CN114652495B

CN114652495B - Covered stent

Info

Publication number: CN114652495B
Application number: CN202210536253.5A
Authority: CN
Inventors: 朱永锋; 周敏; 刘昭; 李晓强; 朱清; 徐健伟; 刘金宏; 薛彦慧
Original assignee: Shanghai Minimally Invasive Heart Pulse Medical Technology Group Co ltd
Current assignee: Shanghai Minimally Invasive Heart Pulse Medical Technology Group Co ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-08-30
Anticipated expiration: 2042-05-18
Also published as: CN114652495A; WO2023221712A1

Abstract

The invention provides a covered stent, which is used for enabling a main body part to be in butt joint communication with a renal artery through two fenestrations; through every embedded branch structure respectively with one the windowing links to each other, two embedded branch structure all is located in the inner chamber of main part, just embedded branch structure's orientation with renal artery's opening orientation is unanimous to play the drainage effect to the blood flow of renal artery's opening outflow, and follow the nature trend of blood flow, make its original blood vessel form that is more close the human body, still reduced the compliance requirement to the ball that the cooperation was used and expanded the tectorial membrane support or from expanding the support, guarantee that the ball expands the tectorial membrane support or from expanding the good unobstructed rate of support long term, still greatly avoided embedded branch structure to expand the tectorial membrane support with the ball or from expanding the interior concatenation that probably produced of support when leaking.

Description

Covered stent

Technical Field

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

Background

The vascular intervention treatment is a minimally invasive treatment mode, and the survival probability of patients with vascular diseases who cannot tolerate surgical operations is improved. The human blood vessels have a plurality of branches, and the lesion area of some aneurysms can affect the branch vessel area. Taking the abdominal aorta structure as an example, the abdominal aorta supplies blood for a plurality of internal organs of a human body, and the double renal arteries and the superior mesenteric artery are both originated from the abdominal aorta, so that when the intracavity surgical treatment is carried out, the smooth blood flow of the 3 arteries, namely the abdominal aorta, the double renal arteries and the superior mesenteric artery, is required to be ensured so as to ensure the life safety of a patient.

When the initial position of the abdominal aortic aneurysm of a patient is below the superior mesenteric artery and the distance between the initial position and the lower edge of the superior mesenteric artery is more than 4mm, the existing standard vascular stent cannot simultaneously ensure that the stent does not shift and the blood flow of the double renal arteries and the superior mesenteric artery is unobstructed, but the two points are fatal to the patient. The traditional open surgery treatment has the defects of large wound and high risk, and is particularly not suitable for the older patients. While few covered stents available in foreign markets can treat the aneurysms, the structural design and scheme of the covered stents have certain limitations. It has the drawback that the operation formula is complicated, the price is expensive, the risk of internal leakage exists in the splicing part of the bracket, and the blood flow smoothness of the double renal arteries and the superior mesenteric artery can not be ensured for a long time.

Disclosure of Invention

The invention aims to provide a covered stent, which can solve the problems that the risk of internal leakage exists at the splicing part of the stent and the smooth blood flow of double renal arteries and superior mesenteric arteries cannot be ensured for a long time.

In order to solve the problems, the invention provides a covered stent, which comprises a main body part, wherein the main body part comprises a covered section and two embedded branch structures, the covered section is provided with two windows, and the two windows are used for enabling the main body part to be in butt joint communication with a renal artery; each embedded branch structure is arranged at one windowing position and is connected with the windowing position, the two embedded branch structures are located in the inner cavity of the main body portion, and the orientation of the embedded branch structures is consistent with the orientation of the opening of the renal artery.

Optionally, the embedded branch structure is an axially-through tubular structure, and includes a first opening and a second opening, where the first opening is connected to the fenestration;

the second opening is disposed toward the proximal end of the body portion when the opening of the renal artery is toward the proximal end of the body portion; the second opening is disposed toward the distal end of the body portion when the opening of the renal artery is toward the distal end of the body portion; alternatively, when the opening of the renal artery is oriented perpendicular to the axial direction of the main body portion, the second opening is disposed horizontally.

Optionally, the embedded branch structure is a tubular structure which is axially through and comprises a first opening and a second opening, the embedded branch structure comprises a first variable-height stent section, an embedded branch covering film and a first positioning ring structure, the embedded branch covering film wraps the first variable-height stent section, and the embedded branch covering film at the first opening and the first positioning ring structure are fixed at the windowing position.

Further, the first variable-height bracket section comprises at least two first short edges and at least two first high edges, all the first short edges are sequentially connected and then respectively connected with all the first high edges sequentially connected to form an annular wavy structure, wherein the heights of the first short edges are smaller than those of the first high edges;

one end of the embedded branch structure, which is provided with a first short edge and a first high edge, is used as a second opening, and the other end of the embedded branch structure, which is only provided with the first high edge, is used as the first opening;

the orientation of the second opening is determined by splicing the empty membrane section provided with the embedded branch coated membrane at the first opening and the near-end side or the far-end side of the window.

Further, the portion of the embedded branch coating film close to the second opening, which faces the main body portion side, is connected with the main body portion.

Optionally, the axial length of the embedded branch structure is 2 mm-18 mm.

Optionally, the membrane covering section includes a window, the window and the two windows are axially spaced, and the window is used for enabling the main body portion to be in butt joint communication with the superior mesenteric artery.

Further, the tectorial membrane section includes main part support and main part tectorial membrane, main part tectorial membrane cladding main part support, and make the distal end of main part support forms closed inner chamber along the axial, main part support includes that two seconds uprise support section and at least one first equal-height support section, two the second uprises the horizontal symmetry setting of support section and is in the near-end of main part support, all first equal-height support section sets up along the axial in proper order the interval the distal end of main part support, the window is located two the second uprises on the main part tectorial membrane between the support section, the setting of windowing is in the cladding on the main part tectorial membrane of first equal-height support section or second uprising support section.

Furthermore, the second uprises the support section and includes two short arriss of second and many high arriss of second, all the short arriss of second links up in proper order back respectively with all link up in proper order the high arriss of second links up again and forms annular wave structure, the arris height of the short arris of second is less than the arris height of the high arris of second, the window is located two along the axial the second uprises between the short arris of support section.

Further, first equal high support section is by a plurality of isometric prisms end to end joining form cyclic annular wave structure, it is located between two adjacent prisms to open the window, and two it is same to open the window along circumference be located on the main part tectorial membrane of first equal high support section, perhaps two it is different to open the window along circumference be located on the main part tectorial membrane of first equal high support section, perhaps, two it is located the cladding along circumference to open the window on the main part tectorial membrane of second uprising support section.

