Stent graft

Abstract

The present invention provides a stent graft, comprising a main body graft, a window formed on the surface of the main body graft, the stent graft further comprising an inscribed graft, the edge of the inscribed graft being connected to the main body graft, the window comprising a first edge and a second edge extending along the length extension direction of the stent graft, the inscribed graft and the main body graft being separately molded and then spliced ​​together. The inscribed graft of the stent graft of the present invention is separately molded and then spliced ​​together to form the main body graft, thereby greatly reducing the difficulty of manufacturing the stent graft.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a stent graft. Background Art

[0002] Aortic aneurysms and aortic dissections are currently serious life-threatening conditions. Without active treatment, they can continue to expand and eventually rupture, leading to serious complications and death. With the increasing prevalence of hypertension, hyperlipidemia, and hyperglycemia, the incidence of these conditions is also increasing significantly.

[0003] Traditional open surgical treatments for aortic aneurysms and aortic dissections are highly invasive, have high mortality rates, long operative times, high rates of postoperative complications, and high surgical difficulty. Endovascular treatment, on the other hand, is characterized by minimal trauma, fewer postoperative complications, shorter operative times, and lower surgical difficulty, and has gradually become the primary method for treating aortic aneurysms and aortic dissections. By implanting a covered stent in the aorta, vascular lesions are isolated outside the covered stent, and blood flow is restricted to flow through the inside of the covered stent, thereby achieving the purpose of protecting the blood vessels. In order to ensure the fixation of the covered stent implant and prevent blood flow from flowing into the blood vessels through the proximal and distal ends of the stent, the covered stent requires an anchoring area of ​​a certain length. Therefore, when an aortic aneurysm or dissection involves a branch artery, the implantation of a covered stent for treatment will block the branch artery to varying degrees, and may even make endovascular treatment impossible.

[0004] For endovascular treatment of aortic aneurysms or dissections involving branch arteries, fenestrated stent technology and chimney stent technology are often used to achieve blood supply to the branch arteries. The fenestrated stent technology is to make a side hole on the stent by opening a window in vitro or in situ. The position of the side hole corresponds to the position of the opening of the branch artery. During the operation, the stent is implanted, the opening position is aligned with the branch artery, and then a bridging stent is implanted through the branch artery to match the stent graft; the chimney stent technology is to implant a bridging stent through the branch artery to match the stent graft after the stent graft is implanted. Generally, the fenestrated stent technology is difficult to position, requires customization, takes a long time, and cannot be used for emergency treatment; the chimney stent technology is prone to internal leakage and is limited by the vascular anatomy, making it difficult to reconstruct multiple branch arteries. At the same time, whether using a fenestrated stent or a chimney stent technology, the branch artery is always in a state of ischemia before the branch artery is reconstructed, and the probability of postoperative complications is high. Summary of the Invention

[0005] In response to the above problems, the present invention provides a coated stent, including a main body coating, a window formed on the surface of the main body coating, the coated stent also including an inscribed coating, the edge of the inscribed coating is connected to the main body coating, the window includes a first edge and a second edge extending along the length extension direction of the coated stent, the inscribed coating and the main body coating are separately molded and then spliced ​​together.

[0006] In one embodiment, the inscribed coating includes a bottom located between the first edge and the second edge, and a support unit is provided on the inscribed coating, which enables the bottom to at least partially convex outward or partially concave relative to the plane where the first edge and the second edge are located, or to be parallel to the plane.

[0007] In one embodiment, the support unit includes a suture, and the suture passes around the first edge and the edge of the inner coating, passes through the upper and lower surfaces of the inner coating to the second edge, and then passes around the second edge and the other edge of the inner coating to connect the inner coating and the main support.

[0008] In one embodiment, the elongation of the inscribed coating is greater than 0.01 and less than 0.1.

[0009] In one embodiment, the support unit includes a corrugated support structure connected to a surface of the inscribed coating.

[0010] In one embodiment, the membrane-grafting support comprises a window support, which is arranged outside the inner membrane and protrudes outward from the surface of the inner membrane, and the corrugated support structure is integrally formed with the window support.

[0011] In one embodiment, the internal coating includes a bottom, a proximal folding portion and a distal folding portion, and the proximal folding portion and the distal folding portion are respectively arranged at two ends of the bottom, and at least one of the proximal folding portion and the distal folding portion is arranged on the inner surface of the main body coating; the support unit is arranged at the bottom, and the folding portion is closer to the central axis of the coating bracket than the bottom.

[0012] In one embodiment, a sunken section is formed on the surface of the window support, and the cross-sectional area of ​​the stent graft where the sunken section is located is smaller than the cross-sectional area of ​​other parts of the stent graft away from the sunken section.

[0013] In one embodiment, the coated bracket also includes a main body support member, which is connected to the main body coating, and the window support member is a part of the main body support member. On the same cross-section, the circumferential proportion of the window support member is smaller than the circumferential proportion of the main body support member.

[0014] In one embodiment, the window support comprises a mesh structure having meshes, and the size of the meshes can be changed by an external force.

[0015] In one embodiment, the proximal end and / or the distal end of the window support extends beyond the edge of the window in the length direction of the stent graft.

