made of radiopaque material, which can provide support and be radiopaque during the operation to better indicate the position of the branch openings.

[0071] Please see Figure 5 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. The bottom support 71 helps to better maintain the shape of the bottom 51 of the groove, and can reduce or avoid excessive bulging of the bottom area 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 blocking the guide wire or the outer branch stent 500 from entering the inner branch stent 8; in addition, it can also maintain sufficient internal cavity space for the main stent 10.

[0072] Please see Figure 5In some embodiments, the bottom support 71 includes a buffer portion 711 and a plurality of first waveform units 712. The buffer portion 711 and the plurality of first waveform units 712 cooperate to form an integral structure. Each first waveform unit 712 is arranged axially. The first waveform unit 712 includes a first radial end 7121 and a second radial end 7122. The buffer portion 711 includes a first buffer rod 7111. The first buffer rod 7111 connects the first radial ends 7121 of two adjacent first waveform units 712. The second radial ends 7122 of two first waveform units 712 connected to the same first buffer rod 7111 are spaced apart axially and form a first open structure 713.

[0073] In the above embodiment of the film-coated support 100, since the first buffer rod 7111 connects the first radial ends 7121 of two adjacent first waveform units 712 in the radial direction, and the first buffer rod 7111 is closer to the radial sides of the groove 5 than the radial center of the first waveform unit 712, when the groove 5 is subjected to radial pressure, the first buffer rod 7111 is subjected to force and deforms and moves, thus playing a certain buffering role, thereby better maintaining the radial (or transverse) shape of the bottom 51 of the groove and the groove 5. Furthermore, compared to the scheme without the first buffer rod 7111 (i.e., the two radial ends of the two first waveform units 712 are spaced apart to form an open structure with open openings), the film-coating bracket 100 of this embodiment has a buffer portion 711 that cooperates with multiple first waveform units 712 to form an integral structure. The first buffer rod 7111 connects the first radial ends 7121 of two adjacent first waveform units 712. The buffer portion 711 and the first waveform units 712 can effectively support the bottom 51 of the groove, improving the radial support force of the film at the bottom 51 of the groove. The first buffer rod 7111 and the two adjacent first waveform units connected to the same first buffer rod 7111 The elements 712 are connected as a whole, which not only maintains the shape of the bottom 51 of the groove in the axial direction, but also deforms as a whole when the covered support 100 bulges and bends towards the groove opening 52. This causes the bottom 51 of the groove to bulge appropriately, which can maintain sufficient internal space for the main support 10, and avoid the area of ​​the bottom 51 of the groove from bulging excessively towards the groove opening 52 and thus occupying too much space in the groove 5. This reduces the risk of the bottom 51 of the groove blocking the guide wire or the outer branch support 500 from entering the inner branch support 8.

[0074] Furthermore, since the second radial ends 7122 of the two first waveform units 712 connected to the same first buffer rod 7111 are axially spaced and form a first open structure 713, the first open structure 713 allows the radial side of the bottom support member 71 to have a first open opening 7131. The first buffer rod 7111 and the two adjacent first waveform units 712 connected to the same first buffer rod 7111 cooperate to form a first non-closed structure. One of the two radial sides of the first non-closed structure is closed, and the other is open with the first open opening 7131. This allows for a larger blank covering area on the radial side of the first non-closed structure, resulting in more lateral bending space between the second radial ends 7122 of two adjacent first waveform units 712 connected to the same first buffer rod 7111. This, in turn, gives the groove bottom 51 good lateral bending performance, enabling it to 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 adhesion of the covered stent 100 and reducing the risk of leakage and thrombosis. Understandably, because the bottom support 71 has the first buffer rod 7111 and the first open structure 713, the first buffer rod 7111 allows the bottom support 71 to maintain its radial shape better, and the first open structure 713 allows the bottom support 71 to maintain its axial (or longitudinal) shape better, thus maintaining the overall shape of the bottom support 71 and improving the adhesion of the covered stent 100.

[0075] In some embodiments, when the bottom support 71 is unfolded on the same horizontal plane, the phases of each first waveform unit 712 are the same, which can improve the flexibility of the bottom support 71 and also give the bottom support 71 better lateral bending performance.

[0076] Please see Figure 5For example, each first waveform unit 712 includes a first waveform unit 712d and a first waveform unit 712e arranged axially. The first waveform unit 712d and the first waveform unit 712e are in phase. The first waveform unit 712d is closer to the proximal end of the covering bracket 100 than the first waveform unit 712e. When the bottom support 71 is deployed on the same horizontal plane, the crests of the first waveform unit 712e and the crests of the first waveform unit 712d are axially spaced and opposite to each other. The line connecting the peak of waveform unit 712e and the peak of the first waveform unit 712d extends approximately along the axial direction of the coating support 100 (approximately along the axial direction of the coating support 100 means the angle between the peak and the axial direction of the coating support 100 does not exceed 10°), and the troughs of the first waveform unit 712e and the troughs of the first waveform unit 712d are spaced apart and opposite to each other along the axial direction. The line connecting the troughs of the first waveform unit 712e and the troughs of the first waveform unit 712d that are opposite each other in the axial direction extends approximately along the axial direction of the coating support 100. The peak of the first waveform unit 712e may be located in the region between two adjacent peaks of the first waveform unit 712d. For example, the peak of the first waveform unit 712e may be located between two adjacent troughs of the first waveform unit 712d. In other embodiments, the peak of the first waveform unit 712e may be located outside the region between two adjacent peaks of the first waveform unit 712d. Since the first waveform unit 712d and the first waveform unit 712e are in phase, the first waveform unit 712e has a larger axial movement space when subjected to axial compressive force, thereby improving the flexibility and lateral bending performance of the bottom support 71. The structures of other axially adjacent first waveform units 712 are similar to those of the first waveform units 712d and 712e, and will not be described in detail here.

[0077] Understandably, in other embodiments, two adjacent first waveform units 712 may not be completely in phase, but rather have a phase difference. For example, when the bottom support 71 is unfolded on the same horizontal plane, the line connecting the peak of the first waveform unit 712e and the peak of the first waveform unit 712d in the axial direction has an angle greater than 10° with the axial direction of the covering bracket 100, and the line connecting the trough of the first waveform unit 712e and the trough of the first waveform unit 712d in the axial direction has an angle greater than 10° with the axial direction of the covering bracket 100, but the peak of the first waveform unit 712e and the trough of the first waveform unit 712d are not arranged opposite each other in the axial direction. For example, the first buffer rod 7111 is located at the radial end of the first waveform unit 712, closer to the radial edge of the groove 5 than the radial center of the first waveform unit 712. The first buffer rod 7111 can be connected to the bottom film 51a at its location or to the radial edge of the groove 5. It can deform first when subjected to radial force to buffer the radial force, and then transmit the unbuffered force to the first waveform unit 712. The first waveform unit 712 deforms to further resist the radial force.

[0078] For example, the first buffer rod 7111 is approximately parallel to the radial edge of the groove 5, which facilitates uniform force distribution in the radial direction and enables it to perform a more sensitive and efficient buffering function. In other embodiments, the first buffer rod 7111 may also be set at an angle to the radial edge of the groove 5, for example, the included angle between the first buffer rod 7111 and the radial edge of the groove 5 is an acute angle.

[0079] For example, the first buffer rod 7111 is parallel to the axial direction of the film-coated support 100, which facilitates uniform force distribution in the radial direction and enables it to perform a more sensitive and efficient buffering function. In other embodiments, the first buffer rod 7111 may also be arranged at an angle to the axial direction of the film-coated support 100, for example, the included angle between the first buffer rod 7111 and the axial direction of the film-coated support 100 is an acute angle.

