CN114642525A

CN114642525A - Covered stent

Info

Publication number: CN114642525A
Application number: CN202011521383.9A
Authority: CN
Inventors: 黄新鑫; 肖本好
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2022-06-21
Also published as: WO2022134802A1

Abstract

The invention discloses a covered stent, which comprises a main body section, a transition section and a first branch, wherein the main body section is connected with the first branch through the transition section, the central axis of the first branch deviates from the central axes of the main body section and the transition section, and the far end surface of the transition section and the adjacent part of the first branch form a closed surface. After the covered stent is implanted into human tissues, blood flow firstly supplies blood to the tissues on one side through the first branch of the covered stent, the closed surface on the covered stent is opened and butted with the extension stent at a proper time, and the blood flow supplies blood to the tissues on the other side through the extension stent of the covered stent.

Description

Covered stent

Technical Field

The invention relates to the technical field of interventional medical instruments, in particular to a covered stent.

Background

This section merely provides background information related to the present invention and is not necessarily prior art.

The abdominal aortic aneurysm is one of vascular surgical diseases, and has high treatment difficulty and high operation risk. With the recent updating progress of the technology and materials in the blood vessel cavity, more and more doctors and patients select the endovascular repair to treat the abdominal aortic aneurysm, and the treatment result is basically satisfactory. The rupture type abdominal aortic aneurysm is a dangerous type in the abdominal aortic aneurysm, the mortality rate is high, and due to the urgency, danger, severity and danger of patients with the rupture type abdominal aortic aneurysm, the effective treatment time is short, the preparation time is short, and the main intracavity treatment means at present is to use a straight tube stent 100' to be placed at the lesion part of the abdominal aorta to isolate the blood flow from the aneurysm and prevent the rupture part from bleeding again, as shown in fig. 1. Since the straight tube stent 100 ' is used, the distal end of the straight tube stent can only be connected with the common iliac artery 210 ' on one side, so that the common iliac artery 220 ' on the other side is sealed off, and the lower limb does not have blood flow supply, the treatment method is easy to cause a series of complications after the operation of a patient.

Disclosure of Invention

Based on the problems, the invention provides a covered stent, which is mainly realized by the following technical scheme.

The invention provides a tectorial membrane bracket which comprises a main body section, a transition section and a first branch, wherein the main body section is connected with the first branch through the transition section, the central axis of the first branch is deviated from the central axes of the main body section and the transition section, and the far end surface of the transition section and the part adjacent to the first branch form a closed surface.

In one embodiment, the stent graft further includes an anchor disposed on the transition segment adjacent the closure surface.

In one embodiment, the anchor is disposed on an inner surface of the stent graft with a distal end of the anchor adjacent the occlusive face.

In one embodiment, the anchor is disposed outside of the body segment, and a proximal end of the anchor is adjacent a distal end of the closure profile.

In one embodiment, the anchor includes an open loop wave ring disposed at a proximal end of the anchor and coupled to the stent graft, the open loop wave ring having a circumferential opening toward the central axis of the main body segment.

In one embodiment, the stent graft comprises a covering membrane, the proximal end and the distal end of the covering membrane are respectively provided with an opening, and the partial covering membrane at the distal end part of the transition section is connected with the opposite covering membrane to form the closed surface.

In one embodiment, the stent graft includes a second branch, and the closed surface is disposed at a proximal end of the second branch.

In one embodiment, the closing surface is closed by suturing with a suture line, and the suture line comprises a pull line and a suture line, and the suture line is restrained by the pull line after passing through the covering film, so that the closing surface is closed; when the pull wire is removed, the inner cavity of the transition section is communicated with the inner cavity of the second branch.

In an embodiment, a distal end surface of the closed surface is inclined toward the first branch, and an included angle α exists between the distal end surface of the closed surface and a horizontal plane perpendicular to the central axis of the main body segment, and the included angle α has a value range of 0 ° < α < 90 °.

In one embodiment, the stent graft comprises a covering membrane, the proximal end and the distal end of the covering membrane are respectively provided with an opening, and the closed surface comprises a closed structure, the thickness of the closed structure is smaller than that of the covering membrane or the closed structure and the covering membrane are integrally formed.

