bracket

Abstract

The present invention relates to a stent comprising a proximal segment, an intermediate segment, and a distal segment, wherein the intermediate segment is connected between the proximal segment and the distal segment, and the stent comprises a support member and a coating, wherein the support member is disposed on the surface of the coating, and in any cross-section perpendicular to the length direction of the stent, the coating is at least partially not disposed on the circumference of the intermediate segment. In the stent of the present invention, the cross-section of the intermediate segment is arc-shaped, and the second coating of the intermediate segment is located on one of the greater curvature side and the lesser curvature side, thereby reducing the overall volume of the stent while avoiding covering the intercostal arteries, thereby effectively reducing the risk of paraplegia.

Description

Technical Field

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

[0002] Although endovascular repair has been rapidly improving in recent years thanks to the joint efforts of numerous interventionalists both domestically and internationally, many challenges remain. For the treatment of aortic arch lesions, renal artery aneurysms / dissecting aneurysms, and particularly localized dissections or ulcers, as well as asymmetric aneurysms, a whole-section tubular stent graft is often implanted, with additional vascular prostheses implanted in areas without lesions. This can lead to complications such as paraplegia. Furthermore, changes in vascular hemodynamics or restenosis are more common at bends and corners, potentially due to occlusion of intercostal arteries by the added vascular prosthesis.

[0003] Especially when reconstructing curved blood vessels, general vascular stents are prone to forming angled areas in the transition area. These angled areas have the following disadvantages: at the bends, the stent is severely stretched and deformed on the large bend side. At the large corners, it is continuously stretched and prone to rupture. The small bend side is compressed and continuously axially compressed, forming small protrusions (folds) that affect blood flow. After a long period of pulsation, the deformed alloy wire will fatigue and fracture, and thrombus will form in the protruding coating area, causing stenosis, resulting in poor treatment effect or even failure. Summary of the Invention

[0004] The present invention provides a stent, comprising a proximal segment, a middle segment and a distal segment, wherein the middle segment is connected between the proximal segment and the distal segment, and the stent comprises a support member and a coating, wherein the support member is arranged on the surface of the coating, and in any cross-section perpendicular to the length direction of the stent, the coating is not arranged on at least part of the circumference of the middle segment.

[0005] In one embodiment, the support is a sheet-shaped body, and the outline of any cross section is an arc.

[0006] In one embodiment, the proximal segment and / or the distal segment comprises a circumferential closed structure comprising the support member and the membrane, and the circumferential closed structure is arranged away from the middle segment.

[0007] In one embodiment, the support member includes a closed annular structure, and the coating is arranged along the circumference of the closed annular structure and only covers a portion of the closed annular structure.

[0008] In one embodiment, the middle section has a bending angle θ, and the bending angle θ has a value range of 0 degrees < θ < 180 degrees.

[0009] In one embodiment, the stent includes a greater curvature side and a lesser curvature side that are circumferentially connected, and the coating located in the middle section is arranged on the greater curvature side or the lesser curvature side.

[0010] In one embodiment, the support member includes a wave ring structure, the wave ring has a wave number, the wave number of the wave ring located in the proximal section is M, the wave number of the wave ring located in the middle section is n, and 1.5n≤M≤2n.

[0011] In one embodiment, the cross-sectional profile of the proximal segment is an arc, and the central angle corresponding to the arc is greater than or equal to 180 degrees.

[0012] In one embodiment, the stent includes two side edges extending along the length direction of the stent, the two side edges are located on both sides of the middle section, and the two side edges gradually approach each other as they extend toward the distal end.