Further, the first opening and the second opening of the embedded branch structure are both provided with a first positioning ring structure, the window is provided with a second positioning ring structure, the first positioning ring structure at the first opening is located on the outer side of the main body film, the first positioning ring structure at the second opening is located on the inner side of the main body film, and the second positioning ring structure is located on the outer side of the main body film.

Furthermore, second locating ring structure and first locating ring structure all include support silk and development silk, the support silk is the ring form, the winding of development silk is in on the support silk or the development silk with support silk parallel arrangement.

The second heightening support section and/or the first heightening support section are/is circumferentially surrounded by the bundle diameter coil, and the suture coil is arranged on a vertex at the far end of the second heightening support section and/or the first heightening support section, a vertex at the near end of the second heightening support section and/or the first heightening support section or a vertex at the near end of the first heightening support section.

When the seaming loops are arranged on the ridges, two seaming loops are arranged on each ridge, and the distances between the two seaming loops and the corresponding vertexes closest to each other are equal; alternatively, each of the ribs is provided with a suture loop at the midpoint of the rib or at the distal apex and proximal apex of the second elevated stent segment and/or the first equal elevated stent segment.

Further, the main body part further comprises a bare section, the far end of the bare section is connected with the near end of the main body covering film, and the bare section is axially overlapped with the near end part of the main body support.

Further, the bare section comprises a stent ring and a barb structure located at the proximal end of the stent ring, the barb structure comprises a barb and a barb handle, the distal end of the barb handle is connected with the stent ring, the proximal end of the barb handle is connected with the proximal end of the barb, the distal end of the barb is turned outwards in the direction away from the axis of the stent ring, and the included angle between the barb and the axis of the stent ring is 10-70 degrees.

Optionally, the portable electronic device further comprises a splicing part, wherein the splicing part is spliced at the far end of the main body part, the splicing part comprises a first splicing part, and the near end of the first splicing part is connected with the far end of the main body part.

Furthermore, the splicer includes the second splice, the distal end of first splice has homonymy branch and contralateral branch, the proximal end of second splice is connected the homonymy branch for establish homonymy iliac artery blood flow, contralateral branch is used for establishing contralateral iliac artery blood flow after the concatenation.

Compared with the prior art, the invention has the beneficial effects that:

Furthermore, one end of the embedded branch structure, which is provided with the first short ridge and the first high ridge, is used as the second opening, and the other end of the embedded branch structure, which is only provided with the first high ridge, is used as the first opening; the hollow membrane section provided with the embedded branch coating film at the first opening is spliced with the near end side or the far end side of the fenestration to determine the orientation of the second opening, even if the part provided with the first high ridge and the embedded branch coating film forms the large bent side of the embedded branch structure, the hollow membrane section only provided with the embedded branch coating film forms the small bent side of the embedded branch structure, the splicing is easy, and the design of the first variable-height support section can ensure that the flexibility of the small bent side is good; the small bending side can strengthen the ball-expanded covered stent or the self-expanding stent which is used in a matched anchoring way, and simultaneously, the overall pressing and holding size of the covered stent is reduced, so that the requirement on the diameter of the access blood vessel is reduced.

Further, the main part, the concatenation of first concatenation portion and second concatenation portion, and the window, windowing and embedded branch structure all concentrate the setting in the main part, make the main part design according to the demand, first concatenation portion and second concatenation portion can the batch production need not special customization, thereby make first concatenation portion and second concatenation portion preparation degree of difficulty reduce, can join in marriage goods and delivery fast, the latency of dress has been shortened greatly, homonymy branch can directly rebuild homonymy iliac artery blood flow, compare with the internal concatenation of the homonymy iliac artery support of adoption on the market, the III type internal leakage of this department has been eliminated, the economic cost and the time cost of operation have still been reduced.

Furthermore, the second uprises the support section and includes two short arriss of second and many high arriss of second, all the short arriss of second links up in proper order back links up respectively with all high arriss of second that link up in proper order and links up again and form annular wave structure, the arris height of the short arris of second is less than the arris height of the high arris of second, the window is located two along the axial the second uprises between the short arris of support section. This structure can improve the compliance of tectorial membrane support near-end, and the short arris of second can dodge the last artery of mesentery and open the window, and the symmetric distribution of two short arriss of second both can provide sufficient space of dodging for windowing (the last artery of mesentery opens the window promptly), can provide sufficient radial holding power for the tectorial membrane with the last artery of mesentery on the horizontal direction parallel and level again, guarantee and the last artery of mesentery open the window the tectorial membrane of horizontal direction parallel and level and the inseparable laminating of abdominal aorta.

Drawings

FIG. 1 is a schematic structural view of a stent graft according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a main body according to an embodiment of the present invention;

FIGS. 3a-3c are schematic diagrams of an embedded branch structure with different orientations according to an embodiment of the invention;

FIG. 4 is a circumferential expanded schematic view of a first variable height stent section wrapped with an embedded branch cover in accordance with one embodiment of the present invention;

fig. 5 is a schematic structural diagram of a spliced portion according to an embodiment of the invention.

Description of reference numerals:

1-a body portion; 2-splicing part; 3-superior mesenteric artery window; 4-embedded branch structure;

100-a bare segment; 110-a scaffold ring; 120-barb handle; 130-barbs; 141-8 font development points; 142-O font development points; 200-a first coating section; 210. 220-a second high cradle section; 211. 221-a second short edge; 212. 222-a second high edge; 300-a second film coating section; 310-a first equal high rack section; 311-prisms; 410-a first variable height stent section; 411-a first short edge; 412-first high edge; 413-major bend side; 414-minor curve side; 415-fasting section; 420-embedded branch film covering; 400 a-first opening; 400 b-a second opening; 500-beam diameter structure; 510-beam diameter coil; 520-a seaming loop; 600-a first splice; 610-lower body section; 611-a second, equal-height rack section; 620-a bifurcated segment; 621-ipsilateral branch; 622-contralateral branch; 623-elliptical ring stent section; 700-a second splice; 710-a first radius section; 720-a transition section; 730-second equal radius section.

Detailed Description

A stent graft of the present invention will be described in further detail below. The present invention will now be described in more detail with reference to the accompanying drawings, in which preferred embodiments of the invention are shown, it being understood that one skilled in the art may modify the invention herein described while still achieving the advantageous effects of the invention. Accordingly, the following description should be construed as broadly as possible to those skilled in the art and not as limiting the invention.

In the interest of clarity, not all features of an actual implementation are described. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific details must be set forth in order to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art.

In order to make the objects and features of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise ratio for the purpose of facilitating and distinctly aiding in the description of the embodiments of the invention. As used herein, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. The terms "inner", "outer", and the like as used herein are for illustrative purposes only and do not denote a unique embodiment. Herein, the terms "distal" and "proximal" are each relative orientation, relative position, direction of elements or actions relative to one another from the perspective of a physician using the medical device, although "distal" and "proximal" are not intended to be limiting, but generally refer to the end of the medical device that is near the operator during normal operation, and generally refer to the end that is near the patient's heart. Herein, the term "rib height" refers to the length of two adjacent apices A and A' in the axial direction of the stent graft, such as in the second taller stent section of FIG. 2. Herein, "lateral" refers to a direction perpendicular to the axis of the main body, that is, a direction from left to right in fig. 1.

