Stent artificial blood vessel

Abstract

The utility model provides a stent artificial blood vessel which comprises an inner blood vessel part and an outer blood vessel part. The inner blood vessel part comprises a first covering film and a first stent, and the first covering film covers the inner periphery or the outer periphery of the first stent; the outer blood vessel part is arranged outside the inner blood vessel part in a sleeving mode and comprises a second support and a second covering film, the second covering film is provided with an expansion section and two fixing sections, the two fixing sections are connected to the two ends, in the axial direction, of the expansion section respectively, the fixing sections are fixedly connected with the inner blood vessel part, and at least one part, in the circumferential direction, of the expansion section is not fixed to the inner blood vessel part; the second support is fixed to the inner periphery or the outer periphery of the expansion section. Wherein the first covering film is provided with a channel penetrating through the film wall, and the channel corresponds to the position of the expansion section of the second covering film; wherein the area of the part, not in fixed relation with the inner blood vessel part, of the expansion section is larger than that of the inner blood vessel part corresponding to the part, so that the stent artificial blood vessel can be at least partially separated from the inner blood vessel part through the expansion section, and an expansion cavity is formed in the outer blood vessel part.

Description

Technical Field

[0001] The utility model relates to the technical field of artificial blood vessels, in particular to a stent artificial blood vessel. Background Art

[0002] In the application of existing artificial blood vessel technology, endovascular support-type artificial blood vessels have been used as a means to repair aortic aneurysms or aortic dissections, such as treating infrarenal abdominal aortic aneurysms. For lesions of abdominal aortic aneurysms adjacent to the renal arteries, the preferred repair solution is to both isolate the abdominal aortic aneurysm and maintain the patency of renal artery blood flow. In addition to surgical methods of repairing lesions, existing interventional treatment solutions are to bridge the normal aorta at both ends of the aneurysm (i.e., the "tumor neck") with an endovascular support-type artificial blood vessel to achieve isolation of the aneurysm while maintaining patency of aortic blood flow. However, when the length of the "tumor neck" is insufficient, the effectiveness of the artificial blood vessel in sealing the gap between the artificial blood vessel and the aortic wall at the "tumor neck" is affected, causing aortic blood flow to enter the gap between the artificial blood vessel and the aortic wall at the "tumor neck" and enter between the endovascular support-type artificial blood vessel and the aneurysm, forming "endoleakage" and leading to treatment failure. To solve the problem of insufficient "tumor neck" length, methods of covering the branch arteries after "windowing" the artificial blood vessel and placing stents in the branch arteries have been proposed. After years of attempts, the above-mentioned remedial solutions have been found to rely on different defects in the intravascular support artificial blood vessels or repair devices, and have not solved the treatment problem of insufficient "tumor neck" length.

[0003] A review of the aforementioned existing technologies reveals a commonality: they utilize an intravascular stent to secure the artificial blood vessel at the "tumor neck" region. However, when the "tumor neck" region is insufficiently long, the stent fails to maintain adequate contact with the vessel's neck, preventing the gap between the artificial blood vessel and the aneurysm wall from being completely sealed by closing the "tumor neck" region.

[0004] Therefore, designing a device that can isolate the aortic aneurysm and avoid "endoleakage" within the maximum "anesthesia neck" length of the artificial blood vessel has become an urgent issue to be solved in the design of related devices in this field. Utility Model Content

[0005] A main purpose of the present invention is to overcome at least one of the above-mentioned defects of the prior art and to provide a stent artificial blood vessel that can effectively avoid the problem of internal leakage and has high structural strength.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] According to one aspect of the present invention, a stent artificial blood vessel is provided, comprising an inner vascular portion and an outer vascular portion; the inner vascular portion comprises a first coating and a first stent, the first coating covering the inner periphery or outer periphery of the first stent; the outer vascular portion is sleeved on the outside of the inner vascular portion and comprises a second stent and a second coating, the second coating having an expansion section and two fixed sections, and the two fixed sections are respectively connected to the two ends of the expansion section along the axial direction, the fixed section is fixedly connected to the inner vascular portion, at least a part of the expansion section along the circumferential direction has no fixed relationship with the inner vascular portion, and the second stent is fixed to the inner periphery or outer periphery of the expansion section; wherein the first coating is provided with a channel penetrating the membrane wall, the channel corresponding to the position of the expansion section of the second coating; wherein the area of ​​the portion of the expansion section that has no fixed relationship with the inner vascular portion is larger than the area of ​​the inner vascular portion corresponding to the portion, so that the stent artificial blood vessel can be at least partially separated from the inner vascular portion via the expansion section to form an expansion cavity in the outer vascular portion.

