Stent graft

Abstract

The present invention provides a stent-graft, which comprises a stent and a first film; the first film covers the outer periphery of the stent, the first film has a fixed section and an expansion section, and both ends of the expansion section along the axial direction are respectively connected with the fixed section, the fixed section is fixedly connected with the stent, and at least a part of the expansion section along the circumferential direction has no fixed relationship with the stent; wherein, the area of the part of the expansion section that has no fixed relationship with the stent is larger than the area of the corresponding stent of this part, so that the stent-graft can at least partially separate from the stent via the expansion section to form an expansion cavity with the first film. Through the above design, the stent-graft provided by the present invention can, through the design of the expansion section, make the first film contact the blood vessel wall more fully by using the expansion cavity, and completely seal the gap between the graft and the blood vessel wall. In particular, the present invention is applicable to isolating aortic aneurysms within the limit "aneurysmal neck" length to avoid the occurrence of endoleakage.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial blood vessels, and particularly to a stent artificial blood vessel. Background Art

[0002] In the application of existing artificial blood vessel technologies, endovascular stent-grafts have been used as a means to repair aortic aneurysms or aortic dissections, such as treating infrarenal abdominal aortic aneurysms. For lesions adjacent to the renal artery in abdominal aortic aneurysms, the preferred repair option is to isolate the abdominal aortic aneurysm while maintaining unobstructed blood flow in the renal artery. In addition to surgical methods for repairing lesions, existing interventional treatment options involve bridging an endovascular stent-graft across the normal aorta (i.e., the "aneurysm neck") at both ends of the aneurysm to isolate the aneurysm while maintaining unobstructed aortic blood flow. However, when the length of the "aneurysm neck" is insufficient, the effect of the artificial blood vessel in closing the gap between the artificial blood vessel and the aortic wall at the "aneurysm neck" is affected, resulting in aortic blood flow entering the space between the endovascular stent-graft and the aneurysm through the gap between the artificial blood vessel and the aortic wall of the "aneurysm neck", forming an "endoleak" and leading to treatment failure. To solve the problem of insufficient "aneurysm neck" length, methods of covering branch arteries after "fenestrating" the artificial blood vessel and methods of placing stents in branch blood vessels have been proposed. After years of attempts, the endovascular stent-grafts or repair devices on which the above remedial solutions rely have different defects and have not solved the treatment problem of insufficient "aneurysm neck" length.

[0003] Looking at the above existing technical solutions, their common point is to fix the artificial blood vessel using the stent of the endovascular stent-graft. Since the stent is used for positioning in the blood vessel lumen and requires corresponding support rigidity, the contact between the stent and the blood vessel wall is insufficient point contact, so that the artificial blood vessel fixed to the stent cannot fully contact the blood vessel wall either, and the gap between the artificial blood vessel and the blood vessel wall cannot be completely closed.

[0004] Therefore, designing a device that can isolate an aortic aneurysm within the limit "aneurysm neck" length and avoid the occurrence of "endoleak" has become an urgent problem to be solved in the design of related devices in this field. Summary of the Invention

[0005] A main object of the present invention is to overcome at least one defect of the above existing technologies, and to provide a stent artificial blood vessel that can effectively avoid the generation of endoleak problems.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] According to one aspect of the present invention, there is provided a stent-graft, comprising a stent and a first film; the first film is wrapped around the outer periphery of the stent, the first film has a fixed section and an expansion section, and both ends of the expansion section along the axial direction are respectively connected with the fixed section, the fixed section is fixedly connected with the stent, and at least a part of the expansion section along the circumferential direction has no fixed relationship with the stent; the area of the part of the expansion section that has no fixed relationship with the stent is larger than the area of the corresponding part of the stent, so that the stent-graft can be at least partially separated from the stent via the expansion section to form an expansion cavity by the first film.

[0008] According to one embodiment of the present invention, the entire circumferential direction of the expansion section has no fixed relationship with the stent, so that the expansion cavity is in a ring shape surrounding the stent.

[0009] According to one embodiment of the present invention, a part of the expansion section along the circumferential direction has no fixed relationship with the stent, so that the expansion cavity is in an arc shape surrounding the stent.

[0010] According to one embodiment of the present invention, multiple parts of the expansion section along the circumferential direction have no fixed relationship with the stent, and the multiple parts are arranged at intervals along the circumferential direction, so that multiple expansion cavities are in a petal shape surrounding the stent.

[0011] According to one embodiment of the present invention, the axial length of the expansion section of the first film accounts for less than or equal to 80% of the axial length of the first film.

[0012] According to one embodiment of the present invention, the lengths of the two fixed sections on both sides of the expansion section of the first film along the axial direction are not equal.