[0016] The covered stent provided by the present invention can effectively isolate aortic dissection and aortic aneurysm involving the aortic branch arteries, effectively reconstruct the blood supply of the branch arteries, and avoid prolonged ischemia of the branch arteries. The operation is easy, does not require customization, and can be used for emergency treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of a covered stent according to an embodiment of the present invention, including a main stent, branch stents and an internal covered membrane;

[0018] Figure 2 for Figure 1 A schematic diagram of the main stent structure in the stent graft is shown;

[0019] Figure 3 for Figure 1 A schematic diagram of the connected inscribed membrane and branch stent in the stent graft is shown;

[0020] Figure 4 for Figure 1 A schematic diagram of the inscribed membrane structure in the stent graft is shown;

[0021] Figure 5 for Figure 4 A side view of the inscribed coating is shown;

[0022] Figure 6 Shown Figure 1 A top view of the stent graft is shown, with some structures omitted;

[0023] Figure 7 This is a partial structural diagram of a stent graft according to another embodiment of the present invention;

[0024] Figure 8 This is a partial structural diagram of a stent graft according to another embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram of the stent graft of the present invention after being implanted into an aneurysmal vessel;

[0026] Figure 10 This is a schematic structural diagram of a stent graft according to an embodiment of the present invention, including a window support;

[0027] Figure 11 for Figure 10A schematic structural diagram of the window support shown;

[0028] Figure 12 for Figure 11 A partial structural diagram of a window support shown;

[0029] Figure 13 Schematic diagram of the outline of a window support of a stent graft according to another embodiment of the present invention;

[0030] Figure 14 for Figure 13 A simplified cross-sectional profile diagram of the stent graft shown;

[0031] Figure 15 This is a schematic structural diagram of a window support member of a stent graft according to an embodiment of the present invention;

[0032] Figure 16 for Figure 15 An enlarged schematic diagram of a local structure of a window support member is shown;

[0033] Figure 17 This is a schematic structural diagram of a window support of a stent graft according to another embodiment of the present invention;

[0034] Figure 18 This is a schematic diagram of the branch stent structure of a stent graft according to an embodiment of the present invention;

[0035] Figure 19 To include Figure 18 A side view of the stent graft of the branch stent is shown;

[0036] Figure 20 This is a schematic diagram of the branch stent structure of a stent graft according to another embodiment of the present invention;

[0037] Figure 21 To include Figure 20 A side view of the stent graft of the branch stent is shown;

[0038] Figure 22 This is a schematic diagram of the branch stent structure of a stent graft according to another embodiment of the present invention;

[0039] Figure 23 To include Figure 22 A side view of the stent graft of the branch stent is shown;

[0040] Figure 24 This is a partial structural diagram of a stent graft according to an embodiment of the present invention;

[0041] Figure 25 for Figure 24 A schematic diagram of a partial structure of the stent graft shown;

[0042] Figure 26Schematic diagram of the inscribed film before and after stretching;

[0043] Figure 27 This is a partial structural diagram of a stent graft according to an embodiment of the present invention, including a reinforcement member;

[0044] Figure 28 for Figure 27 Several variations of the reinforcement are shown. DETAILED DESCRIPTION

[0045] In order to better understand the concept of the present invention, the following detailed description of the embodiments of the present invention is given in conjunction with the accompanying drawings. The following specific embodiments are only some embodiments of the present invention and are not intended to limit the present invention.

[0046] For the coated stent of the present invention, the end where blood flows in is defined as the "proximal end", and the end where blood flows out is defined as the "distal end", that is, when in use, blood flows from the proximal end to the distal end of the coated stent.

[0047] Example 1

[0048] like Figure 1 As shown, the stent graft 10 of this embodiment is a hollow tubular structure with openings at both ends, including a main stent 11, a branch stent 12, an internal stent graft 14 and a window support 15. Among them, the surface of the main stent 11 is provided with a window 13, and the edge of the internal stent graft 14 is connected to the main stent 1; the window support 15 is provided on the surface outside the internal stent graft 14 and protrudes outward from the internal stent graft 14. A through hole is opened on the internal stent graft 14, and the through hole is connected to the inner cavity of the stent graft 10; as shown in FIG. Figure 3 As shown, branch stent 12 is a hollow cylindrical structure, disposed within stent graft 10 and communicating with the through-holes in internal graft 14, thereby allowing blood to flow through branch stent 12 and into the branched vessels. In this embodiment, stent graft 10 includes three branch stents 12, two of which are disposed proximal to window 13, and one branch stent 12 is disposed distal to window 13.

[0049] like Figure 2 As shown, the main body bracket 11 includes a main body support member 111 and a main body covering 112, and the main body support member 111 is arranged on the surface of the main body covering 112. It should be understood that the main body support member 111 can be arranged on the inner surface of the main body covering 112, or on the outer surface of the main body covering, or a part of the main body support member is arranged on the outer surface of the main body covering, and the other part of the main body support member is arranged on the inner surface of the main body covering.

