Covered stent

Abstract

The invention provides a covered stent. The covered stent comprises a tubular main stent body, a branch stent body arranged on the side portion of the main stent body and a flexible connecting film connecting the main stent body and the branch stent body. An opening is formed in the tube wall of the main body stent, the maximum caliber of the opening is larger than the tube diameter of the branch stent, the flexible connecting film is connected with the opening and the branch stent and surrounds the opening and the branch stent by a circle in the circumferential direction, the branch stent and the main body stent are flexibly communicated through the flexible connecting film, and the connected flexible connecting film has the radial extension height. The proximal end of the branch stent is displaceable relative to the body stent within the opening. According to the covered stent, the flexibility of the branch stent of the covered stent is improved, so that the application range of the covered stent is expanded, and the operation difficulty and risk are reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a covered stent. BACKGROUND

[0002] Aortic aneurysm and aortic dissection are diseases that seriously endanger human life and safety at present. If not actively treated, the aortic aneurysm and dissection will continue to expand, and finally rupture, causing serious complications and death. With the continuous increase of patients with hypertension, hyperlipidemia and hyperglycemia, the incidence of aortic aneurysm and aortic dissection is also significantly increasing.

[0003] Traditional open surgery for aortic aneurysm and aortic dissection has the characteristics of large trauma, high mortality, long operation time, high incidence of postoperative complications and high surgical difficulty, while endovascular treatment has the characteristics of small trauma, fewer postoperative complications, short operation time and low surgical difficulty, and gradually becomes the main way to treat aortic aneurysm and aortic dissection at present. By implanting a stent in the aorta, the vascular lesions are isolated outside the stent, and the blood flow is constrained to flow through the inside of the stent, thereby achieving the purpose of protecting the blood vessels.

[0004] The single-branch stent in the existing stent has the advantage of one-piece design of the main stent and the branch stent, which makes the operation simpler, convenient to use, shortens the operation time, and is particularly suitable for aortic arch type B dissection. However, the anatomic morphology of the branches above the human body arch varies, such as the branch angle, the distance between the left common carotid artery and the left subclavian artery, and the relative position relationship of the branch length and the like, and the single-branch stent in the existing one-piece design is directly connected with the main stent, which limits the range of movement of the single-branch stent, making it difficult to adapt to the endovascular environment in different states, reducing the application range, and increasing the difficulty and risk of surgery, especially the difficulty of complex cases of complex lesions. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a covered stent to improve the flexibility of the branch stent of the covered stent, thereby expanding the application range and reducing the difficulty and risk of surgery.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] The present application provides a covered stent, which comprises a tubular main stent, a branch stent arranged on the side of the main stent, and a flexible connecting film connecting the main stent and the branch stent; an opening is formed on the tube wall of the main stent, the maximum diameter of the opening is larger than the tube diameter of the branch stent, the flexible connecting film connects the opening and the branch stent and surrounds one circumferential turn of the opening and the branch stent, the branch stent is in flexible communication with the main stent through the flexible connecting film, and the flexible connecting film after connection has a radial extension height, so that the proximal end of the branch stent can be displaced relative to the main stent within the range of the opening.

[0008] In one of the embodiments, the circumferential turn of the flexible connecting film has an outer convex and / or an inner concave relative to the central axis of the branch stent.

[0009] In one of the embodiments, the circumferential turn of the flexible connecting film comprises an axially opposite proximal curved surface and a distal curved surface, and two side transition curved surfaces connecting the proximal curved surface and the distal curved surface; the distal curved surface has a redundant amount for the branch stent to bend from the proximal side to the distal side.

[0010] In one of the embodiments, the circumferential turn of the flexible connecting film has an outer convex relative to the central axis of the branch stent, the distal curved surface and the proximal curved surface are both convex relative to the central axis of the branch stent, and the distal curved surface is more convex relative to the central axis of the branch stent than the proximal curved surface.

[0011] In one of the embodiments, the branch stent comprises a branch skeleton, and the branch skeleton at least comprises a first branch wave ring located at the proximal end of the branch stent, the first branch wave ring is in a wave shape, and the first branch wave ring in the wave shape comprises a plurality of first branch wave valleys located on the proximal side.

[0012] In one of the embodiments, the wave height of the first branch wave ring at the position opposite to the proximal side of the main stent is smaller than the wave height of other regions in the circumferential direction, and the corresponding first branch wave valley is farther away from the proximal side, and the branch stent is biased to be closer to the proximal side of the main stent within the range of the opening.

[0013] In one of the embodiments, a fixing ring is fixedly arranged at the periphery of the opening on the main stent.