[0013] According to one embodiment of the present invention, the stent-graft further comprises a second film; the second film is wrapped around and fixed to the inner or outer periphery of the stent, and the second film is provided with a channel penetrating the film wall, and the position of the channel corresponds to the expansion section of the first film; wherein, when the second film is fixed to the inner periphery of the stent, the fixed section of the first film is directly fixed to the stent, and when the second film is fixed to the outer periphery of the stent, the fixed section is wrapped around and fixed to the outer periphery of the second film, so that the fixed section is indirectly fixed to the stent.

[0014] According to one embodiment of the present invention, among others: a through hole is formed in the second film, and the through hole defines the channel; alternatively, a plurality of through holes are formed in the second film, the plurality of through holes are arranged at intervals and jointly define the channel; alternatively, the second film has a structure that is axially disconnected, and the disconnected position corresponds to the position of the expansion section, and an opening is formed at the disconnected position of the second film, and the opening defines the channel.

[0015] According to one embodiment of the present invention, a plurality of through holes are formed in the second film, among others: at least two of the through holes are arranged at intervals along the axial direction of the second film; and / or, at least two of the through holes are arranged at intervals along the circumferential direction of the second film.

[0016] According to one embodiment of the present invention, a plurality of through holes are formed in the second film, the plurality of through holes are divided into multiple groups arranged at intervals along the axial direction of the second film, the number of through holes in each group is at least two, and each of the through holes in the same group is arranged at intervals along the circumferential direction of the second film.

[0017] According to one embodiment of the present invention, the second film has a structure that is axially disconnected, among others: the second film is completely disconnected along the circumferential direction at the disconnected position, so that the opening is a circumferentially annular closed opening; alternatively, the second film is partially disconnected along the circumferential direction at the disconnected position, so that the opening is a circumferentially arc-shaped opening.

[0018] According to one embodiment of the present invention, the axial length of the stent is greater than or equal to the axial length of the first film.

[0019] As can be seen from the above technical solutions, the advantages and positive effects of the stent artificial blood vessel proposed by the present invention are as follows:

[0020] The stent artificial blood vessel proposed by the present invention includes a stent and a first film coated on the outer periphery of the stent. The first film has an expansion section and fixed sections connected to both ends of the expansion section. The fixed sections are fixedly connected to the stent, and at least a part of the expansion section along the circumferential direction has no fixed relationship with the stent. Accordingly, the stent artificial blood vessel can form an expansion cavity by at least partial separation of the expansion section from the stent. Through the above design, the stent artificial blood vessel proposed by the present invention can, through the design of the expansion section, make the first film come into more sufficient contact with the blood vessel wall by using the expansion cavity, and achieve complete closure of the gap between the artificial blood vessel and the blood vessel wall. In particular, the present invention is applicable to isolating aortic aneurysms within the limit "aneurysm neck" length and avoiding the occurrence of endoleakage. Description of the Drawings

[0021] The various objects, features, and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The drawings are only illustrative diagrams of the present invention and are not necessarily drawn to scale. In the drawings, the same reference numerals always denote the same or similar components. Among them:

[0022] Figure 1 is an axonometric sectional view of a stent graft shown according to an exemplary embodiment;

[0023] Figure 2 is a sectional view taken along Figure 1 the straight line A-A in

[0024] Figure 3 is a sectional view taken along Figure 1 the straight line B-B in

[0025] Figure 4 is an axonometric sectional view of a stent graft shown according to another exemplary embodiment;

[0026] Figure 5 is a sectional view taken along Figure 4 the straight line C-C in

[0027] Figure 6 is a sectional view taken along Figure 4 the straight line D-D in

[0028] Figure 7 is a sectional view of a stent graft shown according to another exemplary embodiment;

[0029] Figure 8 is a sectional view of a stent graft shown according to another exemplary embodiment;

[0030] Figure 9 is an axonometric sectional view of a stent graft shown according to another exemplary embodiment;

[0031] Figure 10 is an axonometric sectional view of a stent graft shown according to another exemplary embodiment;

[0032] Figure 11 is a sectional view taken along Figure 10 the straight line E-E in

[0033] Figure 12 is a sectional view taken along Figure 10 the straight line F-F in

[0034] Figure 13 is an axonometric sectional view of a stent graft shown according to another exemplary embodiment;

[0035] Figure 14 is an axonometric sectional view of a stent-graft shown according to another exemplary embodiment;

[0036] Figure 15 is an axonometric sectional view of a stent-graft shown according to another exemplary embodiment;

[0037] Figure 16 is an axonometric sectional view of a stent-graft shown according to another exemplary embodiment;

[0038] Figure 17 is Figure 1 a schematic diagram of the stent-graft shown in an application step in an exemplary application scenario;

[0039] Figure 18 is Figure 1 a schematic diagram of the stent-graft shown in another application step in an exemplary application scenario.