After the covered stent is implanted into human tissues, blood flow firstly supplies blood to the tissues on one side through the first branch of the covered stent, the closed surface on the covered stent is opened to form a butt joint port at a proper time, and then an extension stent is implanted into the human tissues and is in butt joint with the butt joint port on the covered stent, so that the blood flow can supply blood to the tissues on the other side through the extension stent of the covered stent.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic view of a prior art straight tube stent for use in the abdominal aorta;

FIG. 2 is a schematic structural view of a stent graft according to the first embodiment of the present application;

FIG. 3 is a top view of an embodiment of the stent graft of FIG. 2;

FIG. 4 is a top view of another embodiment of the stent graft of FIG. 2;

FIG. 5 is a schematic view of the stent graft of FIG. 2 after implantation in a human body;

FIG. 6 is a schematic view of the stent graft of FIG. 5 after implantation of an elongate stent;

FIG. 7 is a schematic view of a stent graft with an internal anchor according to the second embodiment of the present application;

FIG. 8 is a schematic structural view of a first embodiment of an endoprosthesis anchor (a bare stent structure of interconnected undulating rings) of the stent graft of FIG. 7;

FIG. 9 is a schematic structural view of a second embodiment of an endoprosthesis anchor (a bare stent structure with Z-shaped undulating rings) of the stent graft of FIG. 7;

FIG. 10 is a schematic view of the stent graft of FIG. 7 coupled to an internal anchor;

FIG. 11 is a schematic view of another stent graft of the second embodiment of the present application with an external anchor;

FIG. 12 is a right side view of an external anchor (a bare stent having a proximal open-loop waveform) on the stent graft of FIG. 11;

FIG. 13 is a left side view of an external anchor (a bare stent having a proximal open-loop waveform) on the stent graft of FIG. 11;

FIG. 14 is a schematic view of the attachment of the external anchor of FIG. 11 to a stent graft;

FIG. 15 is a schematic view of the attachment of one of the external anchors of FIG. 11 to the undulating ring of the stent graft;

FIG. 16 is a schematic view of the connection of another external anchor (a bare stent structure with undulating rings inter-mounted) to the undulating rings of the stent graft shown in FIG. 11;

FIG. 17 is a schematic view of the connection of the external anchor (bare stent structure with Z-shaped wave rings) to the wave rings on the stent graft shown in FIG. 11;

FIG. 18 is a front view of a stent graft according to the third embodiment of the present application;

FIG. 19 is a left side view of the stent graft of FIG. 18;

FIG. 20 is a top view of the stent graft shown in FIG. 18;

FIG. 21 is a schematic view of a suturing method.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," "third," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience in description, the relationship of one element or feature to another element or feature as illustrated in the figures may be described herein using spatially relative terms, such as "inner", "surface", "inner", "outer", "lower", "below", "upper", "over", and the like. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In the field of medical devices, the direction of blood inflow is defined as "proximal" and the direction of blood outflow is defined as "distal". When the stent is implanted in a blood vessel, blood flows from the proximal end of the stent into the stent lumen and out the distal end of the stent.

The specific structure and technical effects of the stent graft 10 proposed in the present application are explained in detail by the specific embodiments below.

Example one

As shown in FIG. 2, the stent graft 10 of the present embodiment has a generally tubular configuration with openings at both ends. The stent graft 10 includes a plurality of wave rings 1012 and a stent graft 1011. The plurality of wave rings 1012 are arranged along the longitudinal direction of the stent graft 10, and the plurality of wave rings 1012 are provided on the inner surface and/or the outer surface of the stent graft 1011 by sewing or heat treatment. The covering film 1011 can be made of a material with good biocompatibility such as PET or PTFE, and the wave ring 1012 is also made of a material with good biocompatibility such as nickel titanium.

To enhance the anchoring capability of the stent graft 10 to the body tissue, the proximal end of the stent graft 10 may also be provided with a bare stent 1013, and the bare stent 1013 may not have a covering film thereon. And the bare stent 1013 may further be provided with an anchor 1014, and the stent graft 10 is anchored to the human tissue through the bare stent 1013 and the anchor 1014 arranged on the bare stent 1013, so as to improve the anchoring stability of the stent graft 10 on the human tissue.

