Covered stent and stent system

Abstract

The application relates to a covered stent, which comprises a main stent and a branch stent, the main stent comprises a first side and a second side, the branch stent is located on the first side, the main stent comprises a first bare coil, a main coil and a main covering film, the main covering film is arranged on the main coil, the first bare coil is connected with the proximal end of the main covering film, the first bare coil comprises a foldable part, a supporting part and an axial positioning part in the circumferential direction; the foldable part is close to the first side, the axial positioning part is close to the second side, and the supporting part is connected between the foldable part and the axial positioning part; the proximal end of the main covering film is provided with a circumferential unfolding part, the circumferential unfolding part is arranged in the circumferential direction and corresponds to the supporting part, so that the main covering film does not limit the unfolding of the supporting part. The covered stent provided by the application is provided with the circumferential unfolding part corresponding to the supporting part in the circumferential direction at the proximal end of the main covering film, so that the main covering film does not limit the opening of the supporting part in the circumferential direction, and the foldable part is smoothly folded.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a covered stent and a stent system. 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 enlarge, eventually rupture, causing serious complications, and even leading to patient death. With the increasing number 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 involving branch vessels is traumatic, has a high mortality rate, takes a long time to operate, has a high incidence of postoperative complications, and is difficult to perform. Endovascular treatment has the characteristics of less trauma, fewer postoperative complications, shorter operation time and lower surgical difficulty, and has gradually become the main method for treating aortic aneurysm and aortic dissection. By implanting a covered stent in the aorta, the vascular lesion is isolated outside the covered stent, and blood flow is restricted from flowing through the inside of the covered stent, thereby achieving the purpose of protecting the blood vessel. The traditional aortic covered stent generally follows the main body wire selected into the main lumen. After the main body part is released, the branch wire is selected to the supra-aortic branch. The two wires are easy to entangle, and when the branch wire selects the supra-aortic branch, the branch wire needs to be captured by the upper limb access catcher to capture the branch wire into the supra-aortic branch to complete the selection of the supra-aortic branch. During the operation, the selection of the branch wire is difficult, which prolongs the operation time and increases the risk of surgery. SUMMARY

[0004] One of the technical problems solved by the present application is how to set the main stent structure of a covered stent to reduce the number of wire selections while achieving complete release of the main stent.

[0005] The present application provides a covered stent, which comprises a main stent and a branch stent, the main stent comprises a first side and a second side, the branch stent is located on the first side, the main stent comprises a first bare coil, a main coil and a main covering film, the main covering film is arranged on the main coil, the first bare coil is connected to the proximal end of the main covering film, and the first bare coil comprises a foldable part, a support part and an axial positioning part in the circumferential direction; the foldable part is close to the first side, the axial positioning part is close to the second side, and the support part is connected between the foldable part and the axial positioning part; the proximal end of the main covering film is provided with a circumferential unfolding part, and the circumferential unfolding part corresponds to the arrangement of the support part in the circumferential direction, so that the main covering film does not limit the unfolding of the support part.

[0006] In one of the embodiments, the circumferential unfolding portion comprises a U-shaped notch recessed towards the distal end.

[0007] In one of the embodiments, the notch is V-shaped or U-shaped.

[0008] In one of the embodiments, the circumferential unfolding portion has an unfolding length greater than or equal to the unfolding length of the support portion at the corresponding position.

[0009] In one of the embodiments, the circumferential unfolding portion comprises an axial buffer portion to reduce the axial pulling of the main body covering film when the circumferential unfolding portion is unfolded.

[0010] In one of the embodiments, the circumferential unfolding portion comprises a U-shaped notch recessed towards the distal end, and the axial buffer portion is the inclined bottom or flat bottom of the U-shaped notch.

[0011] In one of the embodiments, the proximal end portion of the main body covering film is in the form of an inclined cut, and the distal end portion of the second side of the first bare coil is axially beyond the distal end portion of the first side, so that the distal end surface of the first bare coil is in the form of an inclined cut.

[0012] In one of the embodiments, the circumferential unfolding portion comprises a U-shaped notch recessed towards the distal end, and the axial buffer portion is the inclined bottom of the U-shaped notch, which is parallel to the distal end surface of the first bare coil.

[0013] In one of the embodiments, the foldable portion comprises a first wave unit, the axial positioning portion comprises a second wave unit, and the support portion comprises a third wave unit, the third wave unit is connected with the first wave unit and the second wave unit respectively, the wave height of the third wave unit is less than the wave height of the first wave unit, and the wave height of the third wave unit is less than the wave height of the second wave unit.

[0014] The present application also provides a stent system, which comprises a delivery device and a covering stent as described above, the delivery device comprises a sheath core assembly and a sheath tube, the sheath core assembly penetrates from the distal end of the main body stent and exits from the branch stent, and the first bare coil is partially folded and loaded in the sheath tube as a whole.