[0080] Please see Figure 5In some embodiments, the buffer portion 711 further includes a second buffer rod 7112, which connects the second radial ends 7122 of two adjacent first waveform units 712. The first radial ends 7121 of the two first waveform units 712 connected to the same second buffer rod 7112 are spaced apart in the axial direction to form a second open structure 714. The first buffer rod 7111, the second buffer rod 7112 and the multiple first waveform units 712 cooperate to form an integral structure. Since the first buffer rod 7111 connects the first radial ends 7121 of two adjacent first waveform units 712 in the axial direction, and the second buffer rod 7112 connects the second radial ends 7122 of two adjacent first waveform units 712, the first buffer rod 7111 and the second buffer rod 7112 are closer to the radial edges of the groove 5 than the radial center of the first waveform unit 712. Therefore, the first buffer rod 7111 and the second buffer rod 7112 can respectively play a buffering role on the radial sides of the bottom support 71, so that the radial sides of the bottom support 71 can deform more evenly when subjected to radial external force, and avoid excessive deformation on one side of the bottom support 71. Therefore, the radial shape of the bottom 51 of the groove can be better maintained. Furthermore, the first buffer rod 7111 and the two adjacent first waveform units 712 connected to the same first buffer rod 7111 are connected as one unit, and the second buffer rod 7112 and the two adjacent first waveform units 712 connected to the same second buffer rod 7112 are connected as one unit. This not only better maintains the shape of the bottom of the groove 51 in the axial direction, but also allows the first buffer rod 7111 and the two adjacent first waveform units 712 connected to the same first buffer rod 7111 to deform as a whole when the covered support 100 bulges and bends towards the groove opening 52. The second buffer rod 7112 and the two adjacent first waveform units 712 connected to the same second buffer rod 7112 to deform as a whole, so that the bottom of the groove 51 is appropriately raised, maintaining sufficient internal cavity space for the main support 10. This avoids the area of ​​the bottom of the groove 51 where it is located from bulging excessively towards the groove opening 52 and thus occupying too much space in the groove 5. This effectively reduces the risk that the bottom of the groove 51 will block the guide wire or the outer branch support from entering the inner branch support 8. Furthermore, since the covered stent 100 will bend laterally to the left to conform to the blood vessel after implantation of the aortic arch 300, that is, the left side of the groove 5 is the convex side of the bend (or the outer side of the bend, i.e. the side that is stretched when bending), and the right side of the groove 5 is the concave side of the bend (or the inner side of the bend, i.e. the side that is compressed when bending), when the second buffer rod 7112 is located to the right of the first waveform unit 712, compared with the scheme without the second buffer rod 7112, the risk of excessive wrinkles in the bottom covered stent 51a in the area where the bottom support 71 is located due to bending can be reduced, thus reducing the disturbance of blood flow in the main stent 10 by the side of the groove bottom 51 located in the inner cavity of the main stent 10.

[0081] Furthermore, since the first radial ends 7121 of the two first waveform units 712 connected to the same second buffer rod 7112 are spaced apart and form a second open structure 714, the second open structure 714 allows the radial side of the bottom support member 71 to have a second open opening 7141. The second buffer rod 7112 and the two adjacent first waveform units 712 connected to the same second buffer rod 7112 cooperate to form a second non-closed structure. One of the two radial sides of the second non-closed structure is closed, and the other is open with the second open structure 714, so that the radial side of the second non-closed structure has more blank covering area, so that there is more lateral bending space between the first radial ends 7121 of the two adjacent first waveform units 712 connected to the same second buffer rod 7112. This makes the bottom of the groove 51 have good lateral bending performance, which is conducive to the bottom of the groove 51 better conforming to the lateral bending of the covered stent 100. This allows the bottom of the groove 51 and the covered stent 100 to adapt well to the lateral bending shape of the blood vessel, improve the wall adhesion of the covered stent 100, and avoid the risk of blood leakage and thrombosis. Because the bottom support 71 has a second buffer rod 7112 and a second open structure 714, the second buffer rod 7112 enables the bottom support 71 to maintain a better radial shape, and the second open structure 714 enables the bottom support 71 to maintain a better axial (or longitudinal) shape, thereby maintaining the overall shape of the bottom support 71, further improving the wall adhesion of the covered stent 100, and reducing the risk of blood leakage and thrombosis.

[0082] The number of first waveform units 712 can be designed according to actual needs, such as two, three, four, or more. In some embodiments, the first waveform units 712 are spaced apart along the axial direction; except for the first waveform units 712 located at both ends of the axial direction, one of the first radial end 7121 and the second radial end 7122 of each of the other first waveform units 712 is connected to a first buffer rod 7111, and the other is connected to a second buffer rod 7112. Please refer to [link / reference]. Figure 5For example, each first waveform unit 712 includes a proximal first waveform unit 712a, a distal first waveform unit 712b, and a middle first waveform unit 712c, with the middle first waveform unit 712c located between the proximal first waveform unit 712a and the distal first waveform unit 712b; one of the first radial end 7121 and the second radial end 7122 of the middle first waveform unit 712c is connected to a first buffer rod 7111, and the other is connected to a second buffer rod 7112, so that the first buffer rod 7111, the second buffer rod 7112, and each first waveform unit 712 cooperate to form an integral bow-shaped structure or a spring-like structure, thereby ensuring that the axial and radial shapes of the bottom support member 71 are well maintained and that it has good lateral bending performance. For example, one of the first radial end 7121 and the second radial end 7122 of the proximal first waveform unit 712a is connected to the first buffer rod 7111 or the second buffer rod 7112, and the other is spaced apart from the buffer portion 711 to form a first open structure 713; one of the first radial end 7121 and the second radial end 7122 of the distal first waveform unit 712b is connected to the first buffer rod 7111 or the second buffer rod 7112, and the other is spaced apart from the buffer portion 711 to form a second open structure 714; the number of the middle first waveform units 712c may include one, two, three or more. In other embodiments, at least two adjacent first waveform units 712 may be directly connected to each other; and / or at least two adjacent second radial ends 7122 may be directly connected, as long as a first buffer rod 7111 connects the first radial ends 7121 of two adjacent first waveform units 712, and the second radial ends 7122 of two first waveform units 712 connected to the same first buffer rod 7111 are spaced apart to form a first open structure 713.

[0083] For example, the second buffer rod 7112 is located at the radial end of the first waveform unit 712, closer to the radial edge of the groove 5 than the radial center of the first waveform unit 712. The second buffer rod 7112 can be connected to the bottom film 51a at its location or to the radial edge of the groove 5. It can deform first when subjected to radial force to buffer the radial force, and then transmit the unbuffered force to the first waveform unit 712. The first waveform unit 712 deforms to further resist the radial force.

[0084] For example, the second buffer rod 7112 is approximately parallel to the radial edge of the groove 5, which facilitates uniform force distribution in the radial direction and enables it to perform a more sensitive and efficient buffering function. In other embodiments, the second buffer rod 7112 may also be set at an angle to the radial edge of the groove 5, for example, the included angle between the second buffer rod 7112 and the radial edge of the groove 5 is an acute angle.

[0085] For example, the second buffer rod 7112 is parallel to the axial direction of the covered support 100, which facilitates uniform radial force distribution and enables more sensitive and efficient buffering. In other embodiments, the second buffer rod 7112 may also be angularly positioned to the axial direction of the covered support 100; for example, the angle between the second buffer rod 7112 and the axial direction is an acute angle. For example, the first buffer rod 7111 and the second buffer rod 7112 are parallel, which facilitates uniform radial force distribution and enables more sensitive and efficient buffering. In other embodiments, the first buffer rod 7111 and the second buffer rod 7112 may also be angularly positioned to the axial direction of the covered support 100; for example, the angle between them is an acute angle.

[0086] Please see Figure 5 In some embodiments, the first open structure 713 includes a first open opening 7131, and the number of second buffer bars 7112 includes multiple second buffer bars 7112, which are spaced apart along the axial direction. The second buffer bars 7112 and the first open opening 7131 are alternately arranged along the axial direction to take into account lateral bending performance and better maintain the overall shape.