[0014] In one of the embodiments, the axial diameter of the opening is larger than the circumferential diameter of the opening, and the axial ring diameter of the fixing ring is larger than the circumferential ring diameter of the fixing ring.

[0015] The main body support comprises a main body framework and a main body covering connected with the main body framework, the main body framework comprises a first main wave ring located at a proximal end side and a second main wave ring located at a distal end side of the first main wave ring, the first main wave ring and the second main wave ring are both in a wave shape, the first main wave ring comprises at least one first main wave crest, and the second main wave ring comprises at least one second main wave trough, and the first main wave crest and the second main wave trough are axially opposite to each other.

[0016] The opening and the fixing ring located at the circumferential edge of the opening are located between the first main wave ring and the second main wave ring, and the two ends of the opening and the fixing ring in the axial direction are axially opposite to the first main wave crest and the second main wave trough respectively.

[0017] In one of the embodiments, the wave angle at the first main wave crest and / or the second main wave trough is larger than the wave angle at other wave crests and wave troughs in the same ring, and the two ends of the opening and the fixing ring in the axial direction respectively extend into the first main wave crest and / or the second main wave trough which are axially opposite to each other and have a larger wave angle.

[0018] In one of the embodiments, the flexible connecting line is further connected with the fixing ring and the first branch wave ring.

[0019] In one of the embodiments, the branch support further comprises a wave ring located at the proximal end side of the first branch wave ring, the branch support can move radially relative to the main body support under the action of an axial force and the flexible connecting membrane connected therewith is concave, so that the wave ring and at least part of the first branch wave ring extend into the main pipe cavity of the main body support, and the wave ring is closer to the central axis of the main pipe cavity than the first branch wave trough of the first branch wave ring.

[0020] In one of the embodiments, a notch is arranged on the wave ring, so that the wave ring is approximately C-shaped, and the notch is opposite to the proximal end side of the main body support.

[0021] The present application has the following advantages:

[0022] The flexible connecting membrane of the covering stent provided by the present application is connected with the opening with a larger diameter and the branch support with a smaller pipe diameter, and has a radial extension height, so that the proximal end side of the branch support can be displaced relative to the main body support within the opening, the displacement of the proximal end side of the branch support can make the branch support have a larger range of motion, the branch support can be freely and flexibly moved to match different vascular anatomical shapes, so as to achieve an efficient matching mechanism of a product with multiple uses, a wider application range, and greatly reduced surgical difficulty and risk. Meanwhile, the problem of the proximal end leakage of the main body support caused by the pulling of the main body support by the branch support due to the small adjustment range of the existing single-branch support is avoided. Attached Figure Description

[0023] The above and other objects, features, and advantages of the present invention will become clearer through a more detailed description of the preferred embodiments illustrated in the accompanying drawings. The same reference numerals denote the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this application.

[0024] Figure 1 This is a schematic diagram of the structure of an exemplary film-coated stent of the present invention;

[0025] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle;

[0026] Figure 3 This is a partial schematic diagram showing the movement of the branch support when the flexible connecting membrane of the scaffold covered with film is configured in a first manner, as exemplary by the present invention.

[0027] Figure 4 This is a partial schematic diagram of the second configuration of the flexible connecting membrane of the exemplary film-coated stent of the present invention;

[0028] Figure 5 for Figure 4 A partial schematic diagram of the branch support movement;

[0029] Figure 6 This is a schematic diagram illustrating the first configuration of the flexible connecting membrane of the embossed support, an exemplary embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram illustrating the second configuration of the flexible connecting membrane of the exemplary film-coated stent of the present invention.

[0031] Figure 8 This is an embodiment of the invention where the flexible connecting membrane of the covered stent has a redundancy on the distal side.

[0032] Figure 9 Another embodiment of the present invention, which provides redundancy on the distal side of the flexible connecting membrane of the covered stent, is provided.

[0033] Figure 10 This is a partial schematic diagram of the unfolded, exemplary film-coated stent of the present invention;

[0034] Figure 11 This is a schematic diagram of the branch stent of the endothelial stent, which is an exemplary embodiment of the present invention;

[0035] Figure 12 This is a schematic diagram of the structure of the branch support of the endothelial stent of the present invention when it is bent, which is an example of the present invention.

[0036] Figure 13This is a schematic diagram of the structure of the branch stent of the exemplary covered stent of the present invention when the proximal end is recessed into the main stent (a wave ring is provided at the proximal end of the branch stent);

[0037] Figure 14 This is a partial three-dimensional schematic diagram of the proximal end of the branch stent of the exemplary covered stent of the present invention recessed into the main stent (a corrugated ring is provided at the proximal end of the branch stent, and the corrugated ring has a notch). Detailed Implementation

[0038] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to the accompanying drawings.