[0015] In one of the embodiments, the delivery device further comprises a guide head, the axial distance from the proximal side connection point of the branch stent to the proximal end of the main body covering film is defined as L5, and the overall length of the branch stent along the axial direction is defined as L6, wherein the L5 and the L6 satisfy: L6>L5, and in the stent system, the branch stent is closer to the guide head in the axial direction than the proximal end of the main body stent.

[0016] In one embodiment, the free end of the foldable portion does not interfere with the proximal end of the axial positioning portion, or the free end of the foldable portion is pressed against the outside of the axial positioning portion.

[0017] One technical effect of one embodiment of the present invention is that it provides a film-coated support, which provides a circumferentially unfolded portion corresponding to the support portion in the circumferential direction at the proximal end of the main film, so that the main film does not restrict the opening of the support portion in the circumferential direction, thereby allowing the foldable portion to be folded smoothly. Attached Figure Description

[0018] Figure 1 This is a side view of the film-coated support provided in Embodiment 1 of the present invention;

[0019] Figure 2 This is a side view of the first bare wave loop provided in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the side view of the first bare wave ring provided in Embodiment 1 of the present invention on the projection plane S;

[0021] Figure 4 This is a schematic diagram of the structure of the film-coated support provided in Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of the structure of the first bare wave loop provided in Embodiment 1 of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of the first bare wave ring provided in Embodiment 1 of the present invention from another perspective;

[0024] Figure 6a This is a schematic diagram of the first bare wave coil provided in Embodiment 1 of the present invention, in which the peak of the second waveform unit along the middle line of the second side is cut along the axial direction and laid flat on a plane.

[0025] Figure 7 for Figure 1 The left view shown;

[0026] Figure 8 This is a schematic diagram showing the connection between the first trough and the main film provided in Embodiment 1 of the present invention;

[0027] Figure 9 This is a schematic diagram showing the connection between the first trough and the main body film provided in Embodiment 1 of the present invention in other embodiments;

[0028] Figure 10 for Figure 9 A schematic diagram of the main body covering when the first trough is omitted;

[0029] Figure 11Connection diagram of the first wave trough and the main body covering film provided in embodiment 1 of the present application and other embodiments of the main body covering film;

[0030] Figure 12 For Figure 1 Enlarged view of the proximal end of the main body stent;

[0031] Figure 13 For

[0032] Figure 14 For the stent system provided in embodiment 1 of the present application, the stent system provided in embodiment 1 of the present application includes a branch stent including a semi-constrained structure;

[0033] Figure 15 For Figure 14 Enlarged view of the semi-constrained structure of the branch stent;

[0034] Figure 16 For the process of loading the covering stent provided in embodiment 1 of the present application into the sheath tube (the first bare coil has not been bunched yet);

[0035] Figure 17 For the process of loading the covering stent provided in embodiment 1 of the present application into the sheath tube (the foldable part is partially folded and is ready to be bunched);

[0036] Figure 18 For the process of loading the covering stent provided in embodiment 1 of the present application into the sheath tube (the foldable part is folded, the supporting part is opened and is radially compressed together with the axial positioning part, and the axial positioning part is bunched in the sheath tube);

[0037] Figure 19 For the process of loading the covering stent provided in embodiment 1 of the present application into the sheath tube (the first bare coil is bunched in the sheath tube as a whole);

[0038] Figure 20 For the process of loading the covering stent provided in embodiment 1 of the present application into the sheath tube (the loading of the covering stent into the sheath is completed);

[0039] Figure 21 For the structure of the guide wire selected into the left subclavian branch artery to be implanted in the stent system provided in embodiment 1 of the present application;

[0040] Figure 22 For the schematic diagram of the stent system provided in embodiment 1 of the present application being transported along the guide wire to the left subclavian branch artery;

[0041] Figure 23 For the relative Figure 22 The schematic diagram of the sheath tube being withdrawn to the third imaging element close to the first imaging element;

[0042] Figure 24 for relative Figure 23 Schematic diagram of the third visualization member being distanced from the first visualization member and approaching the second visualization member by continuous retraction of the sheath;

[0043] Figure 25 for relative Figure 24 Schematic diagram of the foldable part releasing the sheath (support part to be released);

[0044] Figure 26 for relative Figure 25 Schematic diagram of the first bare coil releasing the sheath (distal end of the main body support to be released);

[0045] Figure 27 for relative Figure 26 Schematic diagram of the main body support being entirely released from the sheath;

[0046] Figure 28 for relative Figure 27 The second bare coil of the branch support is completely released from the sheath core;