[0050] The window 13 is formed on the main body coating 112, and is formed in the middle of the main body coating 112, that is, between the end of the window 13 and the end of the main body support 11, there are a main body support 111 and a main body coating 112. In this embodiment, the edge of the window 13 formed on the main body coating 112 is rectangular, that is, when the main body coating 112 is unfolded along a busbar that does not pass through the window, the window 13 is rectangular; the window 13 has a first edge 131, a second edge 132, a third edge 133 and a fourth edge 134, and the four edges enclose the window 13. Among them, the first edge 131 and the second edge 132 are opposite and consistent with the length extension direction of the coating support 10, and the third edge 133 and the fourth edge 134 are opposite and closer to the end of the coating support 10 relative to the first edge 131 and the second edge 132. It is understood that in other embodiments, the window may have other shapes, as long as the first and second edges extend along the length of the stent graft, for example, they may be at a certain angle to the length of the stent graft (e.g., the window is trapezoidal), or the first and second edges are arc-shaped (similar to an elliptical window). The present invention does not limit the specific shape of the window. It is also understood that the window may be close to the proximal end of the stent graft or close to the distal end of the stent graft.

[0051] like Figure 1 and Figure 4 As shown, the coated support 10 of this embodiment includes an internal coating 14, and the edge of the internal coating 14 is connected to the edge of the window. Specifically, the internal coating 14 includes a bottom 141 and a folding portion 142, and the folding portion 142 is provided at the end of the bottom 141. The folding portion 142 is provided on the inner surface of the main support, and the folding portion 142 is recessed toward the inner cavity of the main support 11 to form a receiving cavity 144. The receiving cavity 144 has an upper edge 143, and the upper edge 143 is connected to the third edge 133 of the window 13. Specifically, the folding portion 142 includes an upper folding unit 1421 and a lower bottom unit 1422 connected to the bottom 141, and the sides of the upper folding unit 1421 and the lower bottom unit 1422 are connected and together enclose to form the receiving cavity 144.

[0052] It is understandable that in other embodiments, the edge of the inscribed film may also be connected to the inner surface of the main body film.

[0053] like Figure 5 As shown, the internal graft 14 is further provided with a through hole 147 communicating with the inner lumen of the main stent. Through hole 147 is opposite the opening of the graft 10 and the opening of the receiving cavity 144. Since the folded portion is provided with the receiving cavity, a guidewire or catheter can be extended along the receiving cavity into the branch stent when establishing the implantation path for the bridging stent, thereby quickly establishing the implantation path for the bridging stent and shortening the surgical procedure.

[0054] See again Figure 4 In this embodiment, the internal covering film 14 is provided with two folded portions 142 (including a proximal folded portion and a distal folded portion, respectively, located at the proximal and distal ends of the internal covering film). Both folded portions 142 are provided with through-holes 147, with the proximal folded portion 142 having two through-holes and the distal folded portion 142 having one through-hole. In this embodiment, the folded portions are formed by folding the end of the internal covering film 14 back in half, specifically by folding the end of the internal covering film 14 away from the bottom 141 and toward the inner surface of the main frame 11. It is understood that the structures of the two folded portions in this embodiment can be identical or slightly different.

[0055] When the covered stent of the present invention is used for curved blood vessels, in order to reduce the tension of the internal covering due to adapting to the curvature of the blood vessel, the angle between the extension direction of the braided wire of the internal covering and the length extension direction of the covered stent can be set to be greater than 0 degrees.

[0056] It is understood that in other embodiments, the inscribed coating may only have a folded portion at the proximal end, and the number of through holes may be 1 to 3. In the present invention, the position and number of the branch stents 12 correspond to the position and number of the through holes. That is, when one end of the inscribed coating is provided with multiple through holes, the same number of branch stents 12 is correspondingly provided at this end of the inscribed coating. The through holes may be staggered or arranged on the same cross-section perpendicular to the central axis of the stent graft.

[0057] It can also be understood that, in other embodiments, the folded portion with the receiving cavity can be separately manufactured into a pocket-shaped structure with the receiving cavity and then connected to the bottom and the window edge respectively.

[0058] It is also understandable that in other embodiments, only one folded portion may form the receiving cavity, and the other folded portion may simply be an inclined surface transitioning from the bottom to the inner surface of the main frame. Of course, in this case, a through hole may still be provided on this inclined surface. It is also understandable that the through hole may also be provided on the bottom.

[0059] In this embodiment, the internal covering 14 and the main covering 112 are formed separately and then connected by sutures. In other embodiments, the two can also be connected by adhesive bonding or other means. Because the internal covering is also provided with a branch bracket, the internal covering and the main covering can be formed separately and then connected, which greatly reduces the manufacturing difficulty. It is understood that in other embodiments, when the internal covering does not have a folded portion and a branch bracket, the internal covering can also be formed integrally with the main covering.

[0060] Back again Figure 4 and Figure 5In this embodiment, the inner cavity of the folded portion 142 (i.e., the size of the receiving cavity) gradually decreases from the opening position toward the through hole 147 (i.e., gradually decreases toward the opening of the end of the coated stent). In this way, when the bridging stent is implanted, the guide wire can be more quickly selected into the branch stent along the receiving cavity 3.