[0008] According to one embodiment of the present invention, the first coating is covered on the outer periphery of the first stent, and the second coating is covered on the outer periphery of the second stent.

[0009] According to one embodiment of the present invention, the axial length of the first coating is less than or equal to the axial length of the first stent.

[0010] According to one embodiment of the present invention, the axial length of the second coating is smaller than the axial length of the first coating, so that at least one of the two axial ends of the first coating extends beyond the second coating.

[0011] According to one embodiment of the present invention, the fixing section of the second covering is connected to the first bracket and the first covering at the same time.

[0012] According to one embodiment of the present invention, all positions of the second bracket are not connected to the first bracket.

[0013] According to one embodiment of the present invention, the entire expansion section along the circumferential direction has no fixed relationship with the inner vascular portion, so that the expansion cavity is in a ring shape surrounding the inner vascular portion.

[0014] According to one embodiment of the present invention, a portion of the expansion section along the circumferential direction has no fixed relationship with the inner vascular portion, so that the expansion cavity is in an arc shape surrounding the inner vascular portion.

[0015] According to one embodiment of the present invention, the plurality of portions of the expansion section along the circumferential direction have no fixed relationship with the inner vascular portion, and the plurality of portions are arranged at intervals along the circumferential direction.

[0016] According to one embodiment of the present invention, the first covering film is provided with a through hole, and the through hole defines the channel; or the first covering film is provided with multiple through holes, and the multiple through holes are arranged at intervals and together define the channel; or the first covering film is axially disconnected, and the disconnection position corresponds to the position of the expansion section, and the first covering film forms an opening at the disconnection position, and the opening defines the channel.

[0017] From the above technical solution, it can be seen that the advantages and positive effects of the stent artificial blood vessel proposed by the utility model are:

[0018] The stent artificial blood vessel proposed in the present invention adopts a double-layer blood vessel structural design, and the two layers of blood vessels respectively include a coating and a stent. The second coating of the outer blood vessel portion has an expansion section and a fixed section, the fixed section is fixedly connected to the blood vessel portion, at least a portion of the expansion section along the circumference has no fixed relationship with the inner blood vessel portion, and a second stent is fixed to the inner or outer periphery of the expansion section. Accordingly, the stent artificial blood vessel can form an expansion cavity in the outer blood vessel portion by separating the expansion section at least partially from the inner blood vessel portion. Through the above design, the stent artificial blood vessel proposed in the present invention can, through the design of the expansion section, utilize the expansion cavity to make the second coating fully close to the wall of the hemangioma, so that the gap between the artificial blood vessel and the wall of the hemangioma is filled, and at the same time, the second stent is used to provide structural support to the expansion cavity, thereby enhancing the support stability of the expansion cavity. In particular, the present invention is suitable for achieving direct filling isolation of aortic aneurysms within the limit of the "anesthesia neck" length to avoid the occurrence of internal leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The various objects, features, and advantages of the present invention will become more apparent upon consideration of the following detailed description of preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are merely illustrative illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, like reference numerals denote identical or similar components.

[0020] Figure 1 is an axial cross-sectional view of a stent graft according to an exemplary embodiment;

[0021] Figure 2 It is along Figure 1 A sectional view taken along line AA in FIG.

[0022] Figure 3 It is along Figure 1 A sectional view taken along line BB in FIG.

[0023] Figure 4 and Figure 5 are axial cross-sectional views of stent-grafts according to two other exemplary embodiments;

[0024] Figure 6 is an axial cross-sectional view of a stent graft according to another exemplary embodiment;

[0025] Figure 7 It is along Figure 6 A sectional view taken along line CC in FIG.

[0026] Figure 8 It is along Figure 6 A sectional view taken along line DD in FIG.

[0027] Figure 9 and Figure 10 are cross-sectional views of stent grafts according to two other exemplary embodiments;

[0028] Figure 11 FIG. 1 is an axial cross-sectional view of a stent-graft according to another exemplary embodiment.