FIG. 1 is a schematic structural view of a stent graft according to this embodiment. As shown in FIG. 1, the present embodiment provides a stent graft that may be used to treat an abdominal aortic aneurysm having a starting location below the superior mesenteric artery and a distance greater than 4mm from the inferior border of the superior mesenteric artery.

Fig. 2 is a schematic structural diagram of the main body portion of the present embodiment. As shown in FIG. 2, the stent-graft comprises a main body part 1 and a splicing part 2, wherein the proximal end of the splicing part 2 is connected with the distal end of the main body part 1. The main body 1 is intended to be placed in the aortic visceral area.

The main body part 1 comprises a bare section 100 and a covered membrane section, the far end of the bare section is connected with the near end of the covered membrane section, and the bare section 100 is used for anchoring the near end of the covered membrane stent. The film covering section comprises a main body support and a main body film, the main body film covers the main body support, and the far end of the main body support forms a closed inner cavity along the axial direction. The main body film is coated on the main body bracket to form the film coating section. The graft segment of the body portion 1 may isolate the aneurysm from blood flow and allow blood flow to pass from within the stent graft 100.

The film covering section comprises a first film covering section 200 and a second film covering section 300 which are arranged along the axial direction, a main body film covering at the near end of the first film covering section 200 is connected with the far end of the naked section 100, and a main body film covering at the far end of the first film covering section 200 is connected with a main body film covering at the near end of the second film covering section 300. An upper mesenteric artery window 3 is formed in the main body tectorial membrane of the first tectorial membrane section 200, and the upper mesenteric artery window 3 is used for being communicated with an upper mesenteric artery; the main body coating film of the second coating film section 300 is provided with an embedded branch structure 4, and the embedded branch structure 4 is used for being communicated with the renal artery. The stent graft in this embodiment provides radial support for anchoring the proximal end of the stent graft from the bare segment 100 to the first stent graft 200. The radial cross sections of the bare section 100, the first film coating section 200 and the second film coating section 300 are annular, and the diameters of the bare section 100, the first film coating section 200 and the second film coating section 300 are the same.

The bare section 100 is used to anchor the proximal end of the stent graft to the normal blood vessel, and also to extend the anchoring area of the stent graft and to achieve the purpose of release after the bare section when the stent graft is mated with a delivery device. In order to ensure sufficient adherence of the bare section 100 to the normal blood vessel, the bare section 100 needs to have sufficient radial support force, which is achieved by, but not limited to, cutting the bare section from 316 stainless steel, cobalt-chromium alloy or nickel-titanium alloy pipe diameter.

To further enhance the anchoring effect of the bare section 100, the bare section 100 has a plurality of barb structures for anchoring the proximal end of the stent graft. As shown in fig. 2, the bare segment 100 includes a wavy stent ring 110, and the wavy stent ring 100 has good radial scalability so that the bare segment can be easily crimped and can also provide anchoring support force. The stent ring 100 has a diameter of 18 mm-38 mm to fit the size of the blood vessel. The barb structure is disposed on the crest (apex M) of the stent ring 110 near the proximal end of the bare segment 100.

The barb structure comprises a barb handle 120 and a barb 130, the distal end of the barb handle 120 is connected to the vertex M of the stent ring 110 near the proximal end of the bare section for supporting the barb 130, the proximal end of the barb 130 is connected to the proximal end of the barb handle 120, the barb 130 and the barb handle 120 are respectively connected after being formed, for example, after being respectively cut and formed, by welding, or the barb 130 and the barb handle 120 are in an integral structure, for example, can be integrally cut and formed. The far end of the barb 130 is a free end, the barb 130 is turned outwards in the direction far away from the axis of the stent ring 110, the included angle between the barb 130 and the axis of the stent ring 110 is 10-70 degrees, the barb structure is convenient for realizing barb protection before the covered stent is completely released from a conveyor, and the covered stent can not scratch a blood vessel when being adjusted in a blood vessel cavity under a semi-restrained state. The length of the barb 130 is 1mm ~6mm, and the distal end of the barb 130 is conical. The above-described shape of the bare section 100 may provide space for the introduction of other consumables in the semi-constrained state of the stent graft.

In the embodiment, the distal end of the bare section 100 is sewn on the main body covering film at the proximal end of the first covering film section 200, the bare section 100 axially overlaps with the proximal end part of the main body stent, that is, the distal end of the bare section 100 and the proximal end of the first covering film section 200 have an overlapping region along the axial direction of the main body stent, the vertex M 'of the distal end of the bare section 100 close to the proximal end of the first covering film section 200 is located in the overlapping region, and the distance from the vertex M' of the bare section 100 close to the proximal end of the first covering film section 200 to the proximal end edge of the main body covering film is 2 mm-4 mm, so that the second high-height stent sections at the proximal ends of the bare section 100 and the first covering film section 200 have an overlapping region in the axial direction of the main body stent (for example, 2mm is close to the proximal end edge of the first covering film section, and the second high-height stent sections at the proximal ends of the bare section 100 and the first covering film section have an overlapping region in the axial direction of the main body stent), can increase the position that the radial of covered stent supported for the rounding of covered stent's near-end is better, thereby effectively prevents because the Ia type that the near-end of covered stent and the inseparable production of vascular inner wall laminating leak in.

First tectorial membrane section 100 includes two second and becomes high support section, in this embodiment, first tectorial membrane section 100 includes two second and becomes

high support section

210, 220, two the second becomes

high support section

210, 220 horizontal symmetry sets up the near end of main part support (two promptly the second becomes

high support section

210, 220 along main part support's radial symmetry, and set up the near end at main part support), and two second become

high support section

210, 220 along the axial interval of main part support sets up, two the minimum axial interval between the second becomes

high support section

210, 220 is 1mm ~6mm, two axial interval between the second becomes

high support section

210, 220 can adjust according to the vascular bending degree to in order to adjust the compliance second near arterial window on the mesentery and become the support section, finally the complete adaptation blood vessel trend. When the degree of bending of the abdominal aorta vessel at the superior mesenteric artery opening is severe, the axial distance between the two second uprising stent sections can be increased, and on the contrary, the axial distance between the two second uprising stent sections can be reduced.