[0061] Back again Figure 1 and Figure 2 The window 13 of the stent graft 10 is also provided with a window support 15. The window support 15 has an arched cross-section and is positioned above the inscribed graft 14, protruding outward from the surface of the inscribed graft 14. In this embodiment, the window support 15 is integrally formed with a portion of the main body support 111. That is, the window support 15 is a part of the main body support 111. During manufacture, a window is first formed in the main body graft, and then the main body support 111 is connected to the main body graft. The portion of the main body support 111 where the window is exposed constitutes the window support. Preferably, the window support in this embodiment has a smaller circumferential proportion than the main body support. That is, on the same cross-section, the proportion of the window support to the cross-sectional circumference is smaller than the proportion of the main body support to the cross-sectional circumference. This ensures that the inner lumen size of the main body stent is not excessively reduced at the location where the inscribed graft is positioned, thereby preventing hemodynamics within the aorta. It is understood that in other implementations, the circumferential proportion of the window support can be equal to or greater than that of the main body support.

[0062] like Figure 6 As shown, the window support 15 of this embodiment includes a plurality of support segments 151, the plurality of support segments 151 are axially spaced and distributed, and the support segments 151 are connected to the main support 11 in the circumferential direction ( Figure 6 Only part of the structure of the main support is shown). In this embodiment, the support segment 151 includes a plurality of Z-shaped structures connected end to end, and the Z-shaped structure has crests and troughs, and the axial distance between the crests and the troughs is the wave height of the Z-shaped structure. In order to better implant the bridging stent into the branch stent to cooperate with it and minimize the interference and obstruction of the window support to the bridging stent, in the window support 15 of this embodiment, the distance between the crest of the support segment 151 near the third edge 133 of the window and the third edge 133 is preferably 10 to 20 mm. This ensures that when the bridging stent is implanted, it is not necessary to specifically select between the trough of the support segment 151 and the third edge 133. Similarly, the distance between the trough of the support segment near the fourth edge of the window and the fourth edge can also be selected as 10 to 20 mm. It is understandable that in other embodiments, when the bridging stent can be accurately selected to be placed between the trough of the support segment and the third edge, the distance between the crest of the support segment near the third edge of the window and the third edge can also be not limited. At this time, the wave height of the support segment can be preferably 6 to 12 mm. in, Figure 6Reference numeral 01 indicates some optional placement locations for the bridging stent. In other embodiments, the implantation location of the bridging stent can be optimized by changing the wave height of the support segments. For example, the wave height of the support segments near the third edge and / or the fourth edge can be set to be higher than the wave height of other support segments. Alternatively, a support segment with a higher wave height can be set at the location where the bridging stent is to be placed, not limited to the support segments near the third edge and the fourth edge.

[0063] It can be understood that in other embodiments, the two adjacent support segments near the through hole of the internal coating have an inverted structure, that is, in the two adjacent support segments, the crest of one support segment and the trough of the other support segment are opposite, so that when selecting the implantation position of the bridging stent, the position between the relative crest and trough can be selected.

[0064] like Figure 6 As shown, in this embodiment, the third edge 133 of the window 13 is located between the window support 15 and the main body support 111, and the upper edge 143 of the folded portion 142 is connected to the third edge 133. In this case, to maintain a good opening shape of the folded portion 142, a reinforcement member can be provided on the opening of the folded portion 142. For example, stitching can be added or removed on the upper edge 143 to appropriately reduce the deformation capacity of the upper edge 143. It is understood that in other embodiments, the third edge can also partially overlap with the main body support or window support (i.e., the support section partially covers the third edge of the window). In this case, the opening edge (i.e., the upper edge) of the receiving cavity also partially overlaps with the main body support or window support. In other words, on a plane parallel to the bottom of the inscribed coating, the projections of the third edge and the upper edge of the receiving cavity both overlap with the main body support or window support. In this case, the main body support or window support also serves to support the opening of the receiving cavity of the folded portion, acting as a reinforcement member. It is also understandable that in other embodiments, reinforcement members may be provided separately, which will be described in detail later.

[0065] In other embodiments, Figure 7As shown, the stent graft may further include a connector 252 positioned above the window 23, and the plurality of support segments 251 are connected by the connector 252. Furthermore, the proximal and / or distal ends of the connectors 252 may extend to the main support member 211 to connect thereto. The connectors 252 are preferably connected to the crests of adjacent support segments 251. More preferably, when the stent graft is implanted in a curved vessel, the connectors are positioned directly on the greater curvature of the stent graft. In this embodiment, the connector 251 is a connecting rod, and its length extends in the same direction as the stent graft. It is understood that in other embodiments, the connector may only connect to the support segments of the window support and not extend to the main stent. The connector may be made of a medical-grade metal material, such as superelastic nickel-titanium wire or medical stainless steel wire. The connector and support segments may be connected by crimping or welding. It is understood that in other embodiments, the connector may also be angled relative to the length of the stent graft. By setting up connectors, the mutual interference between the support segments can be reduced, while avoiding the shortening of the stent and improving the overall support performance of the window support. It can also ensure that when the coated stent is used in a curved blood vessel, due to the limitation of the connector, the crest of the support segment 251 will not be raised, and it can better adapt to the curved shape of the blood vessel.