Referring to FIG. 2, the stent graft 10 of the present embodiment includes a main body section 101, a transition section 102, and a first branch 103. The distal end of the main body section 101 is connected to the proximal end of the first branch 103 through the transition section 102, and in a natural state, the central axis of the first branch 103 is deviated from the central axes of the main body section 101 and the transition section 102, and a closed surface 104 is formed on the distal end surface of the transition section 102 adjacent to the first branch.

In particular, the distance between the central axis of the first branch 103 and the central axis of the main body segment 101 is L, preferably 0 < L < D/2(D being the diameter of the main body segment 101). Preferably, the diameter of the main body segment 101 is greater than twice the diameter of the first branch 103, that is, there is a gap between the tube wall of the first branch 103 and the central axis of the main body segment 101, so that a sufficient implantation space is reserved on the closing surface 104 of the transition segment for the later implantation of the extension stent, which is beneficial to reducing the operation difficulty of the implantation operation, reducing the time of the implantation operation, and reducing the probability of complications of the patient due to the overlong operation time.

As shown in fig. 1, the closing surface 104 includes a slope inclined toward the first branch, and a distal end surface of the closing surface 104 is at an angle α to the horizontal. In order to prevent blood flowing into the stent graft 10 from accumulating at the occlusive face 104 to form thrombus after the stent graft 10 is implanted into tissue and before the prolonged stent implantation, the value of α may range from 0 ° < α < 90 °, preferably 30 °. Thereby causing the closing surface 104 to form a slope that slopes toward the first branch 103, and blood that flows into the stent graft 10 can flow into the first branch 103 at the slope of the closing surface 104, thereby reducing the formation of thrombus by blood that accumulates at the closing surface 104. Meanwhile, the problem that the subsequent opening implantation operation is difficult due to the overlarge angle of the inclined plane of the closing surface 104 can be avoided, and the probability of complications of a patient caused by the overlong operation time is reduced.

Referring to fig. 3 and 4, the closing surface 104 is provided with a closing structure 109, the closing structure of the present embodiment is made of a covering film, and the closing structure 109 of the closing surface 104 may be integrally formed with the covering film 1011 of the stent graft 10 (as shown in fig. 3). The closure 109 may also be attached to the closure profile 104 by a subsequent sewing or heat treatment (as shown in fig. 4), in which case the closure 109 may be of the same or smaller area than the closure profile 104. Preferably, the closure structure 109 is thinner and easier to open than the cover 1011 on the stent graft 10, so as to avoid the failure of opening or the too small opening caused by the too thick cover at the closing surface 104, which affects the docking of the stent graft 10 with the elongate stent and the therapeutic effect of the stent graft 10.

As shown in FIGS. 5 and 6, in the treatment of a patient with ruptured abdominal aortic aneurysm, when the stent graft 10 of the present embodiment is implanted in the body of the patient, blood flowing into the stent graft 10 is supplied to one iliac artery through the first branch 103, and a certain survival time is taken for the patient. After the patient is stable in the later period, the closing surface 104 on the covered stent 10 is opened, so that a butt joint port capable of being in butt joint with the extension stent 110 is formed on the covered stent 10, the extension stent 110 is connected to the butt joint port to recover blood supply of the opposite iliac artery, and a series of complications caused by ischemia of the lower limb due to long-term sealing of the one iliac artery are avoided.

It should be noted that the above embodiment illustrates the stent graft 10 through the iliac artery, but the type and application scope of the stent graft 10 are not limited, for example, in other embodiments of the present application, the stent graft 10 may be used in other tissues in the human body, and will not be described one by one here. In addition, the above-described embodiments illustrate implantation of one elongate stent on the stent graft 10, however, there is no limitation on the number of elongate stents implanted on the stent graft 10, and for example, in other embodiments of the present application, two or more elongate stents may be provided on the stent graft 10, such adjustments also falling within the spirit of the present application.