[0047] Figure 29 Schematic diagram of the structure of the proximal end of another covered stent provided by the embodiment 2 of the present application;

[0048] Figure 30 for Figure 29 Schematic diagram of the structure of the first bare stent and the positioning coil in the embodiment 1 of the present application;

[0049] Figure 31 for Figure 30 Schematic diagram of one combination mode of the first bare stent and the positioning coil in the embodiment 1 of the present application;

[0050] Figure 32 for Figure 30 Schematic diagram of another combination mode of the first bare stent and the positioning coil in the embodiment 1 of the present application;

[0051] Figure 33 Schematic diagram of the structure of the proximal end of still another covered stent provided by the embodiment 2 of the present application;

[0052] Figure 34 Schematic diagram of the structure of the proximal end of yet another covered stent provided by the embodiment 2 of the present application;

[0053] Figure 35 for Figure 34 Schematic diagram of the two second wave units of the wave trough of the axial positioning part of the first bare coil in the embodiment 1 of the present application being cut along the axial direction and laid on a plane;

[0054] Figure 36 Schematic diagram of the side view of the covered stent provided by the embodiment 3 of the present application;

[0055] Figure 37 for Figure 37An enlarged view of the structure of the middle circumferential expansion portion;

[0056] Figure 38 A side view of yet another covered stent provided in Embodiment 3 of the present application;

[0057] Figure 39 A side view of Figure 38 An enlarged view of the structure of the middle circumferential expansion portion;

[0058] Figure 40 A side view of yet another covered stent provided in Embodiment 3 of the present application;

[0059] Figure 41 A side view of Figure 40 An enlarged view of the structure of the middle circumferential expansion portion;

[0060] Figure 42 A side view of yet another covered stent provided in Embodiment 3 of the present application. DETAILED DESCRIPTION

[0061] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. There can, of course, be many embodiments of the application and the specific embodiments described herein are not intended to limit the scope of the application but rather they are intended to provide exemplary embodiments of the application. The principles of the application will be better understood by reference to the drawings, wherein like reference numerals indicate corresponding elements throughout the several views.

[0062] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the terms "inner," "outer," "left," "right," and the like describe orientations of the embodiments only as they appear in the figures and are not intended to be limiting of the application.

[0063] "Axial" generally refers to the lengthwise direction of the medical device when it is being delivered, and "radial" generally refers to the direction perpendicular to the "axial" direction of the medical device, and by this principle, the "axial" and "radial" directions of any component of the medical device are defined. In addition, when a tubular stent or covered stent is described, the orientation can be defined according to the direction of blood flow in the blood vessel, and in the present application, the blood flow is defined as flowing from the proximal end to the distal end of the stent. A wave unit is defined as a single periodic wave shape including one wave crest and two wave legs, or a single periodic wave shape including one wave trough and two wave legs. In the field of interventional medical devices, the end closer to the operator is defined as the "proximal end", and the end farther from the operator is defined as the "distal end" for the delivery device that delivers the medical device into the human or animal body, and by this principle, the "proximal end" and "distal end" of any component of the delivery device are defined.

[0064] Example 1

[0065] like Figures 1-31 As shown, this embodiment provides a film-coated stent 100, which includes a main stent 10 and branch stents 20, as... Figure 1 As shown.

[0066] like Figures 1-6 As shown, the main support 10 is a tubular structure with openings at both ends, including a first bare wave coil 11, a main wave coil 12, and a main coating 13. The proximal portion of the main coating 13 is its proximal end portion 131. The first bare wave coil 11 is connected to the proximal end portion of the main coating 13. In this embodiment, the distal end portion of the first bare wave coil is connected to the proximal end portion of the main coating and has the same inclination trend. The distal portion of the first bare wave coil is its distal end portion (not shown in the figure, but can be compared to the proximal end portion of the main coating). Multiple main wave coils 12 are arranged axially and connected by the tubular main coating 13. One to 30 main wave coils 12 can be provided.

[0067] In this embodiment, the main waveguide 12 is located on the outer side of the main cover 13. When implanted into a blood vessel, it can enhance the friction between the main stent 10 and the inner wall of the blood vessel, which helps to prevent the main stent 10 from shifting or shortening relative to the inner wall of the blood vessel. In other embodiments, the main waveguide 12 may also be located on the inner side of the main cover 13, or the main waveguide 12 may be partially located on the inner side and partially located on the outer side of the main cover 13; no limitation is made here.

[0068] The main support 10 includes a first side 101 and a second side 102. When the covered stent 100 is in the implantation form, and the branch stent 20 is facing the branch of the arch, the first side 101 is the side of the main support 10 close to the branch of the arch, and the second side 102 is the side of the main support 10 away from the branch of the arch. The first side and the second side each occupy an arc of 180°, and the branch stent 20 can be located in the middle of the arc of the first side 101.