[0066] In other embodiments, Figure 8 As shown, the connector 352 may include multiple segments 353, two adjacent segments 353 are staggered, and two adjacent support segments are connected by a segment 353. In this case, the segment 353 can be connected to any position of the two adjacent support segments, and preferably the extension direction of the segment 353 is consistent with the extension direction of the stent graft. Of course, multiple segments can also be staggered, which is equivalent to Figure 7 The connector shown includes multiple segments. When the connector includes multiple segments arranged in a staggered manner, the selection of the insertion site of the bridging stent is more flexible, and the bridging stent after implantation has a better matching shape with the branch vessel.

[0067] like Figure 9As shown, the covered stent 10 of the present invention can be used for the intracavitary treatment of aortic arch aneurysms and the treatment of thoracic and abdominal aortic aneurysms. Since the covered stent 10 of the present invention is provided with a window support on the window, it can provide good radial support force, especially when used to treat dissecting aneurysms, even if the true cavity is small, the covered stent 10 can provide good radial support force before the bridging stent 100 is implanted. In particular, when the covered stent 10 of the present invention is used for curved blood vessels, after the covered stent 10 adapts to the curved shape of the blood vessel, due to the presence of the window support, the space between the window and the blood vessel wall will not be excessively squeezed, thereby retaining sufficient selection space for the implantation of the bridging stent 100. In addition, the blood supply of the branch vessels can be always maintained before the bridging stent 100 is implanted, and the probability of ischemic complications after surgery is greatly reduced, while providing doctors with ample operating time.

[0068] Example 2

[0069] like Figure 10 As shown, the structure of the stent graft 40 of this embodiment is substantially the same as that of the stent graft 10 of the first embodiment, except for the window support 45. The window support 45 of this embodiment is formed separately, and the main body support 411 opposite the window support 45 is an open structure. In other words, the support members of the other parts of the main body are closed annular structures, while the main body support 411 opposite the window support 45 is not a complete annular structure.

[0070] like Figure 11 and Figure 12 As shown, the window support 45 of this embodiment includes a plurality of support segments 451, and the plurality of support segments 451 are connected to the edge of the main support window 43, and the plurality of support segments 451 are connected by hooking with each other, thereby forming a mesh structure with meshes 456. The mesh structure includes a portion formed by weaving braided wires, and the intersections of the braided wires form the vertices of the meshes 456. The vertices of the meshes 456 are formed by the braided wires through mutual pressure or mutual hanging, so that the intersections of the braided wires are movable. Therefore, the size of the mesh can be changed by external force. For example, when the bridging stent is implanted, the outer diameter of the sheath of the conveyor is larger than the mesh. At this time, the size of the mesh can be enlarged under the squeezing of the sheath, or when the outer diameter of the implanted bridging stent is larger than the size of the mesh, the braided wire will not squeeze the bridging stent, and can also fix the position of the bridging stent to a certain extent, thereby increasing the stability of the bridging stent against blood flow impact after implantation.

[0071] like Figure 12As shown, two adjacent support segments 451 are connected by mutual hanging, that is, the crest of one support segment 451 is hooked and connected to the trough of another adjacent support segment 451. The height h of a single support segment 451 ranges from 6 to 20 mm, and the distance L0 between adjacent crests or troughs of a single support segment 451 is between 10 and 25 mm, which can ensure that the space is not too small when the bridging stent is implanted. There is a certain distance h0 between the crests and troughs of the two support segments 451 that are hooked to each other, and the distance is between 0 and 5 mm. In this way, a certain stretching distance can be left between adjacent support segments. When the coated stent of this embodiment is implanted into a curved blood vessel, the window support is oriented toward the larger curved side, so that there can be a certain stretching margin between the multiple support segments 451, and the coated stent can better adapt to the curved blood vessel.

[0072] Preferably, in the circumferential direction, the same support segment 451 includes two overlapping support rings, thereby forming a diamond-shaped mesh in the mesh structure, which also enhances the wall-adherence and support of the window support to a certain extent. It is understood that in other embodiments, the same support segment may include multiple overlapping support rings. The more support rings, the smaller the mesh size. Therefore, the number of overlapping support rings on the same support segment is preferably 2 to 4.

[0073] In this embodiment, the window support 45 partially overlaps the main body covering of the main frame to facilitate suturing of the window support. Furthermore, the window support near the opening of the folded-over receiving cavity also serves as a reinforcement, ensuring a good opening shape. It is understood that in other embodiments, the window support may not overlap the main body covering at all, in which case direct suturing with sutures is also possible.

[0074] It can also be understood that in other embodiments, the sum of the cross-sectional circumference of the window support and the cross-sectional circumference of the corresponding main body support is greater than the circumference of the coating on the cross-section, that is, the window support and the main body support are partially overlapped in the circumferential direction. In this way, the wall adhesion of the first and second edges of the window and the supporting force of this part can be appropriately enhanced, and the coating support is not easy to collapse.

[0075] In this embodiment, the window support 45 transitions naturally with the surface of the main support, that is, basically, any cross section of the stent graft 40 is substantially equal.