[0029] The following are the descriptions of the reference numerals:

[0030] 100.Internal vascular department;

[0031] 110. First coating;

[0032] 111.Through hole;

[0033] 112. Open your mouth;

[0034] 120. First bracket;

[0035] 200. External vascular part;

[0036] 210. Second coating;

[0037] 211. Fixed segment;

[0038] 212. Expansion section;

[0039] 220. Second bracket;

[0040] P. dilated cavity;

[0041] X. Axial direction. DETAILED DESCRIPTION

[0042] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the description and drawings are essentially for illustrative purposes and are not intended to limit the present invention.

[0043] In the following description of different exemplary embodiments of the present invention, reference is made to the accompanying drawings, which form a part of the present invention and in which different exemplary structures, systems and steps that can implement various aspects of the present invention are shown by way of example. It should be understood that other specific schemes of components, structures, exemplary devices, systems and steps can be used, and structural and functional modifications can be made without departing from the scope of the present invention. Moreover, although the terms "above", "between", "within" and the like may be used in this specification to describe different exemplary features and elements of the present invention, these terms are used herein only for convenience, such as according to the directions of the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of the present invention.

[0044] See Figure 1 , which represents an axial cross-sectional view of the stent-graft of the present invention. In this exemplary embodiment, the stent-graft of the present invention is described using an example of a stent-graft for isolating an aortic aneurysm. Those skilled in the art will readily appreciate that various modifications, additions, substitutions, deletions, or other variations may be made to the following specific embodiments to adapt the relevant designs of the present invention to other types of stent-grafts, and such variations remain within the scope of the principles of the stent-graft of the present invention.

[0045] like Figure 1 As shown, in one embodiment of the present invention, the stent graft provided by the present invention comprises an inner blood vessel portion 100 and an outer blood vessel portion 200. Figures 2 to 3 , Figure 2 Representatively shown in Figure 1 A sectional view taken along line AA in FIG. Figure 3 Representatively shown in Figure 1 The following will be combined with the above drawings to describe in detail the structure, connection mode and functional relationship of the main components of the stent artificial blood vessel proposed by the present invention.

[0046] like Figures 1 to 3As shown, in one embodiment of the present invention, the outer vascular portion 200 is sleeved on the outside of the inner vascular portion 100. Specifically, the inner vascular portion 100 includes a first coating 110 and a first stent 120, wherein the first coating 110 covers the outer circumference of the first stent 120. The outer vascular portion 200 includes a second stent 220 and a second coating 210. The second coating 210 has an expansion segment 212 and two fixed segments 211, and the two fixed segments 211 are respectively connected to the two ends of the expansion segment 212 along the axial direction X. The fixed segments 211 are fixedly connected to the inner vascular portion 100, and at least a portion of the expansion segment 212 along the circumferential direction is not fixed to the inner vascular portion 100. The second stent 220 is fixed to the inner circumference of the expansion segment 212, that is, the expansion segment 212 of the second coating 210 covers the outer circumference of the second stent 220, which is equivalent to the axial length of the second coating 210 being greater than the axial length of the second stent 220. On this basis, the first covering 110 is provided with a channel extending through the membrane wall, which corresponds to the position of the expansion section 212 of the second covering 210. Furthermore, the area of ​​the portion of the expansion section 212 not fixedly associated with the inner vascular portion 100 is larger than the area of ​​the inner vascular portion 100 corresponding to this portion, so that the stent-graft can be at least partially separated from the inner vascular portion 100 via the expansion section 212, thereby forming an expansion cavity P in the outer vascular portion 200. Through the above-described design, the stent-graft proposed in the present invention can, through the design of the expansion section 212 and the expansion cavity P, bring the second covering 210 into close contact with the aneurysm wall, thereby filling the gap between the graft and the aneurysm wall. Simultaneously, the second stent 220 provides structural support to the expansion cavity P, thereby enhancing the support stability of the expansion cavity P. In particular, the present invention is suitable for achieving direct filling isolation of aortic aneurysms within the maximum "anesthesia neck" length, thereby avoiding the occurrence of endoleaks.

[0047] like Figures 1 to 3 As shown, in one embodiment of the present invention, the first coating 110 can be coated on the outer periphery of the first bracket 120, that is, the first bracket 120 is supported on the inner periphery of the first coating 110. Furthermore, the second coating 210 can be coated on the outer periphery of the second bracket 220, that is, the second bracket 220 is supported on the inner periphery of the second coating 210. In some embodiments, the first coating 110 can also be coated on the inner periphery of the first bracket 120, or the second coating 210 can also be coated on the inner periphery of the second bracket 220, both of which are not limited to this embodiment.