The second high-height stent section 210 can make the close end of the covered stent close to the normal vascular wall so as to effectively prevent the Ia-type internal leakage caused by the close joint of the close end of the covered stent and the normal vascular wall. In this embodiment, the second elevated stent section 210 and the bare section 100 serve as anchoring regions for the proximal end of the stent graft, both of which can provide radial support for anchoring the proximal end of the stent graft and together ensure sufficient adherence of the proximal end of the stent graft to the normal blood vessel.

In this embodiment, the second variable-

height bracket sections

210 and 220 are two identical brackets, the second variable-height bracket section 210 includes a second short rib 211 and a second high rib 212, and the second variable-height bracket section 220 includes a second short rib 221 and a second high rib 222, where the number of the second

short ribs

211 and 221 is 2, the number of the second

high ribs

212 and 222 is multiple, all the second short ribs 211 are sequentially connected and then respectively connected with all the sequentially connected second high ribs 212 to form the second variable-height bracket section 210 in a circular wave shape, and all the second short ribs 221 are sequentially connected and then respectively connected with all the sequentially connected second high ribs 222 to form the second variable-height bracket section 220 in a circular wave shape. The height of the second

short edges

211 and 221 is smaller than that of the second

high edges

212 and 222, the height of the second

short edges

211 and 221 is 2 mm-8 mm, and the height of the second

high edges

212 and 222 is 8 mm-16 mm. Because the ridges of the second high ridge and the second low ridge are both small in height, the formed second

high stent sections

210 and 220 are small in length along the axial direction of the stent graft, and the flexibility of the proximal end of the stent graft can be improved. Because the second

heightened leg sections

210, 220 are laterally symmetrically arranged, the vertex a formed at the distal end of the second heightened leg section 210 after the two second short edges are joined and the vertex a 'formed at the proximal end of the second heightened leg section 220 after the two second short edges are joined are arranged facing each other, and the vertex formed at the distal end of the second heightened leg section 210 after any two second high edges are joined and the vertex formed at the proximal end of the second heightened leg section 220 after the two second high edges are joined are arranged facing each other, which results in the distance between the vertices a and the vertices a' between the second

heightened leg sections

210, 220 being the largest distance between the vertex of the second heightened leg section 210 at the distal end thereof and the vertex of the second heightened leg section 220 facing thereto at the proximal end thereof. The space can be effectively reserved for the superior mesenteric artery window 3, so the design of the second

short ribs

211 and 221 is mainly used for avoiding the superior mesenteric artery window 3 and can also be used for providing enough radial supporting force for wrapping the covering films of the second high-

variable support sections

210 and 220 in the radial direction so as to ensure that the covering films around the superior mesenteric artery window 3 are tightly attached to the abdominal aorta. The apex A, A' is spaced less than 3mm from the superior mesenteric artery window 3, respectively, depending on the size of the vessel.

The superior mesenteric artery window 3 is used for reshaping the unobstructed blood flow of the superior mesenteric artery. The superior mesenteric artery window 3 includes a window (e.g., a circular window) cut out of the main body cover between the vertices A, A' and a second positioning ring structure provided at the window, preferably, the second positioning ring structure is a circular ring structure, and the second positioning ring structure is sewn to the main body cover outside the window, and the superior mesenteric artery window 3 is sized to the inner diameter of the second positioning ring structure so that the superior mesenteric artery window 3 is aligned with the opening of the superior mesenteric artery. The second locating ring structure is composed of a supporting wire and a developing wire, and further, the supporting wire and the developing wire are arranged in parallel (independent from each other and not wound) or the supporting wire and the developing wire are wound with each other, the rigidity requirement of the superior mesentery artery windowing is guaranteed through the composition of the second locating ring structure, and the position tracking under the ray is also guaranteed, so that the visibility of the covered stent is increased, and the operation is facilitated. The supporting wire is made of 316 stainless steel, cobalt-chromium alloy or nickel-titanium alloy and the like, and the developing wire is made of gold and the like with good developing performance. Preferably, the supporting wire and the developing wire are annular, and the diameters of the annular formed by the supporting wire and the developing wire are the same. Preferably, the developing wire is wound (for example, spirally wound) around the main body of the support wire to form the second positioning ring structure having an annular shape. The inner diameter of the second positioning ring structure is 6 mm-14 mm so as to match the opening diameter of the superior mesenteric artery. A ball-expanded covered stent or a self-expanding stent can be placed in the superior mesenteric artery window 3 to reconstruct the superior mesenteric artery blood flow.

The second covered section 300 is used for supporting the wall of a blood vessel so as to improve the adherence of the covered stent. The second film segment 300 comprises at least one first equal-height stent segment 310, which is formed into a ring-shaped wavy stent segment by joining a plurality of equal-length prisms 311 end-to-end. The first equal height bracket section 310 may effectively make room for the embedded branching structure 4. The second high-

height stent sections

210 and 220 and the at least one first high-height stent section 310 are sequentially arranged at intervals along the axial direction of the covered stent and are fixedly connected through a main body covering membrane. Prismatic 311's arris height is 6mm ~12mm, because prismatic 311's arris height is less, can guarantee tectorial membrane support's holistic compliance. The distance between the second heightened bracket section 220 and the adjacent first equal-height bracket section 310 is 1 mm-5 mm. When the number of the first equal-height bracket sections 310 is at least two, the distance between the adjacent first equal-height bracket sections 310 is 1 mm-5 mm, and the at least two first equal-height bracket sections 310 can be uniformly distributed along the axial direction or non-uniformly distributed along the axial direction, so as to achieve the purpose of avoiding the opening of the embedded branch structure 4.

The main body part further comprises two embedded branch structures 4, wherein the embedded branch structures 4 are arranged on the main body coating of the second coating section 300, so that the interior of the coated stent is respectively communicated with the two renal arteries through the two embedded branch structures 4. In this embodiment, two windows are located on the main body coating of the second coating segment 300, and the two windows may be circumferentially disposed between two adjacent prisms in the same first equal-height stent segment 310, or between two adjacent prisms in different first equal-height stent segments 310. In other embodiments, two of the fenestrations may also be disposed on the main body cover film covering the second high-stent section, and the two fenestrations are located on the main body cover film covering the second high-stent section along the circumferential direction. Each fenestration is aligned with an opening of one renal artery, and each fenestration is used to connect one embedded branch structure 4. During operation, a ball expanding covered stent can be placed in the embedded branch structure or a self-expanding stent can be used for reconstructing renal artery blood flow.