[0013] The stent of the present invention is provided with a middle section that is not covered by a membrane, thereby reducing the overall volume of the stent and avoiding covering the intercostal arteries, thereby effectively reducing the risk of paraplegia. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is a schematic structural diagram of a bracket according to Example 1;

[0016] Figure 2 for Figure 1 A schematic diagram showing a state where a stent is implanted in an aortic arch;

[0017] Figure 3 is a schematic structural diagram of a bracket according to another embodiment;

[0018] Figure 4 Schematic diagram of a stent in an expanded state according to one embodiment;

[0019] Figure 5 This is a schematic structural diagram of a bracket according to Example 2;

[0020] Figure 6 for Figure 5 A schematic top view of the stent in an expanded state is shown;

[0021] Figure 7 for Figure 5A schematic diagram showing a state where a stent is implanted in an aortic arch;

[0022] Figure 8 This is a schematic structural diagram of a bracket according to Example 3;

[0023] Figure 9 for Figure 8 A schematic diagram showing a state where a stent is implanted in an aortic arch;

[0024] Figure 10 This is a schematic structural diagram of a bracket according to Example 4;

[0025] Figure 11 for Figure 10 A schematic top view of the stent in an expanded state is shown;

[0026] Figure 12 for Figure 10 A schematic diagram showing a state where a stent is implanted in an aortic arch;

[0027] Figure 13 This is a schematic structural diagram of a bracket according to Example 5;

[0028] Figure 14 for Figure 13 A schematic diagram showing a state where a stent is implanted in an aortic arch;

[0029] Figure 15 This is a schematic structural diagram of a bracket of Example 6. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate positions or state relationships based on the positions or state relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0033] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0034] The present invention defines blood flow as flowing from the proximal end to the distal end of the stent. Taking a curved blood vessel as an example, the side with a longer bending radius is the larger bend side, and the side with a shorter bending radius is the smaller bend side. Alternatively, for the stent, the side that is compressed during bending or the side with a smaller bending radius is the smaller bend side, and the side that is stretched or the side with a larger bending radius is the larger bend side.

[0035] Example 1

[0036] See Figure 1 As shown, a stent 40 according to one embodiment of the present invention includes a proximal segment 401, an intermediate segment 403, and a distal segment 402. The proximal end of the intermediate segment 403 is connected to the distal end of the proximal segment 401, and the distal end of the intermediate segment 403 is connected to the proximal end of the distal segment 402. The stent 40 has a bending angle of θ in the intermediate segment 403, with 0°≤θ≤180°. At this point, the stent 40 forms opposing greater and lesser curvatures.

[0037] In this embodiment, a support member and a coating are provided on one side of the stent 40 close to the greater curvature of the blood vessel. The support member is provided on the surface of the coating, thereby enclosing a flow cavity of the stent 40. The middle section has an open structure, and on any cross section perpendicular to the length direction of the stent, at least part of the circumference of the middle section is not coated, so that the part of the flow cavity of the stent 40 located in the middle section is connected to the outside, that is, on any cross section of the middle section, the coating is open, not closed.

[0038] It should be noted that the proximal segment 401, the middle segment 403, and the distal segment 402 may have distinct boundaries or may be formed integrally without distinct boundaries. For ease of description, the structure of the stent 40 is divided into the proximal segment 401, the middle segment 403, and the distal segment 402. Specifically, the structure of the three segments of the stent 40 is not restricted, as long as the three segments form corresponding greater and lesser curvatures. When implanted in a curved blood vessel, the greater curvature of the stent 40 is positioned adjacent to the greater curvature of the vessel, while the lesser curvature of the stent 40 is positioned adjacent to the lesser curvature of the vessel.

[0039] For ease of understanding, in a plane perpendicular to the longitudinal center axis of the bracket 40, the plane located at the connection between the middle section 403 and the proximal section 401 is used as the proximal end face of the middle section 403, and the plane located at the connection between the middle section 403 and the distal section 402 is used as the distal end face of the middle section 403. The angle between the proximal end face and the distal end face of the middle section 403 is the bending angle θ of the middle section 403.

[0040] The bending angle θ can also be determined as follows: on any generatrix of the stent 40, there is a connection point between the middle segment and the proximal segment, or between the middle segment and the distal segment. A tangent line is drawn through each of these two connection points, and a perpendicular line is drawn through each of these two connection points, perpendicular to the two tangent lines. The angle formed by the intersection of these two perpendicular lines is the bending angle θ of the middle segment. Therefore, it can be understood that when the bending angle of the middle segment is 0° < θ < 180°, the generatrix located in the middle segment can be a single arc, or it can include multiple arcs with different central angles and / or radii.