[0048] See Figure 4 , Figure 4 1 represents an axial cross-sectional view of another exemplary embodiment of a stent graft that can embody the principles of the present invention.

[0049] like Figure 4As shown, in one embodiment of the present invention, the axial length of the first coating 110 can be less than the axial length of the first bracket 120. On this basis, the two ends of the first bracket 120 along the axial direction X can extend respectively from the two ends of the first coating 110 along the axial direction X. In some embodiments, the axial length of the first coating 110 can also be equal to the axial length of the first bracket 120, for example Figure 1 The illustrated embodiments are not limited thereto.

[0050] See Figure 5 , Figure 5 1 represents an axial cross-sectional view of another exemplary embodiment of a stent graft that can embody the principles of the present invention.

[0051] like Figure 5 As shown, in one embodiment of the present invention, the axial length of the second coating 210 can be smaller than the axial length of the first coating 110. Based on this, the two ends of the first coating 110 along the axial direction X can extend beyond the two ends of the second coating 210 along the axial direction X. In some embodiments, when the axial length of the second coating 210 is smaller than the axial length of the first coating 110, only one of the two ends of the first coating 110 along the axial direction X can extend beyond the second coating 210, and this embodiment is not limited thereto.

[0052] In one embodiment of the present invention, the fixing section 211 of the second covering 210 can be connected to both the first bracket 120 and the first covering 110. In some embodiments, the fixing section 211 of the second covering 210 can also be connected only to the first bracket 120, or only to the first covering 110, and the present invention is not limited to this embodiment.

[0053] like Figure 3 As shown, in one embodiment of the present invention, all positions of the second bracket 220 are not connected to the first bracket 120 .

[0054] like Figures 1 to 3 As shown, in one embodiment of the present invention, the expansion section 212 of the second covering 210 is not fixedly connected to the inner vascular portion 100 at all locations along the circumference, so that the expansion cavity P is annular and surrounds the inner vascular portion 100. Based on this, regardless of whether the second stent 220 is disposed on the outer or inner circumference of the expansion section 212 of the second covering 210, the second stent 220 is not connected to the first stent 120 at all locations.

[0055] See Figures 6 to 8 , Figure 6 : A representative axial cross-sectional view of a stent graft in another exemplary embodiment that can embody the principles of the present invention is shown; Figure 7 Representatively shown in Figure 6A sectional view taken along line CC; Figure 8 Representatively shown in Figure 6 A sectional view taken along line DD.

[0056] like Figures 6 to 8 As shown, in one embodiment of the present invention, the circumferential portion of the expansion section 212 of the second coating 210 has no fixed relationship with the inner vascular portion 100, that is, the other portion of the expansion section 212 has a fixed relationship with the inner vascular portion 100, thereby making the expansion cavity P arc-shaped surrounding the inner vascular portion 100.

[0057] See Figure 9 , Figure 9 The cross-sectional view of another exemplary embodiment of a stent graft that can embody the principle of the present invention is representatively shown in FIG. Figure 3 Of Figure 1 The cutting position, or refer to Figure 8 Of Figure 6 The cutting position.

[0058] like Figure 9 As shown, in one embodiment of the present invention, multiple circumferential portions of the expansion section 212 of the second coating 210 have no fixed relationship with the inner vascular portion 100, and these portions are arranged at intervals along the circumferential direction so that the multiple expansion cavities P are in a petal shape surrounding the inner vascular portion 100.

[0059] like Figure 9 As shown, in one embodiment of the present invention, multiple circumferential portions of the expansion section 212 of the second coating 210 are not fixedly connected to the inner vessel portion 100, and these portions are spaced apart along the circumference, while the remaining circumferential portions of the expansion section 212 are fixedly connected to the inner vessel portion 100. Accordingly, the stent graft proposed in the present invention can be separated from the inner vessel portion 100 via the multiple portions of the expansion section 212 of the second coating 210, allowing the second coating 210 to form multiple expansion cavities P, each of which is arc-shaped and surrounds the inner vessel portion 100. Through this design, the present invention can form multiple, roughly arc-shaped thrombi through the multiple arc-shaped expansion cavities P, making it suitable for situations where multiple lesions are located at multiple circumferential sections of the blood vessel.