The embedded branch structure 4 comprises a first variable-height stent section, an embedded branch coating 420 and two first positioning ring structures, wherein the embedded branch coating 420 wraps the first variable-height stent section to form an axially through tubular structure, namely, the embedded branch structure 4 is a tubular structure with openings at two ends, and for convenience of description, the openings at two ends are a first opening 400a and a second opening 400b respectively. Specifically, the first positioning ring structure is fixed at the first opening 400a and the second opening 400b of the tubular structure, wherein the first positioning ring structure connected with the first opening 400a is firstly arranged on the outer surface of the main body coating film and then is connected with the embedded branch structure 4. Embedded branch structure 4 sets up the inner chamber of covered stent, just embedded branch structure 4 of first opening part with first retaining ring structure is fixed windowing department, just first retaining ring structure of first opening part is located the outside of main part tectorial membrane, second opening 400b is for not having connection structure's free end, first retaining ring structure of second opening part is located the inboard of main part tectorial membrane. The first positioning ring structure and the second positioning ring structure are made of the same materials and are in the same shape, and the inner diameter of the first positioning ring structure is 3 mm-9 mm so as to match the diameter of a renal artery blood vessel of a human body.

The part of the embedded branch coating film close to the second opening and facing the side of the main body part is connected with the main body part. In detail, fig. 3a to 3c are schematic structural diagrams of the embedded branch structure of the present embodiment in different orientations. As shown in fig. 3a-3c, the orientation of the embedded branch structure 4 is designed according to the vessel trend, and specifically, the orientation of the embedded branch structure 4 (i.e. the orientation of the second opening of the embedded branch structure 4) is consistent with the opening orientation of the renal artery. As shown in fig. 3b, when the renal artery opening is near the abdominal aorta and is towards the proximal end (i.e. above), the second opening of the embedded branch structure 4 can be towards the proximal end (i.e. above) to conform to the natural trend of the blood vessel, so that the flexibility requirement of the spherical expansion covered stent or the self-expanding stent used in cooperation is reduced, and meanwhile, the shape of the original blood vessel of the human body is closer to ensure the long-term good patency rate of the spherical expansion covered stent or the self-expanding stent. As shown in fig. 3a, when the renal artery is open distally (i.e., below), the second opening of the in-line branching structure 4 can be open distally (i.e., below), which also achieves the same effect. As shown in fig. 3c, when the renal artery is substantially horizontal near the abdominal aorta (i.e. the opening of the renal artery is oriented perpendicular to the axial direction of the main body), sewing can be performed in a horizontal manner to reduce the compliance requirement for the balloon stent or the self-expandable stent, and the second opening is horizontally arranged, i.e. the line connecting the second opening of the embedded branch structure 4 and the renal artery opening is perpendicular to the axial direction of the main body. The sewing mode of the embedded branch structure 4 in the embodiment can be upward sewing, downward sewing and horizontal sewing, therefore, the two embedded branch structures 4 can be combined and used according to the trend of the blood vessel of the patient to form a combination of double upward, double downward, double horizontal, upward and downward, upward and horizontal or downward, and the like, the orientation of the two embedded branch structures 4 can be controlled by the sewing of the second opening, and also can be controlled by the size of the hollow membrane section.

Fig. 4 is a schematic view of the first variable height stent section wrapped with the embedded branch coating of the present embodiment after circumferential deployment. As shown in fig. 4, the first high-height stent section 410 includes first short ribs 411 and first high ribs 412, all the first short ribs and the first high ribs are connected end to end in sequence and then connected to form a ring-shaped wavy stent section, and the connecting lines of all the vertexes on at least one end of the stent section are on the same straight line. The number of the first short edges 411 is 4 to 8, the number of the first high edges 412 is 4 to 8, and all the first short edges 411 are sequentially connected and then sequentially connected with all the first high edges 412. The height of the first short edge 411 is smaller than that of the first high edge 412, the height of the first short edge 411 is 2 mm-10 mm, and the height of the first high edge 412 is 3 mm-16 mm.

Furthermore, the connection lines of all the vertexes on one end of the first variable-height bracket segment 410 are on the same straight line, that is, all the vertexes of one end of the embedded branch structure 4 provided with the first short ridge and the first high ridge are located on the same straight line, then the end is the second opening, and the other end (that is, one end of all the vertex connection lines which are not on the same straight line, that is, one end of all the vertex connection lines which are curved lines or broken lines) is the end of the embedded branch structure provided with only the first high ridge and serves as the first opening. Specifically, due to the difference in the heights of first short ribs 411 and first high ribs 412, the area of the embedded branched structure 4 near the coated membrane where the first short ribs 411 are not supported at the first opening is an empty membrane section 415, as shown in fig. 4, when the first opening 400a of the embedded branched structure 4 is spliced with the fenestration, the orientation of the second opening 400b can be determined by adjusting the splicing of the empty membrane section 415 on the first opening 400a with the proximal side or the distal side of the fenestration. The principle is as follows: by retracting the hollow section 415 from the proximal or distal side of the fenestration to the side of the second opening 400b corresponding to the hollow section during sewing, a small curved side 414 adjacent to the main body covering membrane and a large curved side 413 opposite to the small curved side 414 are formed. In this embodiment, the large bending side 413 is located in the area where all the first high ribs 412 in the first high support section 410 are connected, and the small bending side 414 is located in the hollow section 415. The small bent side 414 is bent to a greater extent than the large bent side 413, and the requirement for the compliance of the embedded branch structure 4 is high, so that the hollow film section 415 is formed as the small bent side 414 in this embodiment.

With reference to fig. 3a to 3c and fig. 4, when the embedded branch structure 4 is sewn to the main body coating, and the embedded branch structure 4 is sewn upward or downward, the first opening 400a of the embedded branch structure 4 is sewn at the window of the coating of the second coating segment, and the second opening 400b of the embedded branch structure 4 may be a free end, or a portion of the embedded branch coating 420 close to the second opening 400b facing the main body coating may be sewn to the main body coating of the second coating segment, so as to fix the second opening 400b of the embedded branch structure 4 to the coating of the second coating segment, specifically, the embedded branch structure 4 is sewn to the main body coating of the second coating segment. Further, the orientation of the second opening 400b is determined by the splicing of the portion of the first opening 400a provided with the embedded branched overlaminate (i.e., the blank section 415) to the proximal or distal side of the fenestration. Specifically, the first opening 400a may be sewn to the fenestration of the coating of the second coating segment during sewing. As shown in fig. 3a and 4, taking the example of sewing the embedded branch structure 4 with the second opening facing downward, the first opening 400a of the embedded branch structure 4 corresponds to the opening window, and the blank film section 415 is located at the far end side of the opening window, and the method of sewing the first heightening bracket section as shown in fig. 4 is adopted, that is: according to the direction requirement, at the first opening 400a, the area provided with the first high ridge 412 corresponds to the far end side of the window, the empty film section 415 only with the embedded branch coating film 420 corresponds to the far end side of the window, and the first positioning ring structure is arranged on the outer surface of the coating film at the window; the embedded branch tectorial membrane 420 of embedded branch structure 4 stretches out to the surface of second tectorial membrane section from the department of windowing to the first orientation ring structure of cladding is made up with this, stretches out the inclination of the length steerable embedded branch structure 4 of windowing through control empty membrane section 415 department, can guarantee that the compliance of little curved side 414 is good like this, can also reduce the holistic size of pressing of tectorial membrane support, and then reduces the requirement of tectorial membrane support to the vascular diameter of going into the way. When the embedded branch structure 4 is used in conjunction with a ball-expanded stent graft or a self-expanding stent, the ball-expanded stent graft or self-expanding stent has a larger ball expansion (expansion) size in the hollow section because the hollow section 415 has no stent support, and the ball-expanded stent graft or self-expanding stent can be clamped between the first short edge 411 of the first elevated stent section and the first positioning ring structure.