[0040] The description of the reference numerals is as follows:

[0041] 100. Stent-graft;

[0042] 110. Stent;

[0043] 111. Fixed section;

[0044] 112. Expansion section;

[0045] 120. First membrane;

[0046] 121. Fixed section;

[0047] 122. Expansion section;

[0048] 1221. Expansion cavity;

[0049] 130. Second membrane;

[0050] 131. Through hole;

[0051] 132. Opening;

[0052] 200. Auxiliary graft;

[0053] L0. Length;

[0054] L1. Length;

[0055] X. Axial direction. Detailed implementation manners

[0056] Exemplary embodiments embodying 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, all of which do not depart from the scope of the present invention, and the descriptions and drawings therein are for illustrative purposes in nature and are not intended to limit the present invention.

[0057] 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 solutions 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 terms such as "above", "between", "within", etc. 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, for example, 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 direction of the structure to fall within the scope of the present invention.

[0058] Refer to Figure 1 , which representatively shows an axonometric sectional view of the stent graft 100 proposed by the present invention. In this exemplary embodiment, the stent graft 100 proposed by the present invention is described by taking the graft used for isolating aortic aneurysms as an example. It is easy for those skilled in the art to understand that, in order to apply the relevant designs of the present invention to other types of stent grafts 100, various modifications, additions, substitutions, deletions, or other changes are made to the following specific embodiments, and these changes are still within the scope of the principle of the stent graft 100 proposed by the present invention.

[0059] As Figure 1 shown, in this embodiment, the stent graft 100 proposed by the present invention at least includes a stent 110 and a first membrane 120. With reference to Figures 2 to 3 , Figure 2 representatively shows the sectional view taken along the straight line A - A in Figure 1 ; Figure 3 representatively shows the sectional view taken along the straight line B - B in Figure 1 . The structures, connection methods, and functional relationships of the main components of the stent graft 100 proposed by the present invention will be described in detail below with reference to the above-mentioned drawings.

[0060] As Figures 1 to 3As shown, in an embodiment of the present invention, the first coating film 120 is wrapped around the outer periphery of the stent 110. The first coating film 120 has a fixed section 121 and an expansion section 122, and the two ends of the expansion section 122 along the axial direction X are respectively connected to the fixed section 121. It should be noted that the expansion of the expansion section 122 does not refer to the deformation of the first coating film 120 due to the elasticity of its own material, but means that the area of the expansion section 122 is larger than the area of the corresponding part of the stent 110, and the expansion deformation of the expansion section 122 is formed by blood flow pressure. Among them, the fixed section 121 of the first coating film 120 is fixedly connected to the stent 110, and at least a part of the expansion section 122 of the first coating film 120 has no fixed relationship with the stent 110 along the circumferential direction. Moreover, the area of the part of the expansion section 122 that has no fixed relationship with the stent 110 is larger than the area of the corresponding part of the stent 110 (the so-called "area" of the stent 110 refers to the area of the cylindrical surface of the columnar structure corresponding to the stent 110, rather than the area of the metal wire of the stent 110), so that the stent artificial blood vessel 100 can be at least partially separated from the stent 110 via the expansion section 122 to form an expansion cavity 1221 in the first coating film 120. Through the above design, the stent artificial blood vessel 100 proposed by the present invention can, through the design of the expansion section 122, utilize the expansion cavity 1221 to make the first coating film 120 contact the blood vessel wall more fully, and achieve complete closure of the gap between the artificial blood vessel and the blood vessel wall. In particular, the present invention is applicable to isolating aortic aneurysms within the limit "aneurysm neck" length to avoid the occurrence of endoleakage.

[0061] As Figure 2 and Figure 3 shown, in an embodiment of the present invention, all of the expansion section 122 of the first coating film 120 along the circumferential direction can have no fixed relationship with the stent 110. Accordingly, the stent artificial blood vessel 100 proposed by the present invention can be separated from the stent 110 via all of the expansion section 122 of the first coating film 120 to form an expansion cavity 1221 in the first coating film 120, and the formed expansion cavity 1221 is in a ring shape surrounding the stent 110. Through the above design, the present invention can form a substantially ring-shaped thrombus through the ring-shaped expansion cavity 1221, so as to be applicable to the situation where the lesion location surrounds the blood vessel circumferentially for one week.

[0062] Based on the above detailed description of an exemplary embodiment of the stent artificial blood vessel 100 proposed by the present invention, to further deepen the understanding of the present invention, the following will take this kind of stent artificial blood vessel 100 as an example to exemplarily describe the process of placing it into a blood vessel through a delivery device.

