Covered stent, stent system and usage

Abstract

A covered stent, a stent system and a usage. The covered stent comprises a main body stent (10) and a connecting stent (20), wherein the main body stent (10) is of a tubular structure; the connecting stent (20) is of a tubular structure having a first opening (201) and a second opening (202); the first opening (201) and the second opening (202) are provided at two tail ends of the connecting stent in the axial direction of the connecting stent; either of the first opening (201) and the second opening (202) is fixed to the main body stent (10); and an inner cavity of the connecting stent (20) is in communication with a tube cavity of the main body stent (10). The connecting stent (20) has a first form and a second form, wherein the first form and the second form can be switched to each other, and the axial length of the connecting stent (20) in the first form is greater than the axial length of the connecting stent (20) in the second form. In this way, the connecting stent (20) can extend outside of the main body stent (10) to form an epitaxial branch, thereby reducing the loss rate of the tube cavity of the main body stent; and the connecting stent (20) can also retract towards the tube cavity of the main body stent (10) to form an embedded branch, so as to reconstruct some blood vessels which do not have enough space to accommodate an epitaxial branch structure at a branch blood vessel.

Description

Covered stent, stent system and application method

[0001] This application claims priority to the patent application filed with the China Patent Office on September 8, 2023, with application number CN202311161041.4 and application name "Coated stent, stent system and application method". All the above contents are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of medical device technology, and in particular to a stent graft, a stent system, and an application method. Background Art

[0003] Transluminal aortic repair (TEVAR) or endovascular aneurysm repair (EVAR) involves the use of a stent-like artificial vascular graft, radially compressed and assembled within an interventional sheath. This graft is typically delivered through a small incision in the iliofemoral artery. Using interventional techniques, the graft is delivered through the aortic lumen through the interventional sheath to the desired location in the aorta. The sheath is then withdrawn to release the graft, which then seals or isolates the aortic dissection or aneurysm within the aorta, thereby opening blood flow to the true aortic lumen and branching arteries, and closing or reducing blood flow to the dissection or aneurysm. Compared to open surgery, TEVAR or EVAR offers advantages such as less invasiveness, lower perioperative mortality, and faster recovery. In recent years, an increasing number of physicians and patients are choosing TEVAR or EVAR. With the successful application of branched stent technology in visceral endovascular repair, the progressive development of branched stent technology in TEVAR or EVAR has transformed the treatment landscape for arterial disease and expanded the indications for total endovascular repair.

[0004] Summary of the Invention

[0005] In some embodiments, the present application provides a stent graft. The stent graft includes a main stent, the main stent including two openings disposed along two axial ends of the main stent and a lumen extending axially between the two openings, and at least one window disposed on a sidewall of the main stent;

[0006] a connecting bracket, the connecting bracket comprising a first opening, a second opening, and an inner cavity extending between the first opening and the second opening, the first opening and the second opening being arranged along two axial ends of the connecting bracket, and one of the first opening and the second opening being fixed to one of the fenestrations of the main bracket, such that the inner cavity of the connecting bracket communicates with the lumen of the main bracket through the fenestration;

[0007] The connecting bracket includes a first form and a second form, the first form and the second form are switchable with each other, and the axial length of the first form of the connecting bracket is greater than the axial length of the second form of the connecting bracket. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a schematic structural diagram of a connecting bracket on a bracket system in a first embodiment of the present application in an extended state;

[0009] FIG2 is a schematic structural diagram of the connecting bracket on the stent graft shown in FIG1 in an extended state;

[0010] FIG3 is a schematic structural diagram of the connecting bracket on the bracket system shown in FIG1 in a retracted state;

[0011] FIG4 is a schematic structural diagram of the connecting stent on the stent graft shown in FIG3 in a retracted state;

[0012] FIG5 is a partial enlarged view of the stent graft shown in FIG2 at point A;

[0013] FIG6 is a partial enlarged view of the stent graft shown in FIG4 at position B;

[0014] FIG7 is a schematic structural diagram of the stent graft shown in FIG5 in other embodiments;

[0015] FIG8 is a schematic structural diagram of the stent graft shown in FIG6 in other embodiments;

[0016] FIG9 is a schematic structural diagram of some embodiments of the main support;

[0017] FIG10 is a diagram illustrating an exemplary application scenario of a stent graft according to the first embodiment;

[0018] FIG11 is a schematic structural diagram of a stent graft according to a second embodiment;

[0019] FIG12 is a schematic structural diagram of the stent graft of FIG11 from another perspective;

[0020] FIG13 is a schematic structural diagram of a stent graft according to some embodiments;

[0021] FIG14 is a schematic structural diagram of the stent graft of FIG13 from another perspective;

[0022] FIG15 is a diagram illustrating an exemplary application scenario of a stent graft according to the second embodiment;

[0023] FIG16 is a schematic structural diagram of the stent graft according to the third embodiment;

[0024] FIG17 is a schematic structural diagram of the stent graft of FIG16 from another perspective;

[0025] FIG18 is a diagram illustrating an exemplary application scenario of a stent graft according to the third embodiment;

[0026] FIG19 is a schematic structural diagram of a stent graft according to a fourth embodiment;

[0027] FIG20 is a partial enlarged schematic diagram of point C in FIG19;

[0028] FIG21 is a schematic structural diagram of the stent graft shown in FIG19 from another perspective;

[0029] FIG22 is a schematic diagram of the rotation of the first stent in the stent graft in any direction according to the fourth embodiment;

[0030] FIG23 is a schematic structural diagram of the first stent in the stent graft according to the fourth embodiment in a contracted state;

[0031] FIG24 is another schematic diagram of the structure of the first stent inside the stent graft in some embodiments;

[0032] FIG25 is a diagram illustrating an exemplary application scenario of the stent graft according to the fourth embodiment;

[0033] FIG26 is a schematic structural diagram of the stent system according to the fifth embodiment (a schematic diagram showing that the proximal end of the stent graft is at least partially released).

[0034] Figure numerals: 1, stent graft; 10, main body stent; 101, main body stent; 102, main body support skeleton; 1021, support rod; 1022, crest; 1023, trough; 1024, wrapping angle; 1025, wall-attaching angle; 1026, sealing angle; 11, window; 111, first window; 112, second window; 113, third window; 12, support ring; 121, first support ring; 122, second support ring; 123, third support ring; 13, first support section; 14, concave section; 141, avoidance section; 142, flaring portion; 15, second support section; 20, connecting bracket; 201, first opening; 2 02. Second opening; 203. First section; 204. Second section; 205. Neck; 206. Connector; 207. Connecting membrane; 208. Support; 209. Development structure; 2091. First annular development member; 2092. Second annular development member; 210. Third opening; 30. Anchoring stent; 31. First stent; 32. Second stent; 40. Reinforced semi-annular structure; 2. Branch stent; 21. Branch membrane; 22. Branch support skeleton; 3. Aortic arch; 4. Branch blood vessel; 401. Brachiocephalic artery; 402. Left common carotid artery; 403. Left clavicular artery; 5. Interventional sheath; 6. Guide head; 7. Interventional sheath core. DETAILED DESCRIPTION

[0035] In some embodiments, the stent graft comprises:

[0036] A main body stent, the main body stent comprising two openings provided along two axial ends of the main body stent and a lumen extending axially between the two openings, and a side wall of the main body stent having at least one window;

[0037] a connecting bracket, the connecting bracket comprising a first opening, a second opening, and an inner cavity extending between the first opening and the second opening, the first opening and the second opening being arranged along two axial ends of the connecting bracket, the connecting bracket being fixed to at least one of the openings of the main bracket through an end portion where the second opening is located, so that the connecting bracket and the main bracket are in communication;

[0038] The connecting bracket includes a first form and a second form, the first form and the second form are switchable with each other, and the axial length of the first form of the connecting bracket is greater than the axial length of the second form of the connecting bracket.

[0039] In some embodiments of the stent graft, the connecting stent is at least partially composed of a bellows along its axial direction.

[0040] In some embodiments of the stent graft, the connecting stent includes a first section that is interconnected and a second section that is fixed to the first section, and at least one of the first section and the second section of the connecting stent is composed of a bellows along its axial direction.

[0041] In some embodiments of the stent graft, the first shape of the connecting stent enables the connecting stent to be located outside the main stent.

[0042] In some embodiments of the stent graft, the second shape of the connecting stent enables at least a portion of the connecting stent to be located within the lumen of the main stent.

[0043] In some embodiments of the coated stent, the connecting stent includes a first section that is interconnected and a second section that is fixed to the first section. In the first form of the connecting stent, the first section and the second section are arranged along the axial direction of the connecting stent, and the connection between the first section and the second section forms the neck of the connecting stent, and the cross-sectional diameter of the neck is smaller than at least one of the cross-sectional diameters of the first opening and the second opening.

[0044] In some embodiments of the coated stent, in the first form of the connecting stent, the first section is farther away from the window of the main stent than the second section, the first opening is located at one end of the first section away from the second section, and the second opening is located at one end of the second section away from the first section, and the cross-sectional diameter of the first section gradually decreases from one end of the first opening along the axial direction of the connecting stent to the neck, and / or the cross-sectional diameter of the second section gradually decreases from one end of the second opening along the axial direction of the connecting stent to the neck.

[0045] In some embodiments, the stent graft comprises a connecting stent graft and at least one support member. The connecting stent graft forms the first and second sections through the neck portion, and the at least one support member is fixed to the peripheral wall of the first section. The cross-sectional diameter of the support member gradually decreases along the axial direction of the connecting stent graft from one end of the first opening to the neck portion.

[0046] In some embodiments of the stent graft, the second section is a flexible section formed by the connecting graft.

[0047] In some embodiments of the stent graft, the connecting stent includes a connecting member that surrounds at least a portion of the neck and is fixed to the neck.

[0048] In some embodiments of the stent graft, the connecting member is at least one of a suture set and a connecting rod, and the suture set is at least one suture sutured and fixed to the neck.

[0049] In some embodiments of the stent graft, the second shape of the connecting stent enables at least a portion of the connecting stent to be located within the lumen of the main stent.

[0050] In some embodiments of the stent graft, the second shape of the connecting stent enables at least a portion of the second segment to be located within the lumen of the main stent.

[0051] In some embodiments of the coated stent, at least part of the first segment and the second segment can overlap axially along the connecting stent, and the second form of the connecting stent enables at least part of the second segment and at least part of the first segment to be located in the lumen of the main stent.

[0052] In some embodiments of the stent graft, in the second form of the connecting stent, the first opening is located either outside the main stent or on the same plane as the cross section where the second opening is located.

[0053] In some embodiments of the stent graft, the cross-sectional diameter of the first opening is greater than, less than, or equal to the cross-sectional diameter of the second opening.

[0054] In some embodiments of the coated bracket, the main bracket further includes at least one developing structure, at least one developing structure surrounds at least a portion of the first opening of the connecting bracket or the anchoring bracket and is fixed to the first opening, and / or, at least one developing structure surrounds at least a portion of the second opening of the connecting bracket or the anchoring bracket and is fixed to the second opening.

[0055] The coated stent in some embodiments includes at least one anchoring stent, and the side wall of the main stent is provided with at least two windows, and the at least two windows are respectively a first window and a second window; the connecting stent and at least one anchoring stent are fixed to the first window and the second window, respectively, the connecting stent is connected to the lumen of the main stent through the first window, and at least one anchoring stent is connected to the lumen of the main stent through the second window; at least one anchoring stent is located at least one of inside the lumen of the main stent and outside the lumen of the main stent.

[0056] In some embodiments of the stent graft, the first fenestration is closer to the proximal end of the main stent than the second fenestration, the connecting stent is fixed to the first fenestration, and at least one anchoring stent is fixed to the second fenestration.

[0057] In some embodiments of the stent graft, the first fenestrations and the second fenestrations are arranged axially with or without intervals along the direction from the proximal end to the distal end of the main stent.

[0058] In some embodiments of the coated stent, at least one of the anchoring stents is named as a first stent; at least one of the first stents includes a first opening, a second opening, and an inner cavity extending between the first opening and the second opening, and the first opening and the second opening are arranged along the two axial ends of the first stent; at least one of the first stents is fixed to the second window through the end where the second opening is located, so that the at least one of the first stents is connected to the main stent; at least one of the first stents includes a first form and a second form, the first form and the second form of at least one of the first stents can switch with each other, and the axial length of the first form of at least one of the first stents is greater than the axial length of the second form.

[0059] In some embodiments of the stent graft, the first shape of at least one first stent enables the at least one first stent to be located within the lumen of the main stent.

[0060] In some embodiments of the stent graft, at least one of the first stents in the second form is at least partially located outside the main stent.

[0061] In some embodiments of the coated stent, at least one of the first stents includes a first section and a second section fixed to the first section. In the first form of at least one of the first stents, the first section and the second section of at least one of the first stents are arranged along the axial direction of the connecting stent, and the connection between the first section and the second section of at least one of the first stents forms the neck of the first stent; the first opening of at least one of the first stents is located at an end of the first section of at least one of the first stents away from the second section, and the second opening of at least one of the first stents is located at an end of the second section of at least one of the first stents away from the first section; the cross-sectional dimension of at least one of the first stents at its neck is smaller than at least one of the cross-sectional dimensions of its first opening and second opening.

[0062] In some embodiments of the coated stent, for at least one of the first stents, the cross-sectional diameter of the first section gradually decreases from one end of the first opening along the axial direction of the first stent to the neck, and / or the cross-sectional diameter of the second section gradually decreases from one end of the second opening along the axial direction of the first stent to the neck.

[0063] In some embodiments of the stent graft, the cross-sectional size of the first opening of at least one of the first stents is smaller than, larger than, or equal to the cross-sectional size of the second opening thereof.

[0064] In some embodiments of the coated stent, at least one of the first stents includes a connecting coating and at least one support member, the connecting coating of at least one of the first stents forms the first section and the second section through the neck, and at least one support member is fixed to the peripheral wall of the first section of at least one of the first stents.

[0065] In some embodiments of the stent graft, at least a portion of the second segment of at least one of the first stents is a flexible segment formed by the connecting graft.

[0066] In some embodiments of the stent graft, the second shape of at least one of the first stents enables at least a portion of the second segment to be located outside the lumen of the main stent.

[0067] In some embodiments of the coated stent, at least part of the first segment and the second segment of at least one of the first stents can overlap along the axial direction of the first stent, and the second form of the first stent enables at least part of the second segment and at least part of the first segment to be located outside the lumen of the main stent.

[0068] In some embodiments of the stent graft, the axial length of the connecting stent in the first form is greater than the axial length of at least one of the first stents in the first form.