[0069] like Figures 3-4 Combination Figure 6 and Figure 6aAs shown, the distal end of the first bare wave coil 11 includes a first distal end 11a on the first side 101 and a second distal end 11b on the second side 102, the first distal end 11a and the second distal end 11b are located on different radial sections, so that the line connecting the first distal end 11a and the second distal end 11b of the first bare wave coil 11 forms an acute angle with the axial line of the main support 10, thereby facilitating the folding of the first bare wave coil 11; in this embodiment, the circumferential position of the first distal end 11a is deviated from the circumferential position of the branch support by not more than 20°, and the circumferential relative interval between the second distal end 11b and the first distal end 11a is in the range of 160-180°. Among them, since the foldable part 111 is located on the first side 101 and the axial positioning part 112 is located on the second side 102, generally, the first distal end 11a is the distal end of the foldable part 111 and is circumferentially closest to one end (the end connected with the main support) of the branch support 20, and the second distal end 11b is the distal end of the axial positioning part 112 and is circumferentially farthest from one end (the end connected with the main support) of the branch support 20. In this embodiment, in order to facilitate description, the wave element is a single periodic wave shape including one wave crest and two wave rods (the end points of the two wave rods away from the wave crest are the wave valley positions of the wave element), as shown in Figure 6 As shown, the first distal end 11a is the two symmetrical wave valley end portions of the first wave element 1111 in the middle of the foldable part 111, and the second distal end 11b is the two symmetrical wave valley end portions of the second wave element 1121 in the middle of the axial positioning part.

[0070] As shown in Figures 1-6 The first bare wave coil 11 includes a plurality of wave elements similar to sine waves, and the number of wave elements of the first bare wave coil 11 is 4-10; the wire diameter of the first bare wave coil 11 ranges from 0.3mm to 0.45mm; the wave height of the wave element ranges from 1mm to 15mm, and the wave height H1 of the first wave element 1111 is taken as an example, as shown in Figure 3 As shown, Figure 3 The dashed line in the figure is an auxiliary line, and the structure is not the first bare wave coil.

[0071] In this embodiment, as shown in Figure 1As shown, the distal end of the second side 102 of the first bare wave coil 11 extends axially beyond the distal end of its first side 101, making the distal end of the second side of the first bare wave coil 11 closer to the distal end of the main body support 10, thus making the distal end face of the first bare wave coil 11 obliquely cut. Similarly, the proximal end of the first side of the main body cover 13 extends axially beyond the proximal end of the second side of the main body cover 13, making the proximal end of the first side of the main body cover 13 closer to the proximal end of the first bare wave coil 11, thus making the proximal end face of the main body cover 11 obliquely cut. The proximal end face of the first bare wave coil 11 and the distal end face of the first bare wave coil 13 have the same inclination trend, which facilitates the matching and connection between the distal end of the first bare wave coil 11 and the proximal end of the main body covering film 11; or in other embodiments, the distal end of the first side of the first bare wave coil extends axially beyond the distal end of its second side, so that the distal end of the first side of the first bare wave coil is closer to the distal end of the main body support, thereby making the distal end face of the first bare wave coil obliquely cut. This is not limited here, as long as the first distal end 11a and the second distal end 11b are located on different radial sections.

[0072] like Figure 5 Combination Figures 2-3 As shown, the first bare wave coil 11 includes a first waveform unit 1111, a second waveform unit 1121, and a third waveform unit 1131. The first waveform unit 1111 is located on the first side 101, the second waveform unit 1121 is located on the second side 102, and the third waveform unit 1131 is located between the first waveform unit 1111 and the second waveform unit 1121. The axial line T1 passing through the midpoint E of the circumferential direction on the first side 101 and the axial line T2 passing through the midpoint F of the circumferential direction on the second side 102 form a projection plane S, as shown. Figure 4 As shown (in this embodiment, the branch bracket is located on the axial line where the midpoint of the first side circumferential direction is located); the line connecting the endpoints of the projections of the first waveform unit 1111 and the second waveform unit 1121 on the projection plane S forms a parallelogram or trapezoid, as shown. Figure 3 As shown, the projection plane S is the plane where the graphic is located. When the distal end of the second side 102 of the first bare wave coil 11 extends axially beyond the distal end of its first side 101, the distal end of the second side 102 of the first bare wave coil 11 is brought closer to the distal end of the main support 10. The distal endpoint of the first side 101, which is located in a parallelogram or trapezoid, is closer to the distal end of the main support 10 than the proximal endpoint of the second side 102, which is located in a parallelogram or trapezoid. This allows all radial sections between the distal endpoint of the first side 101 and the proximal endpoint of the second side 102 to pass through the wave rods of each waveform unit of the foldable part 111 and the axial positioning part, so that the radial section can cut more wave rods, and the first bare wave coil 11 can still maintain a certain radial support function under the inclined structure.