When the embedded branch structure 4 is sewn on the main body covering film and the embedded branch structure 4 is sewn horizontally, the first opening of the embedded branch structure 4 is sewn at the windowing position of the covering film of the second covering film section, namely, when the ball-expanded covered stent used in a matched mode enters the way to be the far end, the second opening 400b of the first heightening stent section 410 faces the far end, the pressing and holding size of the covered stent is reduced, and the pressing and holding is facilitated. Meanwhile, when the spherical expansion covered stent is used in a matched mode, when the spherical expansion covered stent is expanded in the inner cavity of the embedded branch structure, the spherical expansion covered stent has a larger expansion space in a hollow membrane section, so that the anchoring spherical expansion covered stent is reinforced, and displacement is prevented. When the approach of the cooperating spherical stent graft is proximal, the second opening 400b of the first taller stent section faces proximally, which has the same effect.

In other embodiments, the embedded branch structure may comprise an contoured stent section, an embedded branch cover surrounding the contoured stent section, the contoured stent section comprising a plurality of contoured ridges that join end-to-end, and a first positioning loop structure when the renal artery is oriented substantially horizontally adjacent the abdominal aorta.

The axial length of the embedded branch structure 4 is 2 mm-18 mm, so that smooth blood flow of renal artery can be guaranteed, and internal splicing leakage (i.e. III-type internal leakage) which is possibly generated when the main body part 1 is spliced with the spherical expansion covered stent or the self-expansion stent body is greatly avoided.

As shown in fig. 5, the splice 2 includes a first splice 600 located at the proximal end and a second splice 700 located at the distal end, the first splice 600 is a tubular structure, the first splice 600 is an integrated bifurcated structure, and the distal end of the first splice 600 includes two tubular leg structures separated from the proximal end to the distal end, i.e., an ipsilateral branch 621 and an contralateral branch 622, wherein the axial length of the ipsilateral branch 621 is longer than the axial length of the contralateral branch 622. The proximal end of the first splicing part 600 is connected to the distal end of the main body 2, and the distal end of the same side branch 610 is connected to the proximal end of the second splicing part 700. The main body part 1 is positioned in an aorta visceral area of a human body and is mainly used for providing the sealing performance of the proximal end of the covered stent and providing a passage for the reconstruction of visceral branches. The first splicing part 600 is located in the aneurysm cavity and is mainly used for providing a closed blood flow channel in the abdominal aortic aneurysm cavity to isolate the abdominal aortic aneurysm cavity. The second splice 700 is located distal to the abdominal aortic aneurysm cavity and extends into the ipsilateral iliac artery of the patient. In this embodiment, the main body portion 1, the first splicing portion 600 and the second splicing portion 700 are spliced into a whole stent graft by sewing. Compared with the in-vivo splicing of the iliac artery stent on the same side in the market, the suture type integrated stent eliminates the III-type internal leakage at the position, reduces the economic cost and time cost of the operation, and can realize quick delivery by the splicing structure, so that the waiting time of a patient is reduced as much as possible. The same side is the side with the same direction of the conveying system, and the opposite side is the side opposite to the same side.

The first splicing part 600 comprises a main body lower section 610, a bifurcation section 620 and a first splicing coating film, wherein the main body lower section 610 is arranged at the near end of the bifurcation section 620, the main body lower section 610 and the bifurcation section 620 are coated by the first splicing coating film, and the near end of the first splicing coating film is connected with the far end of the main body coating film of the main body part 1. Wherein the body lower section 610 comprises at least one second equal-height cradle section 611, the shape, diameter, material, etc. of which are the same as the shape, diameter, material, etc. of the first equal-height cradle section 310, respectively. The first splice graft covering encapsulates at least one of the second equal-height stent sections 611.

The bifurcation section 620 comprises a wavy elliptical ring stent section 623, the proximal end of the elliptical ring stent section 623 has a circular radial cross section, the distal end of the elliptical ring stent section 623 has an elliptical radial cross section, and the major axis and the minor axis of the radial cross section of the elliptical ring stent section 623 gradually decrease from the proximal end to the distal end, so that the bifurcation of the bifurcation section 620 is smooth. The diameter, material and shape of the stent section of the ipsilateral branch 621 and the stent section of the contralateral branch 622 are respectively the same, wherein the stent section of the contralateral branch 622 adopts an equal-height stent, so that the radial diameter of the contralateral branch 622 is designed in a constant diameter mode, and the contralateral iliac artery branch stent section can be better matched with the contralateral iliac artery branch stent section for establishing contralateral iliac artery blood flow after splicing; the support sections of the same side branches 621 also adopt equal-height supports, so that the radial diameter of the same side branches 621 is designed to be a fixed diameter, and the second splicing part 700 is connected with the same diameter, thereby being beneficial to the batch production of the second splicing part 700.

The proximal end of the second splicing part 700 is connected to the distal end of the same side branch 621, and further, the proximal end of the film of the second splicing part 700 is sewn on the first splicing film at the distal end of the same side branch 621. The second splicing part 700 comprises a first equal-diameter section 710, a transition section 720 and a second equal-diameter section 730 which are sequentially connected along the axial direction, the proximal end of the first equal-diameter section 710 is connected with the distal end of the same side branch 621, the proximal end of the transition section 720 is connected with the distal end of the first equal-diameter section 710, the distal end of the transition section 720 is connected with the proximal end of the second equal-diameter section 730, the stent sections of the first equal-diameter section 710 and the second equal-diameter section 730 are both equal-height stents and are both in a wave-shaped annular structure, the diameter of the stent section of the first equal-diameter section 710 is the same as that of the stent section of the same side branch, the diameter of the second equal-diameter section 730 is larger than that of the first equal-diameter section 710, and the stent section of the transition section 720 is a variable-diameter stent, so that the diameter of the transition section 720 is gradually increased from the proximal end to the distal end. The diameter of the second equal-diameter section 730 is equal to the diameter of the far end of the transition section 720, and specifically, the diameter of the second equal-diameter section 730 ranges from 6mm to 28mm, and the length ranges from 20mm to 180 mm. The second equal-diameter section 730 is used for attaching the second splice 700 to the wall of the diseased vessel and for sealing the distal end of the second equal-diameter section 730.