[0039] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Typically, in the field of covered stents, after a covered stent is implanted into a blood vessel, the end from which blood flows in is defined as the "proximal end" and the end from which blood flows out is defined as the "distal end," meaning that blood flows from the proximal end of the covered stent to the distal end of the covered stent.

[0042] Please refer to Figure 1 and Figure 2 This invention provides an exemplary covered stent 100, which includes a tubular main stent 10, a tubular branch stent 20, and a flexible connecting membrane 30 connecting the main stent 10 and the branch stent 20. The proximal and distal ends of the covered stent 100 of this invention will be described using the aforementioned "proximal" and "distal" ends as examples, such as... Figure 1 , Figure 1 The left inlet (indicated by the arrow) of the main stent 10 is the proximal end of the main stent 10, and the right outlet (indicated by the arrow) is the distal end of the main stent 10. Blood flows into the branch stent 20 after entering from the proximal end of the main stent 10 and passing through the flexible connecting membrane 30. It then flows out from the free end (indicated by the arrow) of the branch stent 20, which is the distal end of the branch stent 20. The end opposite to the free distal end is the proximal end. The proximal end of the branch stent 20 is connected to the flexible connecting membrane 30.

[0043] Both the tubular main support 10 and the tubular branch support 20 can be radially compressed under radial external force and can self-expand after the external force is removed. Here, "radial" refers to the direction perpendicular to the axis of the tubular main support 10. Specifically, the branch support 20 is located outside the main support 10. Before connection, the branch support 20 is spaced apart outside the tube wall of the main support 10, with a certain radial distance between the proximal end of the branch support 20 and the outer tube wall of the main support 10. The tube wall of the main support 10 has at least one opening 10a, connecting the inner cavity of the main support 10 to the outside. The maximum diameter of the opening 10a is Wmax, which is greater than the tube diameter D1 of the branch support 20. The shape of the opening 10a can be arbitrary, such as circular, elliptical, spindle-shaped, rectangular, or triangular, but regardless of the shape, it must have a maximum diameter Wmax.

[0044] A flexible connecting membrane 30 connects the opening 10a and the branch support 20, which is spaced apart and located outside the main support 10. The proximal end of the flexible connecting membrane 30 is connected to the opening 10a of the main support 10, and the distal end of the flexible connecting membrane 30 is connected to the proximal end of the branch support 20. The flexible connecting membrane 30 wraps around the opening 10a and the branch support 20 in a circumferential direction. The branch support 20 and the main support 10 are flexibly connected through the flexible connecting membrane 30. After one circumference, the flexible connecting membrane 30 is a cylindrical shape with a diameter that is not entirely equal along its extension direction. The connected flexible connecting membrane 30 has a radial extension height. Here, "radial" refers to the direction perpendicular to the axis of the tubular main support 10. The flexible connecting membrane 30 of this invention connects a branch stent with a large-diameter opening and a small-diameter tube, and has its own radial extension height, allowing the proximal side of the branch stent 20 to shift relative to the main stent 10 within the opening 10a. This shifting of the proximal side of the branch stent 20 provides a large range of motion, allowing it to move freely and flexibly to match different vascular anatomy, achieving a highly efficient matching mechanism for multiple uses in one product, broadening its applicability, and greatly reducing surgical difficulty and risk. Simultaneously, it avoids the problem of proximal endoleak of the main stent caused by the branch stent pulling on the main stent due to the excessively small adjustment range of existing single-branch stents.

[0045] Please refer to Figures 1-7 As shown, the circumferential surface of the flexible connecting membrane 30, which is circumferentially connected in a ring, is convex outward and / or concave inward relative to the central axis of the branch support 20.

[0046] In one embodiment, please refer to Figures 1-3 as well as Figure 6As shown, the circumferential surface of the flexible connecting membrane 30, which forms a ring around the periphery, is concave relative to the central axis yy of the branch support 20. The proximal end of this concave curved surface connects to an opening 10a, and then extends distally towards the central axis yy of the branch support 20, with its distal end connecting to the proximal end of the branch support 20. This extended concave curved surface has a radial extension height h, as shown in the figure. Figure 3 As shown, the proximal side of the branch support 20 can be displaced relative to the main support 10 within the opening 10a. This displacement of the proximal side of the branch support 20 allows the branch support 20 to swing in multiple directions. Figure 3 The dashed line indicates the position of the branch support after it has swung.