[0041] The bending angle of the bracket in this embodiment ranges from 0°≤θ≤180°. When θ=0°, the middle section 403 is not bent, that is, the bracket 40 is a straight cylinder; when the bending angle ranges from 0°<θ<180°, it indicates that the bracket 40 is a curved bracket; when θ=180°, it indicates that the bracket 40 is a semicircular arch.

[0042] In this embodiment, the stent 40 is a sheet-like body, and the outline of any cross-section of the stent 40 is an arc. The open end surface 404 of the proximal segment 401 is arc-shaped. This end surface 404 extends along the curved direction (from A to B) to the distal segment 402, forming two side edges 405 and 406 extending along the length of the stent, and a sheet-like surface, which constitute the overall outline of the stent 40. It is understood that the outline of the stent 40 can also be viewed as the circumferential extension of the side edges 405 or 406 using the outline of the end surface 404 as a guide.

[0043] The proximal section 401 includes a first coating 4011 and a first support member 4012. The first support member 4012 is disposed on the surface of the first coating 4011 and forms the proximal sidewall of the stent 40. The thickness of the proximal sidewall forms the end surface at the proximal end of the stent 40, which serves as the open end surface 404 of the proximal section 401. The first support member 4012 includes a plurality of corrugated rings arranged along the length of the stent 40. The corrugated rings can be Z-shaped, V-shaped, Y-shaped, or U-shaped, without limitation.

[0044] The middle section 403 includes a second support member 4031 and a second coating 4032. The second support member 4031 is disposed on the surface of the second coating 4032, forming the middle sidewall of the stent 40. Within this middle sidewall, the side AB with the shorter bending radius is defined as the lesser curvature of the stent 40, while the side CD with the longer bending radius is defined as the greater curvature of the stent 40. The second support member 4031 includes multiple convolutions arranged along the length of the stent 40. The bending angle θ of the middle section 403 can adapt to the angle of the blood vessel to a certain extent.

[0045] When the wire diameters and wave heights of the first and second support members are equal, the wave number n of each wave loop in the middle section 403 and the wave number M of the wave loop in the proximal section 401 preferably maintain the following relationship: 1.5n≤M≤2n. With this structural arrangement, the proximal section 401 closely contacts the blood vessel, and the middle section 403 has fewer waves than the proximal section 401, resulting in less radial force and making it easier to navigate curved blood vessels.

[0046] Correspondingly, the distal segment 402 may also adopt a similar structural form to the proximal segment 401 , so that the wave turns of the middle segment 403 are fewer than those at the two ends of the stent 40 , so that the stent 40 can better cross the curved blood vessels.

[0047] The distal section 402 includes a third support member 4021 and a third coating 4022. The third support member 4021 is disposed on the surface of the third coating 4022 to form the distal sidewall of the stent 40. The third support member 4021 includes a plurality of corrugations arranged along the length of the stent 40.

[0048] The central angle of the arc of the cross section of the proximal segment 401 is greater than or equal to 180°, so as to ensure that the stent 40 is relatively stable after implantation and is not prone to displacement.

[0049] It should be noted that the aforementioned support members may be provided only on the inner surface of the graft, or only on the outer surface of the graft, or on both the inner and outer surfaces of the graft, as long as the stent can effectively seal the rupture or isolate the aneurysm at the corresponding location. Preferably, adjacent support members are connected to each other to improve the continuity of the support members, ensure a smooth transition of the stent, and enhance wall adhesion.

[0050] It should be understood that the drawings in this specification only schematically illustrate some of the support members of the bracket. Multiple support members can be provided along the length direction of the bracket, and the specific structures of the multiple support members can be the same or different. The distances between adjacent support members can be equal or different. Those skilled in the art can choose according to actual needs, and the present invention does not impose any restrictions.

[0051] It is also understandable that the first, second and third coatings can be integral structures or split structures, that is, the proximal segment, middle segment and distal segment can be integrally formed or separately formed and then connected together.