With reference to fig. 2, two kinds of development points are disposed at the proximal end of the main body coating to realize position calibration of the proximal end of the coating stent under the radiation, the development points are O-shaped development points 142 and 8-shaped development points 141, respectively, and the O-shaped development points 142 and the 8-shaped development points 141 are uniformly distributed along the circumferential direction of the proximal end of the main body coating.

In this embodiment, the proximal end of the main body stent is provided with one 8-shaped development point 141 and three O-shaped development points 142, the distance between each two development points is the same (the included angle between each two development points is 90 °), the 8-shaped development point 141 is arranged on the same side or opposite side of the stent graft, and the three O-shaped development points 142 are arranged in other three directions.

To implement the bundle diameter function of the stent graft, the stent graft further includes a bundle diameter structure 500 disposed on the main stent and the main stent graft. The bundle diameter structure 500 includes a plurality of bundle diameter coils 510 and a plurality of suture coils 520, and the bundle diameter coils 510 are made of a soft polymer material with good biocompatibility, such as PTFE, PET, or ultra-high molecular polyethylene. The beam diameter coils circumferentially encircle the second elevated leg and/or the first equal-height leg, i.e., at least one of each leg (e.g., second elevated leg, first equal-height leg, first elevated leg, second equal-height leg, leg of the lower body leg, etc.) has at least two of the beam diameter coils 510. In this embodiment, each stent segment has two of the beam diameter coils 510, the two beam diameter coils 510 may overlap, or may be disposed at intervals along the axial direction of the stent graft, and the beam diameter coils 510 may be disposed in any position of the edge or vertex of the stent segment, specifically according to the actual requirement. Two diameter coil 510 one end can follow same point or different points and go to opposite direction, along circumference "hugs" the support section, and two diameter coil 510 are "hugged" the support section along circumference after, the main part seal wire passes two diameter coil's the other end to in radial constraint support section, in order to reach the effect of restrainting the warp. In this embodiment, two of the radial coils 510 are spaced apart and disposed at the proximal and/or distal apices of each stent segment.

The sewing coil 520 is a hollow coil sewn on the main body covering film of the main body part and the first splicing covering film of the second equal-height stent section, and the diameter of the hollow coil is 0.5 mm-2 mm. The sewing loops 520 are disposed at the distal apices (i.e., a apices), the proximal apices (i.e., V apices), or at the edges of each stent segment. When the seaming loops 520 are disposed on the edges of each stent segment, two seaming loops 520 may be disposed on each edge, with the two seaming loops being equidistant from their respective nearest vertices; each rib may also have a suture loop 520 positioned at the midpoint of the rib, i.e., equidistant from the apices on either side, or at the distal apex and the proximal apex of the second elevated stent segment and/or the first elevated stent segment. The A peak is the peak of each stent section, and the V peak is the trough of each stent section.

In the present embodiment, the bundle diameter coil 510 is inserted into the suture loop, and passes through the suture loop at the overlapping position of all the suture loops and the support sections and then encircles the support sections, so that the suture loop 520 fixes each support section and the coating film wrapping the support section on the a vertex, the V vertex or the edge. By adopting the structure, the problem that the bracket section cannot be bounced off due to the fact that the line junction is clamped by the main body during releasing can be effectively avoided. The bundle diameter coil 510 is restricted to move only in the circumferential direction after passing through the sewing coil 520, thereby ensuring the stability of the bundle diameter. By adjusting the length of the beam diameter coil, the proportion of the beam diameter can be adjusted to 40-90% of the nominal diameter.

It should be noted that the bundle loops 510 and suture loops 520 need to be avoided when encountering the fenestrations and windows. That is, the tether coil 510 does not block the fenestration of the superior mesenteric artery window 3 and the embedded branch structure in the main body cover, and therefore, the suture coil 520 fixes the tether coil 510 to the outside of the superior mesenteric artery window 3 and the embedded branch structure 4 in the second positioning ring structure of the superior mesenteric artery window 3 and the first positioning ring structure of the embedded branch structure 4. The number of the suture loops on the superior mesenteric artery window 3 and the embedded branch structure can be respectively 1-4.

The second heightening bracket section, the first equal-height bracket section, the first heightening bracket section, the second equal-height bracket section, the bracket section of the lower section of the main body, the bracket section of the bifurcation section 620 and the bracket of the second splicing part are all made of nickel-titanium, cobalt-chromium alloy or 316 stainless steel materials, and are in annular wave shapes. The main body coating film, the embedded branch coating film, the main body lower section coating film, the bifurcation section coating film and the second splicing part 700 coating film are all made of high polymer soft materials with good biocompatibility, so that the stent section can form a closed inner cavity in the axial direction.

In summary, the present invention provides a covered stent, wherein the two fenestrations are used for enabling the main body part to be in butt joint communication with the renal artery; through every embedded branch structure respectively with one the windowing links to each other, two embedded branch structure all is located in the inner chamber of main part, just embedded branch structure's orientation with renal artery's opening orientation is unanimous to play the drainage effect to the blood flow of renal artery's opening outflow, and follow the nature trend of blood flow, make its original blood vessel form that is more close the human body, still reduced the compliance requirement to the ball that the cooperation was used and expanded the tectorial membrane support or from expanding the support, guarantee that the ball expands the tectorial membrane support or from expanding the good unobstructed rate of support long term, still greatly avoided embedded branch structure to expand the tectorial membrane support with the ball or from expanding the interior concatenation that probably produced of support when leaking.

Furthermore, the first height-variable support section and the embedded branch film which are located in the first high edge connection area are used as large bending sides of the embedded branch structure, the embedded branch film which is located in the first low edge connection area and is not supported by the first low edges is used as small bending sides of the embedded branch structure, and the small bending sides are located at the first opening, so that the first low edges can avoid the first opening. The design of the first variable-height bracket section can ensure that the flexibility of the small bending side is good; the small bending side can strengthen the ball-expanded covered stent or the self-expanding stent which is used in a matched anchoring way, and simultaneously, the overall pressing and holding size of the covered stent is reduced, so that the requirement on the diameter of the access blood vessel is reduced.

Furthermore, the second uprising support section includes two short arriss of second and many high arriss of second, all the short arriss of second links up in proper order and links up with all high arriss of second that link up in proper order respectively again and form annular wave structure, the arris height of the short arriss of second is less than the arris height of the high arris of second, the window is located two along the axial the second uprises between the short arriss of support section. This structure can improve the compliance of tectorial membrane support near-end, and the short arris of second can dodge the last artery of mesentery and open the window, and the symmetric distribution of two short arriss of second both can provide sufficient space of dodging for windowing (the last artery of mesentery opens the window promptly), can provide sufficient radial holding power for the tectorial membrane with the last artery of mesentery on the horizontal direction parallel and level again, guarantee and the last artery of mesentery open the window the tectorial membrane of horizontal direction parallel and level and the inseparable laminating of abdominal aorta.