[0069] In some embodiments, the stent graft comprises at least two anchoring stents, and the side wall of the main stent is provided with at least three fenestrations, wherein the at least three fenestrations are respectively a first fenestration, a second fenestration, and a third fenestration;

[0070] The connecting bracket and at least two of the anchoring brackets are respectively fixed to the first window, the second window and the third window. The connecting bracket is connected to the lumen of the main bracket through the first window, at least one of the anchoring brackets is connected to the lumen of the main bracket through the second window, and at least one of the anchoring brackets is connected to the lumen of the main bracket through the third window. Any one of the anchoring brackets is located inside the lumen of the main bracket or outside the lumen of the main bracket.

[0071] In some embodiments of the coated stent, the first window is closer to the proximal end of the main stent than the second window, and the second window is closer to the proximal end of the main stent than the third window; the connecting stent is fixed to the first window, at least one anchoring stent is fixed to the second window, and at least one anchoring stent is fixed to the third window.

[0072] In some embodiments of the stent graft, the first fenestration, the second fenestration and the third fenestration are arranged axially with or without intervals along the direction from the proximal end to the distal end of the main stent.

[0073] In some embodiments, the coated stent includes at least one anchoring stent, at least two of the connecting stents are provided, and the side wall of the main stent is provided with at least three windows, and the at least three windows are respectively a first window, a second window and a third window; at least two connecting stents and at least one anchoring stent are fixed to the first window, the second window and the third window, respectively, at least one of the connecting stents is connected to the lumen of the main stent through the first window, at least one of the connecting stents is connected to the lumen of the main stent through the second window, and at least one of the anchoring stents is connected to the lumen of the main stent through the third window; at least one of the connecting stents is located outside the lumen of the main stent in the first form, or at least one of the connecting stents is located inside the lumen of the main stent in the first form.

[0074] In some embodiments of the coated stent, at least three connecting stents are provided, and the side wall of the main stent is provided with at least three windows. At least three connecting stents are respectively fixed to at least three windows, and the connecting stent is connected to the lumen of the main stent through the windows to which it is fixed; at least one connecting stent is located outside the lumen of the main stent in the first form, or at least one connecting stent is located inside the lumen of the main stent in the first form.

[0075] In some embodiments of the stent graft, at least one of the two ports connecting the axial direction of the stent is arranged obliquely.

[0076] In some embodiments of the stent graft, at least one of the two axial ports of at least one of the anchoring stents is arranged obliquely.

[0077] In some embodiments of the coated stent, at least two windows are spaced or non-spaced along the proximal to distal direction of the main stent; the projections of at least two of the windows along the axial direction of the main stent at least partially overlap, and / or the central axes of at least two of the windows overlap.

[0078] In some embodiments of the coated stent, at least three windows are arranged in an interval or non-interval direction from the proximal end to the distal end of the main stent, and the projections of at least three of the windows along the axial direction of the main stent at least partially overlap or completely overlap, and / or the central axes of at least three of the windows overlap.

[0079] In some embodiments of the stent graft, the axial lengths of the plurality of fenestrations increase sequentially from the proximal end to the distal end of the main stent.

[0080] In some embodiments of the stent graft, the circumferential lengths of the plurality of fenestrations increase sequentially from the proximal end to the distal end of the main stent.

[0081] A coated stent, wherein the side wall of the main stent is provided with at least two windows, the at least two windows being a first window and a second window respectively, the first window being closer to the proximal end of the main stent than the second window, and the circumferential length of the second window being at least 50%-70% of the diameter of the main stent.

[0082] In some embodiments of the coated stent, the side wall of the main stent is provided with at least three windows, and the at least three windows are respectively a first window, a second window and a third window, the first window is closer to the proximal end of the main stent than the second window, and the second window is closer to the proximal end of the main stent than the third window; the circumferential length of the second window is at least 50%-70% of the diameter of the main stent, and / or the circumferential length of the third window is at least 60%-90% of the diameter of the main stent.

[0083] In some embodiments of the coated stent, the main stent includes a main coating and a plurality of main support skeletons fixed on the main coating, and the plurality of main support skeletons are arranged at intervals along the axial direction of the main coating; the main support skeleton includes a plurality of support rods connected in sequence at an angle, and two adjacent angles along the circumference of the main stent are respectively a crest and a trough, and the crest is closer to the proximal end of the main stent than the trough; the main support skeleton on at least one side in the axial direction of at least one window, the angle formed by two of the circumferentially adjacent support rods is a surrounding angle, and the surrounding angle and the two support rods forming the surrounding angle together form a semi-annular structure that at least partially surrounds at least one window.

[0084] In some embodiments of the stent graft, at least a portion of the semi-annular structure is tilted away from the central axis of the main stent.

[0085] In some embodiments of the coated stent, the surrounding angle is tilted in a direction away from the central axis of the main stent compared to other angles on the main support frame where it is located, or the surrounding angle and at least part of the rod shape of the two support rods forming the surrounding angle are tilted.

[0086] In some embodiments of the coated stent, the main stent includes a first support segment, a concave segment, and a second support segment extending sequentially from the proximal end to the distal end. The radial dimension of the first support segment is larger than the radial dimensions of the concave segment and the second support segment, and the radial dimension of the concave segment is smaller than the radial dimension of the second support segment, so that the concave segment is at least partially concave in the radial direction of the main stent.

[0087] In some embodiments of the stent graft, at least two fenestrations are located on the concave section; or at least one fenestration is located on the first supporting section.

[0088] In some embodiments of the coated stent, the concave section includes an avoidance section and at least one flared portion; at least one of the flared portions extends along the proximal end of the avoidance section toward the proximal end of the main stent, and the concave section is fixed to the distal end of the first support section through the proximal end of the flared portion; along the circumference of the flared portion, at least part of the flared portion is in an outward-turned shape in a direction away from the central axis of the concave section.

[0089] In some embodiments of the stent graft, the windows near the proximal end of the main stent are located on the flared portion near the proximal end of the main stent; or, the windows are all located on the avoidance section.

[0090] In some embodiments, the stent system includes a branch stent and a coated stent; the branch stent can be inserted into the connecting stent through either the first opening or the second opening of the connecting stent; and / or the branch stent can be inserted into the anchoring stent.

[0091] The stent system in some embodiments includes the coated stent and an interventional instrument for delivering the coated stent to a target position; the interventional instrument includes a guide head, an interventional sheath core fixed to the distal end of the guide head, an interventional sheath tube sleeved outside the interventional sheath core, and an operating handle for controlling the axial movement of the interventional sheath tube, and a gap is provided between the interventional sheath tube and the interventional sheath core for accommodating the coated stent after radial compression; the proximal end of the coated stent is detachably fixed to the interventional sheath core.

[0092] In some embodiments of the stent system, a pre-buried guide wire is passed through the connecting stent, and the pre-buried guide wire is also passed through the main stent, one end of the pre-buried guide wire is located outside the connecting stent, and the other end of the pre-buried guide wire is located outside the interventional sheath.

[0093] In some embodiments, the application method of the covered stent includes: when implanting the covered stent, first aligning the first fenestration or the second fenestration with the target branch vessel, and then aligning it with the other fenestrations.

[0094] The following embodiments of the present application are described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0095] In the description of the embodiments of the present application, it should be noted that the term "integrated molding" means that in the process of forming one of the multiple components, the component is connected to the other components, and there is no need to connect the two components together by reprocessing (such as bonding, welding, snap connection, screw connection). The terms in the specification and claims of this application and the above-mentioned drawings are only for describing specific embodiments and are not intended to limit this application. The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. The directional terms mentioned in the embodiments of the present application, such as "inside", "outside", "side", etc., are only referenced to the directions of the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0096] In intravascular interventional treatment, the proximal end of the vascular stent refers to the end of the vascular stent that is close to the human heart after the vascular stent is used for interventional treatment, and the distal end refers to the end of the vascular stent that is away from the human heart after the vascular stent is used for interventional treatment.

[0097] Branched stent technology uses one or more branches embedded or extended from the main stent. During surgery, bridging stents are implanted into the target vessel through each branch to reconstruct the visceral artery. However, embedded branches increase the risk of lumen loss in the main stent, while extended branches require sufficient space within the vessel for branch expansion. Whether to choose an extended or embedded branch presents challenges during surgery.

[0098] As shown in Figures 1 and 2, Figure 1 is a schematic structural diagram of a connecting stent 20 in an extended state on a stent system provided in the first embodiment of the present application. Figure 2 is a schematic structural diagram of the connecting stent 20 in an extended state on the coated stent shown in Figure 1. The stent system includes a coated stent 1 and a branch stent 2. The coated stent 1 includes a main stent 10 for reconstructing a main vessel and a connecting stent 20 for anchoring the branch stent 2. The branch stent 2 is plugged into the connecting stent 20 for reconstructing a branch vessel 4.

[0099] The main stent 10 includes two openings provided at two axial ends of the main stent 10 and a tubular lumen extending axially between the two openings. A window 11 is provided on the side wall of the main stent 10. The window 11 is connected to the tubular lumen of the main stent 10. Either end of the connecting stent 20 is fixed to the side wall of the main stent 10, and the connecting stent 20 is connected to the tubular lumen of the main stent 10 through the window 11 of the main stent 10. Exemplarily, the main stent 10 includes a main covering 101 and a main support skeleton 102 fixed to the main covering 101.

[0100] In some embodiments, at least one window 11 is provided on the side wall of the main frame 10 .

[0101] In some embodiments, the window 11 is provided on the main body film 101 .

[0102] In some embodiments, the central portion of the main stent 10 is at least partially concave. In other words, the peripheral wall of the main stent 10, at least on the side adjacent to the connecting stent 20, may be recessed into the lumen of the main stent 10, thereby reducing the chance of the main stent 10 squeezing the branch stent 2 after the interventional procedure. It is understood that the peripheral wall of the central portion of the main stent 10 may also be concave, such that the main stent 10 has large openings at both ends and a smaller central portion.

[0103] The connecting bracket 20 includes a first opening 201, a second opening 202, and an inner cavity extending between the first opening 201 and the second opening 202. The first opening 201 and the second opening 202 are arranged along the two axial ends of the connecting bracket 20. Either the first opening 201 or the second opening 202 is fixed to the window 11 of the main bracket 10, so that the inner cavity of the connecting bracket 20 is connected to the tubular cavity of the main bracket 10 through the window 11.

[0104] In some embodiments, either the first opening 201 or the second opening 202 is fixed to at least one fenestration 11 of the main stent 10 , so that the inner cavity of the connecting stent 20 is connected to the lumen of the main stent 10 through the fenestration 11 .

[0105] As shown in Figures 3 and 4, Figure 3 is a schematic structural diagram of the connecting stent 20 on the stent system shown in Figure 1 in a retracted state. Figure 4 is a schematic structural diagram of the connecting stent 20 on the coated stent 1 shown in Figure 3 in a retracted state. The connecting stent 20 includes a first form (for example, the connecting stent 20 is in an extended state) and a second form (for example, the connecting stent 20 is in a retracted state). The axial length of the first form of the connecting stent 20 is greater than the axial length of the second form of the connecting stent 20. The connecting stent 20 can form an extended branch in the first form, that is, the connecting stent 20 is located on the outer side wall of the main stent 10 in the first form; the connecting stent 20 can form an embedded branch in the second form, that is, at least part of the connecting stent 20 is located in the lumen of the main stent 10 in the second form. The branch stent 2 is plugged into the connecting stent 20, that is, the branch stent 2 is plugged into the connecting stent 20, for example, the branch stent 2 is partially plugged into the connecting stent 20 along its own axial length, and can be used to reconstruct various types of branch blood vessels 4 to meet different needs during the operation.

[0106] As shown in FIG2 , in the first configuration of the connecting stent 20 , the connecting stent 20 can extend outside the main stent 10 to form an extended branch. In this way, the connecting stent 20 can be located outside the main stent 10 , thereby reducing the lumen loss rate of the main stent 10 .

[0107] As shown in Figure 4, in the second configuration of the connecting stent 20, the connecting stent 20 can be retracted into the lumen of the main stent 10 through the fenestration 11 of the main stent 10, forming an inset branch. This allows at least a portion of the connecting stent 20 to reside within the lumen of the main stent 10, eliminating the need for sufficient space within the main vessel for the connecting stent 20 to deploy. This makes it suitable for reconstruction of vessels where the main vessel lacks sufficient space for extended branch structures, such as those with complex morphologies.

[0108] In some other embodiments, the first form of the connecting stent 20 is located in the lumen of the main stent 10 .

[0109] In some other embodiments, the second form of the connecting bracket 20 is located outside the main bracket 10 .

[0110] 2 , in the first configuration of the connecting bracket 20 , the second opening 202 of the connecting bracket 20 is fixed to the window 11 of the main bracket 10 . In some embodiments, the cross-sectional diameter of the first opening 201 is larger than that of the second opening 202 .

[0111] In other embodiments, the cross-sectional diameter of the first opening 201 may be smaller than the cross-sectional diameter of the second opening 202 .

[0112] The first opening 201 is located at the distal end of the connecting bracket 20. The second opening 202 is located at the proximal end of the connecting bracket 20. The proximal end of the connecting bracket 20 is fixed to the main bracket 10, and the inner lumen of the connecting bracket 20 is connected to the lumen of the main bracket 10. For example, the inner lumen of the connecting bracket 20 is connected to the lumen of the main bracket 10 through at least one fenestration 11.

[0113] In some embodiments, the second opening 202 of the connecting bracket 20 is sutured to the fenestration 11 of the main bracket 10 by sutures. The second opening 202 of the connecting bracket 20 is connected to the fenestration 11 of the main bracket 10.

[0114] In some embodiments, the second opening 202 of the connecting bracket 20 is sutured to at least one window 11 of the main bracket 10 by sutures. The second opening 202 of the connecting bracket 20 is communicated with the main bracket 10 through the window 11.

[0115] As shown in FIG5 , FIG5 is a partial enlarged view of the stent graft 1 shown in FIG2 at point A. In some embodiments, the connecting stent 20 includes a first section 203 and a second section 204 fixed to the first section 203 .

[0116] In some embodiments, the first opening 201 of the connecting bracket 20 is located at an end of the first section 203 away from the second section 204 , and the second opening 202 of the connecting bracket 20 is located at an end of the second section 204 away from the first section 203 .

[0117] The connection between the first section 203 and the second section 204 forms the neck 205 of the connecting stent 20. That is, the connecting stent 20 forms the first section 203 and the second section 204 through the neck 205. In the first form of the connecting stent 20, the first section 203 and the second section 204 are arranged along the axial direction of the connecting stent 20 and are connected to each other. In the first form of the connecting stent 20, the first section 203 of the connecting stent 20 is unfolded relative to the second section 204. At this time, the axial length of the connecting stent 20 is the sum of the lengths of the first section 203 and the second section 204. The first form of the connecting stent 20 enables the connecting stent 20 to be located outside the main stent 10, and the first section 203 is farther away from the window 11 of the main stent 10 than the second section 204. The connecting stent 20 is an extended branch, thereby reducing the lumen loss rate of the main stent 10.