[0047] In another embodiment, please combine Figure 4 , Figure 5 and Figure 7 As shown, the circumferential surface of the flexible connecting membrane 30, which forms a ring around the periphery, bulges outward relative to the central axis yy of the branch support 20. The proximal end of this bulging surface connects to an opening 10a, and then extends distally, with its distal end connecting to the proximal end of the branch support 20. This extended bulging surface also has a radial extension height h, as shown... Figure 5 As shown, the proximal side of the branch support 20 can be displaced relative to the main support 10 within the opening 10a. This displacement of the proximal side of the branch support 20 allows the branch support 20 to swing in multiple directions. Figure 5 The dashed line indicates the position of the branch support after it has swung.

[0048] In other embodiments, the circumferentially connected flexible connecting membrane 30 has a circumferentially convex portion relative to the central axis yy of the branch support 20, and another portion also convex relative to the central axis yy of the branch support 20, thus possessing both an outwardly convex curved surface and an inwardly concave curved surface (not shown). Similarly, the proximal side of the flexible connecting membrane 30 with the outwardly convex and inwardly concave curved surfaces is connected to the opening 10a, and then extends towards the distal side, with its distal end connected to the proximal side of the branch support 20. This extended flexible connecting membrane with both outwardly convex and inwardly concave curved surfaces also has a radial extension height h. Similarly, the proximal side of the branch support 20 can be displaced relative to the main support 10 within the range of the opening 10a, and the displacement of the proximal side of the branch support 20 can cause the branch support 20 to swing in multiple directions.

[0049] Please refer to Figure 8 and Figure 9To further facilitate the bending and sheathing of the branch support 20, in other embodiments, the circumferentially connected flexible connecting membrane 30 includes a proximal curved surface 31 and a distal curved surface 32 located axially on the proximal and distal sides of the main support 10, respectively, and two transition curved surfaces 33 connecting the proximal curved surface 31 and the distal curved surface 32. The proximal curved surface 31, the distal curved surface 32, and the two transition curved surfaces 33 enclose and form the outer peripheral surface of the flexible connecting membrane 30, wherein the proportion of each of the proximal curved surface 31, the distal curved surface 32, and the transition curved surface 33 to the outer peripheral surface of the flexible connecting membrane 30 can be set as needed. In this embodiment, the distal curved surface 32 has a redundancy that allows the branch support 20 to be bent and folded distally based on its proximal root. The redundancy of the distal curved surface 32 allows the branch support 20 to be as close as possible to the main support 10 when its free end bends around its proximal root towards the proximal side of the main support 10, without creating constraint or tension on the distal side. Simultaneously, there is minimal stacking on the proximal side, facilitating compression and reducing the overall outer diameter, thus making sheathing easier. Furthermore, this configuration further enhances the flexibility of the branch support 20. In the preferred configuration, this redundancy allows the branch support 20 to be parallel to the main support 10 after bending, with the distal curved surface 32 of the branch support stretched and straightened, without wrinkles or arches.

[0050] As one implementation method, such as Figure 8 As shown, the curved surface formed by the flexible connecting membrane 30 includes a proximal curved surface 31 and a distal curved surface 32, as well as two transition curved surfaces 33 connecting the proximal curved surface 31 and the distal curved surface 32. (The peripheral surface formed by the flexible connecting membrane 30 can be a convex curved surface, a concave curved surface, or a combination of convex and concave curved surfaces.) Figure 8 (Taking the convex curved surface as an example), the distal curved surface 32 has a stacked portion stacked along the extension direction of the flexible connecting membrane 30. This stacked portion allows the distal curved surface 32 to have a redundancy that allows the branch support 20 to be bent and folded toward the distal side based on its proximal root.

[0051] As another implementation method, such as Figure 9 As shown, the curved surface formed by the flexible connecting membrane 30 is a curved surface that convex outward relative to the central axis of the branch support 20. That is, both the distal curved surface and the proximal curved surface are curved surfaces that convex outward relative to the central axis of the branch support. The degree of convexity of the distal curved surface 32 relative to the central axis of the branch support 20 is greater than the degree of convexity of the proximal curved surface 31 relative to the central axis of the branch support 20. This results in a redundancy on the distal curved surface 32 that allows the branch support 20 to bend and fold towards the distal side based on its proximal root. In the arrangement of this embodiment, the branch support 20 can be offset from the center of the opening 10a, i.e., as shown... Figure 9As shown, the central axis yy of the branch support 20 is positioned closer to the proximal end relative to the radial axis xx passing through the center of the opening 10a. This allows the branch support 20 to be closer to the proximal end, resulting in a shorter proximal anchoring area L between the branch support 20 and the main support 10. This prevents the anchoring area L from being too long and blocking other branches on the bow, thus affecting the reconstruction of other branches. Furthermore, the method of locally increasing the protrusion in this embodiment, compared to increasing the protrusion entirely, effectively ensures the radial support force of the tubular flexible connecting membrane, avoiding closure due to insufficient radial support force.