In addition, unless otherwise specified or indicated, the terms "first", "second", "third", and the like in the specification are used only for distinguishing various components, elements, steps, and the like in the specification, and are not used for indicating logical relationships or sequential relationships among the various components, elements, steps, and the like.

It is to be understood that while the present invention has been described in conjunction with the preferred embodiments thereof, it is not intended to limit the invention to those embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are within the scope of the technical solution of the present invention, unless the technical essence of the present invention is not departed from the content of the technical solution of the present invention.

Claims

1. A covered stent is characterized by comprising a main body part, wherein the main body part comprises a covered section and two embedded branch structures, the covered section is provided with two windows, and the two windows are used for enabling the main body part to be in butt joint communication with a renal artery; each embedded branch structure is arranged at one windowing part and is connected with the windowing part, the two embedded branch structures are positioned in the inner cavity of the main body part, and the orientation of the embedded branch structures is consistent with that of the opening of the renal artery;

the embedded branch structure is arranged in an inner cavity of the covered stent and is an axially-through tubular structure and comprises a first opening and a second opening, the embedded branch structure comprises a first heightening stent section and an embedded branch covering film, the embedded branch covering film wraps the first heightening stent section, and the embedded branch covering film at the first opening is fixed at the windowing position;

the first variable-height bracket section comprises at least two first short edges and at least two first high edges, all the first short edges are sequentially connected and then respectively connected with all the first high edges which are sequentially connected to form an annular wavy structure, wherein the heights of the first short edges are smaller than those of the first high edges; one end of the embedded branch structure, which is provided with a first short edge and a first high edge, is used as a second opening, and the other end of the embedded branch structure, which is only provided with the first high edge, is used as the first opening; the film covering area, which is close to the first opening and is not supported by the first short edge, in the embedded branch structure is a hollow film section, and the orientation of the second opening is determined by splicing the hollow film section, which is provided with the embedded branch film at the first opening, with the near-end side or the far-end side of the window.

2. The stent graft of claim 1, wherein the embedded branch structure is an axially through tubular structure comprising a first opening and a second opening, the first opening being connected to the fenestration;

3. The stent graft of claim 1, wherein the embedded branch structure further comprises a first positioning ring structure, the first positioning ring structure being fixed at the fenestration.

4. The stent graft of claim 1, wherein a portion of the stent graft proximal to the second opening of the inline branched stent graft and facing the main body portion is attached to the main body portion.

5. The stent-graft of claim 1, wherein the embedded branch structure has an axial length of 2mm to 18 mm.

6. The stent graft of claim 1, wherein said graft segment includes a window axially spaced from both of said fenestrations, said window adapted to allow said body portion to be in abutting communication with the superior mesenteric artery.

7. The stent graft of claim 6, wherein the cover segment comprises a main body stent and a main body cover, the main body cover covers the main body stent and enables the distal end of the main body stent to form a closed inner cavity along the axial direction, the main body stent comprises two second heightening stent segments and at least one first heightening stent segment, the two second heightening stent segments are transversely and symmetrically arranged at the proximal end of the main body stent, all the first heightening stent segments are sequentially arranged at the distal end of the main body stent along the axial direction at intervals, the window is arranged on the main body cover between the two second heightening stent segments, and the window is arranged on the main body cover covering the first heightening stent segment or the second heightening stent segment.

8. The stent graft of claim 7, wherein the second taller stent section comprises two second short ribs and a plurality of second tall ribs, wherein all of the second short ribs are sequentially connected and then respectively connected with all of the sequentially connected second tall ribs to form an annular wavy structure, wherein the height of the second short ribs is less than that of the second tall ribs, and wherein the windows of the two second short ribs of all of the second taller stent sections are axially located between the second short ribs of the two second taller stent sections.

9. The stent graft of claim 7, wherein said first altemate stent segment is formed by joining a plurality of equal length prisms end to form an annular undulating configuration, said fenestrations are located between two adjacent prisms, and two of said fenestrations are located circumferentially on the same main stent graft of said first altemate stent segment, or two of said fenestrations are located circumferentially on different main stent grafts of said first altemate stent segment, or two of said fenestrations are located circumferentially on the main stent graft covering said second altemate stent segment.

10. The stent graft of claim 7, wherein the first and second openings of the embedded bifurcation structures each have a first retaining ring structure, the window has a second retaining ring structure, the first retaining ring structure at the first opening is located on the outside of the main body graft, the first retaining ring structure at the second opening is located on the inside of the main body graft, and the second retaining ring structure is located on the outside of the main body graft.

11. The stent graft of claim 10, wherein the second and first retaining ring structures each comprise a support wire and a developer wire, the support wire being annular, the developer wire being wound around the support wire or the developer wire and the support wire being arranged in parallel.

12. The stent graft of claim 7, further comprising a bundle diameter structure disposed on the body stent and the body graft, the bundle diameter structure comprising a bundle diameter coil circumferentially encircling the second elevated stent segment and/or the first isocontourous stent segment and a suture coil disposed at a distal apex, proximal apex or edge of the second elevated stent segment and/or the first isocontourous stent segment.

13. The stent graft of claim 12, wherein when said suture loops are disposed on said ribs, two suture loops are disposed on each of said ribs, the two suture loops being equally spaced from their respective nearest neighbor apices; alternatively, 1 suture loop is provided on each of the ribs, the suture loops being located at the midpoint of the ribs or at the distal apex and proximal apex of the second elevated stent section and/or first equal elevated stent section.

14. The stent graft of claim 7, wherein the main body portion further comprises a bare segment, a distal end of the bare segment being connected to a proximal end of the main body stent, and the bare segment axially overlapping a proximal portion of the main body stent.

15. The stent graft of claim 14, wherein the bare segment comprises a stent ring and a barb structure at a proximal end of the stent ring, the barb structure comprising a barb and a barb handle, a distal end of the barb handle being attached to the stent ring, a proximal end of the barb handle being attached to the proximal end of the barb, a distal end of the barb being everted away from the axis of the stent ring, and the barb making an angle of 10 ° to 70 ° with the axis of the stent ring.

16. The film-covered stent of claim 1, further comprising a splice spliced to the distal end of the body portion, the splice comprising a first splice, a proximal end of the first splice connecting the distal end of the body portion.

17. The stent graft of claim 16, wherein the splice comprises a second splice, the distal end of the first splice having an ipsilateral branch and a contralateral branch, the proximal end of the second splice connecting the ipsilateral branch and configured to establish ipsilateral iliac artery blood flow, the contralateral branch configured to establish contralateral iliac artery blood flow after splicing.