[0087] Please see Figure 5 In some embodiments, the second open structure 714 includes a second open opening 7141, and the number of first buffer bars 7111 includes a plurality of first buffer bars 7111, which are spaced apart along the axial direction. The first buffer bars 7111 and the second open opening 7141 are alternately arranged along the axial direction to take into account both lateral bending performance and overall shape retention capability.

[0088] The number of the first buffer bar 7111 and / or the second buffer bar 7112 can be designed according to actual needs. For example, the number of the first buffer bar 7111 can be one, two, three or more, and the number of the second buffer bar 7112 can be zero, one, two, three or more.

[0089] Please see Figure 4 , Figure 5In some embodiments, the number of first buffer rods 7111 is greater than the number of second buffer rods 7112; the number of first open structures 713 is greater than the number of second open structures 714. Understandably, after implantation into the aortic arch 300, the covered stent 100 will laterally bend to the left, conforming to the blood vessel. That is, after implantation, the left side of the groove 5 is the convex side of the bend (or the outer side of the bend, i.e., the side stretched during bending), and the right side of the groove 5 is the concave side of the bend (or the inner side of the bend, i.e., the side compressed during bending). In this embodiment, by setting the number of first buffer rods 7111 to be greater than the number of second buffer rods 7112, the right side of the groove 5 has a greater shortening space than the left side after implantation, allowing the bottom 51 of the groove to adapt well to the lateral bending shape of the blood vessel, improving the adhesion of the covered stent 100 to the vessel wall, and reducing the risk of leakage or thrombosis. In other embodiments, the number of second buffer bars 7112 may be equal to or less than the number of second buffer bars 7112.

[0090] The shapes of the first buffer rod 7111 and / or the second buffer rod 7112 can be designed according to actual needs. In some embodiments, please refer to... Figure 5 The first buffer rod 7111 has a straight shape. In some embodiments, the first buffer rod 7111 has at least one of the following shapes: arc-shaped, serrated, wavy, S-shaped, curved, etc., so that the left side of the bottom support 71 has better extensibility and better conformity to the blood vessel, allowing the covered stent 100 to better fit the blood vessel. For example, please refer to... Figure 6 When the first buffer rod 7111 has an arc shape, it protrudes towards the side away from the second radial end 7122. This allows the first buffer rod 7111 to elongate axially when the groove 5 is subjected to radial pressure, enabling it to deform. A portion of the first buffer rod 7111 can move towards the direction closer to the second radial end 7122, allowing it to straighten or tend to straighten, thus providing better buffering against the radial force and better maintaining the radial shape of the bottom support 71. Furthermore, the arc shape of the first buffer rod 7111 also improves the lateral bending performance of the bottom support 71. In other embodiments, the arc-shaped first buffer rod 7111 may also protrude towards the side closer to the second radial end 7122. For example, please refer to... Figure 7 The first buffer rod 7111 has a wave-like shape, and the left side of the bottom support 71 has good extensibility, which can better conform to the lateral bending of the blood vessel towards the left side of the groove 5, so that the covered stent 100 can better fit the blood vessel.

[0091] In some embodiments, the shape of the first buffer rod 7111 includes an arc shape, and the number of the first buffer rods 7111 includes a plurality of first buffer rods 7111, which are spaced apart along the axial direction; the arc of the first buffer rods 7111 located at both ends of the axial direction is greater than the arc of the first buffer rod 7111 located in the middle of the axial direction, so that when the axial ends of the bottom support member 71 are subjected to radial pressure, a guide channel with a narrowing width in the direction of the branch opening can be formed near the branch opening corresponding to the first buffer rods 7111 at the ends, so as to effectively guide the guide wire or the outer branch support 500 into the corresponding branch opening.

[0092] In some embodiments, the second buffer rod 7112 has a straight shape, and the processing and connection of the second buffer rod 7112 and the bottom covering film 51a are convenient, quick and simple; in other embodiments, the second buffer rod 7112 can also be any other suitable shape, such as arc, serrated, wavy, S-shaped, curved serrated, etc.

[0093] Referring to Figures 8(A) and 8(B), in some embodiments, the bottom support 71 includes a first radial support edge 701 and a second radial support edge 702 arranged radially at intervals, with the second radial support edge 702 positioned to the right of the first radial support edge 701. In its natural expansion state, the second radial support edge 702 protrudes and bends toward the side closer to the first radial support edge 701. For example, the overall shape of the second radial support edge 702 includes an arc or other curved shape that protrudes toward the side closer to the first radial support edge 701. The second radial support edge 702 can be made to protrude and bend toward the side closer to the first radial support edge 701 by changing the radial position of the second radial ends 7122 of one or more first waveform units 712. For example, the second radial ends 7122 of the first waveform units 712 in the middle region can be offset to the left relative to the second radial ends 7122 of the first waveform units 712 in the end regions, such that the line connecting the second radial ends 7122 of the plurality of first waveform units 712 generally forms an arc that protrudes and bends toward the side closer to the first radial support edge 701. In other embodiments, the bottom support 71 may adopt a structure different from that in Figures 8(A) and 8(B), and the implementation of the second radial support edge 702 protruding and bending toward the side closer to the first radial support edge 701 may also be different from that in Figures 8(A) and 8(B). Compared to the straight second radial side 512, in this embodiment, the covered stent 100 has a second radial support edge 702 that protrudes and bends towards the side closer to the first radial support edge 701. After the covered stent 100 is implanted, the straightening force of the second radial support edge 702 is smaller. Even when implanted into a vessel with a large degree of lateral curvature, it can adapt well to the lateral curvature of the vessel, reducing the probability of the covered stent 100 deflecting circumferentially due to excessive curvature on the right side of the groove bottom 51 after implantation. This reduces the probability of the mesh cover 6 or the groove opening 52 deviating from the branch vessel 200 due to circumferential deflection of the covered stent 100, effectively reducing the risk of the covered stent 100 obstructing or blocking the branch vessel 200, thereby ensuring normal blood flow in the branch vessel 200. It is understood that in other embodiments, the shape of the second radial support edge 702 can also be other shapes, such as a straight line or other curved shapes. In other embodiments, the first buffer rod 7111 and / or the second buffer rod 7112 may be omitted. As long as the second radial support edge 702 protrudes and bends toward the side closer to the first radial support edge 701, the covered stent 100 can adapt well to the lateral bending shape of the blood vessel, reducing the probability that the covered stent 100 will deflect in the circumferential direction due to excessive bending on the right side of the bottom 51 of the groove after implantation.

[0094] Further, referring to FIG8(A), in some embodiments, the first radial support edge 701 is curved and protrudes toward the side away from the second radial support edge 702. For example, the overall shape of the first radial support edge 701 includes an arc or other curved shape that is curved and protrudes toward the side away from the second radial support edge 702. The first radial support edge 701 can be curved and protrudes toward the side away from the second radial support edge 702 by changing the radial position of the first radial ends 7121 of one or more first waveform units 712. For example, the first radial ends 7121 of the first waveform units 712 in the middle region can be offset to the left relative to the first radial ends 7121 of the first waveform units 712 in the end regions, such that the line connecting the first radial ends 7121 of the plurality of first waveform units 712 is approximately an arc that is curved and protrudes toward the side away from the second radial support edge 702. In other embodiments, the bottom support 71 may adopt a structure different from that in Figures 8(A) and 8(B), and the implementation of the first radial support edge 701 protruding and bending towards the side away from the second radial support edge 702 may also differ from that in Figures 8(A) and 8(B). Compared to the first radial support edge 701 and the second radial support edge 702 being straight, after the covered stent 100 is implanted, the straightening force of the first radial support edge 701 and the second radial support edge 702 in this embodiment is smaller, which can better adapt to the lateral bending shape of the blood vessel and further reduce the probability of the covered stent 100 deflecting in the circumferential direction due to excessive bending on the right side of the bottom 51 of the groove. It is understood that in other embodiments, the shape of the first radial support edge 701 may also be other shapes, such as a straight line or other curved shapes. In other embodiments, the first buffer rod 7111 and / or the second buffer rod 7112 may be omitted.