[0118] In some embodiments, the cross-sectional dimension of the connecting bracket 20 at the neck portion 205 is smaller than at least one of the cross-sectional dimensions of the first opening 201 and the second opening 202 of the connecting bracket 201 .

[0119] In some embodiments, the connecting bracket 20 includes a first section 203 and a second section 204 fixed to the first section 203. The cross-sectional dimension of the end of the first section 203 near the second section 204 is smaller than the cross-sectional dimension of the end of the first section 203 away from the second section 204, that is, the cross-sectional dimension of the end of the first section 203 near the second section 204 is smaller than the cross-sectional dimension of the first opening 201 of the connecting bracket 20, so that the connection between the first section 203 and the second section 204 forms a neck 205 of the connecting bracket 20; or the cross-sectional dimension of the end of the second section 204 near the first section 203 is smaller than the cross-sectional dimension of the end of the second section 204 away from the first section 203, that is, the cross-sectional dimension of the end of the second section 204 near the first section 203 is smaller than the cross-sectional dimension of the second opening 202 of the connecting bracket 20, so that the connection between the first section 203 and the second section 204 forms the neck 205 of the connecting bracket 20.

[0120] In some embodiments, the connecting bracket 20 includes a first section 203 and a second section 204 fixed to the first section 203. The cross-sectional dimension of the end of the first section 203 close to the second section 204 is smaller than the cross-sectional dimension of the end of the first section 203 away from the second section 204, and the cross-sectional dimension of the end of the second section 204 close to the first section 203 is smaller than the cross-sectional dimension of the end of the second section 204 away from the first section 203, so that the connection between the first section 203 and the second section 204 forms the neck 205 of the connecting bracket 20.

[0121] In some embodiments, the cross-sectional diameter of the neck 205 is smaller than the cross-sectional diameters of the first opening 201 and the second opening 202 .

[0122] Exemplarily, the first opening 201 is located at one end of the first section 203 away from the second section 204. From one end of the first opening 201 along the axial direction of the connecting bracket 20 to the neck 205, the cross-sectional diameter of the first section 203 gradually decreases.

[0123] Exemplarily, the second opening 202 is located at one end of the second section 204 away from the first section 203. From one end of the second opening 202 along the axial direction of the connecting bracket 20 to the neck 205, the cross-sectional diameter of the second section 204 gradually decreases.

[0124] In some embodiments, the first section 203 and the second section 204 are both designed to have a tapered shape, which is conducive to making the first section 203 and the second section 204 fit more tightly, so that the branch bracket 2 can be more stably inserted into the connecting bracket 20, or in other words, the branch bracket 2 can be more stably inserted into the connecting bracket 20 in the second form.

[0125] In some embodiments, the first section 203 and the second section 204 of the connecting bracket 20 are both truncated cone-shaped. The connecting bracket 20 may be shaped like a small waist or an hourglass. Compared to a cylindrical structure, the design of the connecting bracket 20 of the present application (e.g., the connecting bracket 20 being shaped like a small waist or an hourglass) allows the connecting bracket 20 to bend at the neck 205, making the connecting bracket 20 retractable, thereby having both an extended and a contracted configuration.

[0126] In some embodiments, either the first section 203 or the second section 204 of the connecting bracket 20 is in a truncated cone shape, and either the first section 203 or the second section 204 of the connecting bracket 20 is in a conical shape.

[0127] In some embodiments, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 to the cross-sectional diameter of the neck 205 is greater than 1. For example, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 to the cross-sectional diameter of the neck 205 is 1.1-2.1.

[0128] For example, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 to the cross-sectional diameter of the neck 205 is 1.2. In this case, the connecting bracket 20 has good scalability.

[0129] In some other embodiments, the connecting bracket 20 is at least partially composed of a bellows along its axial direction, so as to adjust a variety of different axial telescopic lengths.

[0130] As shown in FIG6 , FIG6 is a partial enlarged view of the coated stent 1 shown in FIG4 at point B. The first section 203 and the second section 204 of the connecting stent 20 can overlap along the axial direction of the connecting stent 20, thus forming a second configuration of the connecting stent 20. In the second configuration of the connecting stent 20, at least a portion of the first section 203 and the second section 204 can overlap along the axial direction of the connecting stent 20.

[0131] The axial length of the connecting bracket 20 is less than the sum of the lengths of the first section 203 and the second section 204 , that is, the axial length of the connecting bracket 20 is less than the axial length of the connecting bracket 20 in the first form, and the space occupied by the connecting bracket 20 is reduced.

[0132] In some embodiments, the connecting stent 20 is bent at the neck 205 (for example, when the connecting stent 20 is converted to the second form), and the connecting stent 20 forms a third opening 210 at the neck 205. The third opening 210 is located in the lumen of the main stent 10. The first opening 201 and the second opening 202 are located on the same side of the third opening 210. For example, the first opening 201 is farther away from the third opening 210 than the second opening 202; or the first opening 201 is located in the same plane of the cross-section where the second opening 202 is located; or the first opening 201 is closer to the third opening 210 than the second opening 202. In the second form of the connecting stent 20, at least part of the first section 203 and at least part of the second section 204 of the connecting stent 20 are both located in the lumen of the main stent 10. The connecting stent 20 is an embedded branch, which is suitable for reconstructing some blood vessels where there is not enough space near the connection between the main blood vessel and the branch blood vessel 4 to accommodate the extended branch structure. When the connecting bracket 20 is retracted into the lumen of the main bracket 10, the axial length of the connecting bracket 20 is reduced, and the space occupied by the connecting bracket 20 in the lumen of the main bracket 10 is smaller, thereby reducing the lumen loss rate of the main bracket 10 to a certain extent.

[0133] In some embodiments, the first opening 201 is located outside the main stent 10. In this case, the second section 204 of the connecting stent 20 is located within the lumen of the main stent 10. A portion of the first section 203 of the connecting stent 20 is located within the lumen of the main stent 10, while another portion is located outside the main stent 10. Because the cross-sectional diameter of the first opening 201 of the connecting stent 20 is larger or smaller than the cross-sectional diameter of the second opening 202, a portion of the peripheral wall of the first section 203 of the connecting stent 20 is engaged with the fenestration 11 of the main stent 10, thereby enhancing the secure connection between the connecting stent 20 and the main stent 10.

[0134] In another embodiment, the first opening 201 of the connecting stent 20 is located in the same plane as the cross-section of the second opening 202. Thus, the first section 203 and the second section 204 of the connecting stent 20 are largely located within the lumen of the main stent 10. This reduces the space occupied by the connecting stent 20 in the branch vessel 4, thereby improving the space utilization of the lumen of the branch vessel 4.

[0135] As shown in Figures 5 and 6, the connecting stent 20 switches between the first form and the second form to form an extended branch or an embedded branch. The connecting stent 20 switches from the first form to the second form, and can be used to reconstruct some blood vessels that do not have enough space near the connection between the main blood vessel and the branch blood vessel 4 to accommodate the extended branch structure. In the first form of the connecting stent 20, by pushing the first section 203 along the axial direction of the connecting stent 20 into the lumen of the main stent 10, the connecting stent 20 is bent at the neck 205, at least part of the first section 203 and the second section 204 overlap in the axial direction of the connecting stent 20, and at least part of the first section 203 is pushed into the lumen of the main stent 10. The connecting stent 20 switches from the first state to the second state, and the connecting stent 20 changes from an extended branch to an embedded branch, and the branch stent 2 is plugged into the connecting stent 20 to reconstruct the branch blood vessel 4.

[0136] In some other embodiments, the first section 203 may be pulled from a convenient position (eg, from the lumen of the main stent 10 ) and moved into the lumen of the main stent 10 , so that at least a portion of the first section 203 is located in the lumen of the main stent 10 .

[0137] When the trunk vessel to be reconstructed has enough space at the branch vessel 4 to accommodate the extended branch structure, the connecting stent 20 switches from the second form to the first form to reduce the lumen loss rate of the main stent 10.

[0138] In some embodiments, when the connecting stent 20 is in the second configuration, for example, a balloon can be inserted into the lumen of the connecting stent 20. After expansion, the balloon can adhere to at least a portion of the inner circumferential wall of the connecting stent 20. The expanded balloon cooperates with the inner circumferential wall of the connecting stent 20, and the friction between the balloon and the inner circumferential wall of the connecting stent 20 is used to stretch the connecting stent 20 and pull the connecting stent 20 out of the lumen of the main stent 10, so that the connecting stent 20 is stretched from an embedded branch to an extended branch. The connecting stent 20 switches from the second configuration to the first configuration, and the branch stent 2 is inserted into the connecting stent 20 to reconstruct the branch vessel 4, thereby reducing the lumen loss rate of the main stent 10.

[0139] It can be understood that by controlling the extent to which the connecting stent 20 is pulled out of the lumen of the main stent 10, the first section 203 and the second section 204 overlap to different degrees in the axial direction of the connecting stent 20 to adapt to the angular angle between the main blood vessel and the branch blood vessel 4 and the space between the main blood vessel and the branch blood vessel 4 of different patients.

[0140] In other embodiments, other methods may also be used, such as directly pulling the connecting stent 20 to form an extended branch, and then inserting the branch stent 2 to reconstruct the branch vessel 4. This application does not limit this in detail.

[0141] As shown in Figures 5 and 6, in some embodiments, the connecting bracket 20 further includes a connector 206. The connector 206 at least partially surrounds and is fixed to the neck 205. The connector 206 is used to connect the first section 203 and the second section 204. Exemplarily, the connector 206 is a suture set. The suture set includes at least one suture that is sutured and fixed to the neck 205.

[0142] In some embodiments, the first section 203 and the second section 204 of the connecting bracket 20 are sutured to the neck 205 by a suture set.

[0143] As shown in Figures 7 and 8, Figure 7 is a schematic diagram of the structure of the coated stent 1 shown in Figure 5 in other embodiments. Figure 8 is a schematic diagram of the structure of the coated stent 1 shown in Figure 6 in other embodiments. In some embodiments, the connecting member 206 is an annular connecting rod. The first section 203 and the second section 204 of the connecting stent 20 are fixed to the neck 205 via the connecting rod. The connecting rod at least partially surrounds and is fixed to the neck 205.

[0144] In some embodiments, a connector 206 is provided on the neck 205 of the connecting bracket 20. Thus, the first section 203 and the second section 204 of the connecting bracket 20 can be processed separately. For example, the first section 203 and the second section 204 can be processed into a frustum shape and then connected by the connector 206 to form a waist-shaped or hourglass-shaped connecting bracket 20.

[0145] The connecting member 206 serves to position and divide the first section 203 and the second section 204 , thereby facilitating the division of the respective positions of the first section 203 and the second section 204 , thereby facilitating the conversion of the connecting bracket 20 between the first form and the second shape.

[0146] In other embodiments, the connecting bracket 20 is an integrally formed structural member. Specifically, the first section 203, the neck section 205, and the second section 204 of the connecting bracket 20 are integrally formed. Thus, no additional components are required to connect the first section 203, the neck section 205, and the second section 204 of the connecting bracket 20. This simplifies the structure of the connecting bracket 20 and improves overall sealing performance.

[0147] As shown in Figure 5, in one or more embodiments, the connecting bracket 20 includes a connecting coating 207. The shape of the connecting coating 207 changes with the shape of the connecting bracket 20, for example, both have a neck 205. The connecting coating 207 forms a first section 203 and a second section 204 through the neck 205. The connecting coating 207 forms the tubular main structure of the connecting bracket 20. That is, the connecting coating 207 encloses the inner cavity of the connecting bracket 20. In some embodiments, the material of the connecting coating 207 is similar to that of the main body coating 101, and the details will not be repeated here. It can be understood that the connecting coating 207 is a flexible material, which facilitates the folding and unfolding of the connecting coating 207.

[0148] As shown in FIG5 , in some embodiments, the connecting bracket 20 further includes at least one support member 208. The support member 208 is fixed to the peripheral wall of the first section 203. For example, the support member 208 is arranged along the circumference of the connecting bracket 20. The support member 208 is fixed to the peripheral wall of the first section 203 by sutures.

[0149] The shape of the support member 208 is adapted to the shape of the first section 203. For example, the cross-sectional diameter of the support member 208 gradually decreases from one end of the first opening 201 along the axial direction of the connecting bracket 20.

[0150] For example, the structure of the support member 208 may be one or more of a zigzag shape, a wavy shape, or a straight shape.

[0151] In some embodiments, the structure of the support member 208 is the same as the structure of any main support frame 102.

[0152] For example, the number of the support members 208 may be one or more. When the number of the support members 208 is plural, the plurality of support members 208 are arranged along the axial direction of the connecting bracket 20 .

[0153] For example, the material of the support member 208 is similar to that of the main support frame 102. The details are not described in detail here.

[0154] In one or more embodiments, a support member 208 is secured to the first segment 203 of the connecting stent 20. The support member 208 supports the first segment 203, providing a certain strength, such as radial support, to the first segment 203 of the connecting stent 20. In this case, the first segment 203 of the connecting stent 20 can serve as a support segment. The support member 208 increases the anchoring force between the connecting stent 20 and the branch stent 2, thereby enhancing the secure connection between the connecting stent 20 and the branch stent 2.

[0155] In some embodiments, the second section 204 of the connecting stent 20 is a flexible section formed by connecting the covering 207. The second section 204 is folded toward the lumen of the main stent 10 so that at least a portion of the connecting stent 20 can be located in the lumen of the main stent 10.

[0156] In other embodiments, a support member 208 is also fixed to the second section 204 of the connecting bracket 20 .

[0157] In other embodiments, the second section 204 of the connecting bracket 20 is also fixed with a support member 208, and the stiffness of the support member 208 on the second section 204 is less than the stiffness of the support member 208 on the first section 201, or the wire diameter of the support member 208 on the second section 204 is less than the wire diameter of the support member 208 on the first section 201, so that the strength of the second section 204 of the connecting bracket 20 is less than the strength of the first section 203 of the connecting bracket 20.

[0158] In some other embodiments, at least one of the first section 203 and the second section 204 of the connecting bracket 20 is composed of a bellows along its axial direction, so that a variety of different axial telescopic lengths can be adjusted.

[0159] In some embodiments, the second section 204 of the connecting bracket 20 is composed of a bellows along its axial direction, so that a variety of different axial telescopic lengths can be adjusted.

[0160] As shown in FIG5 , in some embodiments, the main support 10 further includes at least one display structure 209 . The display structure 209 at least partially surrounds and is fixed to the first opening 201 , or at least partially surrounds and is fixed to the second opening 202 .