Example two

Referring to FIG. 7, the stent graft 10 of the present embodiment is substantially identical in construction to the stent graft of the first embodiment, except that the stent graft 10 of the present embodiment further includes an anchor 105 disposed on the transition segment, with the anchor 105 being adjacent to the occlusive face 104. The anchoring member 105 comprises a naked support structure consisting of wave rings, when the extension support 110 is implanted in the later stage, the extension support is connected with the covered support 10 through the anchoring member 105, the anchoring member 105 can enhance the connection stability between the extension support and the covered support 10, and the extension support is prevented from shifting on the covered support 10.

Referring to FIGS. 7 and 8, the anchor 105 is disposed on an inner surface of the stent graft 10, specifically within the transition segment 102, near the proximal end of the closure profile 104, i.e., the closure profile 104 is adjacent to the distal end of the anchor 105, and preferably the distal end of the anchor 105 is flush with the end surface of the closure profile 104. Further, since the angle between the closing surface 104 and the horizontal direction of the main body segment 101 of the stent graft 10 is α, the angle β between the distal end of the anchor 105 disposed on the closing surface 104 and the horizontal direction should be equal to the angle α between the closing surface 104 and the horizontal direction, so as to ensure that the contact surface between the anchor 105 and the closing surface 104 is completely engaged, and avoid the phenomenon that the closing surface 104 is damaged during the process of assembling and releasing the stent graft 10, which results in the closing surface 104 opening in advance, due to the fact that the contact surface between the anchor 105 and the closing surface 104 is not engaged.

With continued reference to FIG. 8, the anchor 105 has a height L₀Preferably 10 mm. ltoreq.L₀The sum of the heights of the main body section 101 and the transition section 102 is less than or equal to, so that the phenomenon that the prolonged stent 110 is displaced or leaks inside due to insufficient connecting force after the prolonged stent 110 is connected into the closed surface 104 and the anchoring elements 105 because the anchoring elements 105 are not high enough can be avoided, or the compression diameter of the covered stent 10 during assembly is increased due to too high height of the anchoring elements 105, and the difficulty of assembly and release of the covered stent 10 is increased.

Referring to fig. 8 and 9, the bare stent structure on the anchor 105 may be a suspended wave ring structure or a separately formed Z-shaped wave ring structure, and then connected by a connecting member. The internal anchor 105 of this embodiment is preferably an inter-engaging undulating structure, which reduces the effect of the anchor 105 on the compressed diameter of the stent graft 10 during assembly, since the inter-engaging undulating structure may be braided from a thinner gauge nitinol material, without the need for additional fixation.

Referring to fig. 10, the anchoring member 105 may be attached to the inner surface of the stent graft 10 by suturing, heat treatment, or adhesion. The lateral axial position of the anchor 105 requires attachment to the stent graft 10, and the attachment points 106 ensure that the axial position of the anchor 105 does not shift or shorten. At least a part of the distal end face of the anchor 105 in the circumferential direction needs to be connected to the closing surface 104 to ensure that the anchor 105 is not displaced in the radial direction after setting.

In addition, referring to FIG. 11, in other embodiments, the anchoring elements 105 'may also be disposed outside of the stent graft 10, with the proximal ends of the anchoring elements 105' attached to the distal ends of the closure profiles 104. That is, the proximal end of the anchoring element 105 'is adjacent to the closing surface 104, so as to avoid interference of the anchoring element 105' with the blood flow in the lumen of the main body segment 101 and ensure the patency of the blood flow in the lumen of the stent graft 10.

One embodiment of an external anchor 105 'is shown in fig. 12 and 13, the anchor 105' including a proximal open loop coil 1051 'and a body coil 1052'. The proximal open loop wave coil 1051' is adapted to be connected to the stent graft 10, with the circumferential opening of the open loop wave coil 1051 facing toward the central axis of the main body segment. The height L1 of the proximal open loop 1051 'is preferably 0 < L1 ≦ 15mm to secure the connection between the anchor 105' and the stent graft 10. Preferably, the circumferential length of the open loop wave ring is less than half of the circumferential length of the other main body wave rings, so as to reduce the influence of the open loop wave ring on blood flow as much as possible.