[0060] like Figure 9As shown, in one embodiment of the present invention, for the multiple portions of the expansion segment 212 that are not fixedly associated with the internal vascular portion 100, the shapes of the various portions may be substantially the same or different. The so-called shape can be understood as the corresponding arc range along the circumferential direction, the size of the radially outwardly expanded protrusion, etc. It should be noted that the substantially identical shapes of the multiple expansion cavities P shown in the drawings are merely for ease of drawing and understanding. Based on the actual dimensions of the multiple lesion locations, such as the axial X and circumferential lengths, radial depth, etc., the relevant dimensions of the multiple portions of the expansion segment 212 that are not fixedly associated with the internal vascular portion 100 can be adjusted accordingly, and are not limited to the shapes shown in the drawings.

[0061] See Figure 10 , Figure 10 The cross-sectional view of another exemplary embodiment of a stent graft that can embody the principle of the present invention is representatively shown in FIG. Figure 3 Of Figure 1 The cutting position, or refer to Figure 8 Of Figure 6 The cutting position.

[0062] like Figure 10 As shown, in one embodiment of the present invention, multiple circumferential portions of the expansion section 212 of the second covering 210 are not fixedly connected to the inner vessel portion 100, and these portions are evenly spaced along the circumference. The remaining circumferential portions of the expansion section 212 are fixedly connected to the inner vessel portion 100. Accordingly, the stent graft of the present invention can be separated from the inner vessel portion 100 via the multiple portions of the expansion section 212 of the second covering 210, allowing the second covering 210 to form multiple evenly distributed expansion cavities P. The formed expansion cavities P are generally petal-shaped and surround the inner vessel portion 100.

[0063] like Figure 1 and Figure 3 As shown, in one embodiment of the present invention, the first covering film 110 may have a plurality of through holes 111, which are arranged at intervals and collectively define the aforementioned channel. In some embodiments, the first covering film 110 may have only one through hole 111, and the through hole 111 defines the aforementioned channel, which is not limited to this embodiment.

[0064] like Figure 1 and Figure 3 As shown, based on the structural design that the first coating 110 is provided with a plurality of through holes 111, in one embodiment of the present invention, the plurality of through holes 111 provided in the first coating 110 can be divided into a plurality of groups arranged at intervals along the axial direction X, and the number of through holes 111 in each group is at least two, and at least two through holes 111 in the same group are arranged at intervals along the circumference of the first coating 110.

[0065] See Figure 11 , Figure 11 1 represents an axial cross-sectional view of another exemplary embodiment of a stent graft that can embody the principles of the present invention.

[0066] like Figure 11 As shown, in one embodiment of the present invention, the first coating 110 can be disconnected along the axial direction X, and the disconnection position corresponds to the position of the expansion section 212 of the second coating 210, so that the first coating 110 forms an opening 112 at the disconnection position, and the opening 112 defines the above-mentioned channel. Specifically, the first coating 110 can be completely disconnected along the circumferential direction at the disconnection position, that is, the first coating 110 is disconnected into two sections spaced apart along the axial direction X at this position, so that the opening 112 has a circumferentially closed annular structure. Alternatively, the first coating 110 can also be partially disconnected along the circumferential direction at the disconnection position, so that the opening 112 has a circumferentially arc-shaped structure, without limitation.

[0067] It should be noted that the stent grafts shown in the drawings and described in this specification are merely examples of the many stent grafts that can employ the principles of the present invention. It should be clearly understood that the principles of the present invention are in no way limited to any detail or component of the stent grafts shown in the drawings or described in this specification.