[0095] In some embodiments, the bottom of the groove 51 includes a first radial side 511 and a second radial side 512 arranged radially at intervals, with the second radial side 512 located to the right of the first radial side 511. Exemplarily, the bottom film 51a includes the first radial side 511 and the second radial side 512, and the first edge 531 and the second edge 532 of the groove 5 are respectively connected to the first radial side 511 and the second radial side 512 of the bottom film 51a. The second radial side 512 has an arcuate shape, protruding towards the side closer to the first radial side 511, and forming a recessed space 513 on the side of the second radial side 512 away from the first radial side 511. This arrangement makes the second edge 532 of the groove 5 (such as the right edge) generally arcuate, and the edge of the intermediate support 3a of the main body support 10 that matches the second edge 532 of the groove 5 also forms an arcuate shape protruding towards the side closer to the first radial side 511, so as to match the second edge 532 of the groove 5. Therefore, the recoil force of the second radial side 512 after implantation of the covered stent 100 in the recessed space 513 can be further reduced. Even when implanted into a vessel with a large degree of lateral curvature, it can adapt well to the lateral curvature of the vessel, thus further reducing the probability of the covered stent 100 deflecting circumferentially due to excessive curvature on the right side of the bottom 51 of the recess after implantation. In other embodiments, the shape of the second radial side 512 can also be other shapes, such as a straight line or other curved shapes.

[0096] Referring to Figure 8(A), in some embodiments, the shape of the first radial side 511 may also include an arc shape, with the first radial side 511 bulging and curving away from the side away from the second radial side 512. This arrangement makes the first edge 531 of the groove 5 (such as the left edge) generally arc-shaped, and the edge of the intermediate support 3a of the main support 10 that matches the first edge 531 of the groove 5 also forms an arc shape bulging away from the side away from the second radial side 512, so as to match the second edge 532 of the groove 5. Thus, after the covered stent 100 is implanted, the recoil forces of both the first radial side 511 and the second radial side 512 in this embodiment are relatively small, which can better adapt to the lateral curvature of the blood vessel, further reducing the probability of circumferential deflection of the groove 5, and further reducing the risk of blockage of the branch blood vessel 200 due to circumferential deflection of the groove 5. In other embodiments, the shape of the first radial side 511 may also be other shapes, such as a straight line or other curved shapes. For example, referring to FIG8(B), in the naturally expanded state, only the middle segment 3 of the covered stent 100 may be curved, while the proximal segment 2 and the distal segment 1 extend coaxially to better position the implantation site of the covered stent 100. Referring to FIG9(B), in the naturally expanded state, the covered stent 100 is arc-shaped overall, with the proximal segment 2 extending along the tangent direction of the proximal end of the middle segment 3, and the distal segment 1 extending along the tangent direction of the distal end of the middle segment 3. This configuration can reduce the straightening force of the covered stent 100 when it is laterally bent after implantation. In other embodiments, the covered stent 100 may also be entirely straight or have other curved shapes.

[0097] In some embodiments, the second radial side 512 is parallel to the first radial side 511, so that both the proximal and distal ends of the groove 5 have sufficient operating space to facilitate the entry of the guidewire or outer branch support 500 into the inner branch support 8. In other embodiments, the second radial side 512 and the first radial side 511 may not be parallel.

[0098] In some embodiments, the length of the second radial side 512 is less than or equal to the length of the first radial side 511. Referring to FIG8(A), for example, the length of the second radial side 512 is approximately equal to the length of the first radial side 511 (the difference between the length of the second radial side 512 and the length of the first radial side 511 does not exceed 5 mm), so that when at least part of the covered support 100 is compressed within the sheath of the conveyor, the compression length of the area where the first radial side 511 is located and the area where the second radial side 512 is located are substantially the same, preventing the two adjacent first waveform units 712 from hooking due to excessive difference in compression length, thereby ensuring that the covered support 100 has a good unfolded shape after being released from the conveyor.

[0099] In some embodiments, referring to FIG8(C), the first radial side 511 and the second radial side 512 of the groove bottom 51 are both straight and substantially parallel (i.e., the included angle between the first radial side 511 and the second radial side 512 does not exceed 10°, for example, it can be 0°, 3°, 5°, 8°, 10°, etc.), while the second radial support edge 702 protrudes and bends toward the side closer to the first radial support edge 701. A compressible gap 703 is formed on the side of the second radial support edge 702 away from the first radial support edge 701. The compressible gap 703 is located between the second radial support edge 702 and the second radial side 512. The compressible gap 703 may only include the blank film section and not other support structures. In other embodiments, the compressible gap 703 may also include a gap support structure (not shown) with a radial support force less than that of the first waveform unit 712. By setting a compressible gap 703, a larger space for movement is provided between the second radial support edge 702 and the second radial side edge 512, allowing the second radial side edge 512 of the groove bottom 51 to deform more flexibly according to different blood vessel shapes and better adapt to various curved shapes. Furthermore, since both the first radial side edge 511 and the second radial side edge 512 are straight and approximately parallel, the radial sides of the groove bottom 51 experience more even force during sheath retraction or after compression into the sheath tube, preventing damage caused by excessive pressure on one side. In addition, the straight structure of the groove bottom 51 ensures that the matching main stent 10 is also straight, facilitating precise positioning during stent implantation. In this embodiment, the first radial support edge 701 can bend and protrude towards the side away from the second radial support edge 702; the specific beneficial effects are described above. In other embodiments, the first radial support edge 701 can be straight or have other curved shapes.

[0100] Please refer to Figures 9(A) and 9(B). For example, in the natural expansion state, the length of the second radial side 512 may be less than the length of the first radial side 511.

[0101] Please refer to Figures 10(A) and 10(B). In some embodiments, the groove 5 includes a first edge 531 and a second edge 532. The first edge 531 and the second edge 532 are connected to the first radial side 511 and the second radial side 512, respectively. The second edge 532 includes a toothed region 532a. The toothed region 532a includes a plurality of suture teeth spaced apart along the axial direction of the second edge 532. The second edge 532 is at least partially formed by suturing two adjacent suture teeth of the toothed region 532a to reduce the phenomenon of wrinkles after the second edge 532 is sutured and avoid affecting the blood flow in the main body stent 10. Understandably, suturing the adjacent two suture teeth (i.e., the edges of the suture teeth extending away from the groove 5, which are located on the outer surface of the main body scaffold 10) makes the second edge 532 smoother after suturing, reducing the disturbance to blood flow in the main body scaffold 10 after implantation; wherein, Figure 10(A) shows the state of the two adjacent suture teeth of the toothed region 532a of the second edge 532 when the suture teeth are not sutured; Figure 10(B) shows the state of the two adjacent suture teeth of the toothed region 532a of the second edge 532 after suturing the suture teeth.

[0102] Please see Figure 11 In some embodiments, the covered support 100 further includes a sealing element 9, which covers the inner side (closer to the inner cavity of the main support 10) and / or the outer side (farther from the inner cavity of the main support 10) of the second edge 532 having a serrated region 532a. The sealing element 9 is used to seal the serrated region 532a. Since there are many pinholes in the serrated region 532a, it may affect the sealing effect of the bottom of the groove 51. This embodiment improves the sealing effect of the bottom of the groove 51 by providing a sealing element 9 in the serrated region 532a. The connection method between the sealing element 9 and the bottom cover 51a or the serrated region 532a includes at least one of the following: adhesive connection, stitching connection, heat fusion connection, etc.