[0063] First, the stent graft 100 in a compressed state is manually placed into the delivery device. Specifically, the delivery device may include a sheath, a restraining wire, and an operating end for the operator to operate, etc. The stent graft 100 in a compressed state is entirely sleeved inside the sheath, and the restraining wire is connected to and restrains the stent 110 (in other embodiments, the restraining wire may also tightly restrain a part of the stent 110, such as Figure 16 the embodiment shown). At this time, the stent 110 is simultaneously restrained by the restraining wire and the sheath, and the fixed section 121 of the first film 120 fixed to the stent 110 is also restrained. The expanded section 122 of the first film 120 has no fixed relationship with the stent 110, so it is not restrained by the restraining wire, but is still restrained by the sheath.

[0064] After the stent graft 100 is delivered to the desired position in the blood vessel by the delivery device, the operator operates the delivery device (such as controlling the movement of the sheath) to cause the stent graft 100 to extend out of the sheath. Since the stent 110 is still restrained by the restraining wire, and the fixed section 121 of the first film 120 is fixed to the stent 110 and is also restrained by the restraining wire relative to it, the stent 110 and the fixed section 121 of the first film 120 still cannot expand after the stent graft 100 extends out of the sheath. At this time, since the expanded section 122 of the first film 120 is not fixed to the stent 110, that is, the expanded section 122 is not indirectly restrained by the restraining wire, and the expanded section 122 is no longer restrained by the sheath, the expanded section 122 can freely expand under the pressure of the blood flow. Then, the operator operates the delivery device to release the restraint of the restraining wire on the stent 110, and the stent 110 expands under the action of its own material elasticity, and at the same time drives the fixed section 121 of the first film 120 to expand. After the above expansion action, the blood flow flowing through the stent graft 100 further increases, and under the pressure of the blood flow, the expanded section 122 of the first film 120 further expands completely.

[0065] Refer to Figures 4 to 6 shown in Figure 4 which representatively shows an axonometric sectional view of the stent graft 100 proposed by the present invention in another embodiment; Figure 5 which representatively shows Figure 4 the sectional view taken along the straight line C-C in Figure 6 which representatively shows Figure 4 the sectional view taken along the straight line D-D in

[0066] As shown in Figures 4 to 6As shown, in an embodiment of the present invention, a part of the circumferential direction of the expansion section 122 of the first film 120 has no fixed relationship with the stent 110. In other words, another part of the circumferential direction of the expansion section 122 is fixedly connected to the stent 110. Accordingly, the stent artificial blood vessel 100 proposed by the present invention can be separated from the stent 110 via a part of the expansion section 122 of the first film 120, so that the first film 120 forms an expansion cavity 1221, and the formed expansion cavity 1221 is in an arc shape surrounding the stent 110. Through the above design, the present invention can form a thrombus substantially in an arc shape through the arc-shaped expansion cavity 1221, so as to be applicable to the situation where the diseased position is located in a certain section along the circumferential direction of the blood vessel.

[0067] Refer to Figure 7 As shown, Figure 7 Figure 7 representatively shows a cross-sectional view of the stent artificial blood vessel 100 proposed by the present invention in another embodiment. The specific intercept position can refer to Figure 4 the position of the straight line D-D in

[0068] As Figure 7 shown, in an embodiment of the present invention, multiple parts of the circumferential direction of the expansion section 122 of the first film 120 have no fixed relationship with the stent 110, and these parts are arranged at intervals along the circumferential direction. The remaining part of the circumferential direction of the expansion section 122 is fixedly connected to the stent 110. Accordingly, the stent artificial blood vessel 100 proposed by the present invention can be separated from the stent 110 via multiple parts of the expansion section 122 of the first film 120, so that the first film 120 forms multiple expansion cavities 1221, and each formed expansion cavity 1221 is in an arc shape surrounding the stent 110. Through the above design, the present invention can respectively form multiple thrombi substantially in an arc shape through multiple arc-shaped expansion cavities 1221, so as to be applicable to the situation where multiple diseased positions are respectively located in multiple sections along the circumferential direction of the blood vessel.