[0161] Illustratively, the connecting bracket 20 includes a first annular developing member 2091. The first annular developing member 2091 surrounds the first opening 201 and is fixed to the connecting film 207, thereby reinforcing the predetermined shape of the first opening 201 of the connecting bracket 20. Specifically, the first annular developing member 2091 can be fixed outside the end of the first opening 201; alternatively, the first annular developing member 2091 can be fixed to the end surface of the end of the first opening 201.

[0162] In one or more embodiments, the connecting bracket 20 further includes a second annular developing member 2092. The second annular developing member 2092 surrounds the second opening 202 and is fixed to the connecting film 207, thereby reinforcing the predetermined shape of the second opening 202 of the connecting bracket 20. Specifically, the second annular developing member 2092 is fixed to the outside of the end where the second opening 202 is located; alternatively, the second annular developing member 2092 is fixed to the end surface of the end where the second opening 202 is located.

[0163] In some embodiments, a first annular developing member 2091 and a second annular developing member 2092 are provided on the connecting bracket 20. The first annular developing member 2091 surrounds the first opening 201, and the second annular developing member 2092 surrounds the second opening 202. When the branch bracket 2 needs to be plugged into the connecting bracket 20, the positions of the first annular developing member 2091 and the second annular developing member 2092 can be clearly observed using imaging equipment, that is, the positions of the first opening 201 and the second opening 202 of the connecting bracket 20 can be clearly observed, thereby facilitating the assembly of the connecting bracket 20 and the branch bracket 2.

[0164] As shown in FIG9 , FIG9 is a schematic structural diagram of some embodiments of the main frame 10. In some embodiments, there are multiple main frame support skeletons 102, and the multiple main frame support skeletons 102 are arranged along the axial direction of the main frame 10.

[0165] The main support skeleton 102 includes multiple support rods 1021 connected in sequence at an angle. Two adjacent angles along the circumference of the main support 10 are a crest 1022 and a trough 1023. The crest 1022 is closer to the proximal end of the main support 10 than the trough 1023.

[0166] In some embodiments, the main support skeleton 102 on at least one side in the axial direction of at least one window 11 has an angle formed by two circumferentially adjacent support rods 1021, which is a wrapping angle 1024. The wrapping angle 1024 is set as a rounded angle. The wrapping angle 1024 and the two support rods 1021 forming the wrapping angle 1024 together form a semi-annular structure that at least partially surrounds the window 11.

[0167] In some embodiments, a support ring 12 is fixed to the window 11 to reinforce the shape of the window 11 .

[0168] In some embodiments, the two axial ends of the support ring 12 are in a raised shape, that is, the two axial ends of the support ring 12 are in a raised shape compared to other areas on the support ring 12, which is beneficial for lifting the position of the main body coating 101 away from the central axis of the main stent 10, thereby helping to further reduce the lumen loss rate of the main stent 10, and helping more blood flow through the lumen of the main stent 10, thereby helping more blood flow through the window 11 to the branch blood vessel 4, reducing the occurrence of complications.

[0169] Referring to Figures 1 and 2 , the branch stent 2 includes a branch covering 21 and a branch support frame 22 secured to the branch covering 21. There may be multiple branch support frames 22. For example, the branch support frames 22 are secured to a peripheral wall, such as an outer peripheral wall, of the branch covering 21. The structure, shape, and material of the branch covering 21 and the branch support frame 22 are similar to those of the main covering 101 and the main support frame 102, and details thereof will not be repeated here.

[0170] The first opening 201 or the second opening 202 of the connecting bracket 20 is fixed to the main bracket 10. The branch bracket 2 can be inserted into the connecting bracket 20 through the first opening 201 or the second opening 202 of the connecting bracket 20. The inner cavity of the branch bracket 2 communicates with the lumen of the main bracket 10.

[0171] In some embodiments, the second opening 202 of the connecting stent 20 is fixed to the main stent 10 . The branch stent 2 can be inserted into the connecting stent 20 through the first opening 201 of the connecting stent 20 . The inner lumen of the branch stent 2 communicates with the lumen of the main stent 10 .

[0172] In some embodiments, the outer diameter of the branch stent 2 is larger than the cross-sectional diameter of the neck 205 of the connecting stent 20. The interference fit between the branch stent 2 and the connecting stent 20 allows a portion of the outer circumferential wall of the branch stent 2 to fit over a portion of the inner circumferential wall of the connecting stent 20, thereby enhancing the secure connection between the branch stent 2 and the connecting stent 20 and effectively preventing internal leakage.

[0173] In some embodiments, the outer diameter of the branch stent 2 is larger than the cross-sectional diameter at any location of the connecting stent 20 .

[0174] In some embodiments, by providing a branch support skeleton 22 on the branch covering 21, the branch support skeleton 22 helps to increase the friction between the outer peripheral wall of the branch stent 2 and the inner peripheral wall of the connecting stent 20, thereby improving the connection strength between the branch stent 2 and the connecting stent 20, making the connection between the branch stent 2 and the connecting stent 20 more secure. Relative movement between the connecting stent 20 and the branch stent 2 is not likely to occur, and the branch stent 2 is not likely to fall off the connecting stent 20.

[0175] In some embodiments, in the first form of the connecting stent 20, the proximal end of the branch stent 2 passes through the opening at one end of the connecting stent 20 away from the window 11 (such as the first opening 201 as shown in Figures 1 and 2) and the inner cavity of the connecting stent 20, and the proximal end of the branch stent 2 extends out of the opening at one end of the connecting stent 20 close to the window 11 (such as the second opening 202 as shown in Figures 1 and 2), and the proximal end portion of the branch stent 2 is located outside the connecting stent 20, that is, the proximal end portion of the branch stent 2 is located in the lumen of the main stent 10. As shown in Figures 1 and 2, in the first form of the connecting stent 20, the proximal end of the branch stent 2 passes through the first opening 201 of the connecting stent 20 and the inner cavity of the connecting stent 20 and extends out of the second opening 202, and the proximal end portion of the branch stent 2 is located in the lumen of the main stent 10.

[0176] In other embodiments, the proximal end of the branch stent 2 does not extend beyond the second opening 202, that is, the proximal end of the branch stent 2 is located within the lumen of the connecting stent 20, and the proximal end of the branch stent 2 is not configured to extend into the lumen of the main stent 10. The branch stent 2 is not configured to extend into the lumen of the main stent 10, which helps to reduce the loss rate of the lumen of the main stent 10.

[0177] In the second form of the connecting stent 20 , the proximal end of the branch stent 2 passes through the first opening 201 and the second opening 202 of the connecting stent 20 and extends out of the third opening 210 . The proximal end of the branch stent 2 is located in the lumen of the main stent 10 .

[0178] In other embodiments, the proximal end of the branch stent 2 is not configured to extend out of the third opening 210, that is, the proximal end of the branch stent 2 is located in the inner cavity of the connecting stent 20 in the second form, and the proximal end of the branch stent 2 is not configured to extend into the interior of the tubular cavity of the main stent 10.

[0179] In the case where there is not enough space in the main blood vessel to accommodate the extended branch structure, the connecting stent 20 is switched to the second state to form an embedded branch, thereby reducing the space occupied by the connecting stent 20 in the blood vessel, and the branch stent 2 is inserted into the connecting stent 20 to reconstruct the branch blood vessel 4.

[0180] For blood vessels with sufficient space at the main trunk to accommodate extended branch structures, the connecting stent 20 is switched to the first state to form an extended branch, and the branch stent 2 is inserted into the connecting stent 20 to reconstruct the branch blood vessel 4, thereby reducing the lumen loss rate of the main stent 10.

[0181] In other embodiments, the first opening 201 of the connecting stent 20 is fixed to the main stent 10. The branch stent 2 can be inserted into the connecting stent 20 through the second opening 202 of the connecting stent 20. The inner cavity of the branch stent 2 can communicate with the lumen of the main stent 10 through the first opening 201.

[0182] Referring to Figure 10 , in an exemplary application scenario of a covered stent 1, the reconstruction of a branch vessel 4 on the aortic arch 3 is used as an example, with the connecting stent 20 in the second configuration. Branch vessel 4 is any one of the brachiocephalic artery 401, the left common carotid artery 402, and the left clavicular artery 403. The covered stent 1 is released into the aortic arch 3 via an interventional sheath, and the branch stent 2 is released into the connecting stent 20. The state of the main stent 10, connecting stent 20, and branch stent 2 after release into the aortic arch 3 is shown in Figure 10 .

[0183] The second embodiment of the present application provides a stent graft, as shown in Figures 11 and 12. Figure 11 is a schematic structural diagram of the stent graft 1 of the second embodiment (the main support skeleton 102 located on the inner peripheral wall of the proximal end of the main stent 10 is not shown), and Figure 12 is a schematic structural diagram of the stent graft 1 from another perspective of Figure 11. The second embodiment of the present application can adopt any possible implementation of the above-mentioned embodiments. At the same time, the structure of the stent graft 1 of the second embodiment of the present application can also have the following implementations.

[0184] The coated stent 1 includes a main stent 10, a connecting stent 20 and at least one anchoring stent 30. The connecting stent 20 and the anchoring stent 30 are both used for plugging and matching with the branch stent 2. In some embodiments, the implementation of the main stent 10 and the connecting stent 20 is the same as any possible implementation of the above-mentioned embodiments, which will not be repeated here. Exemplarily, the anchoring stent 30 includes a built-in coating (not shown in the figure) and at least one support ring (not shown in the figure) fixed to the built-in coating. The structure of the support ring is the same as the structure of any main support skeleton 102, which will not be repeated here.

[0185] The first form of the connecting bracket 20 is located outside the main bracket 10. The side wall of the main bracket 10 is provided with at least two windows 11, which are sequentially spaced from the proximal end to the distal end of the main bracket 10, and the two windows 11 are connected to the lumen of the main bracket 10.

[0186] One end of the connecting stent 20 and one end of the anchoring stent 30 are respectively fixed to the two fenestrations 11, so that the connecting stent 20 and the anchoring stent 30 are connected to the lumen of the main stent 10 through the two fenestrations 11. In other words, one end of the connecting stent 20 is fixed to one of the two fenestrations 11, and the connecting stent 20 is connected to the lumen of the main stent 10 through either fenestration 11; while the anchoring stent 30 is fixed to the other fenestration 11 and is connected to the lumen of the main stent 10 through that fenestration 11.

[0187] For ease of distinction, the at least two fenestrations 11 are labeled as a first fenestration 111 and a second fenestration 112, respectively. The first fenestration 111 is located closer to the proximal end of the main frame 10 than the second fenestration 112. The axial length of the second fenestration 112 is greater than the axial length of the first fenestration 111. In other words, the axial lengths of the fenestrations 11 increase from the proximal end to the distal end of the main frame 10, for example, the axial lengths of the first fenestration 111 and the second fenestration 112 increase.

[0188] In some embodiments, at least two fenestrations 11 on the main stent 10 are spaced apart along the axial direction of the main stent. The axial distance between the edges of two adjacent fenestrations 11 at the proximal end of the main stent 10 is 2 mm to 15 mm. For example, the axial distance between the distal end of the first fenestration 111 and the proximal end of the second fenestration 112 is 2 mm to 15 mm, thereby making the distance between the first fenestration 111 and the second fenestration 112 relatively close.

[0189] In some embodiments, the at least two windows 11 on the main stent 10 are arranged non-intervally along the axial direction of the main stent 10 , that is, the at least two windows 11 may at least partially overlap along the axial direction of the main stent 10 .

[0190] The main stent 10 is typically released from the interventional sheath by withdrawing the interventional sheath. That is, the main stent 10 is exposed relative to the inner lumen of the interventional sheath by withdrawing the interventional sheath. During the withdrawal of the interventional sheath, the proximal end of the main stent 10 is typically released first. At this point, the first fenestration 111, which is closer to the proximal end of the main stent 10, may be aligned with the root opening of the corresponding branch vessel 4. Therefore, it can be understood that once the first fenestration 111 and the root opening of the corresponding branch vessel 4 are aligned, the position of the main stent 10 within the main vessel is essentially determined. Given a predetermined distance between the center positions of the two fenestrations 11, the axial length of the second fenestration 112 is set larger, bringing the edge of the second fenestration 112 closer to the edge of the first fenestration 111. This improves the error tolerance of the second fenestration 112 and eliminates the need to precisely align the centerline of the second fenestration 112 with the centerline of the target branch vessel 4 when the main stent 10 is released into the main vessel. This reduces the interventional technique requirements for the operator and reduces surgical time. At the same time, setting the axial length of the second fenestration 112 larger and closer to the first fenestration 111 is more conducive to superselective positioning. Furthermore, setting the axial length of the second fenestration 112 larger and closer to the first fenestration 111 has a wider adaptability, and can accommodate different distances between two adjacent branch vessels 4 on the main blood vessels of different patients.

[0191] The circumferential length of the second window 112 is greater than that of the first window 111. In other words, along the axial direction of the main frame 10, the circumferential lengths of the windows 11 increase sequentially, for example, the circumferential lengths of the first window 111 and the second window 112 increase sequentially.

[0192] The circumferential length of the second window 112 is at least 50%-70% of the diameter of the main stent 10. While ensuring the supporting performance of the main stent 10 in the blood vessel, the fault tolerance of the second window 112 is further improved, and it is more convenient for super-selective positioning. It is of course ideal that the multiple branch vessels 4 on the main blood vessel are located on the same axial straight line, but the main blood vessels of some patients are twisted, and the anatomical morphology of the main blood vessels is more complex. The multiple branch blood vessels 4 on the main blood vessels cannot be located on the same axial straight line. By setting the circumferential length of the second window 112 to be larger, the reconstruction of the branch blood vessels 4 under different vascular anatomical morphologies can be covered, and the scope of application is wider.

[0193] In some embodiments, the connecting stent 20 is located closer to the proximal end of the main stent 10 than the anchoring stent 30. The connecting stent 20 is fixed to the first fenestration 111, and at least one anchoring stent 30 is fixed to the second fenestration 112. The placement of at least one anchoring stent 30 in the second fenestration 112 facilitates superselective positioning of the second fenestration 112, saving surgical time and reducing the occurrence of complications.

[0194] In some embodiments, at least one anchoring stent 30 is positioned within the lumen of the main stent 10. The radial dimension of the anchoring stent 30 gradually decreases from the end closest to the fenestration 11 to the end further from the fenestration 11, resulting in a tapered shape. The smaller radial dimension of the anchoring stent 30 at the end facilitates improved connection reliability with the branch stent 2, while the larger radial dimension of the anchoring stent 30 at the end facilitates increased tolerance for errors in the fenestration 11, facilitates superselective positioning, and is adaptable to a wider range of applications.

[0195] In some embodiments, the end of the anchoring stent 30 away from the fenestration 11 extends toward the proximal end of the main stent 10 , so that the end of the anchoring stent 30 away from the fenestration 11 faces the proximal end of the main stent 10 .