[0076] like Figure 13 and Figure 14As shown, in other embodiments, a sinking section 554 is formed on the surface of the window support 55, and the sinking section 554 is closer to the inscribed film than other parts of the window support 55, so that the cross-sectional area of ​​the film support where the sinking section 554 is located is smaller than the cross-sectional area of ​​other parts of the film support away from the sinking section 554. A transition section 555 and a connecting section 556 are further provided at both ends connected to the sinking section 554, wherein the transition section 555 is an inclined surface and is arranged between the sinking section 554 and the connecting section 556, and the connecting section 556 is connected to the main support and is within the same curved surface as the outer surface of the main support. It is understandable that in other embodiments, the connecting section may not be included, in which case the other end of the transition section is directly connected to the main support; or, in other embodiments, the transition section is a vertical surface. When the window support of the covered stent has a sunken section, after the covered stent is implanted into a curved blood vessel, the deformation of the window support is small and the compression by the vascular wall on the large bend side of the blood vessel is relatively small, thereby reducing the reaction force of the window support on the blood vessel wall, resulting in better long-term effects after reconstruction of the diseased blood vessel and less prone to secondary rupture and other problems.

[0077] In other embodiments, the window support and the opposite main body support may be integrally woven. In this case, the weaving density of the window support may be controlled to be greater than that of the opposite main body support. This improves the conformability of the stent graft as a whole (particularly where the window is provided) while also improving the wall adhesion at the first and second edges of the window. Of course, in other embodiments, the window support and the opposite main body support may be woven separately, with the weaving density of the window support being greater than that of the opposite main body support.

[0078] Example 3

[0079] The structure of the stent graft of this embodiment is substantially the same as that of the stent graft of the second embodiment, except for the window support 65. Figure 15 and Figure 16 As shown, the window support 65 of this embodiment is formed by cross-weaving of braided wires 657, and the mesh 656 has a diamond structure. When forming the mesh 656, adjacent braided wires overlap each other to form a movable intersection, so that the four vertices of the mesh 656 can be movable, and the range of motion is larger than the range of motion of the movable intersection formed by the mutual hanging method. Therefore, this embodiment does not have too many restrictions on the size of the mesh. Even if the mesh size is small, it can adapt to the implantation of the bridging stent and stabilize the bridging stent. In addition, the window support of this embodiment does not have a structure similar to a crest or trough except for the end. When the coated stent of this embodiment is used for a curved blood vessel, it will cause less stimulation to the blood vessel.

[0080] like Figure 17As shown, in other embodiments, the window support 75 may include at least two support segments 751, and adjacent support segments 751 are connected by hooking each other, and each support segment may be formed by cross-weaving of braided wires, that is, Figure 15 At this time, since the adjacent support segments 751 are connected by hooking with each other, there can be a certain stretch margin between the adjacent support segments 751, and the covered stent can better adapt to curved blood vessels.

[0081] Example 4

[0082] In the first embodiment, the branch stent is a hollow cylindrical structure. The branch stent of the stent graft of this embodiment is as follows. Figure 18 As shown. Specifically, the branch bracket 82 includes a first section 822 and a second section 821 connected to one end of the first section 822, wherein the first section 822 is a cylindrical structure, the second section 821 is a truncated cone structure, and both ends of the branch bracket 82 have openings connected to its inner cavity. The opening of the first section 822 is larger than the opening of the second section 821, and the outer diameter of the second section 821 gradually decreases as it extends from the opening toward the first section 822 (that is, the first section 821 is a flared section). Figure 19 As shown, on a cross section perpendicular to the central axis of the coated stent, the projection of the first section 822 falls within the projection of the second section 821. When the branch stent 82 of this embodiment is arranged between the proximal end of the window and the proximal end of the coated stent (that is, when the branch stent 82 is connected to the proximal through hole of the internal coating), the end of the first section 822 opposite to the second section 821 is connected to the folded portion of the internal coating, and the end of the second section 821 opposite to the first section 822 is a free end, that is, the first section 822 is the proximal section of the branch stent, and the second section 821 is the distal section of the branch stent. Conversely, when the branch stent 82 of this embodiment is arranged between the distal end of the window and the distal end of the coated stent, the first section 822 is the distal section of the branch stent, and the second section 821 is the proximal section of the branch stent.

[0083] The branch stent 82 of this embodiment has a first section in the shape of a truncated cone, and a second section with a larger opening is connected to the through hole of the internal coating, so that when the branch is selected, the guide wire or conveyor can more easily enter the branch stent, and the bridging stent can be implanted more quickly.

[0084] It is understood that in other embodiments, the branch bracket 92 may also be an open structure. Figure 20 and Figure 21As shown, branch stent 92 is a sheet-like structure with an arcuate surface, and its cross-sectional profile is C-shaped. The two edges between the proximal and distal ends of branch stent 92 are connected to the inner surface of the main stent. Thus, the space enclosed by branch stent 92 and the inner surface of the main stent constitutes the inner cavity of branch stent 92. Because there is no additional coating between the inner cavity of branch stent 92 and the inner surface of the main stent, this portion of the material is reduced, thereby reducing the overall thickness of this portion of the coated stent, and correspondingly reducing the difficulty of assembly of the coated stent.