The proximal open loop coil 1051 'of the anchor 105' is connected to the stent graft 10 in a manner as shown in fig. 14 and 15, i.e., the proximal open loop coil 1051 'at least partially overlaps the stent graft of the transition segment 102, and preferably the proximal open loop coil 1051' is connected to the outer surface of the stent graft by a suture 106, so as to avoid the overlap with the upper coil of the stent graft 10 as much as possible, reduce the increase in the compressed diameter of the stent due to the coil overlap, and further increase the difficulty in assembling and releasing the stent graft 10. It will be appreciated that the proximal open loop 1051 'of the anchor 105' may also be secured to the loop 107 on the stent graft 10 by a suture 106.

With continued reference to FIGS. 12 and 13, the height L0 of the main body wave circle 1052 'of the anchor 105' is preferably 0 < L0 ≦ 60 mm. The preferred height of L0 is 30mm in this embodiment, which ensures that the anchoring length of the stent 110 and the anchoring elements 105' is increased after the closed surface 104 of the stent graft 10 is opened, thereby ensuring the stability of the connection between the stent 110 and the stent graft 10. If L0 is too small, the stability of the connection between the stent graft and the stent graft may be impaired.

In other embodiments, as shown in FIGS. 16 and 17, the anchor 105 "may be connected to the undulating stent 117 on the stent graft by a separate connector. The connector comprises a stainless steel sleeve 116' and a connecting rod 108. The number of the connecting rods 108 is at least 1, and the number of the connecting rods 108 is preferably 3 in the embodiment, so as to ensure the connection stability of the anchor 105 ″ and the wave ring bracket 117 on the covered bracket 10. The anchor 105 "of the present embodiment eliminates subsequent connections to other components of the stent graft 10, reducing the risk of damage to other components of the stent graft 10. Moreover, the anchoring elements 105 ″ of the present embodiment do not need to be sutured to the stent graft 10, so that no suture holes are formed, and the risk of internal leakage of the stent graft 10 due to excessive porosity of the stent graft is reduced.

It is understood that in other embodiments, the anchor may be an open structure, such as a curved sheet-face structure.

EXAMPLE III

Referring to FIGS. 18 and 19, the stent graft 10 'of the present embodiment is substantially identical in construction to the stent graft 10 of the first embodiment, except for the closed surfaces 104'. The closing surface 104 ' of the present embodiment is not provided with an additional closing structure, but directly connects the partial coating film of the upper distal end part of the transition section 102 ' with the opposite coating film by means of sewing or heat treatment, so as to form the closing surface 104 '.

The stent graft of the embodiment further comprises a second branch 111 ', after the closing surface 104 ' is opened, the extension stent is directly connected with the second branch 111 ' on the stent graft 10 ' in a matching manner, and after the second branch 111 ' is connected with the extension stent, the film structure on the second branch 111 ' can increase the matching contact area with the extension stent, increase the friction force between the second branch 111 ' and the extension stent, improve the connection strength between the stent graft 10 ' and the extension stent, and ensure the connection stability between the stent graft 10 ' and the extension stent. In addition, the probability of endoleak at the connection portion is also reduced because the mating area between the second branch 111 'on the stent graft 10' and the elongate stent is increased by one layer of coating. Furthermore, the extended stent is directly connected to the second branch after implantation without extending into the transition section and without affecting blood flow prior to flowing into the branch.

Referring to FIG. 18, the closed surface 104 ' of the present embodiment is disposed at the proximal end of the second branch 111 ', and the included angle α between the distal end surface of the closed surface 104 ' and the horizontal direction of the stent graft 10 ' is 0 ° < α < 90 °, so as to prevent blood flowing into the stent graft 10 ' from accumulating at the closed surface 104 ' to form thrombus before the closed surface 104 ' is opened after the stent graft 10 ' is implanted, and the thrombus may flow along with blood flow in the direction of the lower limb to block the artery of the lower limb, thereby affecting the therapeutic effect after the closed surface 104 ' is opened.