[0073] In this embodiment, the distal end of the second side of the first bare wave coil 11 extends axially beyond the distal end of its first side, making the distal end face of the first bare wave coil 11 beveled. This results in the first distal end 11a of the first bare wave coil 11 being closer to the proximal end of the first bare wave coil 11 than the second distal end 11b. Figures 1-3 As shown. In this embodiment, the first bare wave coil 11 is configured such that, relative to the case where the distal end of the first side of the first bare wave coil extends axially beyond the distal end of its second side (the distal end of the first side of the first bare wave coil is closer to the distal end of the main support), the first bare wave coil 11 is configured as follows: Figure 18 Combination Figure 25 As shown, when the foldable portion 111 of the first bare wave coil 11 is folded and compressed inside the sheath 32, it faces away from the branch stent 20. Since the delivery device 30 is attached to the greater curvature side of the aortic arch 800 (the side of the aortic arch 800 with branches), the delivery device 30 releases the first bare wave coil 11 along the greater curvature side of the vessel. When the first bare stent is partially released, only the foldable portion 111 is released from the sheath 32. At this time, the entire first bare stent acts as a single wave coil, with part of it released from the sheath 32 (foldable portion 111), and the other part remaining inside the sheath 32 (axial positioning portion 112). This allows the released foldable portion 111 to... The proximal end of 11 bends toward the lumen center of the covered stent 100; when the first bare wave coil 11 is in its natural state, the distal end of the second side of the first bare wave coil 11 extends axially beyond the distal end of its first side, so that the distal end of the second side 102 of the first bare wave coil 11 is closer to the distal end of the main stent 10 than the distal end of the first side 101; when only the foldable portion 111 is released, the released foldable portion 111 bends toward the lumen center of the main stent 10 away from the large bend of the blood vessel. After the foldable portion 111 of the first bare stent is released, the possibility of the distal end of the released foldable portion 111 causing damage to the blood vessel can be reduced.

[0074] like Figure 1As shown, the proximal end of the main body cover 13 is obliquely cut, and the proximal end of the first side of the main body cover 13 extends axially beyond the proximal end of its second side, such that the proximal end of the first side 101 of the main body cover 13 is farther from the distal end of the main body cover 13 than the proximal end of the second side 102; or, in other embodiments, the proximal end of the second side of the main body cover extends axially beyond the proximal end of its first side. In this embodiment, the distal end face of the main body cover 13 is flat, and the proximal end of the first side 101 of the main body cover 13 extends axially beyond the proximal end of its second side 102, that is, the proximal end of the second side 102 of the main body cover 13 is closer to the distal end of the main body stent 10 than the proximal end of the first side 101 of the main body cover 13. This improves the beak effect when the proximal end of the main body stent 10 is placed in the aortic arch 800, allowing the second side 102 (the side away from the branch of the arch) to adhere to the vascular arch. In this embodiment, the troughs at the distal end of the first bare wave loop 11 are on the same plane, and the shape of the distal end of the first bare wave loop 11 corresponds to the shape of the proximal end of the main body coating 13, so as to facilitate the connection of the troughs of the first bare wave loop 11 to the proximal end of the main body coating 13, such as... Figures 1-6 As shown.

[0075] The first bare wave coil 11 includes a foldable portion 111, a support portion 113, and an axial positioning portion 112. In this embodiment, the foldable portion 111 is close to the first side 101, the axial positioning portion 112 is close to the second side 102, and the support portion 113 is connected between the foldable portion 111 and the axial positioning portion 112. The connection point between the foldable portion 111 and the support portion 113 on one side is the first connection point P. The foldable portion 111 can be folded to the support portion 113 with the first connection point P as the fulcrum, and can be radially compressed together.

[0076] like Figure 7 As shown, the foldable portion 111, support portion 113, and axial positioning portion 112 in the first bare wave coil 11 are symmetrically arranged relative to the line T connecting the first side 101 and the second side 102, wherein the direction of the connecting line T is substantially consistent with the extension direction of the branch support 20 (substantially consistent means that the angle between the connecting line T and the extension direction of the branch support 20 is 0° to 10°). That is, from the first side 101 to the second side 102, the first bare wave coil 11 includes a foldable portion 111, a support portion 113, and an axial positioning portion 112 on both sides of the connecting line T in sequence, such as... Figure 7As shown, in order to facilitate the labeling, the two auxiliary dashed lines are used together with the connecting line T to divide the covering stent 100 into six parts in the circumferential direction. The foldable part 111 is symmetrically arranged relative to the connecting line T, which does not mean that the specific structure of the foldable part 111 on both sides of the connecting line T is completely symmetrical and consistent, but means that the corresponding positions on both sides of the connecting line T are foldable parts 111; Similarly, the support part 113 (axial positioning part 112) is symmetrically arranged relative to the connecting line T, which does not mean that the specific structure of the support part 113 (axial positioning part 112) on both sides of the connecting line T is completely symmetrical and consistent, but means that the corresponding positions on both sides of the connecting line T are support parts 113 (axial positioning parts 112), so as to facilitate the folding and compression of the first bare coil 11.