[0103] Referring to Figures 12(A) and 12(B), in some embodiments, the length of the second radial side 512 of the bottom film 51a before shaping is longer than the length of the second radial side 512 after shaping (e.g., heat shaping). Before shaping, the second radial side 512 is fixedly connected to the second edge 532 of the groove 5 to form a fixed edge, for example, by sewing, gluing, heat fusion, etc. The fixed edge is then folded and shaped into a retractable edge 532a according to a preset scheme. The retractable edge 532a includes at least one folded portion arranged sequentially along its axial direction. Each folded portion includes an unfolded state and a folded state along the axial (or length) direction of the retractable edge 532a. When the film support 100 is in a naturally expanded state, each folded portion is in a folded state. By applying external force to the folded portion, the folded portion can be changed from a folded state to an unfolded state, thereby lengthening the retractable edge 532a or changing the curvature of the retractable edge 532a. This design helps improve the shape adaptability of the area where the stretchable edge 532a is located, enabling the covered stent 100 to better adapt to the lateral curvature of the blood vessel and further reducing the probability that the covered stent 100 will deflect in the circumferential direction due to excessive curvature on the right side of the groove 5.

[0104] Exemplarily, the folding portion includes a first folding unit and a second folding unit. The first folding unit is located at the second edge 532 (or the fixed edge), and the second folding unit is located at the bottom 51 of the groove. The first folding unit includes a first protrusion located within the cavity of the main support 10. The first protrusion protrudes towards the cavity of the main support 10 and forms a first folding ridge 541 at its apex. This first folding ridge 541 points towards the distal end of the covered stent 100. Since blood flow within the main support 10 is from proximal to distal, the first folding ridge 541 pointing towards the distal end of the covered stent 100 helps reduce the obstruction and interference of the first protrusion within the cavity of the main support 10 to blood flow. The first protrusion also includes a first folding piece 551 and a second folding piece 552 that jointly connect the first folding ridge 541. The first folding unit also includes a third folding piece 553 and a second folding ridge 542, which jointly connect to the second folding ridge 542. The first folding piece 551 and the second folding piece 552 are both formed by folding the fixed edges along the first folding ridge 541 and the second folding ridge 542. When the first folding unit is in the folded state, the second folding ridge 542 points towards the proximal end of the covered support 100 and is closer to the proximal end of the covered support 100 than the first folding ridge 541. The second folding piece 552 is located between the first folding piece 551 and the third folding piece 553. The first folding piece 551 is closer to the inner cavity of the main support 10 than the second folding piece 552 and the third folding piece 553, and the third folding piece 553 is farther away from the inner cavity of the main support 10 than the first folding piece 551 and the second folding piece 552. A first recessed region is formed between the first folded flap 551 and the second folded flap 552. The first recessed region has a first opening 561 facing away from the first folded ridge 541, with the first opening 561 facing the proximal end of the covered stent 100. The second recessed region has a second opening 562 facing away from the second folded ridge 542, with the second opening 562 facing the distal end of the covered stent 100. The first recessed region is located on the outer surface of the main stent 10, and the second recessed region is located on the inner surface of the main stent 10 (i.e., in the inner cavity of the main stent 10). Since the first opening 561 of the first recessed region located on the outer surface of the main stent 10 faces the proximal end of the covered stent 100, even if blood leaks from the proximal end of the covered stent 100 into the space between the main stent 10 and the vessel wall, it will more easily enter the first recessed region and coagulate there. The blood coagulated in the first recessed region helps to improve the sealing effect between the outer surface of the main stent 10 and the vessel wall, and also helps to accelerate the endothelialization process of the covered stent 100. Since the second recessed area located in the main stent 10 has its second opening 562 facing the distal end, the blood flowing from the proximal end to the distal end in the main stent 10 does not easily enter the second recessed area, so it has little impact on the blood flow of the main stent 10.Furthermore, along the axial direction of the covered stent 100, support structures, such as wave-shaped units, are provided on both sides of the first folding unit. This facilitates the close fit between the second folding piece 552 and the third folding piece 553 after the covered stent 100 is implanted, minimizing the volume of the second recessed area and further reducing the impact of the second recessed area on blood flow within the main stent 10. In addition, when an external force is applied to the first folding unit, the first folding piece 551 and the second folding piece 552 can rotate relative to the first folding ridge 541, and the second folding piece 552 and the third folding piece 553 can rotate relative to the second folding ridge 542. This allows the first folding unit to be transformed into an unfolded state, enabling the retractable edge 532a to lengthen or change its curvature.

[0105] Referring to Figures 12(A), 12(B), and 12(C), the second folding unit, by way of example, includes a second protrusion that protrudes toward the inner cavity of the main support 10, and its protruding tip forms a third folding ridge 543. This third folding ridge 543 points toward the proximal end of the covered support 100, which helps reduce obstruction to the guidewire and the external branch support 500. The second protrusion also includes a fourth folding piece and a fifth folding piece that jointly connect the second folding ridge 542. The fourth folding piece 554 and the fifth folding piece 555 are formed by folding the bottom covered film 51a along the third folding ridge 543. When the third folding unit is in the folded state, the fourth folding piece 554 is further away from the inner cavity of the main support 10 than the fifth folding piece 555. A third recessed area is formed between the fourth folding piece 554 and the fifth folding piece 555, and the third recessed area has a third opening 563 toward the distal end of the covered support 100, pointing away from the third folding ridge 543. The third recessed area is located within the cavity of the main stent 10. Since the third opening 563 of the third recessed area within the cavity of the main stent 10 faces the distal end of the covered stent 100, blood flowing from the proximal to the distal end within the main stent 10 is unlikely to enter the third recessed area, thus having little impact on blood flow within the main stent 10. Furthermore, along the axial direction of the covered stent 100, support structures, such as the first wave unit 712, are provided on both sides of the second folding unit. This facilitates the close fit of the fourth fold piece 554 and the fifth fold piece 555 after implantation of the covered stent 100, minimizing the volume of the third recessed area and further reducing its impact on blood flow within the main stent 10. In addition, when an external force is applied to the second folding unit, the fourth fold piece 554 and the fifth fold piece 555 can rotate relative to the third folding ridge 543, thereby allowing the second folding unit to unfold, extending the retractable edge 532a or changing its curvature. In other embodiments, the retractable edge 532a may employ any other suitable structure to enable its retraction, such as providing a retractable elastic element on the fixed edge.

[0106] In other embodiments, extendable edges 532a can be provided on both radial sides of the groove 5, which helps the radial sides of the groove 5 to better conform to the shape of the blood vessel and improves its lateral bending performance. The specific configuration method can be referred to the above description and will not be repeated here. Please refer to... Figure 5 In some embodiments, the bottom support 71 further includes a second waveform unit 715 and a third waveform unit 716. The second waveform unit 715 is connected to a first waveform unit 712 at the axial proximal end, and the third waveform unit 716 is connected to a first waveform unit 712 at the axial distal end. This allows the end of the bottom support 71 to better maintain the shape of the bottom 51 of the groove near the branch opening of the inner branch support 8 in the direction of the groove 5, facilitating better entry of the guide wire and the outer branch support 500 into the corresponding inner branch support 8. For example, the second waveform unit 715 and the first waveform unit 712a located at the proximal end of the bottom support 71 overlap each other. The wave height of the second waveform unit 715 is less than the wave height of the first waveform unit 712a, and the wave angle of the second waveform unit 715 is greater than the wave angle of the first waveform unit 712a, which helps to improve the overall radial support force of the proximal end of the bottom support 71. The second waveform unit 715 includes multiple first end waves 7151 that bulge towards the proximal end of the bottom support 71. Figure 5 The diagram shows three first end waves 7151; in other embodiments, the number of first end waves 7151 may differ. Figure 5 As shown, the number of first end waves 7151 can be one or more. Multiple first end waves 7151 are sequentially connected radially in the groove 5. The apex of the first end wave 7151 is denoted as the crest of the second waveform unit 715, and the connection point of two adjacent first end waves 7151 forms the trough of the second waveform unit 715. The first waveform unit 712a includes multiple first support waves 7123 that bulge towards the proximal end of the bottom support member 71. Figure 5 The diagram shows two first support waves 7123; in other embodiments, the number of first support waves 7123 may be different. Figure 5As shown, the number of first support waves 7123 can be two or more. Multiple first support waves 7123 are sequentially connected radially in the groove 5. The apex of each first support wave 7123 is denoted as the crest of the first waveform unit 712a, and the connection point of two adjacent first support waves 7123 forms the trough of the first waveform unit 712a. The first waveform unit 712a includes at least one first support wave 7123 overlapping with the second waveform unit 715. The crest of this first support wave 7123 is closer to the proximal end of the bottom support member 71 than the trough of the second waveform unit 715, and the crest of this first support wave 7123 is axially opposite to the branch opening of one of the inner branch supports 8 facing the groove 5. This arrangement helps improve the shape retention capability of the bottom 51 of the groove in the area near the branch opening. For example, Figure 5 In the first waveform unit 712a, both first support waves 7123 overlap with the second waveform unit 715. The peaks of the two first support waves 7123 are closer to the proximal end of the bottom support member 71 than the troughs of the second waveform unit 715. Furthermore, the peaks of the two first support waves 7123 are axially opposite to the two branch openings located near the proximal end of the groove 5. The peaks of the first support waves 7123 are located between two adjacent first end waves 7151, and are axially spaced and opposite to the troughs of the second waveform unit 715. This arrangement ensures a more uniform area of ​​blank film-coated region near the bottom of the groove 51, avoiding excessively large blank film-coated areas, thereby further reducing the probability of the bottom of the groove 51 clogging the branch openings of the inner branch support 8. In other embodiments, the relative positional relationship between the first support waves 7123 and the first end waves 7151 may differ from... Figure 5 As shown. One radial end of the second waveform unit 715 is connected to the first radial end 7121 of the first waveform unit 712a near the end, and the other end is connected to the second radial end 7122 of the first waveform unit 712a near the end. This arrangement allows the first waveform unit 712a and the second waveform unit 715 to better resist the radial compressive force together, which is beneficial to improving the shape retention ability of the bottom of the groove 51 in the area near the branch opening.