[0052] like Figure 2 As shown, stent 40 is implanted in aortic arch 10. Blood flows through stent 40 in inflow direction 601 and outflow direction 602. Under the impact of the blood flow, stent 40 adheres to the inner surface of the blood vessel. Stent 40 adheres to the lesion located on the greater curvature of the vessel, effectively sealing the lesion. This reduces excess implant material on the lesser curvature of the vessel and preserves the intercostal artery 603 on the opposite side of the aneurysm lesion, leaving it uncovered. This reduces the risk of paraplegia and prevents wrinkles on the lesser curvature of the stent.

[0053] Furthermore, in other embodiments, the stent may be provided with a coating and support member only on the side closest to the lesser curvature of the vessel, to accommodate lesions on the lesser curvature of the vessel. Furthermore, when the stent's bending angle is 0° < θ < 180° (i.e., the stent is designed as a curved stent), wrinkles in the coating can be avoided when the stent is applied to curved vessels.

[0054] In some embodiments, the stent 40 can be stably fixed inside the blood vessel by oversizing the stent 40 itself (i.e., the outer diameter of the stent before implantation is larger than the inner diameter of the blood vessel, so that after implantation, the stent exerts an outward squeezing force on the blood vessel). For example, the oversize of the stent 40 is selected to be 15%-20% (i.e., the outer diameter of the stent before implantation, when not subject to external forces, is 15%-20% larger than the inner diameter of the blood vessel). Alternatively, in other embodiments, the oversize of the stent 40 is selected to be 5%-10%.

[0055] It should be understood that the stent of the present invention is particularly suitable for treating non-vascular lesions, such as dissections or ulcers, and some asymmetric tumors. Therefore, there is no need to implant too much implant material in areas where no lesions exist. It is preferred that the central angle corresponding to the arc profile of the cross-section of the middle section is not greater than 180 degrees, so as to reduce the implant material while achieving the treatment purpose as much as possible.

[0056] like Figure 3As shown, in other embodiments, the stent 40 may also be straight and can be used to treat local aneurysms or ruptures of the thoracic and abdominal aorta, thereby reducing the introduction of implant materials.

[0057] In other embodiments, the bracket 40 is roughly a rectangular structure after being unfolded, and in a top view after being unfolded, the two side edges are parallel to each other.

[0058] It should be noted that, in other embodiments, the cross-sectional dimensions of the bracket 40 may also be a gradual structure, such as Figure 4 As shown, in the top view after deployment, the opposing side edges 405 and 406 are not parallel. The top view after deployment can be either a right trapezoid or an inverted trapezoid, preferably an inverted trapezoid, where the two sides gradually approach each other as they extend toward the distal end. As long as the anchoring force of the proximal end of the stent 40 implant is guaranteed, the central angle corresponding to the arc of the cross section of the proximal end section 401 is preferably greater than or equal to 180°. This will ensure that the stent 40 is more stable after implantation and less likely to shift.

[0059] It is also understandable that in other embodiments, after the bracket 40 is unfolded, the two side edges may also be arc-shaped.

[0060] It should be noted that the membrane used in the stent 40 can be made of ePTFE or PTFE material, or can also be made of PET material.

[0061] Example 2

[0062] like Figure 5 As shown, the stent 70 of this embodiment includes a proximal section 701, a distal section 702 and a middle section 703. The proximal section 701 includes a first support member 7012 and a first coating 7011. The first support member 7012 is provided on the surface of the first coating 7011.

[0063] The proximal segment 701 of this embodiment differs from the proximal segment 401 of the stent 40 of Example 1 in that the proximal segment 701 includes a complete circumferentially closed structure. The length of the circumferentially closed structure of the proximal segment 701 is L1, i.e., the length of the cylindrical portion of the proximal segment 701 extending along the longitudinal center axis of the stent is L1, preferably L1 ≥ 10 mm. This portion corresponding to L1 is thus anchored at the starting position, i.e., at the proximal end of the blood vessel. After the stent is implanted in the vessel, the circumferentially closed structure adheres to the inner wall of the vessel, thereby enhancing the anchoring force between the proximal segment 701 and the vessel wall. This prevents the stent 70 from shifting after being anchored to the vessel wall.