[0069] As Figure 7 shown, in an embodiment of the present invention, for multiple parts of the expansion section 122 that have no fixed relationship with the stent 110, the shapes of each part can be substantially the same or different. The so-called shape can be understood as the radian range corresponding to the circumferential direction, the size of the outward expansion and protrusion along the radial direction, etc. It should be noted that the substantially same shapes of the multiple expansion cavities 1221 shown in the drawings are only for the convenience of drawing and understanding. According to the actual sizes of multiple diseased positions, such as the axial and circumferential lengths, the radial depth, etc., multiple parts of the expansion section 122 that have no fixed relationship with the stent 110 can respectively adjust the relevant sizes accordingly, and are not limited to the shapes shown in the drawings. Refer to Figure 8 As shown, Figure 8 Figure 23 representatively shows a cross-sectional view of the stent artificial blood vessel 100 proposed by the present invention in another embodiment. The specific intercept position can refer toFigure 4 The position of the straight line D-D in

[0070] As Figure 8 shown, in an embodiment of the present invention, multiple circumferential portions of the expansion section 122 of the first film 120 have no fixed relationship with the stent 110, and these portions are evenly spaced circumferentially. The remaining circumferential portions of the expansion section 122 are fixedly connected to the stent 110. Accordingly, the stent artificial blood vessel 100 proposed by the present invention can be separated from the stent 110 through multiple portions of the expansion section 122 of the first film 120, so that the first film 120 forms a plurality of evenly distributed expansion cavities 1221, and the formed plurality of expansion cavities 1221 are substantially petal-shaped around the stent 110.

[0071] Refer to Figure 9 shown in Figure 9 which is an axonometric sectional view of the stent artificial blood vessel 100 proposed by the present invention in another embodiment.

[0072] As Figure 9 shown, in an embodiment of the present invention, the length L1 of the expansion section 122 of the first film 120 along the axial direction X may be less than or equal to 80% of the overall length L0 of the first film 120 along the axial direction X, such as 15%, 30%, 55%, 80%, etc. In some embodiments, the proportion of the length L1 of the expansion section 122 of the first film 120 along the axial direction X in the overall length L0 of the first film 120 along the axial direction X may also be greater than 80%, such as 85%, etc., and is not limited thereto.

[0073] It should be noted that in some embodiments, the proportion of the length L1 of the expansion section 122 of the first film 120 along the axial direction X in the overall length L0 of the first film 120 along the axial direction X may be further less than or equal to 30%, such as 10%, 15%, 20%, 30%, etc. Through the above design, based on the flow characteristics of blood, a viscous liquid, when a design with a relatively small proportion of the length L1 of the expansion section 122 along the axial direction X is adopted, after a thrombus is formed in the expansion cavity 1221 formed by the expansion section 122, the blood flow velocity passing through this position will be greatly reduced, thereby ensuring the formation and retention of the thrombus at this position.

[0074] As Figure 9 shown, in an embodiment of the present invention, the lengths of the two fixed sections 121 on both sides of the expansion section 122 of the first film 120 along the axial direction X may not be equal. In other words, the expansion section 122 is offset in the axial direction X of the first film 120. In some embodiments, the lengths of the two fixed sections 121 on both sides of the expansion section 122 along the axial direction X may also be equal, that is, the expansion section 122 may also be centered in the axial direction X of the first film 120, and is not limited thereto.

[0075] Refer to Figures 10 to 12 as shown Figure 10 which representatively shows an axonometric sectional view of the stent artificial blood vessel 100 proposed by the present invention in another embodiment; Figure 11 which representatively shows Figure 10 a sectional view taken along the straight line E-E in Figure 12 which representatively shows Figure 10 a sectional view taken along the straight line F-F in

[0076] As Figures 10 to 12As shown, in an embodiment of the present invention, the stent-graft 100 proposed by the present invention may further include a second membrane 130. Specifically, the second membrane 130 is coated and fixed to the inner circumference of the stent 110. On this basis, the fixed section 121 of the first membrane 120 is directly fixed to the stent 110. The second membrane 130 is provided with a channel penetrating the membrane wall, and the position of this channel corresponds to that of the expansion section 122 (the part having no connection relationship with the stent 110) of the first membrane 120. Accordingly, at least a part of the expansion section 122 of the first membrane 120 is separated from the stent 110, and when the expansion cavity 1221 is formed in the first membrane 120, the channel can communicate the inner cavity of the second membrane 130 with the expansion cavity 1221. In some embodiments, when the stent-graft 100 proposed by the present invention includes the second membrane 130, the second membrane 130 may also be fixed to the outer circumference of the stent 110. At this time, the fixed section 121 of the first membrane 120 is coated and fixed to the outer circumference of the second membrane 130, so that the fixed section 121 is indirectly fixed to the stent 110 through the second membrane 130. Specifically, in the illustrated embodiment, the second membrane 130 is provided with a plurality of through holes 131, and these through holes 131 are arranged at intervals, thereby jointly defining the above-mentioned channel. Through the above design, in order to further stabilize the formation and retention of thrombus in the expansion section 122. For example, when the length L1 of the expansion section 122 of the first membrane 120 along the axial direction X accounts for more than 30% of the overall length L0 of the first membrane 120 along the axial direction X, the present invention adopts the design of the second membrane 130, which can use the second membrane 130 to enclose a part of the expansion cavity 1221 and use the channel opened therein to ensure that blood flows into the expansion cavity 1221 to form thrombus. Accordingly, based on the flow characteristics of blood, a viscous liquid, when the design of the second membrane 130 is adopted, after the blood enters the expansion cavity 1221 through the channel of the second membrane 130 to form thrombus, the blood flowing through this position is restricted by the channel, so that its flow rate will decrease, thereby ensuring the formation and retention of thrombus at this position. It should be noted that, in some embodiments, when the second membrane 130 is provided, in order to ensure that there is enough contact length between the second membrane 130 and the fixed section 121 of the first membrane 120, the proportion of the length of each of the two fixed sections 121 on both sides of the first membrane in the overall length can be greater than 5%.