[0196] In some embodiments, as shown in Figures 13 and 14, Figure 13 is a schematic structural diagram of a stent graft 1 in some embodiments (for example, the main support skeleton 102 located on the inner circumferential wall of the proximal end of the main stent 10 may not be shown), and Figure 14 is a schematic structural diagram of the stent graft 1 from another perspective of Figure 13. An end of the anchoring stent 30 away from the fenestration 11 in which it is located extends toward the distal end of the main stent 10, such that the end of the anchoring stent 30 away from the fenestration 11 in which it is located faces the distal end of the main stent 10.

[0197] In some embodiments, the central axis of the anchoring bracket 30 is parallel to the central axis of the main bracket 10; or the central axis of the anchoring bracket 30 has an angle with the central axis of the main bracket 10, so that the axial direction of the anchoring bracket 30 is tilted relative to the axial direction of the main bracket 10.

[0198] In some embodiments, the central axis of the anchoring stent 30 is perpendicular to the central axis of the main stent 10. One end of the anchoring stent 30 away from the fenestration 11 in which it is located extends into the lumen of the main stent 10 along the centerline of the fenestration 11 in which it is located.

[0199] In some embodiments, the main stent 10 includes a first support segment 13, a concave segment 14, and a second support segment 15 extending sequentially from the proximal end to the distal end, wherein the radial dimension of the concave segment 14 is smaller than the radial dimensions of the first support segment 13 and the second support segment 15, such that the concave segment 14 is at least partially concave in the radial direction of the main stent 10. For example, the radial dimension of the first support segment 13 is greater than or equal to the radial dimensions of the concave segment 14 and the second support segment 15, and the radial dimension of the concave segment 14 is smaller than the radial dimension of the second support segment 15, such that the concave segment 14 is at least partially concave in the radial direction of the main stent 10.

[0200] In some embodiments, at least two windows 11 are located on the concave section 14. It is understood that the concave section 14 may have an entire circumferential sidewall that is concave relative to the first support section 13 and the second support section 15 toward the lumen of the main stent 10; or the concave section 14 may have a partially circumferential sidewall that is concave, for example, the side of the concave section 14 where the window 11 is located may be concave toward the lumen of the main stent 10.

[0201] In some other embodiments, at least one window 11 is located on the first supporting segment 13 .

[0202] In some other embodiments, at least one window 11 is located on the first support segment 13 , and at least one window is located on the concave segment 14 .

[0203] Exemplarily, the concave section 14 includes an escape section 141 and at least one flared portion 142. The at least one flared portion 13 is fixed to the proximal end of the escape section 141. The flared portion 142 extends along the proximal end of the escape section 141 toward the proximal end of the main support 10. The concave section 14 is fixed to the distal end of the first support section 13 through the proximal end of the flared portion 142.

[0204] In some other embodiments, the concave section 14 includes an escape section 141 and at least one flared portion 142. The at least one flared portion 13 is fixed to the distal end of the escape section 141. The flared portion 142 extends along the distal end of the escape section 141 toward the distal end of the main support 10. The concave section 14 is fixed to the proximal end of the second support section 15 through the distal end of the flared portion 142.

[0205] For example, the concave section 14 includes a relief section 141 and two flared portions 142. The two flared portions 142 are located at the axial ends of the relief section 141. The concave section 14 is fixed to the distal end of the first support section 13 and the proximal end of the second support section 15 via the two flared portions 142. The radial dimension of the flared portion 142 is greater than the radial dimension of other areas of the concave section 14.

[0206] In some embodiments, the radial dimension of the flared portion 142 gradually increases from an end close to the avoidance section 141 to an end away from the avoidance section 141 , such that the flared portion 142 is tapered.

[0207] In some other embodiments, along the circumference of the flared portion 142, at least a portion of the flared portion 142 is in an outward-turned configuration in a direction away from the central axis of the concave section 14. For example, along the entire circumference of the flared portion 142, the flared portion 142 is in an outward-turned configuration in a radial direction away from the central axis of the concave section 14, so that the sidewalls of the avoidance section 141 along the entire circumference are recessed relative to the first support section 13 and the second support section 15 in a direction toward the lumen of the main stent 10, that is, the radial dimension of the flared portion 142 gradually increases from an end near the axial middle portion of the concave section 14 to an end away from the axial middle portion of the concave section 14.

[0208] In some other embodiments, along the circumference of the partially flared portion 142, the partially flared portion 142 is outward-turned in the radial direction away from the central axis of the concave section 14, so that the circumferential side wall of the local avoidance section 141 of the concave section 14 is concave. For example, the side of the concave section 14 where the window 11 is provided is concave in the direction of the tubular cavity of the main support 10.

[0209] In other embodiments, the first fenestration 111 is located on the flared portion 142 near the proximal end of the main stent 10. The longer the axial length of the first support segment 13 of the main stent 10 proximal to the first fenestration 111, the longer the anchoring length of the main stent 10, allowing the main stent 10 to be more stably supported within the main vessel and less susceptible to axial displacement. By locating the first fenestration 111 on the flared portion 142, the anchoring length of the main stent 10 can be extended.

[0210] In some embodiments, the proximal edge of the first fenestration 111 is adjacent to the distal edge of the flared portion 142 adjacent to the first support segment 13 , which helps to extend the anchoring length of the main support 10 .

[0211] In some embodiments, the first window 111 and the second window 112 are located on the avoidance section 141 .

[0212] The main body support 10 includes a main body covering 101 and a plurality of main body support frames 102 fixed to the main body covering 101. The plurality of main body support frames 102 are arranged at intervals along the axial direction of the main body covering 101. At least two windows 11 are provided on the sidewalls of the main body covering 101. The flared portion 142 is provided with at least one main body support frame 102 that changes with the shape of the flared portion 142.

[0213] In some embodiments, the proximal end of the main stent 10 is provided with two overlapping main support skeletons 102, and the two main support skeletons 102 at the proximal end of the main stent 10 are respectively fixed to the inner circumferential wall and the outer circumferential wall of the main coating 101. The crests 1022 and troughs 1023 of the two overlapping main support skeletons 102 at the proximal end of the main stent 10 are relatively arranged along the axial direction of the main stent 10 (it can be understood that the axial relative arrangement is not strict and there can be an error of 5%-15%). The support rods 1021 of the two main support skeletons 102 at the proximal end of the main stent 10 cross and overlap each other across the main coating 101, which has the effect of strengthening the radial support force of the proximal end of the main stent 10, making the proximal end of the main stent 10 more adherent to the wall, which is conducive to avoiding or reducing the axial displacement of the main stent 10 along the main blood vessel.

[0214] In one or more embodiments, at least a portion of the wave crest 1022 of at least one main support skeleton 102 located at the proximal end of the main support 10 extends out of the proximal end of the main body coating 101, that is, a local axial length of at least a portion of the support rod 1021 on the main support skeleton 102 is not covered by the main body coating 101.

[0215] In some embodiments, the main support skeleton 102 located on at least one side in the axial direction of the first window 111 has an angle formed by two circumferentially adjacent support rods 1021, which is a wrapping angle 1024. The wrapping angle 1024 and the two support rods 1021 forming the wrapping angle 1024 together form a semi-annular structure that at least partially surrounds the first window 111.

[0216] In some embodiments, the main support frame 102 located on at least one side of the second fenestration 112 in the axial direction has an angle formed by two circumferentially adjacent support rods 1021, which is a wall-adherence angle 1025. The wall-adherence angle 1025 and the two support rods 1021 forming the wall-adherence angle 1025 together form a semi-annular structure that at least partially surrounds the second fenestration 112. For example, along the axial direction of the main support frame 10, at least one main support frame 102 is provided between the first fenestration 111 and the second fenestration 112 to increase the radial support force around the first fenestration 111 and the second fenestration 112, thereby facilitating improved wall-adherence of the first fenestration 111 and the second fenestration 112. The main support frame 102 located on both sides of the second fenestration 112 in the axial direction has an angle formed by two circumferentially adjacent support rods 1021, which is a wall-adherence angle 1025. The wall-adherence angle 1025 is configured as a rounded angle. It can be understood that the wall-adhering angle 1025 located on the proximal side of the second fenestration 112 and the two struts forming the wall-adhering angle 1025 can be a surrounding angle 1024 that encloses a semi-annular structure that at least partially surrounds the first fenestration 111.

[0217] In some embodiments, each of the two fenestrations 11 is secured with a support ring 12 to reinforce the shape of the fenestration 11. For ease of distinction, the at least two fenestrations 11 are labeled as a first fenestration 111 and a second fenestration 112. A first support ring 121 is secured to the first fenestration 111 to reinforce its shape.

[0218] In some embodiments, a second support ring 122 is fixed to the second window 112 to reinforce the shape of the second window 112 .

[0219] In some embodiments, the two axial ends of the second support ring 122 are tilted, that is, the two axial ends of the second support ring 122 are tilted compared to other areas of the second support ring 122. This helps to lift the main covering 101 and the internal covering away from the central axis of the main stent 10, thereby further reducing the lumen loss rate of the main stent 10, facilitating more blood flow through the lumen of the main stent 10, and thus facilitating more blood flow through the second fenestration 112 to the branch vessel 4, thereby reducing the occurrence of complications.

[0220] In some other embodiments, the two axial ends of the first support ring 121 are tilted, that is, the two axial ends of the first support ring 121 are tilted compared to other areas on the first support ring 121. This helps to lift the main covering 101 and the internal covering away from the central axis of the main stent 10, thereby further reducing the lumen loss rate of the main stent 10, facilitating more blood flow through the lumen of the main stent 10, and thus facilitating more blood flow through the first fenestration 111 to the branch vessel 4, thereby reducing the occurrence of complications.

[0221] In some embodiments, the main frame 10 further includes a display structure 209, which is disposed around at least one of the first window 111 and the second window 112 and is used to indicate the location of at least one of the first window 111 and the second window 112. Exemplarily, the display structure 209 includes two annular structures disposed around the first window 111 and the second window 112, respectively.

[0222] In other embodiments, the first window 111 and the second window 112 may also have a developing material. The developing structure 209 is at least partially disposed around the proximal end of the main support 10; or the developing structure 209 is at least partially disposed around the distal end of the main support 10.

[0223] Referring to FIG15 , in an exemplary application scenario of a covered stent 1, the reconstruction of two branch vessels 4 on an aortic arch 3 is used as an example, with the connecting stent 20 in the first configuration. The two branch vessels 4 are the brachiocephalic artery 401 and the left common carotid artery 402. The covered stent 1 is released into the aortic arch 3 via an interventional sheath, and the branch stents 2 are released into the connecting stent 20 and the anchoring stent 30, respectively. The state of the main stent 10, connecting stent 20, anchoring stent 30, and branch stent 2 after release into the aortic arch 3 is shown in FIG15 .

[0224] In some other embodiments, the two branch vessels 4 are the left common carotid artery 402 and the left subclavian artery. In some other embodiments, the two branch vessels 4 are the brachiocephalic artery 401 and the left subclavian artery.

[0225] The third embodiment of the present application provides a covered stent, as shown in Figures 16 and 17. Figure 16 is a schematic structural diagram of the covered stent 1 of the third embodiment, and Figure 17 is a schematic structural diagram of the covered stent 1 of Figure 16 from another perspective. The third embodiment of the present application can adopt any implementation of any of the above embodiments. At the same time, the covered stent 1 of the third embodiment of the present application is provided with at least three windows 11. The covered stent 1 includes a main stent 10, a connecting stent 20 and at least two anchoring stents 30. The connecting stent 20 and the anchoring stent 30 are both used to plug and cooperate with the branch stent 2, and the branch stent 2 is used to be released into the branch vessel 4 to reconstruct the branch vessel 4. The structure, shape and position of the main stent 10 and the connecting stent 20 adopt any possible implementation method of the connecting stent 20 of any of the above embodiments, and will not be repeated here. At least three windows 11 are provided on the side wall of the main stent 10. The at least three windows 11 are arranged in sequence from the proximal end to the distal end of the main stent 10. The three windows 11 are connected to the lumen of the main stent 10.

[0226] For ease of distinction, the at least two anchoring brackets 30 are respectively named as the first bracket 31 and the second bracket 32. The structure, shape, and position of the first bracket 31 and the second bracket 32 ​​adopt any possible implementation of the anchoring bracket 30 or the connecting bracket 20 in any of the above embodiments, and are not further described here.

[0227] In some embodiments, one end of the connecting stent 20, one end of the first stent 31, and one end of the second stent 32 are respectively fixed to the three fenestrations 11, so that the connecting stent 20, the first stent 31, and the second stent 32 are connected to the lumen of the main stent 10 through the three fenestrations 11. In other words, one end of the connecting stent 20 is fixed to any one of the three fenestrations 11, and the connecting stent 20 is connected to the lumen of the main stent 10 through any one of the three fenestrations 11; while the two anchoring stents 30 (i.e., the first stent 31 and the second stent 32) are respectively fixed to the other two fenestrations 11 and are connected to the lumen of the main stent 10 through the corresponding fenestrations 11.

[0228] In some embodiments, the connecting bracket 20, the first bracket 31, and the second bracket 32 ​​are respectively fixed to the three fenestrations 11 along the proximal end to the distal end of the main bracket 10. The end of the second bracket 32 ​​away from the fenestration 11 in which it is located extends toward the distal end of the main bracket 10, so that the end of the second bracket 32 ​​away from the fenestration 11 in which it is located is toward the distal end of the main bracket 10.

[0229] In some embodiments, at least one of the two axial ends of the second bracket 32 ​​is beveled. The side of the beveled end of the second bracket 32 ​​distal to the fenestration 11 faces away from the side of the fenestration 11, thereby facilitating superselective positioning. In other words, the side of the second bracket 32 ​​distal to the fenestration 11 is beveled, with the side of the beveled end proximal to the fenestration 11 being further from the distal end of the main bracket 10 than the side distal to the fenestration 11.

[0230] For ease of distinction, the at least three fenestrations are named as the first fenestration 111, the second fenestration 112, and the third fenestration 113, respectively. The first fenestration 111 is closer to the proximal end of the main support 10 than the second fenestration 112, and the second fenestration 112 is closer to the proximal end of the main support 10 than the third fenestration 113. The axial length of the third fenestration 113 is greater than the axial length of the second fenestration 112. The axial length of the second fenestration 112 is greater than the axial length of the first fenestration 111. In other words, the axial lengths of the fenestrations increase sequentially from the proximal end to the distal end of the main support 10, for example, the axial lengths of the first fenestration 111, the second fenestration 112, and the third fenestration 113 increase sequentially.