[0064] The distal segment 702 and the middle segment 703 of the stent are similar to those in Example 1, and both have arcuate cross-sectional profiles. It should be noted that the proximal segment 701 may also include a portion with an arcuate cross-sectional profile. This portion may be located at the proximal end of the proximal segment or at the distal end of the proximal segment, thereby connecting to the proximal end of the middle segment. Preferably, the circumferential closed structure is located away from the middle segment to minimize bending and wrinkling of the stent near the middle segment.

[0065] Similar to Example 1, in this embodiment, the bending angle θ of the stent 70 in the middle section 703 is selected from the range of 0°≤θ≤180°. In this embodiment, the bending angle θ of the middle section 703 is determined in a similar manner as in Example 1. When defining the generatrix, the circumferentially closed portion of the proximal section can be excluded.

[0066] The middle section 703 includes a second support member 7031 and a second coating 7032. The second support member 7031 is disposed on the surface of the second coating 7032 to form the middle sidewall of the stent 70. In this middle sidewall, the side A1B1 with a shorter bending radius is defined as the smaller curvature side of the stent 70, and the side C1D1 with a longer bending radius is defined as the larger curvature side of the stent 70.

[0067] The distal segment 702 includes a third support member 7021 and a third coating 7022 . The third support member 7021 is disposed on the surface of the third coating 7022 to form a distal side wall of the stent 70 .

[0068] like Figure 6 As shown, the bracket 70 of this embodiment is roughly a T-shaped structure when unfolded.

[0069] Combine Figure 7 As shown, after stent 70 is implanted in aortic arch 10, blood flows through stent 70 in inflow direction 801 and outflow direction 802. Stent 70 adheres to the lesion site, effectively isolating the lesion. Furthermore, stent 70 reduces the amount of implanted material on the lesser curvature of the vessel, thereby preserving the intercostal arteries 803 and leaving them uncovered, reducing the risk of paraplegia.

[0070] In some embodiments, the stent 70 can be stably fixed inside the blood vessel by oversizing the stent 70. For example, the oversizing of the stent 70 can be set to 15%-20%. Alternatively, in other embodiments, the oversizing of the stent 70 can be set to 5%-10%.

[0071] As can be seen from the stents provided in Examples 1 and 2, the unilateral design of the middle section of the stent reduces the overall volume of the stent, making it easier to compress the stent into the delivery sheath. Furthermore, it facilitates manufacturing. By selecting different wave heights of the second support member, stents of varying specifications and bending angles can be designed to accommodate vessels with varying degrees of curvature.

[0072] Example 3

[0073] Compared with Example 1, the stent of Example 3 is different in that the distal segment includes a complete circumferential closed structure.

[0074] Specifically, if Figure 8 As shown, a stent 90 provided in Example 3 includes a proximal segment 901 , a distal segment 902 and a middle segment 903 .

[0075] The distal segment 902 includes a circumferentially closed structure, and the proximal end surface 9011 of the proximal segment 901 located at the proximal end of the stent 90 is arc-shaped.

[0076] In this embodiment, the proximal section 901 includes a first support member 9013 and a first coating 9012. The first support member 9013 is disposed on the surface of the first coating 9012 to form the proximal sidewall of the stent 90. The first support member 9013 includes a plurality of corrugations arranged along the length of the stent 90.

[0077] The bending angle of the bracket 90 in the middle section 903 is θ, and the value range of θ can be selected as 0°≤θ≤180°. In this embodiment, the method for determining the bending angle θ of the middle section 903 is similar to that in Example 1. When defining the busbar, the circumferentially closed part of the distal section can be excluded.

[0078] The middle section 903 includes a second support member 9031 and a second coating 9032. The second support member 9031 is disposed on the surface of the second coating 9032 to form the middle sidewall of the stent 90. In this middle sidewall, the side A1B1 with a shorter bending radius is defined as the smaller curvature side of the stent 90, and the side C1D1 with a longer bending radius is defined as the larger curvature side of the stent 90.