[0077] As Figure 10 and Figure 12 shown, in an embodiment of the present invention, a plurality of through holes 131 correspond to the position of the expansion section 122. It should be noted that when the expansion section 122 has a plurality of parts having no fixed relationship with the stent 110, each part corresponds to at least one through hole 131. When the expansion section 122 has only one part having no fixed relationship with the stent 110, the through holes 131 all correspond to this part of the expansion section 122.

[0078] As Figure 10 and Figure 12 shown, in an embodiment of the present invention, when the second film 130 is provided with a plurality of through holes 131, at least two of these through holes 131 may be arranged at intervals along the axial direction X of the second film 130.

[0079] As Figure 10 and Figure 12 shown, in an embodiment of the present invention, when the second film 130 is provided with a plurality of through holes 131, at least two of these through holes 131 may be arranged at intervals along the circumferential direction of the second film 130.

[0080] As Figure 10 and Figure 12 shown, in an embodiment of the present invention, taking the example that all of the expansion sections 122 of the first film 120 have no fixed relationship with the stent 110 (i.e., the formed expansion cavity 1221 is in a ring shape surrounding the stent 110), the plurality of through holes 131 provided on the second film 130 may be divided into multiple groups arranged at intervals along the axial direction X of the second film 130. The number of through holes 131 in each group is at least two, and the through holes 131 in the same group are arranged at intervals along the circumferential direction of the second film 130.

[0081] Based on the design of dividing the above-mentioned plurality of through holes 131 into multiple groups for arrangement, in an embodiment of the present invention, the multiple groups of through holes 131 may be evenly distributed at intervals along the axial direction X of the second film 130.

[0082] Based on the design of dividing the above-mentioned plurality of through holes 131 into multiple groups for arrangement, in an embodiment of the present invention, the through holes 131 in the same group may be evenly distributed at intervals along the circumferential direction of the second film 130.

[0083] In an embodiment of the present invention, the diameters of each part of the stent 110 along the axial direction X may be equal. On this basis, the diameter of the fixed section 121 of the first film 120 is equal to the diameter of the stent 110, and the diameter of the expansion section 122 is greater than the diameter of the stent 110.

[0084] Referring to Figure 13 shown Figure 13 FIG. shows an axonometric sectional view of the stent artificial blood vessel 100 proposed by the present invention in another embodiment.

[0085] As Figure 13 shown, in an embodiment of the present invention, the second film 130 may be provided with only one through hole 131, and the position of this through hole 131 corresponds to the position of the expansion section 122 of the first film 120, that is, the second film 130 defines the above-mentioned channel with one through hole 131.

[0086] Referring to Figure 14 shownFigure 14 An axonometric sectional view of the stent-graft 100 proposed by the present invention in another embodiment is representatively shown.

[0087] As Figure 14 shown, in an embodiment of the present invention, when the stent-graft 100 includes a second membrane 130, the channel opened in the second membrane 130 corresponding to the expansion section 122 can also be realized by other structures. For example, the second membrane 130 can be a disconnected structure along the axial direction, and the disconnected position corresponds to the position of the expansion section 122 of the first membrane 120, so that an opening 132 is formed at the disconnected position of the second membrane 130, and this opening 132 defines the above-mentioned channel.

[0088] Specifically, the second membrane 130 can be completely disconnected along the circumferential direction at the disconnected position, that is, the second membrane 130 is disconnected into two axially spaced sections at this position, so that the opening 132 is a circumferentially annular closed structure. Or, the second membrane 130 can also be partially disconnected along the circumferential direction at the disconnected position, so that the opening 132 is a circumferentially arc-shaped structure, and these are not limited thereto.

[0089] Refer to Figure 15 shown, Figure 15 An axonometric sectional view of the stent-graft 100 proposed by the present invention in another embodiment is representatively shown.