[0052] In other embodiments, the flexible connecting membrane 30 connected in the circumferential direction is partially multi-layered in the circumferential direction. This partially multi-layered approach ensures the radial support force of the connected cylindrical flexible connecting membrane 30, preventing it from closing due to weak radial force. On the other hand, the part without multi-layered structure can reduce the constraint on the proximal root of the branch support, thus ensuring a larger range of motion for the branch support as much as possible.

[0053] See also Figures 1-9 Typically, the opening 10a is positioned near the proximal end of the main support 10, and there is a short anchoring area (e.g., at the top of the proximal end of the opening 10a, from the proximal end of the main support 10) Figure 1 As shown in segment L), when the branch stent 20 pulsates along its axial direction, it causes the membrane covering the proximal anchoring area of ​​the main stent 10 to pulsate synchronously along its axial direction. When the heart pulsates, blood flow may leak into the dissection rupture through the axial pulsation gap of the membrane in the proximal anchoring area of ​​the main stent 10, causing the dissection rupture sealing to fail. Therefore, based on any of the above embodiments, a fixing ring 10b is fixed at the periphery of the opening 10a on the main stent 10 of the covered stent 100 of the present invention. The fixing ring 10b provides a certain anchoring force, controlling the traction of the branch stent 20 as much as possible within the opening range, blocking the traction of the branch stent 20 on the membrane covering the proximal anchoring area of ​​the main stent 10 during pulsation, thereby ensuring the anchoring of the covered stent at the proximal end and preventing proximal leakage. Simultaneously, the fixing ring 10b located at the proximal end also provides a certain proximal sealing effect, forming a double seal with the wave ring on the proximal side of the main stent. Understandably, the shape of the retaining ring 10b can be adapted to the shape of the opening 10a. For example, the retaining ring 10b can also be circular, elliptical, spindle-shaped, rectangular, or triangular. Of course, the shapes of the retaining ring 10b and the opening 10a can also be different. Preferably, the retaining ring 10b is elliptical, with its two ends axially upward and positioned front and back respectively. The elliptical shape of the retaining ring 10b makes it easier to flatten and gather, facilitating sheath installation.

[0054] Preferably, the retaining ring 10b is made of tinfoil, but it is not limited to this. The retaining ring 10b is fixed to the periphery of the opening 10a. As one embodiment of fixation, the retaining ring 10b can be fixedly connected to the film at the opening 10a of the main support 10. The fixation connection method includes heat fusion, sewing, bonding, etc., and is not limited to these.

[0055] Continue to refer to Figure 1 The main support 10 of the film-coated support 100 of the present invention includes a main skeleton 11 and a main film 12 connected to the main skeleton 11. The main skeleton 11 has a tubular structure and provides support; it can be formed by cutting and / or weaving. The main film 12 can be single-layered or multi-layered. When single-layered, the main film 12 can be disposed on the inner or outer wall of the tubular main skeleton 11. When multi-layered, multiple main films 12 can be simultaneously disposed on the inner or outer wall of the tubular main skeleton 11, or partially disposed on the inner wall and partially on the outer wall. Preferably, the main film 12 is multi-layered, with some layers disposed on the inner wall and some on the outer wall. For example, two layers are disposed, one on the inner wall and one on the outer wall, with the main skeleton 11 positioned between the inner and outer films. When a fixing ring 10b is provided, the fixing ring 10b can be fixed between the inner and outer membranes at the periphery of the opening 10a.

[0056] The main frame 11 includes multiple wave-shaped coils, which are arranged sequentially along the axial direction of the main support 10. The multiple wave-shaped coils arranged sequentially along the axial direction are spaced apart or connected. Each wave-shaped coil includes multiple waveform units that are connected end to end in the circumferential direction. Each waveform unit includes a wave crest, a wave trough, and a wave rod connecting the wave crest and the wave trough.