[0231] In some embodiments, at least two fenestrations 11 on the main stent 10 are spaced apart along the axial direction of the main stent. The axial distance between the edges of two adjacent fenestrations at the proximal end of the main stent 10 is 2 mm to 15 mm. For example, the axial distance between the distal end of the first fenestration 111 and the proximal end of the second fenestration 112 is 2 mm to 15 mm, thereby making the distance between the first fenestration 111 and the second fenestration 112 relatively close.

[0232] In some embodiments, the at least three fenestrations 11 on the main stent 10 are spaced apart along the axial direction of the main stent. The axial distance between the edges of any two adjacent fenestrations is 2 mm to 15 mm. For example, the axial distance between the distal end of the first fenestration 111 and the proximal end of the second fenestration 112 is 2 mm to 15 mm, thereby making the first fenestration 111 and the second fenestration 112 relatively close to each other. The axial distance between the distal end of the second fenestration 112 and the proximal end of the third fenestration 113 is 2 mm to 15 mm, thereby making the second fenestration 112 and the third fenestration 113 relatively close to each other.

[0233] In some embodiments, the at least two windows 11 on the main stent 10 are arranged non-intervally along the axial direction of the main stent 10 , that is, the at least two windows 11 may at least partially overlap along the axial direction of the main stent 10 .

[0234] When the distance between the center positions of the first window 111 and the second window 112 is predetermined, setting the axial length of the second window 112 larger can make the proximal edge of the second window 112 closer to the distal edge of the first window 111, thereby improving the fault tolerance of the second window 112. When the main stent 10 is released into the main vessel, it is not necessary to precisely align the centerline of the second window 112 with the centerline of the target branch vessel 4, thereby reducing the requirements for the operator's interventional treatment skills and shortening the operation time. At the same time, setting the axial length of the second window 112 larger than that of the first window 111 and closer to the first window 111 is more conducive to superselective positioning. Furthermore, setting the axial length of the second window 112 larger than that of the first window 111 and closer to the first window 111 has a wider range of adaptability and can adapt to the different distances between two adjacent branch vessels 4 on the main vessels of different patients.

[0235] The same applies to the second fenestration 112 and the third fenestration 113. When the first fenestration 111 and the second fenestration 112 are located and the release is complete, setting the axial length of the third fenestration 113 larger can bring the proximal edge of the third fenestration 113 closer to the distal edge of the second fenestration 112, thereby improving the fault tolerance of the third fenestration 113. When the main stent 10 is released into the main vessel, it is no longer necessary to precisely align the centerline of the third fenestration 113 with the centerline of the target branch vessel 4, thereby reducing the interventional treatment requirements for the operator and shortening the surgical procedure. Furthermore, setting the axial length of the third fenestration 113 larger than that of the second fenestration 112 and closer to the second fenestration 112 further facilitates superselective positioning. Furthermore, setting the axial length of the third fenestration 113 larger than that of the second fenestration 112 and closer to the second fenestration 112 provides a wider range of adaptability, accommodating the varying distances between adjacent branch vessels 4 on the main vessels of different patients.

[0236] In some embodiments, the circumferential length of the second window 112 is at least 50%-70% of the diameter of the main stent 10. While ensuring the supporting performance of the main stent 10 in the blood vessel, the fault tolerance of the second window 112 is improved, and it is more convenient for super-selective positioning and has a wider range of adaptability.

[0237] In some embodiments, the circumferential lengths of at least three fenestrations increase sequentially from the proximal end to the distal end of the main support 10 , for example, the circumferential lengths of the first fenestration 111 , the second fenestration 112 , and the third fenestration 113 increase sequentially.

[0238] In some embodiments, the circumferential length of the second fenestration 112 is greater than the circumferential length of the first fenestration 111 .

[0239] In some embodiments, the circumferential length of the third fenestration 113 is greater than the circumferential length of the second fenestration 112. The circumferential length of the third fenestration 113 is at least 60%-90% of the diameter of the main stent 10. This ensures the support performance of the main stent 10 within the blood vessel while improving the fault tolerance of the third fenestration 113, facilitating superselective positioning, and covering a wider range of branch vessel 4 reconstructions under different vascular anatomies, thus adapting to a wider range of applications.

[0240] In some embodiments, the angle formed by two circumferentially adjacent support rods 1021 of the main support frame 102 located on at least one side of the first window 111 in the axial direction is a wrapping angle 1024. The wrapping angle 1024 is set to be a rounded angle.

[0241] In some embodiments, the main support frame 102 located on at least one axial side of the second fenestration 112 has a wall-attachment angle 1025 formed between two circumferentially adjacent support rods 1021. The wall-attachment angle 1025 is rounded. For example, at the distal end of the second fenestration 112, the wall-attachment angle 1025 and the two support rods 1021 forming the wall-attachment angle 1025 together form a semi-annular structure that at least partially surrounds the second fenestration 112. For example, along the axial direction of the main support frame 10, at least one main support frame 102 is disposed between the first fenestration 111 and the second fenestration 112 to enhance radial support forces around the first fenestration 111 and the second fenestration 112, thereby facilitating improved wall-attachment of the first fenestration 111 and the second fenestration 112. On the main support frame 102 located on both axial sides of the second fenestration 112, the wall-attachment angle 1025 formed between two circumferentially adjacent support rods 1021 is rounded.

[0242] It can be understood that the wall-adhering angle 1025 located on the proximal side of the second fenestration 112 and the two struts forming the wall-adhering angle 1025 can be a surrounding angle 1024 that encloses a semi-annular structure that at least partially surrounds the first fenestration 111.

[0243] In some embodiments, a support ring 12 is secured to at least one of the three fenestrations 11. For example, each of the three fenestrations 11 is secured with a support ring 12 to reinforce the shape of the fenestration 11. Specifically, a first support ring 121 is secured to the first fenestration 111 to reinforce the shape of the first fenestration 111. A second support ring 122 is secured to the second fenestration 112 to reinforce the shape of the second fenestration 112. A third support ring 12312 is secured to the third fenestration 113 to reinforce the shape of the third fenestration 113.

[0244] In some embodiments, the two axial ends of the second support ring 122 are tilted, that is, the two axial ends of the second support ring 122 are tilted compared to other areas of the second support ring 122. This helps to lift the main covering 101 and the internal covering away from the central axis of the main stent 10, thereby further reducing the lumen loss rate of the main stent 10, facilitating more blood flow through the lumen of the main stent 10, and thus facilitating more blood flow through the second fenestration 112 to the branch vessel 4, thereby reducing the occurrence of complications.

[0245] In some embodiments, the main support skeleton 102 located on at least one side in the axial direction of the third window 113 has an angle formed by two circumferentially adjacent support rods 1021, which is a sealing angle 1026. The sealing angle 1026 is set to a rounded angle. For example, on the distal side of the third window 113, the sealing angle 1026 and the two support rods 1021 forming the sealing angle 1026 form a semi-annular structure that at least partially surrounds the third window 113.

[0246] The semi-annular structure surrounding the first window 111, the semi-annular structure surrounding the second window 112, or the semi-annular structure surrounding the third window 113 can better fit the shape of the corresponding window 11, so that the corresponding window 11 can better fit the inner wall of the blood vessel, which is beneficial to improving the sealing of the corresponding window 11, thereby enhancing the anti-internal leakage effect of the corresponding window 11.

[0247] In some embodiments, at least one main support skeleton 102 is provided between the second window 112 and the third window 113 along the axial direction of the main support 10 to increase the radial support force around the second window 112 and the third window 113, which is beneficial to improving the wall adhesion of the second window 112 and the third window 113. The main support skeleton 102 located on both sides of the axial direction of the third window 113, the angle formed by two of the circumferentially adjacent support rods 1021 is a sealing angle 1026. The sealing angle 1026 is set to a rounded angle. It can be understood that the sealing angle 1026 located on the proximal side of the third window 113 and the two support rods forming the sealing angle 1026 can be a wall adhesion angle 1025 that encloses a semi-annular structure that at least partially surrounds the second window 112.

[0248] In some embodiments, the circumferential length of the third window 113 is greater than the circumferential length of the second window 112. The third window 113 with a larger circumferential length may lead to a higher lumen loss rate of the main stent 10. By setting the sealing angle 1026 to a tilted shape, it is beneficial to lift the main body coating 101 on the proximal side and / or distal side of the third window 113 away from the central axis of the main stent 10, thereby reducing the lumen loss rate of the main stent 10, facilitating more blood flow through the lumen of the main stent 10, and thus facilitating more blood flow through the third window 113 to the branch vessel 4, reducing the occurrence of complications.

[0249] In some embodiments, the two axial ends of the third support ring 12312 are tilted, that is, the two axial ends of the third support ring 12312 are tilted compared to other areas of the third support ring 12312. This helps to lift the main covering 101 and the internal covering away from the central axis of the main stent 10, thereby further reducing the lumen loss rate of the main stent 10, facilitating more blood flow through the lumen of the main stent 10, and thus facilitating more blood flow through the third fenestration 113 to the branch vessel 4, thereby reducing the occurrence of complications.

[0250] In some embodiments, two main support frames 102 are spaced apart along the axial direction of the main frame 10 between the second fenestration 112 and the third fenestration 113. The angle proximal to the third fenestration 113 is a wall-attaching angle 1025. The wall-attaching angle 1025 proximal to the third fenestration 113 and the two support rods 1021 forming the wall-attaching angle 1025 together form a semi-annular structure that at least partially surrounds the second fenestration 112. The angle distal to the second fenestration 112 is a wall-attaching angle 1025. The wall-attaching angle 1025 proximal to the second fenestration 112 and the two support rods 1021 forming the wall-attaching angle 1025 together form a semi-annular structure that at least partially surrounds the second fenestration 112.

[0251] In some embodiments, the semi-annular structure located proximal to the third fenestration 113 and the semi-annular structure located distal to the second fenestration 112 at least partially overlap along the axial direction of the main support 10 to form a reinforcing semi-annular structure 40, and the reinforcing semi-annular structure 40 is at least partially disposed around the second fenestration 112. Overlapping can be understood as the two being fixedly connected together; or, the main support frame 102 where one of the semi-annular structures is located is an open-annular structure with a notch, and the support rod 1021 corresponding to the open-annular structure is fixed to the main support frame 102 where the other semi-annular structure is located, to form a semi-annular structure with only one rod.

[0252] In some embodiments, the main support 10 further includes a display structure 209, which is arranged around at least one of the first window 111, the second window 112, and the third window 113, and is used to indicate the location of at least one of the first window 111, the second window 112, and the third window 113.

[0253] In some embodiments, the imaging structure 209 is an annular structure disposed around at least one of the first fenestration 111, the second fenestration 112, and the third fenestration 113. In other embodiments, the first fenestration 111, the second fenestration 112, and the third fenestration 113 may contain a developing material. The imaging structure 209 may also be disposed at least partially around the proximal end of the main support 10. The imaging structure 209 may also be disposed at least partially around the distal end of the main support 10.

[0254] Referring to FIG18 , in an exemplary application scenario of a covered stent 1, for example, reconstruction of three branch vessels 4 on an aortic arch 3 is performed, with the connecting stent 20 in the first configuration. These three branch vessels 4 may be the brachiocephalic artery 401, the left common carotid artery 402, and the left subclavian artery. The covered stent 1 is released into the aortic arch 3 via an interventional sheath, and the branch stents 2 are released into the connecting stent 20 and the anchoring stent 30, respectively. FIG18 shows the state of the main stent 10, connecting stent 20, anchoring stent 30, and branch stents 2 after release into the aortic arch 3.

[0255] The fourth embodiment of the present application provides a coated stent 1. The difference between the coated stent 1 of this embodiment and at least one of the second embodiment or the third embodiment is that the anchoring stent 30 fixed on the second window 112 of this embodiment is a rotatable stent, and the anchoring stent 30 is located in the tubular cavity of the main stent 10.

[0256] In some embodiments, the central axis of the anchoring bracket 30 on the second fenestration 112 is perpendicular to the central axis of the main bracket 10 .

[0257] This embodiment uses the provision of at least three fenestrations 11 as an example. For ease of distinction, the at least three fenestrations 11 are labeled as a first fenestration 111, a second fenestration 112, and a third fenestration 113. The first fenestration 111, the second fenestration 112, and the third fenestration 113 are sequentially spaced from the proximal end to the distal end of the stent graft 1. The connecting bracket 20 is provided on the first fenestration 111. The anchoring bracket 30 provided on the second fenestration 112 in this embodiment is designated as a first bracket 31, and the anchoring bracket 30 provided on the third fenestration 113 is designated as a second bracket 32.

[0258] Please refer to Figures 19 to 21. Figure 19 is a structural schematic diagram of the coated bracket 1 of the fourth embodiment, and Figure 20 is an enlarged structural schematic diagram of Figure 19 at C (the main support skeleton 102 is hidden); Figure 21 is a structural schematic diagram of the coated bracket 1 shown in Figure 19 from another perspective. The structure, form, beneficial effects or exemplary usage scenarios of the first bracket 31 can refer to the structure, form, beneficial effects or exemplary usage scenarios of the connecting bracket 20 of any possible implementation method of any of the above embodiments, and will not be repeated here.

[0259] In the fourth embodiment, the first bracket 31 includes a first opening 201, a second opening 202, and an inner cavity extending between the first opening 201 and the second opening 202. The first opening 201 and the second opening 202 of the first bracket 31 are located at opposite ends of the first bracket in the axial direction. The first bracket 31 is fixed to at least one window 11, such as the second window 112, through the end where the second opening 202 is located, so that the first bracket 31 is connected to the main bracket 10. The first bracket 31 includes a first section 203 and a second section 204 fixed to the first section 203. The first opening 201 is located at the end of the first section 203 away from the second section 204, and the second opening 202 is located at the end of the second section 204 away from the first section 203.

[0260] The first section 203 on the first bracket 31 is farther away from the window 11 where it is set, such as the second window 112, than the second section 204 on the first bracket 31, that is, the first bracket 31 has a first form and a second form, and the first form and the second form of the first bracket 31 can be switched with each other. The axial length of the first bracket 31 in the first form is greater than the axial length of the first bracket 31 in the second form, and the first bracket 31 in the first form is located in the tubular cavity of the main bracket 10.

[0261] The first bracket 31 is fixed to the second window 112 through the second opening 202 , so that the second window 112 is in communication with the inner cavity of the first bracket 31 and the lumen of the main bracket 10 through the second opening 202 .

[0262] In some embodiments, the first support 31 in the second configuration is at least partially located outside the main support 10 .

[0263] In some embodiments, the cross-sectional size of the first opening 201 of the first stent 31 is smaller than the cross-sectional size of the second opening 202, so that in the second form of the first stent 31, along the axial direction of the first stent 31, the first stent 31 at least partially extends the window 11 at its position away from the lumen of the main stent 10, such as the second window 112, and is beneficial to further improve the alignment tolerance of the corresponding window 11 (such as the second window 112) and the target blood vessel opening, reduce the risk of bending of the branch stent 2, and facilitate the superselection of the guide wire between the first stent 31 and the target branch blood vessel.