[0077] The foldable part 111 includes a first wave unit 1111, the axial positioning part 112 includes a second wave unit 1121, and the support part 113 includes a third wave unit 1131; as Figures 2-3 In combination Figure 5 As shown, the third wave unit 1131 is connected with the first wave unit 1111 and the second wave unit 1121 respectively, and the wave height of the third wave unit 1131 is less than the wave height of the first wave unit 1111, or / and the wave height of the third wave unit 1131 is less than the wave height of the second wave unit 1121, where the wave height refers to the vertical height of the wave crest to the connecting line of two wave troughs of a wave unit. The wave height of the third wave unit 1131 is less than or equal to half of the smaller wave height of the first wave unit 1111 and the second wave unit 1121, and the smaller wave height of the third wave unit 1131 can prevent the span distance of the support part 113 after being opened from being too different from the natural span distance of the wave form when the first bare coil 11 is loaded into the sheath, which may cause the foldable part 111 to be inconvenient to fold with the film.

[0078] The length of the longer wave rod of the first wave unit 1111 is defined as L3, the length of the longer wave rod of the second wave unit 1121 is defined as L4, and the radius of the lumen of the main stent 10 is defined as R, then the sum of L3 and L4 satisfies: L3+L4≤2R; in this embodiment, the wave height and the wave length of the first wave unit 1111 and the second wave unit 1121 are the same, the wave height of the third wave unit 1131 is half of the wave height of the first wave unit 1111, and the wave troughs of the first wave unit 1111, the second wave unit 1121 and the third wave unit 1131 are on the same inclined cross section, as Figure 3 As shown, the proximal end of the main covering 13 is in the form of an oblique cut, as Figure 1As shown, the inclination of the same oblique section where each trough of the first bare wave ring 11 is located relative to the axial direction is the same as the inclination of the proximal oblique cut of the main covering film 13 relative to the axial direction, facilitating the connection of each trough with the proximal end of the main covering film 13. The length of the longer wave rod in the first wave unit 1111 and the third wave unit 1131 can be set as R, so that when the covering film stent 100 is in the loaded state, the foldable part 111 folded onto the support part 113 and the axially positioned part 112 radially compressed do not overlap in the axial direction, which can reduce the radial dimension in the compressed state, and also prevent mutual interference between the axially positioned part 112 and the foldable part 111 when released.

[0079] The troughs of the first bare wave ring 11 are connected to the outside or inside of the proximal end of the main covering film 13, which is not limited herein. In other embodiments, the inclination of the oblique section where the distal trough of the first bare wave ring 11 is located can also be different from the inclination of the proximal oblique cut of the main covering film 13, as long as the first distal end 11a and the second distal end 11b of the first bare wave ring 11 are located on different radial sections, facilitating the foldable part 111 of the first bare wave ring 11 to be folded towards the distal end onto the support part 113. In other embodiments, the proximal end of the main covering film 13 does not exceed one-third of the length of the first bare stent wave rod in the axial direction, so that the covering film does not affect the folding of the first bare wave ring 11, and at the same time does not cause excessive accumulation of the proximal covering film of the main stent 10 after folding.

[0080] In the present embodiment, the first bare wave ring 11 includes 8 wave units, and the arc length corresponding to the central angle of each of the two troughs of each wave unit in the 8 wave units is substantially the same, as shown in Figures 5-7 As shown, the foldable part 111 includes three first wave units 1111 close to the first side 101, the axially positioned part 112 includes three second wave units 1121 close to the second side 102, and the support part 113 includes two third wave units 1131 located in the middle, and each has 1.5 first wave units 1111 located on both sides of the connecting line T, each has 1.5 second wave units 1121 located on both sides of the connecting line T, and each has one third wave unit 1131 located on both sides of the connecting line T. When the covering film stent 100 is loaded into the sheath, the two wave rods (1131a, 1131b) of the third wave unit 1131 of the support part 113 open with the connecting point of the two wave rods (1131a, 1131b) as the fulcrum, and the included angle between the two wave rods becomes larger and tends to 180°, facilitating the folding of the foldable part 111, as shown in Figures 17-18 In combination with Figure 5As shown; the first waveform unit 1111 of the foldable part 111 is radially compressed, and folds over as the third waveform unit 1131 of the support part 113 opens, and it folds over by about 180° in the axial direction; the second waveform unit 1121 of the axial positioning part 112 is radially compressed, and at the same time it moves closer to the wave rod (1131b) of the adjacent support part 113, and the axial positioning part 112 is only compressed in the radial direction, and the relative position in the axial direction remains basically unchanged.