[0068] In summary, the stent-grafted blood vessel proposed in the present invention adopts a double-layered blood vessel structure design, and the two blood vessel layers respectively include a coating and a stent. The second coating 210 of the outer blood vessel portion 200 includes an expansion section 212 and a fixed section 211. The fixed section 211 is fixedly connected to the blood vessel portion, and at least a portion of the expansion section 212 along the circumference is not fixed to the inner blood vessel portion 100. A second stent 220 is fixed to the inner or outer periphery of the expansion section 212. Accordingly, the stent-grafted blood vessel can be separated from the inner blood vessel portion 100 by at least a portion of the expansion section 212, so that the outer blood vessel portion 200 forms an expansion cavity P. Through the above design, the stent-grafted blood vessel proposed in the present invention can, through the design of the expansion section 212, utilize the expansion cavity P to fully contact the second coating 210 with the wall of the hemangioma, so that the gap between the artificial blood vessel and the hemangioma wall is filled. At the same time, the second stent 220 provides structural support to the expansion cavity P, thereby enhancing the support stability of the expansion cavity P. In particular, the present invention is suitable for achieving direct filling isolation of aortic aneurysms within the limit of the "anesthesia neck" length, thereby avoiding the occurrence of endoleakage.

[0069] The above describes and / or illustrates in detail exemplary embodiments of the stent graft proposed by the present invention. However, the embodiments of the present invention are not limited to the specific embodiments described herein. Rather, the components and / or steps of each embodiment may be used independently and separately from other components and / or steps described herein. Each component and / or each step of one embodiment may also be used in combination with other components and / or steps of other embodiments. When introducing elements / components / etc. described and / or illustrated herein, the terms "a," "an," and "above," etc. are used to indicate the presence of one or more elements / components / etc. The terms "comprising," "including," and "having" are used to indicate open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc. In addition, the terms "first," "second," etc. in the claims and the specification are used merely as labels and do not constitute numerical limitations on their intended objects.

[0070] Although the stent graft of the present invention has been described according to various specific embodiments, those skilled in the art will recognize that modifications may be made to the implementation of the present invention within the spirit and scope of the claims.

Claims

1. A stent-assisted vascular graft, characterized in that: Include: The inner blood vessel portion includes a first covering and a first stent, wherein the first covering covers the inner periphery or the outer periphery of the first stent; and an outer vascular portion, sleeved over the outer portion of the inner vascular portion, and comprising a second stent and a second covering, wherein the second covering comprises an expansion segment and two fixed segments, wherein the two fixed segments are respectively connected to both ends of the expansion segment in the axial direction, the fixed segments are fixedly connected to the inner vascular portion, and at least a portion of the expansion segment in the circumferential direction has no fixed relationship with the inner vascular portion, and the second stent is fixed to the inner circumference or the outer circumference of the expansion segment; The first covering film is provided with a channel penetrating the film wall, and the channel corresponds to the position of the expansion section of the second covering film; The area of ​​the portion of the expansion section that has no fixed relationship with the inner vascular portion is larger than the area of ​​the inner vascular portion corresponding to the portion, so that the stent artificial blood vessel can be at least partially separated from the inner vascular portion via the expansion section to form an expansion cavity in the outer vascular portion.

2. The stent-graft according to claim 1, wherein: The first covering is covered on the outer periphery of the first stent, and the second covering is covered on the outer periphery of the second stent.

3. The stent-graft according to claim 1, wherein: An axial length of the first coating is less than or equal to an axial length of the first stent.

4. The stent-graft according to claim 1, wherein: The axial length of the second coating is smaller than the axial length of the first coating, so that at least one of the two axial ends of the first coating extends beyond the second coating.

5. The stent-graft according to claim 1, wherein: The fixing section of the second covering is connected to the first bracket and the first covering at the same time.

6. The stent-graft according to claim 1, wherein: All positions of the second bracket are not connected to the first bracket.

7. The stent-graft according to claim 1, wherein: The entire expansion section along the circumferential direction has no fixed relationship with the inner vascular portion, so that the expansion cavity is in a ring shape surrounding the inner vascular portion.

8. The stent-graft according to claim 1, wherein: A portion of the expansion section along the circumferential direction has no fixed relationship with the inner blood vessel portion, so that the expansion cavity is in an arc shape surrounding the inner blood vessel portion.

9. The stent-graft according to claim 8, wherein: The plurality of portions of the expansion section along the circumferential direction have no fixed relationship with the inner vascular portion, and the plurality of portions are arranged at intervals along the circumferential direction.

10. The stent-graft according to claim 1, wherein: The first covering film is provided with a through hole, and the through hole defines the channel; or The first covering film is provided with a plurality of through holes, the plurality of through holes are arranged at intervals and collectively define the channel; or The first covering film is in a disconnected structure along the axial direction, and the disconnected position corresponds to the position of the expansion section. The first covering film forms an opening at the disconnected position, and the opening defines the channel.

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