[0264] In some other embodiments, the cross-sectional size of the first opening 201 of the first bracket 31 is greater than or equal to the cross-sectional size of the second opening 202, controlling the extent to which the first bracket 31 in the second form extends beyond the window 112 at the set position, such as controlling the extent to which the first bracket 31 in the second form extends beyond the second window 112.

[0265] In some embodiments, the connection between the first section 203 and the second section 204 forms the neck 205 of the first bracket 31. That is, the first bracket 31 is formed by the neck 205 to form the first section 203 and the second section 204. In the first configuration of the first bracket 31, the first section 203 and the second section 204 are arranged along the axial direction of the first bracket 31 and are interconnected.

[0266] In the first configuration of the first bracket 31, the first section 203 of the first bracket 31 is deployed relative to the second section 204. At this point, the axial length of the first bracket 31 is the sum of the lengths of the first section 203 and the second section 204. The first configuration of the first bracket 31 allows the first bracket 31 to be positioned within the main bracket 10. The first section 203 is further away from the fenestration 11 in which it is positioned, such as the second fenestration 112, than the second section 204. The first bracket 31 thus forms an internally embedded branch.

[0267] In some embodiments, the cross-sectional dimension of the first bracket 31 at the neck portion 205 thereof is smaller than at least one of the cross-sectional dimensions of the first opening 201 and the second opening 202 of the first bracket 311 .

[0268] In some embodiments, the cross-sectional diameter of the neck portion 205 of the first bracket 31 is smaller than the cross-sectional diameters of the first opening 201 and the second opening 202 .

[0269] In some embodiments, the cross-sectional dimension of the end of the first section 203 of the first bracket 31 close to the second section 204 of the first bracket 31 is smaller than the cross-sectional dimension of the end of the first section 203 away from the second section 204, that is, the cross-sectional dimension of the end of the first section 203 close to the second section 204 is smaller than the cross-sectional dimension of the first opening 201 of the first bracket 31, so that the connection between the first section 203 and the second section 204 forms the neck 205 of the first bracket 31; or, the cross-sectional dimension of the end of the second section 204 close to the first section 203 is smaller than the cross-sectional dimension of the end of the second section 204 away from the first section 203, that is, the cross-sectional dimension of the end of the second section 204 close to the first section 203 is smaller than the cross-sectional dimension of the second opening 202 of the first bracket 31, so that the connection between the first section 203 and the second section 204 forms the neck 205 of the first bracket 31.

[0270] In some embodiments, the cross-sectional dimension of the first section 203 of the first bracket 31 at one end close to the second section 204 of the first bracket 31 is smaller than the cross-sectional dimension of the first section 203 at one end away from the second section 204, and the cross-sectional dimension of the second section 204 at one end close to the first section 203 is smaller than the cross-sectional dimension of the second section 204 at one end away from the first section 203, so that the connection between the first section 203 and the second section 204 forms the neck 205 of the first bracket 31.

[0271] Exemplarily, the first opening 201 of the first bracket 31 is located at one end of the first section 203 away from the second section 204. From one end of the first opening 201 along the axial direction of the first bracket 31 to the neck 205, the cross-sectional diameter of the first section 203 gradually decreases.

[0272] Exemplarily, the second opening 202 is located at one end of the second section 204 away from the first section 203. From one end of the second opening 202 along the axial direction of the first bracket 31 to the neck 205, the cross-sectional diameter of the second section 204 gradually decreases.

[0273] In some embodiments, the first section 203 and the second section 204 are both designed to have a tapered shape, which is conducive to making the first section 203 and the second section 204 fit more closely, so that the branch bracket 2 can be more stably inserted into the first bracket 31, or in other words, the branch bracket 2 can be more stably inserted into the first bracket 31 in the second form.

[0274] In some embodiments, the first section 203 and the second section 204 of the first bracket 31 are both truncated cone-shaped. The first bracket 31 is shaped like a small waist or an hourglass. Compared to a cylindrical structure, the design of the first bracket 31 of the present application (e.g., the first bracket 31 is shaped like a small waist or an hourglass) allows the first bracket 31 to bend at the neck 205, making the first bracket 31 retractable, thereby having an extended state and a retracted state.

[0275] In some embodiments, either the first section 203 or the second section 204 of the first bracket 31 is truncated cone-shaped, and either the first section 203 or the second section 204 of the first bracket 31 is conical.

[0276] In some embodiments, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 of the first bracket 31 to the cross-sectional diameter of the neck 205 is greater than 1. For example, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 to the cross-sectional diameter of the neck 205 is 1.1-2.1.

[0277] For example, the ratio of the cross-sectional diameter of the first opening 201 or the second opening 202 to the cross-sectional diameter of the neck 205 is 1.2. In this case, the first bracket 31 has good scalability.

[0278] As shown in Figure 22, Figure 22 is a schematic diagram of the rotation of the first stent 31 in the coated stent 1 of the fourth embodiment in any direction. The second section 204 on the first stent 31 is a flexible section, that is, the second section 204 of the first stent 31 can better assist the 360° rotation of the first stent 31, improve the alignment tolerance of the branch window 11 and the target blood vessel opening, and reduce the risk of bending of the branch stent 2.

[0279] As shown in FIG23 , FIG23 is a schematic structural diagram of the first stent 31 in the coated stent 1 of the fourth embodiment in a contracted state, and the first section 203 of the first stent 31 is provided with a support member 208 of any of the above-mentioned embodiments. The second section 204 of the connecting stent 20 is a flexible section formed by connecting the coating 207. The design of the first section 203 of the first stent 31 as a supporting anchoring section and the second section 204 as a flexible rotating section is conducive to the expansion and contraction of the first stent 31 in the axial direction, reducing the volume of the first stent 31 in the lumen of the main stent 10, and reducing the lumen loss rate of the main stent 10. In some other embodiments, as shown in FIG24 , FIG24 is another schematic structural diagram of the first stent 31 inside the coated stent 1 in some embodiments. For the first stent 31, the support member 208 on the first section 203 extends axially toward the second section 204, so that at least a part of the second section 204 has a supporting function, increasing the anchoring force between the connecting stent 20 and the branch stent 2, thereby improving the connection firmness between the connecting stent 20 and the branch stent 2.

[0280] In some embodiments, the axial length of the connecting stent 20 in the extended state is greater than the axial length of the first stent 31 in the extended state. This arrangement helps to increase the rotation range of the connecting stent 20. Even if the space between the main vessel and the branch vessel 4 is narrow, the connecting stent 20 can be positioned at the root opening of the target branch vessel 4, thereby reducing the impact on the long-term patency of the corresponding branch stent 2.

[0281] In some embodiments, the circumferential length of the second fenestration 112 is greater than its axial length, resulting in the second fenestration 112 exhibiting a "horizontally" elliptical shape. This arrangement improves the positioning tolerance of the second fenestration 112 along the circumference of the main stent 10, better accommodating the varying positions of the branch vessels 4 relative to the main vessel, and providing a wider range of adaptability.

[0282] In some embodiments, the circumferential length of the third fenestration 113 is greater than its axial length, resulting in the third fenestration 113 exhibiting a horizontally elliptical shape. This arrangement improves the positioning tolerance of the third fenestration 113 along the circumference of the main stent 10, better accommodating the varying positions of the branch vessels 4 relative to the main vessel, and providing a wider range of adaptability.

[0283] Referring to FIG. 25 , in an exemplary application scenario of a covered stent 1, taking the reconstruction of three branch vessels 4 on the aortic arch 3 as an example, with the connecting stent 20 in an extended configuration and the first stent 31 in an extended state as an example, the three branch vessels 4 are the brachiocephalic artery 401, the left common carotid artery 402, and the left subclavian artery. The covered stent 1 is released into the aortic arch 3 through an interventional sheath, and the branch stents 2 are released into the connecting stent 20, the first stent 31, and the second stent 32, respectively. The state of the main stent 10, the connecting stent 20, the first stent 31, the second stent 32, and the branch stent 2 after release into the aortic arch 3 is shown in FIG. 25 .

[0284] The fifth embodiment of the present application provides a stent system, which includes a coated stent 1 of any of the above-mentioned embodiments and an interventional device for delivering the coated stent 1 to a target blood vessel. Please refer to FIG26 , which is a schematic structural diagram of the stent system of the fifth embodiment (a schematic diagram illustrating at least partial release of the proximal end of the coated stent), and the interventional device includes an interventional sheath 5, a guide head 6, an interventional sheath core 7, and an operating handle (not shown in the figure). The guide head 6 is fixed to the proximal end of the interventional sheath core 7, and the interventional sheath 5 is sleeved outside the interventional sheath core 7. The radial dimension of the inner cavity of the interventional sheath 5 is smaller than the distal radial dimension of the guide head 6, so that the proximal end of the interventional sheath 5 contacts the distal end of the guide head 6, which is beneficial to prevent the interventional sheath 5 from extending out of the proximal end of the interventional sheath core 7 when the interventional sheath 5 moves toward the proximal end of the interventional device. There is a gap between the interventional sheath 5 and the interventional sheath core 7 for accommodating the coated stent 1 after radial compression. It should be noted that the coated stent 1 after radial compression refers to a radial dimension that is smaller than the radial dimension of the coated stent 1 after self-expansion release. The interventional sheath core 7 is used to detachably fix the proximal end of the coated stent 1, for example, the coated stent 1 is hooked on the interventional sheath core 7 through at least part of the wave crest 1022 of the proximal main body support skeleton 102. The axial length of the coated stent 1 is smaller than the axial length of the interventional sheath core 7, so the coated stent 1 is located in the part of the interventional sheath core 7 close to the proximal end. The operating handle is used to operate the interventional sheath tube 5 to move axially along the axial direction of the interventional sheath core 7. When the operating handle controls the interventional sheath tube 5 to move axially toward the distal end of the interventional sheath core 7, the coated stent 1 is exposed relative to the interventional sheath tube 5; when the operating handle controls the interventional sheath tube 5 to move axially toward the proximal end of the interventional sheath core 7, and the proximal end of the interventional sheath tube 5 does not exceed the proximal end of the interventional sheath core 7, the interventional sheath tube 5 wraps the coated stent 1 so that the coated stent 1 is limited to the gap between the interventional sheath tube 5 and the interventional sheath core 7.

[0285] The main stent 10 is released from the interventional sheath 5 by withdrawing the interventional sheath 5. That is, the main stent 10 is exposed relative to the inner cavity of the interventional sheath 5 by withdrawing the interventional sheath 5. In the process of withdrawing the interventional sheath 5, the proximal end of the main stent 10 is usually released first. At this time, the first fenestration 111 closer to the proximal end of the main stent 10 is preferentially aligned with the root opening of the corresponding branch vessel 4. Therefore, it can be understood that once the first fenestration 111 and the root opening of the corresponding branch vessel 4 are aligned, the position of the main stent 10 in the main vessel is basically determined. When the distance between the center positions of the two windows 11 is fixed, the axial length of the second window 112 is set to be larger, so that the edge of the second window 112 is closer to the edge of the first window 111, which is beneficial to improving the fault tolerance of the second window 112, so that when the main stent 10 is released on the main vessel, there is no need to accurately align the center line of the second window 112 with the center line of the target branch vessel 4, reducing the requirements for the operator's interventional treatment technology and reducing the operation time. At the same time, setting the axial length of the second window 112 larger and closer to the first window 111 is more conducive to superselective positioning. Furthermore, setting the axial length of the second window 112 larger and closer to the first window 111 has a wider range of adaptability and can adapt to different distances between two adjacent branch vessels 4 on the main vessels of different patients. The positioning of the third window 113 is similar.

[0286] In some embodiments, a pre-buried guide wire (not shown in the figure) is provided in the connecting stent 20, and the pre-buried guide wire is also passed through the main stent 10, that is, the pre-buried guide wire and the main stent 10 are radially compressed and assembled in the interventional sheath 5. One end of the pre-buried guide wire is located outside the connecting stent 20, and the other end of the pre-buried guide wire is located outside the interventional sheath 5. After the end of the pre-buried guide wire located outside the connecting stent 20 is sent into the corresponding branch blood vessel 4, it is beneficial for the branch stent 2 to be released into the corresponding branch blood vessel 4 along the pre-buried guide wire. The provision of the pre-buried guide wire is also beneficial for first aligning the window where the connecting stent 20 is located with the root opening of the target branch blood vessel 4. A pre-buried guide wire is passed through the connecting stent, and the pre-buried guide wire is also passed through the main stent. One end of the pre-buried guide wire is located outside the connecting stent, and the other end of the pre-buried guide wire is located outside the interventional sheath.

[0287] The sixth embodiment of the present application provides an application method of a stent graft 1, wherein the stent graft 1 is a stent graft 1 according to any of the above-mentioned embodiments. At least two fenestrations 11 are provided on the side wall of the main stent 10, and the size of the fenestrations 11 gradually increases from the proximal end to the distal end of the main stent 10. When the stent graft 1 is implanted, the smaller fenestrations 11 are first aligned with the target branch vessel 4, while the other larger fenestrations 11 are aligned with other target branch vessels 4. This has a high fault tolerance rate and is conducive to the smooth reconstruction of the branch vessel 4 by the stent graft 1.

[0288] For any of the above embodiments, the material of the main body coating 101 includes but is not limited to polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), thermoplastic polyurethanes (TPU), silicone rubber, polyvinyl alcohol (PVA), hydrogel, expanded polytetrafluoroethylene, polyethylene, high-density polyethylene, polyethylene terephthalate and at least one of other polymer materials.

[0289] The main support frame 102 and the support ring can be laser cut from a material having a shape memory effect; or they can be woven from a filamentary material having a shape memory effect. The material having a shape memory effect includes, but is not limited to, at least one of stainless steel, tungsten alloy, cobalt-chromium alloy, and nickel-titanium alloy.

[0290] The imaging structure 209 can be made of a material with excellent X-ray opacity, strong corrosion resistance, and good biocompatibility, and can be gold, platinum, tantalum, osmium, rhenium, tungsten, iridium, rhodium, or alloys thereof. The imaging structure 209 can take various forms, such as rings, filaments, strips, or dots, and can be secured to the connecting bracket 20 or the anchoring bracket 30 by suturing, stamping, inlaying, hot-melt bonding, bonding, welding, or riveting.

[0291] The above is merely a specific implementation of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A stent graft, characterized in that: include: A main body support, the main body support comprising two openings arranged along two axial ends of the main body support and a lumen extending axially between the two openings, and a side wall of the main body support is provided with at least one window; A connecting bracket, the connecting bracket comprising a first opening, a second opening, and an inner cavity extending between the first opening and the second opening, the first opening and the second opening being arranged along two axial ends of the connecting bracket, the connecting bracket being fixed to at least one of the openings of the main bracket through the end portion where the second opening is located, so that the connecting bracket is in communication with the main bracket; The connecting bracket includes a first form and a second form, the first form and the second form are switchable with each other, and the axial length of the first form of the connecting bracket is greater than the axial length of the second form of the connecting bracket.