[0085] In other embodiments, when two bridging stents need to be placed at one end of the inner covering, the branch stent can also be used. Figure 22 The structure shown in FIG. 1 is that one end of the branch bracket has an opening and the other end has two openings. Figure 22 and Figure 23 The branch stent 102 is an overall hollow tubular structure, comprising a first section 1021 and a second section 1022. The end of the first section 1021 distal to the second section 1022 has a single opening, while the end of the second section 1022 distal to the first section 1021 has two openings. The end of the first section 1021 distal to the second section 1022 is connected to the internal graft, while the end of the second section 1022 distal to the first section 1021 is free. This allows for the implantation of two bridging stents while maintaining only one branch stent connected to the internal graft. This prevents internal leakage between the branch stent openings caused by suturing.

[0086] It can be understood that in other embodiments, the extension direction of the branch stent arranged at the distal end of the internal coating can be at a certain angle to the length extension direction of the coated stent, and the angle is greater than 0 degrees; or, the branch stent connected to the distal end of the internal coating can extend toward the central axis of the coated stent, thereby facilitating the implantation of the supra-arch branch vessel bridging stent and reducing the degree of bending of the bridging stent.

[0087] Example 5

[0088] The structure of the stent graft of this embodiment is similar to that of the first embodiment, except that the graft is internally connected. Figure 24 As shown, a support unit 116 is provided on the inscribed coating 114, and the support unit 116 makes the bottom of the inscribed coating at least partially parallel to the plane where the first edge and the second edge of the window are located, or protrudes outward from the plane, or is concave relative to the plane.

[0089] like Figure 25As shown, in this embodiment, the support unit 116 includes a suture. The suture starts at a position adjacent to the first edge of the window on the main covering, passes through the upper and lower surfaces of the inner covering 114 to the second edge of the window, and then bypasses the second edge to be fixed to the main covering 1112 of the main stent. In other words, the suture wraps around the inner covering and the edge of the main covering adjacent to the second edge and the first edge of the window. The suture material can be a polymer material or a metal material, preferably a thin flexible wire material, so as not to affect the compression loading of the coated stent.

[0090] During suturing, the suture is passed from the inner surface of the main body covering to the outer surface of the main body covering, then bypasses the edge of the main body covering, passes through the inner covering from the upper surface to the lower surface of the inner covering, and then passes the needle back and forth on the inner covering. Next, the suture passes from the inner surface of the inner covering to the outer surface near the second edge, and then bypasses the main body covering and the edge of the inner covering, passes through the main covering from the outer surface to the inner surface of the main covering, thus completing a section of circumferential suturing.

[0091] As the sutures are threaded back and forth across the upper and lower surfaces of the inner covering, multiple suture points are formed on the surface of the inner covering. To minimize the impact of the sutures on the guidewire approach prior to implantation of the bridging stent, the suture points should be spaced appropriately. Preferably, the distance L2 between two adjacent suture points is less than 2 mm, and the distance L3 between the suture points on the inner covering 114 closest to the first or second edge of the window is also less than 2 mm. The distance L4 between the suture points on the main covering 1112 and the first or second edge of the window is also less than 2 mm.

[0092] In addition, the support unit 116 enhances the overall stability of the inscribed film 114 and reduces the deformation capability of the bottom of the inscribed film 114. Figure 26 As shown, the axial length of the inscribed coating 114 in its natural state is designated as L5. The length of the inscribed coating 114 when stretched (e.g., when the stent graft is used in a curved vessel) is designated as L6. The elongation θ is the ratio of the length change of the inscribed coating 114 before and after stretching to the length in its natural state. The presence of the support unit 116 limits the deformation of the inscribed coating 114. In this embodiment, the elongation of the inscribed coating is less than 0.1 and greater than 0.01. This allows the inscribed coating to adapt to curved vessels without tearing, while also preventing excessive deformation and collapse.

[0093] It is understandable that in other embodiments, the support unit of the inscribed coating may also be a corrugated support structure similar to the main body support unit, that is, the support unit is separately formed and then connected to the surface of the inscribed coating by sewing or heat treatment. Alternatively, the support unit may also be woven integrally with the window support. Since the corrugated support structure has a certain wave height (i.e., axial length), the support unit has better integrity, and has better support for the inscribed coating and effect of limiting deformation. It is understandable that the support unit may also be integrally formed with the main body support, or a part of the support unit may be integrally formed with the main body support, and a part of the support unit may be integrally formed with the window support. Alternatively, a part of the support unit may be integrally formed with the main body support, and a part of the window support may be integrally formed with the main body support.

[0094] Preferably, the bottom of the inscribed membrane is convex or flat, so as to ensure that the inner cavity size of the main stent at the position where the inscribed membrane is provided is not too small, thereby not affecting the hemodynamics in the aorta.

[0095] In this embodiment, the inscribed film and the main body film are also formed separately and then spliced ​​together. In this way, it is more convenient to manufacture when the support unit is provided on the inscribed film.