[0057] Please combine Figure 1 and Figure 10The main frame 11 contains multiple wavy wave coil structures, including at least a first main wave coil 111 located on the proximal side and a second main wave coil 112 located on the distal side of the first main wave coil 111. Both the first main wave coil 111 and the second main wave coil 112 are wavy. The first main wave coil 111 includes at least a first main wave peak 111a, and the wavy second main wave coil 112 includes at least a second main wave trough 112b. The opening 10a is formed on the main body covering 12 between the first main wave coil 111 and the second main wave coil 112. Preferably, the first main wave peak 111a in the first main wave coil 111 and the second main wave trough 112b in the second main wave coil 112 are axially opposite each other. The opposite first main wave peak 111a and the opposite second main wave trough 112b create a large accommodating space between them. The opening 10a is formed on the main body covering 12 between the opposite first main wave peak 111a and the opposite second main wave trough 112b. Understandably, when the fixing ring 10b is set, the opening 10a and the fixing ring 10b located at the periphery of the opening 10a are located between the first main wave peak 111a and the second main wave valley 112b between the first main wave coil 111 and the second main wave coil 112, and the two ends of the opening 10a and the fixing ring 10b in the axial direction are respectively opposite to the first main wave peak 111a and the second main wave valley 112b.

[0058] In other embodiments, the wave angle at the first main wave crest 111a is greater than the wave angles at other wave crests in the same loop, such that the proximal ends of the opening 10a and the fixing ring 10b can extend into the first main wave crest 111a with a larger wave angle. And / or the wave angle at the second main wave trough 112b is greater than the wave angles at other wave troughs in the same loop, such that the distal ends of the opening 10a and the fixing ring 10b can extend into the second main wave trough 112b with a larger wave angle.

[0059] In one embodiment, such as Figure 10 As shown, the main frame 11 includes at least a first main wave coil 111 located on the proximal side among the multiple wave-shaped wave coil structures. The waveform of the first main wave coil 111 is smaller than that of the other main wave coils in the main frame 11. Compared with the other wave coils, the first main wave coil 111 has a smaller wave angle, lower wave height, and more waves, thus providing greater radial support force and achieving a good sealing effect. Simultaneously, the first main wave coil 111 includes at least one first main wave peak 111a. The first main wave peak 111a is located on the large bend side of the main support 10, and the wave angle α at the first main wave peak 111a is greater than the wave angle at other wave peaks in the same coil, which can be... Figure 10As shown, when increasing the wave angle α at the first main wave peak 111a, the wave angles of the two waves on the left and right sides of the first main wave peak 111a can be appropriately reduced. In this embodiment, both the opening 10a and the fixing ring 10b are elliptical, and the proximal ends of the opening 10a and the fixing ring 10b can be precisely fitted into the wave angle at the first main wave peak 111a. On the one hand, this achieves a better sealing effect at the proximal end of the double wave, and on the other hand, it does not bring more assembly difficulty to the mounting bracket sheath. The fixing ring formed by the tantalum wire has a relatively thinner wire diameter, and the elliptical shape is easier to flatten. Moreover, the head end of the elliptical shape is round, resulting in a smoother transition. In addition, this method can also provide more design space for the position of the branch bracket. Because of the presence of the first main wavelet loop (111), if the fixation ring (10b) cannot be designed to be embedded within the wavelet loop, the proximal port of the branch stent will have a certain distance from the fixation ring. In summary, this means the proximal port of the branch stent will be at least 10mm-15mm away from the proximal end of the graft. For patients undergoing single-branch reconstruction, i.e., when LSA reconstruction is required without intervention or occlusion of the LCCA, a sufficient and matching anchoring zone is necessary. The anchoring zone between the human LSA and LCCA is generally 4.0mm-11.0mm, with a median distance of approximately 6.5mm. Therefore, LCCA occlusion may be possible.

[0060] For details, see Figure 11 The branch support 20 of the covered support 100 of the present invention includes at least a branch skeleton 21. The branch skeleton 21 has a tubular structure and serves a supporting function. The branch skeleton 21 can be formed by cutting and / or weaving. The branch skeleton 21 includes multiple wave-shaped coils, which are arranged sequentially along the extension direction of the branch support 20. The multiple wave-shaped coils arranged sequentially in the axial direction are spaced apart or connected. Each wave-shaped coil includes multiple wave units connected end to end in the circumferential direction. Each wave unit includes a wave crest, a wave trough, and a wave rod connecting the wave crest and the wave trough. In other embodiments, the branch support 20 also includes a branch cover 22, which is connected to the branch skeleton 21. The branch cover 22 can be provided as a single layer or multiple layers. When provided as a single layer, the single-layer branch cover 22 can be provided on the inner or outer side wall of the tubular branch skeleton 21. When multiple layers are configured, the multi-layer branch coating 22 can be simultaneously disposed on the inner or outer sidewall of the tubular branch framework 21, or it can be partially disposed on the inner wall and partially disposed on the outer wall. Preferably, the branch coating 22 is configured in multiple layers, with some layers disposed on the inner wall and some layers disposed on the outer wall. For example, two layers are configured, with one layer disposed on the inner wall and one layer disposed on the outer wall, and the branch framework 21 is placed between the inner and outer layers. When the branch support 20 does not include the branch coating 22, multiple wave loops are sequentially connected to form an integral structure.