[0081] like Figure 2 As shown, the third waveform unit 1131 includes a first wave rod 1131a and a second wave rod 1131b. The included angle α between the first wave rod 1131a and the second wave rod 1131b satisfies the following range: 46°≤α≤145°. The included angle α between the first wave rod 1131a and the second wave rod 1131b should not be too small. If α is too small, it will be difficult for the first wave rod 1131a and the second wave rod 1131b of the third waveform unit 1131 to move away from each other with the vertex of the angle α as the fulcrum, which will increase the difficulty of the support part 113 opening and compressing into the sheath. The included angle α between the first wave rod 1131a and the second wave rod 1131b should not be too large. If α is too large, the first wave rod 1131a and the second wave rod 1131b will be far apart, resulting in less deformation of the support portion 113 when it is opened to nearly 180° (in the state inside the sheath 32). When the sheath 32 is withdrawn to release the covered stent 100, the contribution to the elastic recovery force of the first wave rod 1131a and the second wave rod 1131b will be smaller, which is not conducive to the covered stent adhering to the inner wall of the blood vessel at the corresponding position of the support portion 113. In other embodiments, the range of the included angle α between the first wave rod 1131a and the second wave rod 1131b is more effective: 77°≤α≤89°. The included angle β is defined as the included angle between the first wave rod 1131a and the wave rod on one side of the foldable portion 111. The range of the included angle β is: 25°≤β≤73°. If the angle β is too large, when the foldable portion 111 is released and the support portion 113 is waiting to be released (e.g. Figure 25 As shown), it is not conducive to the return of the support part 113 to the foldable part 111 (because the deformation of the included angle relative to the angle β in the natural state is small). In other embodiments, the range of the included angle β satisfies: 42°≤β≤58°; the included angle γ between the second wave rod 1131b and the wave rod on one side of the axial positioning part 112 is defined as γ, and the range of the included angle γ satisfies: 52°≤γ≤119°. Wherein, if the angle γ is too small, it is not conducive to the radial return of the axial positioning part 112 (i.e., Figures 25 to 26 During the process, the radial restoring force of the axial positioning part 112 is small, which is not conducive to the radial restoring of the axial positioning part 112 (to move to the aortic arch 800 small bend side to adhere to the wall). In other embodiments, the included angle γ range satisfies: 73°≤γ≤87°.

[0082] like Figure 3 and Figure 6 andFigure 6a As shown, the length of the first wave rod 1131a is defined as L1, and the length of the second wave rod 1131b is defined as L2. The ratio of L1 to L2 satisfies the following range: 2 / 3 ≤ L1 / L2 ≤ 3 / 2. If the first wave rod 1131a or the second wave rod 1131b is too long or too short, it will affect the axial position of the wave crest node after the support part 113 is opened. When the covered bracket 100 is loaded in the sheath tube 32, it is not conducive to the axial distribution of the wave rod length of the foldable part 111 and the rod length of the axially positionable part.

[0083] In this embodiment, as Figure 5 As shown, the connection point between the distal end of the first wave rod 1131a and the foldable part 111 is the first connection point P, thereby forming the first trough 1131c of the support part 113. The first trough 1131c is movably connected to the main body film 13. The connection point between the distal end of the second wave rod 1131b and the axial positioning part 112 is the second connection point, thereby forming the second trough 1131d of the support part 113. The second trough 1131d is movably connected to the main body film 13 support 100. The distal end of the first bare support is located inside the main body film 13. When the first bare support is in its natural state, the position of the first trough 1131c inside the main body film 13 is defined as the first axial limiting position M. Figure 8 As shown, the position of the second trough 1131d located inside the main body film 13 is defined as the second axial limiting position (not shown in the figure). In this embodiment, in the first bare wave ring 11, all troughs except the first trough 1131c and the second trough 1131d are fixed inside the main body film 13. In other embodiments, the second trough 1131d can also be fixedly connected to the main body film 13, as long as the first trough 1131c is not fixedly connected to the main body film 13; or both the first trough 1131c and the second trough 1131d can be fixedly connected to the main body film 13, while the portion of the main body film 13 between the first trough 1131c and the second trough 1131d has excess material (wrinkles) or gaps, without restricting the first wave rod 1131a and the second wave rod 1131b from moving away from each other.