Referring to FIG. 20, the closure surface 104 'of the present embodiment may be formed by directly suturing and closing the proximal end of the second branch 111' of the stent graft 10 'with a suture, or pre-closing the proximal end of the second branch 111' by heat treatment, adhesion, or the like. In this embodiment, the closing is preferably performed by sewing, and the sewing can be performed in the manner shown in fig. 21. Specifically, the suture is made by using a pull line 1041 ' and a suture 1042 ' during the suture, the suture 1042 ' repeatedly goes in and out twice from the same through hole, and bypasses the suture 1042 ' during the passing in and out, so that the suture 1042 ' is not separated from the through hole, and the two sides of the coating film are connected together. After the pull wire 1041 'is removed, the suture 1042' is not restrained any more and can be easily pulled out from the through hole, so that the two sides of the coating film can be correspondingly separated, and the inner cavity of the transition section is communicated with the inner cavity of the second branch. In this embodiment, the set pull wire 1041 ' may be located outside the stent graft 10 ' and be higher than the proximal end or the distal end of the main body segment 101 ', and after the stent graft 10 ' is implanted, when an implantation operation is performed, the pull wire 1041 ' is pulled out of the body only by using a catcher, and the closed surface 104 ' on the stent graft 10 ' can be opened. The present embodiment may effectively reduce the impact of the configuration of the closure profiles 104 'on the compressed diameter of the stent graft 10' during assembly, and avoid the difficulty of assembly and release of the stent graft 10 'due to the configuration of the closure profiles 104'.

In addition, the closing surface 104 ' can be opened and closed by matching the pull wire 1041 ' with the suture 1042 ', so that the opening and closing efficiency of the closing surface 104 ' can be improved, and the butt joint of the covered stent 10 and the extension stent and the treatment effect of the covered stent 10 are prevented from being influenced by the opening failure or the undersize opening caused by the large opening and closing difficulty of the closing surface 104 '.

It should be noted that in the drawings implemented in the present application, the second branch 111 ' is only one embodiment of the present application, and the shape of the second branch 111 ' is not limited, for example, according to other embodiments of the present application, the shape of the second branch 111 ' may be provided with a bent pipe, or the shape of the second branch 111 ' may be matched with the shape of the extension bracket, and these structural adjustments all belong to the protection scope of the second branch 111 ' in the present application.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A stent graft comprising a main body segment, a transition segment, and a first branch, the main body segment and the first branch being connected by the transition segment, wherein a central axis of the first branch is offset from the central axis of the main body segment and the transition segment, and wherein a portion of the transition segment adjacent the first branch forms a closed surface with a distal surface.

2. The stent graft of claim 1, further comprising an anchor disposed on the transition segment adjacent to the occlusive face.

3. The stent graft of claim 2, wherein the anchor is disposed on an inner surface of the stent graft with a distal end of the anchor adjacent the occlusive face.

4. The stent graft of claim 2, wherein the anchor is disposed outside of the body segment with a proximal end of the anchor adjacent a distal end of the occlusive face.

5. The stent graft of claim 4, wherein the anchor comprises an open loop wave ring disposed at a proximal end of the anchor and coupled to the stent graft, the open loop wave ring having a circumferential opening toward the central axis of the main body segment.

6. The stent graft of claim 1, wherein the stent graft comprises a cover, the cover has proximal and distal ends that are each open, and the partial cover at the distal end of the transition segment is joined to the contralateral cover to form the closed surface.

7. The stent graft of claim 6, wherein the stent graft comprises a second limb, and the closed face is disposed proximal to the second limb.

8. The stent graft of claim 7, wherein the closure surface is closed by suturing with a suture thread, and the suture thread comprises a pull wire and a suture thread, the suture thread being constrained by the pull wire after passing through the cover such that the closure surface is closed; when the pull wire is removed, the inner cavity of the transition section is communicated with the inner cavity of the second branch.

9. The stent graft of any one of claims 1-8, wherein the distal end surface of the closed surface slopes toward the first branch, and an included angle α exists between the distal end surface of the closed surface and a horizontal plane perpendicular to the central axis of the main body segment, the included angle α ranging from 0 ° < α < 90 °.

10. The stent graft of claim 9, wherein the stent graft comprises a cover, wherein the proximal end and the distal end of the cover each define an opening, and wherein the closure profile comprises a closure structure having a thickness that is less than the thickness of the cover or the closure structure is integrally formed with the cover.