[0096] It is understood that, to accommodate the opening shape of the inscribed stent graft's folded portion, the opening of the folded portion can be slightly concave. In other words, the folded portion is closer to the central axis of the stent graft than the bottom portion, and the support unit can be located only at the bottom portion of the inscribed stent graft. Because the axial length of the folded portion is significantly shorter than that of the bottom portion, even if the folded portion is concave, it will not affect the blood flow dynamics within the main stent lumen.

[0097] Example 6

[0098] The structure of the stent graft of this embodiment is substantially the same as that of the stent graft of the second embodiment, except for the reinforcement of the folded portion. Figure 27 As shown, the stent graft of this embodiment includes a reinforcement member 127, and the reinforcement member 127 is arranged at the upper edge 1243 of the folded portion. In this embodiment, the reinforcement member 127 is a separate closed structure, which is arranged around the opening of the folded portion to support the opening of the folded portion and reduce the deformation capacity of the opening. The reinforcement member 127 can be a corrugated structure similar to the main support member, or it can be a closed structure surrounded by a metal wire. Figure 28 As shown, when the reinforcement 127 is a closed structure, the part connected to the upper edge 1243 of the folded portion is an arc that adapts to the main support, and the part opposite thereto can be concave toward the central axis of the coated support, or can protrude outward from the central axis of the coated support, or be parallel to the central axis of the window and the coated support.

[0099] It is understood that in other embodiments, the reinforcement member can be a simple open structure, that is, the reinforcement member has two circumferential free ends or free edges. In this case, the projection of the reinforcement member on a cross section perpendicular to the central axis of the stent graft can be a curved surface or curve, or a plane or a straight line segment. In this case, the reinforcement member can be set at any section of the opening of the fold portion, that is, it can be set at the upper surface of the fold portion where the upper edge is located (i.e., the upper fold unit), or it can be set at the lower surface of the fold portion opposite the upper edge (i.e., the lower bottom unit), or it can span both the upper and lower surfaces.

[0100] It is also understandable that the reinforcement member may be formed separately, or may be formed integrally with the window support member, or may be formed integrally with the main body support member.

[0101] The above specific embodiments are only some embodiments of the present invention and are not limitations of the present invention. This specification cannot be an exhaustive list of all embodiments of the present invention. Some features of the above different embodiments can be replaced or combined with each other. Those skilled in the art can also make simple replacements according to actual needs. The concept of the present invention shall be subject to the required scope of protection.

Claims

1. A stent graft comprising a main body graft, wherein a window is formed on the surface of the main body graft, characterized in that: The window includes a first edge and a second edge extending along the length extension direction of the coated bracket, and the coated bracket also includes an inner coating, the edge of the inner coating is connected to the main coating, and the inner coating and the main coating are separately molded and then spliced ​​together; the inner coating includes a bottom and a folding portion located between the first edge and the second edge, the folding portion is arranged at the end of the bottom, and the folding portion is arranged on the inner surface of the main coating.

2. The stent graft according to claim 1, wherein: A support unit is provided on the inscribed coating, and the support unit enables the bottom to at least partially bulge outward or partially concave inward relative to the plane where the first edge and the second edge are located, or to be parallel to the plane.

3. The stent graft according to claim 2, wherein: The support unit includes a suture, and the suture passes around the first edge and the edge of the inner coating, passes through the upper and lower surfaces of the inner coating to the second edge, and then passes around the second edge and the other edge of the inner coating to connect the inner coating and the main support.

4. The stent graft according to claim 1, wherein: The elongation of the inscribed coating is greater than 0.01 and less than 0.

1.

5. The stent graft according to claim 2, wherein: The support unit includes a corrugated support structure connected to the surface of the inscribed coating.

6. The stent graft according to claim 5, characterized in that: The membrane-grafting support comprises a window support, which is arranged outside the inner membrane and protrudes outward from the surface of the inner membrane. The corrugated support structure and the window support are integrally formed.

7. The stent graft according to claim 2, wherein: The folding portion includes a proximal folding portion and a distal folding portion, and the proximal folding portion and the distal folding portion are respectively arranged at the two ends of the bottom, and at least one of the proximal folding portion and the distal folding portion is arranged on the inner surface of the main body coating; the support unit is arranged at the bottom, and the folding portion is closer to the central axis of the coating bracket than the bottom.

8. The stent graft according to any one of claims 6 or 7, characterized in that: A sinking section is formed on the surface of the window support, and the cross-sectional area of ​​the stent graft where the sinking section is located is smaller than the cross-sectional area of ​​other parts of the stent graft away from the sinking section.

9. The stent graft according to any one of claims 6 or 7, characterized in that: The coated bracket also includes a main body support member, which is connected to the main body coating. The window support member is a part of the main body support member, and on the same cross-section, the circumferential proportion of the window support member is smaller than the circumferential proportion of the main body support member.

10. The stent graft according to any one of claims 6 or 7, characterized in that: The window support comprises a mesh structure having meshes, and the size of the meshes can be changed by an external force.

11. The stent graft according to any one of claims 6 or 7, characterized in that: The proximal end and / or the distal end of the window support extends beyond the edge of the window in the length direction of the stent graft.

Images