[0107] For example, the third waveform unit 716 and the first waveform unit 712b located at the distal end of the bottom support 71 overlap each other. The wave height of the third waveform unit 716 is smaller than the wave height of the first waveform unit 712b, and the wave angle of the third waveform unit 716 is larger than the wave angle of the first waveform unit 712b, which is beneficial to improving the overall radial support force of the distal end of the bottom support 71. The third waveform unit 716 includes a plurality of second end waves 7161 that bulge toward the distal end of the bottom support 71. Figure 5 Two second end waves 7161 are shown in the figure. In other embodiments, the number of second end waves 7161 may be different. Figure 5As shown, the number of second end waves 7161 can be one or more. Multiple second end waves 7161 are sequentially connected radially in the groove 5. The apex of the second end wave 7161 is denoted as the crest of the third waveform unit 716, and the connection point of two adjacent second end waves 7161 forms the trough of the third waveform unit 716. The first waveform unit 712b includes a second support wave 7124 that bulges towards the distal end of the bottom support member 71. Figure 5 A second support wave 7124 is shown; in other embodiments, the number of second support waves 7124 may differ. Figure 5 As shown, the number of second support waves 7124 can be more than one, and the apex of the second support wave 7124 is denoted as the peak of the first waveform unit 712b. The first waveform unit 712b includes at least one second support wave 7124 overlapping with the third waveform unit 716. The peak of the second support wave 7124 is closer to the far end of the bottom support member 71 than the trough of the third waveform unit 716, and the peak of the second support wave 7124 is axially opposite to the branch opening of the inner branch support 8 located at the far end of the groove 5 towards the groove 5. This arrangement helps to improve the shape retention capability of the bottom of the groove 51 in the area near the branch opening. The peak of the second support wave 7124 is located between two adjacent second end waves 7161, and is axially spaced and opposite to the trough of the third waveform unit 716. This arrangement makes the area of ​​the blank film area at the far end of the bottom of the groove 51 more uniform, avoiding the appearance of an excessively large blank film area, thereby further reducing the probability of the bottom of the groove 51 blocking the branch opening of the inner branch support 8. In other embodiments, the relative positional relationship between the second support wave 7124 and the second end wave 7161 may differ from that of the second support wave 7124. Figure 5 As shown, one radial end of the third waveform unit 716 is connected to the first radial end 7121 of the far-end first waveform unit 712b, and the other end is connected to the second radial end 7122 of the far-end first waveform unit 712b. This arrangement allows the first waveform unit 712b and the third waveform unit 716 to better resist radial compressive force together, which is beneficial to improving the shape retention ability of the groove bottom 51 in the area near the branch opening.

[0108] In other embodiments, the second waveform unit 715 and / or the third waveform unit 716 may be omitted.

[0109] Please see Figure 13 In some embodiments, the support structure 7 further includes an end support 72, which is connected to at least one of the groove bottom 51 and the bottom support 71. Exemplarily, the end support 72 is disposed at the groove bottom 51, and the provision of the end support 72 helps to maintain the shape of the groove bottom 51.

[0110] In some embodiments, at least one inner branch support 8 is disposed on one axial side of the groove 5. One axial end of at least one end support 72 is connected to the bottom 51 of the groove; the other axial end of the end support 72 extends toward the at least one inner branch support 8 in a direction away from the bottom 51 of the groove and is connected to the inner branch support 8. Since the end support 72 extends from the bottom 51 of the groove to the inner branch support 8, when the coating support 100 undergoes bending deformation, the end support 72 can resist bending to a certain extent. Even if bending deformation occurs, it can cause the inner branch support 8 and the area of ​​the bottom 51 of the groove near the inner branch support 8 to undergo regular deformation together. Therefore, it can prevent the area of ​​the bottom 51 of the groove near the inner branch support 8 from undergoing excessive deformation independently to a certain extent, thereby reducing the risk that the bottom 51 of the groove will block the branch opening due to deformation bulge.

[0111] For example, the end support 72 and the bottom support 71 can be fixedly connected to the side of the bottom cover 51a closer to the inner cavity of the main support 10 (this side is part of the inner surface of the inner cavity of the main support 10), and the end support 72 extends beyond the axial edge of the bottom cover 51a (also beyond the axial edge of the groove 5) to the lower edge of the branch opening of the inner branch support 8 connected to the bottom cover 51a, and then continues to extend to connect with the outer wall of the inner branch support 8. The end support 72 and the bottom support 71 are located on the side of the bottom cover 51a closer to the inner cavity of the main support 10, which can avoid the problem of unevenness of the bottom 51 of the groove caused by the end support 72 and the bottom support 71 being exposed in the groove 5, thereby avoiding the end support 72 from hooking with the guide wire entering the groove 5 and hindering the guide wire from entering the inner branch support 8. The portion of the end support 72 connected to the outer wall of the inner branch bracket 8 allows the lower sidewall of the inner branch bracket 8 to better maintain its shape. This prevents excessive bending deformation of the lower sidewall of the inner branch bracket 8, which would compress the inner cavity space of the inner branch bracket 8 when the covered bracket 100 bulges and bends towards the groove opening 52. Since the left and right sides of the inner branch bracket 8 do not have end supports 72, the radial compression diameter of the inner branch bracket 8 can be reduced, making it easier to retract. In other embodiments, either the end support 72 or the bottom support 71 can be fixedly connected to the side of the bottom covered film 51a further away from the inner cavity of the main bracket 10.

[0112] Please see Figure 13In some embodiments, the bottom 51 of the groove is provided with two end supports 72, namely a first end support and a second end support. In this embodiment, the first end support is located in the proximal region of the bottom 51 of the groove and is denoted as proximal support 72a, and the second end support is located in the distal region of the bottom 51 of the groove and is denoted as distal support 72b. It can be understood that in other embodiments, the first end support may also be located in the distal region of the bottom 51 of the groove, while the second end support may be located in the proximal region of the bottom 51 of the groove. In this embodiment, the proximal support 72a and the distal support 72b have different structures; in other embodiments, they may have the same structure. In other embodiments, the first branch bracket 81 and the second branch bracket 82 may be located at the distal end of the groove 5, and the third branch bracket 83 may be located at the proximal end of the groove 5, which can be adjusted according to the actual application scenario.