[0079] The distal segment 902 includes a third support member 9022 and a third coating 9021. The third support member 9022 is disposed on the surface of the third coating 9021. The distal segment 902 includes a circumferentially closed structure. The length of the circumferentially closed structure of the distal segment 902 is L2, that is, the length of the cylindrical portion of the distal segment 902 extending along the length of the stent is L2. The circumferentially closed structure of the distal segment 902 has a certain length. After the stent is implanted in a blood vessel, the circumferentially closed structure adheres to the inner wall of the vessel to enhance the anchoring force between the stent and the vessel wall, thereby preventing the stent 90 from shifting after being anchored to the vessel wall.

[0080] It should be noted that, in some embodiments, the length of the circular cross-section of the distal segment 902, i.e., L2 ≥ 10 mm, so that the portion corresponding to the length L2 is anchored at the end position, i.e., at the distal end of the blood vessel, to increase the anchoring force.

[0081] The proximal segment 901 and the middle segment 903 of the stent 90 are similar to those in Example 1, and their cross-sectional profiles are arcuate. It should be noted that the distal segment 902 may also include a portion with an arcuate cross-sectional profile, which may be located at the distal end of the distal segment or at the proximal end of the distal segment, thereby connecting to the distal end of the middle segment.

[0082] Combine Figure 9 As shown, after stent 90 is implanted in the aortic arch 10, blood flows through stent 90 in inflow direction 1001 and outflow direction 1002. Stent 90 adheres to the lesion site, effectively isolating the lesion. Furthermore, stent 90 reduces the amount of implanted material on the lesser curvature of the vessel, thereby preserving the intercostal arteries 1003 and leaving them uncovered, reducing the risk of paraplegia.

[0083] In some embodiments, stent 90 can be stably fixed inside the blood vessel by oversizing the stent 90. For example, in some embodiments, the oversizing of stent 90 is set to 15%-20%. Alternatively, in other embodiments, the oversizing of stent 90 is set to 5%-10%.

[0084] Example 4

[0085] like Figure 10 As shown, the stent 11 provided in this embodiment 4 includes a proximal segment 111 , a distal segment 112 and a middle segment 113 .

[0086] The proximal segment 111 and the distal segment 112 are respectively connected to the proximal end and the distal end of the middle segment 113. The proximal segment 111 includes a first coating 1111 and a first support 1112 disposed on the surface of the first coating 1111. The middle segment 113 includes a second coating 1132 and a second support 1131 disposed on the surface of the second coating 1132. The distal segment 112 includes a third coating 1121 and a third support 1122 disposed on the surface of the third coating 1121.

[0087] Among them, the structure of the proximal segment 111 is similar to the structure of the proximal segment 701 of the stent 70 in Example 2. The proximal segment 111 includes a circumferential closed structure, and its length is L3, 30mm≥L3≥10mm. Then, the part of the circumferential closed structure of the proximal segment 111 has a certain length, and has a good wall-adhering anchoring effect with the blood vessel wall, so as to enhance the anchoring force between the proximal segment 111 of the stent 11 and the blood vessel wall, so that the stent 11 is not easily displaced after being anchored to the blood vessel wall.

[0088] The structure of the distal segment 112 is similar to the structure of the distal segment 902 of the stent 90 in Example 3. Specifically, the distal segment 112 includes a circumferential closed structure with a length of L4, 30mm≥L4≥10mm. The circumferential closed structure of the distal segment 112 has a certain length and has a good wall-adhering anchoring effect with the blood vessel wall, so as to enhance the anchoring force between the distal segment 112 of the stent 11 and the blood vessel wall, so that the stent 11 is not easily displaced after being anchored to the blood vessel wall.

[0089] In this embodiment 4, the structure of the middle section 113 is similar to that of embodiments 1 to 3, and will not be described again here.

[0090] like Figure 11 As shown, the bracket 11 of this embodiment is roughly I-shaped when unfolded.