[0061] Continue to refer to Figure 11The branch frame 21 includes at least a first branch wavering structure 21 located at the proximal root of the branch support 20, among its multiple wavy wavering structures. The first branch wavering 21 includes multiple troughs 211b. In other embodiments, the branch frame 21 may also include a second branch wavering (not shown) located at the distal end of the first branch wavering 21. The first branch wavering 21 and the second branch wavering may be directly connected or indirectly connected.

[0062] like Figure 11 As shown, the local wave height in the first branch wave loop 21, opposite to the proximal side of the main support 10, is lower than the wave height in other areas of the circumference, and the wave trough 211b near the proximal side of the main support 10 is further away from the proximal side of the branch support 20, meaning the proximal end of the branch support 20 is designed to be lower in the front and higher in the back. See also Figure 11 and Figure 12 When the branch support 20 is folded and assembled, it can conform to the folded state and fit snugly against the main support, preventing the proximal front wave height of the branch support from sinking into the main body due to inward folding after folding, which could even lead to membrane rupture in severe cases. Figure 12 As shown by the dashed line, the dashed line represents the folded state of the first branch wave ring 21 of the branch bracket 20 when the wave height is set (a schematic diagram). Alternatively, the branch bracket 20 can be positioned closer to the proximal end within the opening 10a range.

[0063] See Figure 13 and Figure 14 In other embodiments, the branch stent 20 of the covered stent 100 of the present invention further includes a wave ring 23, which is disposed on the proximal side of a plurality of first branch wave valleys 211b of the first branch wave ring 21. The branch stent 20 can move radially relative to the main stent 10 under axial force and the flexible connecting membrane 30 connected thereto is concave, so that at least a portion of the wave ring 23 and the first branch wave ring 21 extends into the main lumen. The wave ring 23, which is connected to the proximal side of the first branch wave valley 211b, is closer to the central axis of the main lumen than the first branch wave valley 211b of the first branch wave ring 21. The arrangement of the wave ring 23 changes the contact with the tips of the plurality of first branch wave valleys 211b to the contact with the annular surface of the wave ring 23 during pulsation. During blood flow flushing, the flushing surface is annular, reducing the risk of membrane rupture caused by pulsation. In addition, the wave ring 23 also increases the radial support force of the branch stent 20 itself on the proximal side, preventing closure from forming on the proximal side of the branch stent 20.

[0064] Furthermore, such as Figure 14As shown, the wavering 23 has a notch 23a, making it approximately C-shaped, with the notch 23a facing the proximal end of the main support 10. On one hand, the wavering 23 with the notch 23a facilitates compression and sheathing; on the other hand, since the notch 23a is located on the proximal end of the main support 10, there is no need to consider the design space of the wavering at the notch, allowing the branch support 20 to be positioned as close as possible to the proximal end of the main support 10. Furthermore, when the branch support 20 bends towards the proximal end of the main support 10, it will not create obstruction on its proximal side.

[0065] In one embodiment, when the local wave height in the first branch wave ring 21 opposite to the proximal side of the main support 10 is lower than the wave height in other areas in the circumferential direction, and the wave trough 211b near the proximal side of the main support 10 is further away from the proximal side of the branch support 20 (i.e., the proximal end of the branch support 20 is designed to be lower in the front and higher in the back), the wave ring 23 can only be connected to the proximal side of a portion of the first branch wave trough 211b, and not connected to the local low wave opposite to the proximal side of the main support 10, i.e., the notch 23a is opposite to the proximal side of the main support 10. In summary, in this embodiment, the branch support 20 can be positioned as close as possible to the proximal side of the main support 10, forming annular contact, reducing the risk of membrane rupture, and improving the radial support of the proximal end of the branch support while making it easier to sheath.

[0066] When a fixed ring 10b is set, and the first branch wave loop 21 includes multiple first branch wave troughs 211b, further refer to... Figure 11 The film-coated support 100 of the present invention also includes a flexible connecting line 40, which connects the fixing ring 10b and multiple first branch valleys 211b of the first branch wave ring 21. For example, the connecting line 40 wraps around the fixing ring 10b and hooks onto the first branch valleys 211b, then wraps back around the fixing ring 10b, repeating this cycle circumferentially to further achieve a flexible connection between the main support 10 and the branch support 20, improving the reliability of the connection without restricting the range of motion of the branch support 20. Preferably, the connecting line 40 is connected to the flexible connecting membrane 30 along the extension direction of the flexible connecting membrane 30. For example, the flexible connecting membrane 30 is multi-layered, and the connecting line 40 can be disposed among the multiple layers of the flexible connecting membrane 30, achieving connection while simultaneously increasing the radial support force of the multi-layered flexible connecting membrane 30 after it forms a cylindrical shape.