[0113] For example, both the proximal support 72a and the distal support 72b include waveform units, each waveform unit including at least one wave, and each wave including a vertex and a wave rod connected to the vertex. In this embodiment, the vertex connected to the proximal end of the wave rod in the proximal support 72a is designated as the wave crest, and the vertex connected to the distal end of the wave rod is designated as the wave trough; similarly, the vertex connected to the proximal end of the wave rod in the distal support 72b is designated as the wave trough, and the vertex connected to the distal end of the wave rod is designated as the wave crest.

[0114] In some embodiments, the end support 72 includes a high wave, at least one high wave extending from the bottom 51 of the groove to the inner branch bracket 8 and connected to a corresponding inner branch bracket 8. The inner branch bracket 8 includes a branch opening facing the groove 5, and the end support 72 also includes a low wave located at the bottom 51 of the groove, with the crest of the low wave either at a distance from or abutting against the branch opening of the inner branch bracket 8.

[0115] Please see Figure 14For example, the proximal support includes overlapping fourth and fifth waveform units. The fourth waveform unit retains two high waves connected radially in sequence, denoted as the first high wave 731 and the second high wave 732, respectively. The second waveform unit 715 includes two high waves and one low wave, namely the third high wave 733, the fourth high wave 734, and the first low wave 741, respectively. The first high wave 731 and the third high wave 733 extend from the bottom 51 of the groove to the first branch opening 811 of the first branch bracket 81, and then continue to extend towards the proximal end of the first branch bracket 81 and connect with it. The crests of the first high wave 731 and the third high wave 733 are both located between the proximal and distal ends of the first branch bracket 81. Furthermore, the first high wave 731 and the third high wave 733 partially overlap radially; for example, adjacent wave rods of the first high wave 731 and the third high wave 733 intersect to form an intersection point. The second high wave 732 and the fourth high wave 734 extend from the bottom 51 of the groove to the second branch opening 821 of the second branch support 82, and then continue to extend towards the proximal end of the second branch support 82 and connect with it. The crests of the second high wave 732 and the fourth high wave 734 are both located between the proximal and distal ends of the second branch support 82. The second high wave 732 and the fourth high wave 734 partially overlap radially; for example, adjacent wave rods of the second high wave 732 and the fourth high wave 734 intersect to form an intersection point. The first low wave 741 is located at the bottom 51 of the groove and does not extend outward beyond the edge of the bottom 51 of the groove. The first low wave 741 connects to the third high wave 733 and the fourth high wave 734 on both radial sides, and the first low wave 741 also partially overlaps with the first high wave 731 and the second high wave 732 on both radial sides. For example, the left wave rod of the first high wave 731 overlaps with the right wave rod of the third high wave 733 to form an intersection point; the right wave rod of the first high wave 731 overlaps with the left wave rod of the first low wave 741 to form an intersection point; the left wave rod of the second high wave 732 overlaps with the right wave rod of the first low wave 741 to form an intersection point; and the right wave rod of the second high wave 732 overlaps with the left wave rod of the fourth high wave 734 to form an intersection point. The crest of the first low wave 741 is located at the bottom 51 of the groove, and the crests of the first high wave 731 and the third high wave 733 are located on one radial side of the crest of the first low wave 741, while the crests of the second high wave 732 and the fourth high wave 734 are located on the other radial side of the crest of the first low wave 741.

[0116] Please see Figure 14For example, the left wave rod of the third high wave 733 is connected to the left wave rod of the first high wave 731 via the first connecting rod 751, and the left wave rod of the third high wave 733 is further radially away from the crest of the first low wave 741 relative to the left wave rod of the first high wave 731; the right wave rod of the fourth high wave 734 is connected to the right wave rod of the second high wave 732 via the second connecting rod 752, and the right wave rod of the fourth high wave 734 is further radially away from the crest of the first low wave 741 relative to the right wave rod of the second high wave 732.

[0117] Please see Figure 14 In some embodiments, the crests of the first high wave 731 and the third high wave 733 are both located on the first branch support 81, and the crests of the second high wave 732 and the fourth high wave 734 are both located on the second branch support 82. The first high wave 731 and the third high wave 733 overlap to form a first intersection point 7301. The distance from the first intersection point 7301 to the first branch opening 811 is less than the distance from the first intersection point 7301 to the axial end of the first branch support 81 away from the first branch opening 811, thereby providing strong support for the bottom covering film 51a near the first branch opening 811. The second high wave 732 and the fourth high wave 734 overlap to form a second intersection point 7302, and the distance from the second intersection point 7302 to the second branch opening 821 is less than the distance from the second intersection point 7302 to the axial end of the second branch support 82 away from the second branch opening 821, thereby providing strong support for the bottom covering film 51a near the second branch opening 821.

[0118] Please refer to the following at the same time Figure 14 and Figure 15In 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 761. The coating support 100 includes a proximal support 72a disposed near the first branch opening 811 and the second branch opening 821, and the proximal support 72a includes at least a first low wave 741 disposed axially opposite to the raised gap 761. The edges of 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 apex of the "W" shape forms the upwardly raised gap 761 (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, the upwardly raised gap 761 can guide the portion of the bottom coating 51a connected to it to bulge upwards. Since the high waves in the proximal support 72a (i.e. the first end support) are evenly distributed on both radial sides of the protruding gap 761, and the high waves on both sides are respectively corresponding to the first branch port 811 and the second branch port 821, the high waves on both sides of the protruding gap 761 can provide strong support for the bottom covering film 51a near the first branch port 811 and the second branch port 821. In particular, the first high wave 731 and the third high wave 733 partially overlap in the radial direction, and the second high wave 732 and the fourth high wave 734 partially overlap in the radial direction. Therefore, the combination of the first high wave 731 and the third high wave 733, and the combination of the second high wave 732 and the fourth high wave 734 can respectively act as a whole to resist the radial extrusion force, thereby further improving the radial support force. This can effectively prevent the bottom covering film 51a at the first branch port 811 and the second branch port 821 from irregularly bulging and deforming due to extrusion, thus blocking the guide wire or the outer branch support 500 from entering the branch port.

[0119] The aforementioned first low-profile wave 741 is disposed opposite to the raised gap 761. For example, the crest of the first low-profile wave 741 and the raised gap 761 are disposed opposite each other axially, and the crest of the first low-profile wave 741 and the raised gap 761 are approximately located in the same radial region. The first low-profile wave 741 does not extend to the inner branch support 8 and its radial support force is less than that of the high waves on both sides. Therefore, when subjected to radial compression, the bottom covering film connected to the first low-profile wave 741 will bulge to a certain extent along with the raised gap 761, thereby causing the bottom covering film 51a connected to the first branch port 811 and the second branch port 821 to also regularly form a slightly curved "W" shape. This not only does not obstruct the branch port, but also forms a guide channel near the corresponding branch port, guiding the guide wire into the corresponding branch port. In other embodiments, the aforementioned first low-profile wave 741 may be omitted.

[0120] In some embodiments, a second waveform unit 715 of the bottom support 71 is connected to a first waveform unit 712 near its axial end. A first end support is connected to either the second waveform unit 715 or the first waveform unit 712 connected to the second waveform unit 715. One of the crests of the second waveform unit 715 is axially spaced from and opposite to the first stub wave 741. When subjected to axial compressive force, the crest of the second waveform unit 715 can extend into the space between the two wave rods of the first stub wave 741, thereby improving the flexibility of the support structure 7, preventing the bottom 51 of the groove from bulging or deforming irregularly, and thus minimizing obstruction to the guide wire or the outer branch support 500 entering the inner branch support 8.