[0090] As Figure 15 shown, in an embodiment of the present invention, the axial X length of the stent 110 can be greater than the axial X length of the first membrane 120. On this basis, both ends of the stent 110 can extend out of both ends of the first membrane 120 respectively. In some embodiments, when the axial X length of the stent 110 is greater than the axial X length of the first membrane 120, only one end of the stent 110 can also extend out of the corresponding end of the first membrane 120. Or, the axial X length of the stent 110 can also be equal to the axial X length of the first membrane 120, as Figure 1 shown, and these are not limited thereto.

[0091] It should be noted that taking the stent-graft 100 shown in Figure 14 as an example, in some embodiments, when the second membrane 130 is a disconnected design (or a design with a plurality of through holes 131), that is, when the second membrane 130 has an opening 132, in order to further ensure the formation and retention of thrombus, an auxiliary artificial blood vessel 200 can be used (refer to Figure 17 and Figure 18) After the stent graft 100 proposed by the present invention is placed at a predetermined position in the blood vessel, the auxiliary graft 200 is inserted into the inner cavity of the second film 130 of the stent graft 100. Through the dimensional design of the two grafts, the outer wall of the auxiliary graft 200 is closely attached to the inner wall of the stent graft 100 (such as the inner wall of the stent 110 or the inner wall of the second film 130, etc.). Accordingly, thrombus formed in the dilation cavity 1221 will not be difficult to form due to the large blood flow velocity caused by multiple through holes 131 in the second film 130 or a discontinuous design. The auxiliary graft 200 can block the multiple through holes 131 or openings 132 forming its channels in the second film 130, making the dilation cavity 1221 where the thrombus is formed a closed cavity.

[0092] Furthermore, when the length L1 of the dilation section 122 of the first film 120 along the axial direction X is relatively small in the overall length L0 of the first film 120 along the axial direction X, for example, less than or equal to 30%, even without the auxiliary graft 200, the flow characteristics of this relatively viscous liquid, blood, can be utilized to ensure the formation and retention of thrombus in the dilation cavity 1221. Or, when the second film 130 is provided and only one through hole 131 corresponding to the dilation section 122 is provided in the second film 130, even without the auxiliary graft 200, the flow characteristics of blood can be utilized to ensure the formation and retention of thrombus in the dilation cavity 1221. Accordingly, the surgical operation process can be simplified and the equipment cost can be reduced.

[0093] Refer to Figure 16 as shown Figure 16 which representatively shows an axonometric sectional view of the stent graft 100 proposed by the present invention in another embodiment.

[0094] As Figure 16As shown, on the basis that the proportion of the axial length X of the expansion section 122 of the first film covering 120 in the overall length of the first film covering 120 is less than or equal to 30%, in an embodiment of the present invention, the stent 110 may also include a fixed section 111 and an expansion section 112. Specifically, the fixed section 111 of the stent 110 is fixedly connected to the fixed section 121 of the first film covering 120. The expansion section 112 of the stent 110 has no connection relationship with the first film covering 120, and the position of the expansion section 112 of the stent 110 corresponds to that of the expansion section 122 of the first film covering 120. On this basis, the diameter of the expansion section 112 of the stent 110 is greater than the diameter of its fixed section 111 and less than the diameter of the expansion section 122 of the first film covering 120. Accordingly, when the stent artificial blood vessel 100 proposed by the present invention is placed into a blood vessel through a delivery device, the entire stent artificial blood vessel 100 is constrained in a sheath of the delivery device, and the fixed section 111 of the stent 110 is simultaneously constrained by a constraint wire. When the stent artificial blood vessel 100 is sent to the desired position by the delivery device, the operator operates the delivery device (for example, controls the movement of the sheath) to make the stent artificial blood vessel 100 extend out of the sheath. Since the fixed section 111 of the stent 110 is still constrained by the constraint wire, and the fixed section 121 of the first film covering 120 is fixed to the fixed section 111 of the stent 110 and is also constrained by the constraint wire, the above-mentioned fixed section 111 and fixed section 121 cannot be deployed after the stent artificial blood vessel 100 extends out of the sheath. At this time, since the expansion section 112 of the stent 110 is not constrained by the constraint wire and the expansion section 112 is no longer constrained by the sheath, the expansion section 112 expands under the action of the material elasticity of the metal stent itself, and at the same time pushes the corresponding expansion section 122 of the first film covering 120 to expand. After the expansion section 112 of the stent expands, the operator operates the delivery device to release the constraint of the constraint wire on the fixed section 111 of the stent 110, and the fixed section 111 of the stent 110 expands under the action of the material elasticity of the metal stent itself, and at the same time drives the fixed section 121 of the first film covering 120 to expand. After the above deployment action, blood flow can circulate in the stent artificial blood vessel. Under the pressure of the blood flow, the expansion section 122 of the first film covering 120 expands further completely. Through the above design, the present invention can further ensure the sufficient expansion of the expansion section 122 when the length of the expansion section 122 of the first film covering 120 is small.