[0067] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A covered stent, characterized by, The main body bracket comprises a tubular main body bracket and a branch bracket arranged on the side of the main body bracket, and a flexible connecting film connecting the main body bracket and the branch bracket; an opening is formed on the wall of the main body bracket, the maximum diameter of the opening is larger than the diameter of the branch bracket, the flexible connecting film connects the opening and the branch bracket, and surrounds one circumferential circle of the opening and the branch bracket, the branch bracket and the main body bracket are flexibly connected through the flexible connecting film, and the flexible connecting film after connection has a radial extension height, so that the proximal end of the branch bracket can be displaced in the opening range relative to the main body bracket.

2. The stent graft of claim 1, wherein, The circumferential surface of the flexible connecting film in one circumferential circle is convex and / or concave relative to the central axis of the branch bracket.

3. The stent graft of claim 2, wherein, The circumferential surface of the flexible connecting film in one circumferential circle comprises axially opposite proximal and distal curved surfaces, and two side transition curved surfaces connecting the proximal and distal curved surfaces; the distal curved surface has a redundant amount for the branch bracket to bend from the proximal side to the distal side.

4. The stent graft of claim 3, wherein, The circumferential surface of the flexible connecting film is convex relative to the central axis of the branch bracket, the distal curved surface and the proximal curved surface are both convex curved surfaces relative to the central axis of the branch bracket, and the degree of convexity of the distal curved surface relative to the central axis of the branch bracket is greater than that of the proximal curved surface.

5. The stent graft of claim 1, wherein, The branch bracket comprises a branch skeleton, the branch skeleton at least comprises a first branch wave ring located at the proximal end of the branch bracket, the first branch wave ring is in a wave shape, and the first branch wave ring in a wave shape comprises a plurality of first branch wave valleys located on the proximal side.

6. The stent graft of claim 5, wherein, The wave height of the first branch wave ring opposite to the proximal side of the main body bracket is smaller than that of other regions in the circumferential direction, and the corresponding first branch wave valley is farther away from the proximal side, and the branch bracket is biased to be closer to the proximal side of the main body bracket in the opening range.

7. The stent graft of claim 5, wherein, A fixing ring is fixedly arranged at the periphery of the opening on the main body bracket.

8. The stent graft of claim 7, wherein, The axial diameter of the opening is greater than the diameter in the circumferential direction, and the axial ring diameter of the fixing ring is greater than the ring diameter in the circumferential direction. The main body bracket comprises a main body skeleton and a main body film connected with the main body skeleton, the main body skeleton comprises a first main wave ring located on the proximal side and a second main wave ring arranged on the distal side of the first main wave ring, the first main wave ring and the second main wave ring are both in a wave shape, the first main wave ring at least comprises a first main wave peak, the second main wave ring at least comprises a second main wave valley, and the first main wave peak and the second main wave valley are axially opposite. The opening and the fixing ring arranged at the periphery of the opening are arranged between the first main wave ring and the second main wave ring, and the two ends of the opening and the fixing ring in the axial direction are axially opposite to the first main wave peak and the second main wave valley, respectively.

9. The stent graft of claim 8, wherein, The wave angle at the first main wave peak and / or the second main wave valley is greater than the wave angle at other wave peaks and wave valleys in the same turn, and the two ends of the opening and the fixing ring in the axial direction respectively extend into the first main wave peak and / or the second main wave valley opposite in the axial direction and having a greater wave angle.

10. The stent graft of claim 7, wherein, The flexible connecting line is further connected to the fixing ring and a plurality of the first branch wave valleys of the first branch wave turn.

11. The stent graft of any one of claims 5 to 10, wherein, The branch stent further comprises a wave ring arranged at the proximal side of the plurality of the first branch wave valleys; the branch stent is radially movable relative to the main stent under the action of an axial force and is accompanied by the inward concave of the flexible connecting membrane connected thereto, so that the wave ring and at least part of the first branch wave turn extend into the main pipe cavity of the main stent, wherein the wave ring is closer to the central axis of the main pipe cavity than the first branch wave valleys of the first branch wave turn.

12. The stent graft of claim 11, wherein, The wave ring is provided with a notch, so that the wave ring is approximately C-shaped, and the notch is opposite to the proximal side of the main stent.

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