[0121] Please see Figure 16 In some embodiments, the second end support (i.e., the distal support 72b) is disposed close to the third branch bracket 83, and the distal support 72b includes at least one second low-profile wave 742 disposed axially opposite to the third branch opening. Exemplarily, the distal support 72b includes overlapping sixth and seventh waveform units. The sixth waveform unit includes two high waves connected radially in sequence, denoted as the fifth high wave 735 and the sixth high wave 736, respectively. The fourth waveform unit includes a low-profile wave, denoted as the second low-profile wave 742. The fifth high wave 735 and the sixth high wave 736 extend from the bottom 51 of the groove to the third branch opening 831 of the third branch bracket 83, and then continue to extend towards the proximal end of the third branch bracket 83 and connect with it. The crests of the fifth high wave 735 and the sixth high wave 736 are both located between the proximal and distal ends of the third branch bracket 83. Furthermore, the fifth high wave 735 and the sixth high wave 736 intersect with the two wave rods of the second low-profile wave 742 to form intersection points. The second low-profile wave 742 is located at the bottom 51 of the groove and does not extend outward beyond the edge of the bottom 51 of the groove. Exemplarily, the second low-profile wave 742 is connected to the third connecting rod 753 and the fourth connecting rod 754 on its radial sides, respectively. One radial side of the second low-profile wave 742 is connected to the fifth high-profile wave 735 via the third connecting rod 753, and the other radial side of the second low-profile wave 742 is connected to the sixth high-profile wave 736 via the fourth connecting rod 754. The arrangement of the fourth waveform unit helps to further improve the radial support capacity of the distal support member 72b and can better maintain the shape of the connection between the bottom 51 of the groove and the third branch opening 831 of the third branch bracket 83.

[0122] The aforementioned second low-profile wave 742 is positioned opposite to the third branch port 831 of the third branch stent 83. For example, the crest of the second low-profile wave 742 is axially opposite to the third branch port 831, and the crest of the second low-profile wave 742 may be located approximately in the same radial region as the third branch port 731. When the groove 5 is subjected to radial compression, the bottom coating 51a of the portion connected to the second low-profile wave 742 will, to a certain extent, follow the lower edge of the third branch port 831 and sink downwards. This prevents excessive blank coating between the fifth high-profile wave 735 and the sixth high-profile wave 736 from bulging under the impact of blood in the inner cavity of the main stent 10, thus blocking the guidewire and the outer branch stent 500 from entering the third branch port 831. In other embodiments, the aforementioned second low-profile wave 742 may be omitted, and the sixth or seventh waveform unit may also be omitted.

[0123] For example, a third waveform unit 716 is connected to a first waveform unit 712 at the distal end of the axial direction. A distal support member 72b is connected to either the third waveform unit 716 or the first waveform unit 712 connected to the third waveform unit 716. One of the crests of the third waveform unit 716 is axially spaced from and opposite to the second stub wave 742. When subjected to axial compressive force, the crest of the third waveform unit 716 can extend into the space between the two wave rods of the second stub wave 742, thereby improving the flexibility of the support structure 7, preventing the bottom 51 of the groove from bulging or deforming irregularly, and thus minimizing the obstruction to the guide wire or the outer branch support 500 entering the inner branch support 8.

[0124] In some embodiments, the axial end of the end support 72 is movably connected to the axial end of the bottom support 71. By movably connecting the axial ends of the end support 72 and the bottom support 71, when the covered stent 100 is implanted and bulges and bends toward the groove opening 52, the end support 72 and the bottom support 71 can move relative to each other, thereby allowing the bottom of the groove 51 to bend in segments. This reduces the risk that the bottom of the groove 51 may encroach on the inner cavity space of the inner branch stent 8 or block the branch opening of the inner branch stent 8 due to bending along with the main stent 10.

[0125] For example, the end support 72 includes a first end support and / or a second end support, which are movably connected to the corresponding axial ends of the bottom support 71. The movable connection includes one or more of hook connection, membrane connection and elastic connector connection.

[0126] For example, the proximal support 72a is movably connected to the second waveform unit 715, and the proximal support 72a is movably connected to the proximal first waveform unit 712. For example, the end support 72 is hooked to the axial end of the bottom support 71. For example, both the proximal support 72a and the distal support 72b are hooked to the axial end of the bottom support 71. In other embodiments, the end support 72 can also be connected to the bottom support 71 by any other suitable movable connection method, such as by an elastic element (e.g., a spring). For example, the end support 72 can also be axially spaced from the bottom support 71, with a blank film section between the axial ends of the end support 72 and the bottom support 71. This blank film section does not have a support structure 7, so the end support 72 and the bottom support 71 can move relative to each other. The distal support 72b is similar and will not be described in detail here. In other embodiments, the axial end of the end support 72 may also be fixedly connected to the axial end of the bottom support 71.

[0127] For example, the end support 72 is located between the bottom support 71 and one axial end of the coating bracket 100, and the end support 72 is also located between the bottom support 71 and one axial edge of the groove 5. In other embodiments, the proximal support 72a and / or the distal support 72b may be omitted.

[0128] 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 frame is provided with a groove, the groove including the bottom of the groove; A support structure includes a bottom support member, which is used to support the bottom of the groove; The bottom support includes a buffer section and multiple first waveform units. The buffer section and the multiple first waveform units cooperate to form an integral structure. Each first waveform unit is arranged axially. The first waveform unit includes a first radial end and a second radial end. The buffer section includes a first buffer rod. The first buffer rod connects the first radial ends of two adjacent first waveform units. The second radial ends of two first waveform units connected to the same first buffer rod are spaced apart axially to form a first open structure. The buffer section further includes a second buffer rod, which connects the second radial ends of two adjacent first waveform units. The first radial ends of two first waveform units connected to the same second buffer rod are spaced apart in the axial direction to form a second open structure. The first buffer rod, the second buffer rod, and a plurality of first waveform units cooperate to form an integral structure.

2. The covered stent according to claim 1, characterized in that, Each of the first waveform units is spaced apart along the axial direction; except for the first waveform units located at both ends of the axial direction, one of the first radial ends and the second radial ends of each of the other first waveform units is connected to the first buffer rod, and the other is connected to the second buffer rod.

3. The covered stent according to claim 1, characterized in that, The first open structure includes a first open opening, and the number of the second buffer rods includes a plurality of the second buffer rods, which are spaced apart along the axial direction, and the second buffer rods are alternately arranged with the first open opening along the axial direction; and / or, the second open structure includes a second open opening, and the number of the first buffer rods includes a plurality of the first buffer rods, which are spaced apart along the axial direction, and the first buffer rods and the second open opening are alternately arranged along the axial direction.

4. The covered stent according to claim 1, characterized in that, The number of the first buffer rods is greater than the number of the second buffer rods; the number of the first open structures is greater than the number of the second open structures.

5. The covered stent according to claim 1, characterized in that, The first buffer rod and / or the second buffer rod are approximately parallel to the edge of the groove in the width direction.

6. The covered stent according to claim 1, characterized in that, The shape of the first buffer rod includes at least one of the following: straight, arc, serrated, wavy, S-shaped, and when the shape of the first buffer rod includes an arc, the first buffer rod protrudes toward the side away from the second radial end; and / or, the shape of the second buffer rod includes at least one of the following: straight, arc, serrated, wavy, S-shaped.

7. The covered stent according to claim 1, characterized in that, The first buffer rod has an arc shape, and there are multiple first buffer rods. The multiple first buffer rods are spaced apart along the axial direction, and the arc of the first buffer rods at both ends of the axial direction is greater than the arc of the first buffer rod at the middle of the axial direction.

8. The covered stent according to claim 1, characterized in that, The phases of each of the first waveform units are the same.

9. The covered stent according to any one of claims 1-8, characterized in that, The support structure also includes: An end support member, wherein the axial end of the end support member is movably connected to the axial end of the bottom support member; The covered scaffold also includes: An inner branch support is provided inside the main support and connects the inner cavity of the main support and the groove, and at least one inner branch support is provided on one axial side of the groove. In this embodiment, at least one axial end of the end support is connected to the bottom of the groove, and the other axial end of the end support extends in a direction away from the bottom of the groove to at least one inner branch bracket and is connected to the inner branch bracket.

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