2. The stent graft according to claim 1, characterized in that: The connecting bracket is at least partially composed of a bellows along its axial direction.

3. The stent graft according to claim 2, characterized in that: The connecting bracket comprises a first section which is interconnected and a second section which is fixed to the first section. At least one of the first section and the second section of the connecting bracket is composed of a bellows along its axial direction.

4. The stent graft according to any one of claims 1 to 3, characterized in that: The first shape of the connecting bracket enables the connecting bracket to be located outside the main body bracket.

5. The stent graft according to any one of claims 1 to 4, characterized in that: The second shape of the connecting bracket enables at least a portion of the connecting bracket to be located in the lumen of the main body bracket.

6. The stent graft according to any one of claims 1 to 5, characterized in that: The connecting bracket includes a first section that is interconnected and a second section that is fixed to the first section. In the first form of the connecting bracket, the first section and the second section are arranged along the axial direction of the connecting bracket, and the connection between the first section and the second section forms a neck of the connecting bracket, and the cross-sectional diameter of the neck is smaller than at least one of the cross-sectional diameters of the first opening and the second opening.

7. The stent graft according to claim 6, characterized in that: In the first form of the connecting bracket, the first section is farther away from the window of the main bracket than the second section, the first opening is located at one end of the first section away from the second section, and the second opening is located at one end of the second section away from the first section, and the cross-sectional diameter of the first section gradually decreases from one end of the first opening along the axial direction of the connecting bracket to the neck, and / or the cross-sectional diameter of the second section gradually decreases from one end of the second opening along the axial direction of the connecting bracket to the neck.

8. The stent graft according to any one of claims 6 to 7, characterized in that: The connecting bracket includes a connecting film and at least one supporting member. The connecting film forms the first section and the second section through the neck, and at least one supporting member is fixed to the peripheral wall of the first section.

9. The stent graft according to claim 8, characterized in that: The second section is a flexible section formed by the connecting film.

10. The stent graft according to any one of claims 6 to 9, characterized in that: The connecting bracket includes a connecting piece, and the connecting piece surrounds at least a portion of the neck and is fixed to the neck.

11. The stent graft according to claim 10, characterized in that: The connecting member is at least one of a suture set and a connecting rod, and the suture set is at least one suture sutured and fixed to the neck.

12. The stent graft according to any one of claims 1 to 11, characterized in that: The second shape of the connecting bracket enables at least a portion of the connecting bracket to be located in the lumen of the main bracket.

13. The stent graft according to any one of claims 3 to 12, characterized in that: The second shape of the connecting stent enables at least a portion of the second section to be located in the lumen of the main stent.

14. The stent graft according to any one of claims 3 to 13, characterized in that: At least part of the first section and the second section can overlap along the axial direction of the connecting stent, and the second form of the connecting stent enables at least part of the second section and at least part of the first section to be located in the lumen of the main stent.

15. The stent graft according to any one of claims 1 to 14, characterized in that: The cross-sectional diameter of the first opening is greater than, less than or equal to the cross-sectional diameter of the second opening.

16. The stent graft according to any one of claims 1 to 15, characterized in that: It includes at least one anchoring bracket, and the side wall of the main bracket is provided with at least two windows, and the at least two windows are respectively a first window and a second window; the connecting bracket and at least one anchoring bracket are respectively fixed to the first window and the second window, the connecting bracket is connected with the tubular cavity of the main bracket through the first window, and at least one anchoring bracket is connected with the tubular cavity of the main bracket through the second window; at least one anchoring bracket is located at least one of inside the tubular cavity of the main bracket and outside the tubular cavity of the main bracket.

17. The stent graft according to claim 16, characterized in that: The first window is closer to the proximal end of the main support than the second window, the connecting support is fixed to the first window, and at least one anchoring support is fixed to the second window.

18. The stent graft according to claim 17, characterized in that: The first openings and the second openings are axially arranged with or without intervals along the direction from the proximal end to the distal end of the main body support.

19. The stent graft according to any one of claims 16 to 18, characterized in that: The at least one anchoring stent is named as a first stent; the at least one first stent comprises a first opening, a second opening, and an inner cavity extending between the first opening and the second opening, and the first opening and the second opening are arranged along two axial ends of the first stent; the at least one first stent is fixed to the second window through the end where the second opening is located, so that the at least one first stent is connected to the main stent; At least one of the first brackets includes a first form and a second form, the first form and the second form of at least one of the first brackets can be switched with each other, and the axial length of the first form of at least one of the first brackets is greater than the axial length of the second form.

20. The stent graft according to claim 19, characterized in that: The first shape of at least one first stent enables at least one first stent to be located in the lumen of the main stent.

21. The stent graft according to any one of claims 19 to 20, characterized in that: At least one of the first supports in the second state is at least partially located outside the main support.

22. The stent graft according to any one of claims 19 to 21, characterized in that: At least one of the first brackets includes a first section and a second section fixed to the first section. In the first form of at least one of the first brackets, the first section and the second section of at least one of the first brackets are arranged along the axial direction of the connecting bracket, and the connection between the first section and the second section of at least one of the first brackets forms the neck of the first bracket; the first opening of at least one of the first brackets is located at an end of the first section of at least one of the first brackets away from the second section, and the second opening of at least one of the first brackets is located at an end of the second section of at least one of the first brackets away from the first section; the cross-sectional size of at least one of the first brackets at its neck is smaller than at least one of the cross-sectional sizes of its first opening and the second opening.

23. The stent graft according to any one of claims 19 to 22, characterized in that: For at least one of the first brackets, the cross-sectional diameter of the first section gradually decreases from one end of the first opening along the axial direction of the first bracket to the neck, and / or the cross-sectional diameter of the second section gradually decreases from one end of the second opening along the axial direction of the first bracket to the neck.

24. The stent graft according to any one of claims 19 to 23, characterized in that: The cross-sectional dimension of the first opening of at least one of the first brackets is smaller than, larger than or equal to the cross-sectional dimension of the second opening thereof.

25. The stent graft according to any one of claims 19 to 24, characterized in that: At least one of the first brackets includes a connecting coating and at least one supporting member, the connecting coating of at least one of the first brackets forms the first section and the second section through the neck, and at least one of the supporting members is fixed to the peripheral wall of the first section of at least one of the first brackets.

26. The stent graft according to claim 25, characterized in that: At least part of the second section of at least one of the first brackets is a flexible section formed by the connecting film.

27. The stent graft according to any one of claims 19 to 26, characterized in that: The second shape of at least one of the first stents enables at least a portion of the second section to be located outside the lumen of the main stent.

28. The stent graft according to any one of claims 19 to 27, characterized in that: At least part of the first section and the second section of at least one of the first stents can overlap along the axial direction of the first stent, and the second form of the first stent enables at least part of the second section and at least part of the first section to be located outside the lumen of the main stent.

29. The stent graft according to any one of claims 19 to 28, characterized in that: The axial length of the connecting bracket in the first state is greater than the axial length of at least one of the first brackets in the first state.

30. The stent graft according to any one of claims 1 to 29, characterized in that: It comprises at least two anchoring brackets, the side wall of the main bracket is provided with at least three windows, and the at least three windows are respectively a first window, a second window and a third window; The connecting stent and at least two of the anchoring stents are respectively fixed to the first window, the second window and the third window, the connecting stent is connected to the lumen of the main stent through the first window, at least one of the anchoring stents is connected to the lumen of the main stent through the second window, and at least one of the anchoring stents is connected to the lumen of the main stent through the third window; Any of the anchoring stents is located within the lumen of the main stent or outside the lumen of the main stent.

31. The stent graft according to claim 30, characterized in that: The first window is closer to the proximal end of the main support than the second window, and the second window is closer to the proximal end of the main support than the third window; the connecting bracket is fixed to the first window, at least one anchoring bracket is fixed to the second window, and at least one anchoring bracket is fixed to the third window.

32. The stent graft according to claim 31, characterized in that: The first fenestration, the second fenestration and the third fenestration are arranged axially with or without intervals along the direction from the proximal end to the distal end of the main support.

33. The stent graft according to any one of claims 1 to 29, characterized in that: It comprises at least one anchoring bracket, the connecting brackets are provided with at least two, the side wall of the main body bracket is provided with at least three windows, and the at least three windows are respectively a first window, a second window and a third window; At least two connecting stents and at least one anchoring stent are respectively fixed to the first window, the second window and the third window, at least one connecting stent is connected to the lumen of the main stent through the first window, at least one connecting stent is connected to the lumen of the main stent through the second window, and at least one anchoring stent is connected to the lumen of the main stent through the third window; At least one of the connecting brackets is located outside the lumen of the main bracket in the first state, or at least one of the connecting brackets is located inside the lumen of the main bracket in the first state.

34. The stent graft according to any one of claims 1 to 18, characterized in that: The connecting brackets are provided with at least three, the side wall of the main bracket is provided with at least three windows, at least three connecting brackets are respectively fixed to the at least three windows, and the connecting brackets are connected with the tubular cavity of the main bracket through the windows to which they are fixed; at least one of the connecting brackets is located outside the tubular cavity of the main bracket in the first form, or, at least one of the connecting brackets is located inside the tubular cavity of the main bracket in the first form.

35. The stent graft according to any one of claims 1 to 34, characterized in that: At least one of the two axial ports of at least one of the connecting brackets is arranged with an oblique opening.

36. The stent graft according to any one of claims 16-33, characterized in that: At least one of the two axial ports of at least one of the anchoring brackets is arranged obliquely.

37. The stent graft according to any one of claims 16 to 36, characterized in that: At least two windows are arranged with intervals or without intervals along the direction from the proximal end to the distal end of the main support; the projections of at least two windows along the axial direction of the main support at least partially overlap, and / or the central axes of at least two windows overlap.

38. The stent graft according to any one of claims 16 to 36, characterized in that: At least three windows are arranged in an interval or non-interval manner along the direction from the proximal end to the distal end of the main support, and the projections of at least three windows along the axial direction of the main support at least partially overlap or completely overlap, and / or the central axes of at least three windows overlap.

39. The stent graft according to any one of claims 16 to 38, characterized in that: From the proximal end to the distal end of the main support, the axial lengths of the plurality of windows increase sequentially.

40. The stent graft according to any one of claims 16 to 39, characterized in that: From the proximal end to the distal end of the main support, the circumferential lengths of the plurality of windows increase sequentially.

41. The stent graft according to any one of claims 16 to 40, characterized in that: The side wall of the main support is provided with at least two windows, and the at least two windows are respectively a first window and a second window. The first window is closer to the proximal end of the main support than the second window, and the circumferential length of the second window is at least 50%-70% of the diameter of the main support.

42. The stent graft according to any one of claims 16 to 40, characterized in that: The side wall of the main support is provided with at least three windows, and the at least three windows are respectively a first window, a second window and a third window. The first window is closer to the proximal end of the main support than the second window, and the second window is closer to the proximal end of the main support than the third window; the circumferential length of the second window is at least 50%-70% of the diameter of the main support, and / or the circumferential length of the third window is at least 60%-90% of the diameter of the main support.

43. The stent graft according to any one of claims 1 to 42, characterized in that: The main body support comprises a main body coating and a plurality of main body support skeletons fixed on the main body coating, wherein the plurality of main body support skeletons are arranged at intervals along the axial direction of the main body coating; the main body support skeleton comprises a plurality of support rods connected in sequence at an angle, wherein two adjacent angles along the circumference of the main body support are respectively a crest and a trough, and the crest is closer to the proximal end of the main body support than the trough; The main support skeleton on at least one side in the axial direction of at least one of the window openings has an angle formed by two of the circumferentially adjacent support rods, which is a surrounding angle. The surrounding angle and the two support rods forming the surrounding angle together form a semi-annular structure that at least partially surrounds at least one of the window openings.

44. The stent graft according to claim 43, characterized in that: At least a portion of the semi-annular structure is tilted in a direction away from the central axis of the main support.

45. The stent graft according to any one of claims 43-44, characterized in that: The surrounding angle is tilted in a direction away from the central axis of the main support compared to other angles on the main support frame, or the surrounding angle and at least part of the rod shape of the two support rods forming the surrounding angle are tilted.

46. ​​The stent graft according to any one of claims 1 to 45, characterized in that: The main support includes a first support section, a concave section and a second support section extending sequentially from the proximal end to the distal end. The radial dimension of the first support section is larger than the radial dimensions of the concave section and the second support section, and the radial dimension of the concave section is smaller than the radial dimension of the second support section, so that the concave section is at least partially concave in the radial direction of the main support.

47. The stent graft according to claim 46, characterized in that: At least two windows are located on the concave section; or at least one window is located on the first supporting section.

48. The stent graft according to any one of claims 46 to 47, characterized in that: The concave section includes an avoidance section and at least one flared portion; at least one of the flared portions extends along the proximal end of the avoidance section toward the proximal end of the main support, and the concave section is fixed to the distal end of the first support section through the proximal end of the flared portion; along the circumference of the flared portion, at least part of the flared portion is in an outward-turned shape in a direction away from the central axis of the concave section.

49. The stent graft according to claim 48, characterized in that: The window opening near the proximal end of the main support is located on the flared portion near the proximal end of the main support; or, the window opening is located on the avoidance section.

50. A support system, characterized in that: It comprises a branch stent and a coated stent according to any one of claims 1 to 49; the branch stent can be inserted into the connecting stent through any one of the first opening and the second opening of the connecting stent; and / or the branch stent can be inserted into the anchoring stent.

51. A support system, characterized in that: It comprises the coated stent according to any one of claims 1 to 49 and an interventional instrument for delivering the coated stent to a target position; the interventional instrument comprises a guide head, an interventional sheath core fixed to the distal end of the guide head, an interventional sheath tube sleeved outside the interventional sheath core, and an operating handle for controlling the axial movement of the interventional sheath tube, and there is a gap between the interventional sheath tube and the interventional sheath core for accommodating the coated stent after radial compression; the proximal end of the coated stent is detachably fixed to the interventional sheath core.

52. The stent system according to claim 51, characterized in that: A pre-buried guide wire is inserted into the connecting bracket, and the pre-buried guide wire is also inserted into the main bracket. One end of the pre-buried guide wire is located outside the connecting bracket, and the other end of the pre-buried guide wire is located outside the interventional sheath.

53. A method for using a stent graft, characterized in that: Including the coated stent according to any one of claims 16-49, when the coated stent is implanted, the first window or the second window is first aligned with the target branch blood vessel, and then aligned with the other windows.

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