[0095] It should be understood that even in the above situation where the auxiliary artificial blood vessel 200 is not required, the auxiliary artificial blood vessel 200 may be used as needed to facilitate the auxiliary artificial blood vessel 200 to completely seal the expansion cavity 1221 formed by the expansion section 122 with a small length L1, or the only through hole 131 opened in the second film covering 130, further ensuring the retention of thrombus.

[0096] It should be noted here that the stent graft 100 shown in the drawings and described in this specification is only a few examples of the many stent grafts 100 that can adopt the principles of the present invention. It should be clearly understood that the principles of the present invention are by no means limited to any details or any components of the stent graft 100 shown in the drawings or described in this specification.

[0097] In summary, the stent graft 100 proposed by the present invention includes a stent 110 and a first film 120 coated on the outer periphery of the stent 110. The first film 120 has an expansion section 122 and fixed sections 121 connected to both ends of the expansion section 122. The fixed sections 121 are fixedly connected to the stent 110, and at least a part of the expansion section 122 in the circumferential direction has no fixed relationship with the stent 110. Accordingly, the stent graft 100 can separate at least part of the expansion section 122 from the stent 110 to form an expansion cavity 1221 in the first film 120. Through the above design, the stent graft 100 proposed by the present invention can, through the design of the expansion section 122, use the expansion cavity 1221 to make the first film 120 contact the blood vessel wall more fully, realizing the complete closure of the gap between the artificial blood vessel and the blood vessel wall. In particular, the present invention is applicable to isolating aortic aneurysms within the limit "aneurysm neck" length to avoid the occurrence of endoleakage.

[0098] The exemplary embodiments of the stent graft proposed by the present invention have been described in detail above and / or illustrated. However, the embodiments of the present invention are not limited to the specific embodiments described here. On the contrary, the components and / or steps of each embodiment can be used independently and separately from the other components and / or steps described here. Each component and / or each step of one embodiment can also be combined with the other components and / or steps of other embodiments. When introducing the elements / components / etc. described and / or illustrated here, the terms "a", "one" and "the above" etc. are used to indicate the existence of one or more elements / components / etc. The terms "comprising", "including" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. In addition, the terms "first" and "second" etc. in the claims and the specification are only used as labels and are not numerical limitations on their objects.

[0099] Although the stent graft proposed by the present invention has been described according to different specific embodiments, those skilled in the art will recognize that modifications can be made to the implementation of the present invention within the spirit and scope of the claims.

Claims

1. A stent-graft, comprising: A stent; A first membrane, covering the outer periphery of the stent, the first membrane having a fixed section and an expansion section, and both axial ends of the expansion section are respectively connected to the fixed section, the fixed section is fixedly connected to the stent, and at least a part of the expansion section in the circumferential direction has no fixed relationship with the stent; and A second membrane, covering and fixedly attached to the inner periphery of the stent, the second membrane is provided with a through hole, the through hole defines a channel penetrating the membrane wall, and the channel corresponds to the position of the expansion section of the first membrane, and the fixed section of the first membrane is directly fixed to the stent; Wherein, The area of the part of the expansion section that has no fixed relationship with the stent is larger than the area of the corresponding part of the stent, so that the stent-graft can be at least partially separated from the stent via the expansion section to form an expansion cavity with the first membrane.

2. The stent-graft according to claim 1, Wherein, All of the expansion section in the circumferential direction has no fixed relationship with the stent, so that the expansion cavity is in a ring shape surrounding the stent.

3. The stent-graft according to claim 1, Wherein, A part of the expansion section in the circumferential direction has no fixed relationship with the stent, so that the expansion cavity is in an arc shape surrounding the stent.

4. The stent-graft according to claim 3, Wherein, Multiple parts of the expansion section in the circumferential direction have no fixed relationship with the stent, and the multiple parts are arranged at intervals in the circumferential direction, so that multiple expansion cavities are in a petal shape surrounding the stent.

5. The stent-graft according to claim 1, Wherein, The axial length of the expansion section of the first membrane accounts for less than or equal to 80% of the axial length of the first membrane.

6. The stent-graft according to claim 1, Wherein, The lengths of the two fixed sections on both sides of the expansion section of the first membrane in the axial direction are not equal.

7. The stent-graft according to claim 1, Wherein, The axial length of the stent is greater than or equal to the axial length of the first membrane.

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