[0091] like Figure 12 As shown, after the stent 11 is implanted in the aortic arch 10, blood flows through the stent 11 from the inflow direction 121 and out from the outflow direction 122. The stent 11 adheres to the lesion site, achieving the effect of blocking the lesion. In addition, the stent 11 itself can be oversized to ensure that the stent 11 can be stably fixed inside the blood vessel. For example, in some embodiments, the oversize of the stent 11 is selected to be 15%-20%. Alternatively, in other embodiments, the oversize of the stent 11 is selected to be 5%-10%.

[0092] In this embodiment 4, since both the proximal segment 111 and the distal segment 112 include a circumferential closed structure, after the stent is implanted into the blood vessel, the circumferential closed structure fits against the inner wall of the blood vessel, thereby effectively improving the anchoring force of the proximal and distal ends of the stent 11 on the blood vessel wall. At the same time, it also reduces excess material on the lesser curvature side, thereby preserving the intercostal artery 123, so that the intercostal artery 123 is not covered, reducing the risk of paraplegia.

[0093] Example 5

[0094] The difference between Example 5 and Example 4 is that the structure of the coating on the greater curvature side of the stent 11 of Example 4 is adjusted to the lesser curvature side, that is, the middle section of this embodiment is provided with a support member and a coating on the side close to the lesser curvature side of the blood vessel, and at least no coating is provided on the side close to the greater curvature side of the blood vessel.

[0095] Specifically, if Figure 13 As shown, this embodiment 5 provides a stent 13 including a proximal segment 131 , a distal segment 132 and a middle segment 133 .

[0096] The skeleton and coating structure of stent 13 are similar to those of stent 11 in Example 4. The proximal segment 131 includes a circumferentially closed structure, and the length of proximal segment 131 is L5. The preferred range of L5 is 30 mm ≥ L5 ≥ 10 mm. The distal segment 132 includes a circumferentially closed structure, and the length of distal segment 132 is L6. The preferred range of L6 is 30 mm ≥ L6 ≥ 10 mm.

[0097] The middle section 133 is connected between the proximal section 131 and the distal section 132, and the cross-section of the middle section 133 is an arc. In this embodiment, the coating and support members of the middle section 133 are located on the lesser curvature of the stent 13. After the stent 13 is implanted in a blood vessel, the middle section 133 adheres to the lesser curvature of the blood vessel.

[0098] In some embodiments, the bending angle of the bracket 13 in the middle section 133 is θ1, and the value range of θ1 is 0°≤θ1≤180°. The method for determining the bending angle θ1 of the middle section 13 in this embodiment is similar to that in Example 1. When defining the busbar, the circumferentially closed parts of the proximal section and the distal section can be excluded.

[0099] like Figure 14 As shown, when a tumor develops on the lesser curvature of the aorta, stent 13 is implanted in the aortic arch 14. Blood flows through stent 13 in inflow direction 141 and outflow direction 142. Stent 13's oversize allows it to be fixed to the inner surface of the blood vessel. After implantation, stent 13 adheres to the lesion 143 on the lesser curvature, effectively sealing the lesion.

[0100] Since the proximal segment 131 and the distal segment 132 are provided with a circumferential closed structure, after the stent is implanted into the blood vessel, the circumferential closed structure fits against the inner wall of the blood vessel, thereby effectively improving the anchoring force of the proximal and distal ends of the stent 13 on the blood vessel wall. At the same time, the amount of implants on the greater curvature of the blood vessel is reduced, and the intercostal artery 145 and the left subclavian artery 144 located on the greater curvature are retained, so that the intercostal artery 145 and the left subclavian artery 144, an important branch of the arch, are not covered, thereby reducing the risk of paraplegia and complications.

[0101] It should be noted that in the stent 13 of this embodiment 5, the proximal segment 131 and the distal segment 132 include a circumferential closed structure. At least any one of them can be omitted. Without affecting the performance of the product, one of the proximal segment 131 and the distal segment 132 has a closed structure, which can improve the anchoring effect of the stent 13 in the blood vessel. It will not be repeated here.

[0102] Example 6

[0103] Combine Figure 15 As shown, similar to the structure of the stent 40 in Example 1, the stent 15 of Example 6 includes a proximal segment 151, a distal segment 152, and an intermediate segment 153. The proximal segment 151 includes a first coating 1512 and a first support member 1511 disposed on the surface of the first coating 1512, the intermediate segment 153 includes a second coating 1532 and a second support member 1531 disposed on the surface of the second coating 1532, and the distal segment 152 includes a third coating 1522 and a third support member 1521 disposed on the surface of the third coating 1522.

[0104] The middle section 153 is connected between the proximal section 151 and the distal section 152 and has a bending angle θ2. The value range of θ2 is 0°≤θ2≤180°. In this embodiment, the method for determining θ2 is similar to that in Example 1.

[0105] The stent 15 of Example 6 differs from the stent 40 of Example 1 in that the first support member 1512 of the proximal segment 151, the third support member 1521 of the distal segment 152, and the second support member 1531 of the intermediate segment 153 all comprise closed annular structures. The first coating 1512, the third coating 1522, and the second coating 1532 each cover only the portion located at the greater curvature of the support member, leaving the lesser curvature of the closed support member uncovered.

[0106] In this embodiment, since the support member of the stent 15 includes a closed ring structure, when the stent 15 is implanted in the aortic arch 10, the stent 15 can be anchored through the closed ring structure in the first support member 1512, the third support member 1521 and the second support member 1531. At the same time, the coating of each part will not completely cover the blood vessel openings of important organs, reducing the risk of paraplegia and complications.

[0107] It should be noted that, without affecting the performance of the product, in the bracket 15, the non-coated side can be designed to be on the large bend side, and the coating of each part can be set on the small bend side, which can still meet the usage requirements. It will not be repeated here.

[0108] In some embodiments, as long as one of the first support member 1512 of the proximal segment 151, the third support member 1521 of the distal segment 152, and the second support member 1531 of the middle segment 153 is a closed ring structure, stable anchoring with the blood vessel wall can be achieved.

[0109] It is understandable that in order to improve the overall support performance of the stent, those skilled in the art may further design the stent based on the above embodiments, for example, adding a support member on the side where no coating and support member are provided, or only providing a circumferentially closed support member on the circumferentially closed part of the proximal segment or distal segment, while the coating only covers part of the support member.

[0110] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A stent comprising a proximal segment, an intermediate segment, and a distal segment, wherein the intermediate segment is connected between the proximal segment and the distal segment, the stent comprising a support member and a coating, wherein the support member is disposed on a surface of the coating, characterized in that: On any cross section perpendicular to the length direction of the stent, at least a portion of the circumference of the middle section is not provided with the coating and the support member, and the middle section has two side edges extending along the length direction of the stent; Wherein, the bracket is a sheet-like body, and the outline of any cross section is an arc; Alternatively, the proximal segment and / or the distal segment comprises a circumferentially closed structure comprising the support member and the coating, and the circumferentially closed structure is arranged away from the middle segment.

2. The bracket according to claim 1, wherein: The covering film is made of ePTFE, PTFE or PET material.

3. The bracket according to claim 1, wherein: The support member includes a closed annular structure, and the covering film is arranged along the circumference of the closed annular structure and only covers a portion of the closed annular structure.

4. The bracket according to any one of claims 1 to 3, characterized in that The middle section has a bending angle θ, and the value range of the bending angle θ is 0 degrees < θ < 180 degrees.

5. The bracket according to claim 4, characterized in that The stent includes a greater curvature side and a lesser curvature side connected circumferentially, and the coating located in the middle section is arranged on the greater curvature side or the lesser curvature side.

6. The bracket according to claim 1, wherein: The support member includes a wave ring structure, the wave ring has a wave number, the wave number of the wave ring located in the proximal section is M, the wave number of the wave ring located in the middle section is n, and 1.5n≤M≤2n.

7. The bracket according to claim 6, characterized in that The shape of the wave ring is Z-shaped, V-shaped, Y-shaped or U-shaped.

8. The bracket according to claim 1, wherein: The cross-sectional profile of the proximal segment is an arc, and the central angle corresponding to the arc is greater than or equal to 180 degrees.

9. The bracket according to claim 1, wherein: The two side edges gradually approach each other as they extend toward the distal end.

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