[0084] like Figures 8-11 As shown, the main support 10 also includes a non-fixed limiting member 15 located near the first trough 1131c, which limits the first trough 1131c so that it does not extend beyond the near end of the film, thereby providing support for the film. At the same time, during the opening of the support part 113, the non-fixed limiting member 15 does not restrict the movement of the first trough 1131c within the limiting member, so that the first wave rod 1131a and the second wave rod 1131b can move away from each other without pulling on the film.

[0085] In this embodiment, the non-fixed limiting member 15 is a movable limiting line 151, which can be a polyester wire, a nickel-titanium alloy wire, or a tantalum wire.

[0086] The wire diameter of the first bare wave loop 11 is defined as d, the limiting line is wrapped around the first wave valley 1131c and the proximal end of the main body covering film 13, as shown in Figure 8 The two ends of the limiting line are sewn on the covering film, or one end penetrates through the covering film and is fixed with the other end, so that the limiting line forms a gap Q at the first axial limiting position M, and the width of the gap Q extending from the first axial limiting position M towards the distal end is greater than or equal to 2d. When the covering stent 100 is loaded, it is convenient for the first wave valley 1131c to slide out of the first axial limiting position M and for the first wave rod 1131a to slide in the gap Q; when the covering stent 100 is released, it is beneficial for the first wave rod 1131a to drive the first wave valley 1131c to return to the first axial limiting position M. The setting of the movable limiting line 151 makes the first wave valley 1131c not exceed the proximal end of the main body covering film 13, and the first bare wave loop 11 still has an expanding support effect on the proximal end of the main body covering film 13 corresponding to the support part 113 in the circumferential direction.

[0087] In other embodiments, as shown in Figures 9-10 The limiting line is fixed on the main body covering film 13 at least at two positions (which can be the two ends of the line) to form a first fixed point 151a and a second fixed point 151b, the first fixed point 151a is located on the proximal side of the first axial limiting position M, the second fixed point 151b is located on the distal side of the first axial limiting position M and is spaced apart from the first fixed point 151a, and the gap Q formed between the two fixed points has a width greater than or equal to 2d. In other embodiments, the first fixed point 151a and the second fixed point 151b can also not be on the same axial line, and the second fixed point 151b is closer to the second wave valley 1131d side in the perpendicular axial direction relative to the first fixed point 151a, so that the extension direction (the direction of the line connecting the two fixed points) of the gap Q formed between the first fixed point 151a and the second fixed point 151b relative to the axial direction is inclined, and the inclination direction is opposite to the inclination direction of the first wave rod 1131a relative to the axial direction, which is more beneficial to the movement of the first wave rod 1131a relative to the main body covering film 13 when loaded into the sheath, so that the first wave rod 1131a and the second wave rod 1131b move away from each other without affecting the covering film. And when the covering stent 100 is released, due to the elastic recovery force of the support part 113 itself deforming (the included angle between the first wave rod 1131a and the second wave rod 1131b increases) to return to the natural state during loading, and the non-fixed limiting part 15 limits the maximum proximal position of the first wave valley 1131c, so that the first wave valley 1131c does not exceed the proximal end of the main body covering film 13, and the first bare wave loop 11 still has an expanding support effect on the proximal end of the main body covering film 13 corresponding to the support part 113 in the circumferential direction.

[0088] The proximal end of the main body stent 10 is further provided with a positioning wave coil 14, which is located between the first bare wave coil 11 and the main body wave coil 12. The wire diameter of the positioning wave coil 14 is smaller than that of the first bare wave coil 11. The part of the positioning wave coil 14 located on the first side 101 is arranged on the proximal end side of the branch stent 20, as shown in Figure 12 .

[0089] As shown in Figure 1 and Figure 4 in combination Figure 12 , the branch stent 20 is located on the first side 101 of the main body stent 10, communicates with the lumen inside the main body stent 10, and extends towards the outside of the main body stent 10, forming an outer branch stent 20 on the first side 101 of the main body stent 10.

[0090] The branch stent 20 includes a second bare wave coil 21, a branch wave coil 22, and a branch covering film 23. The second bare wave coil 21 is connected with the branch covering film 23, and the second bare wave coil 21 is arranged at one end of the branch stent 20 away from the main body stent 10. The branch wave coil 22 includes a plurality of branch wave coils 22, which are arranged at intervals and connected by a tubular branch covering film 23. The branch stent 20 and the main body stent 10 can be connected as a whole by the branch covering film, and the connection mode can be stitching, adhesion, or the like. The end of the branch stent 20 away from the second bare wave coil 21 is connected to the main body stent 10 along the circumferential direction of the branch stent 20. A circumferential development ring or development points are arranged at intervals along the circumferential direction at the circumferential connection to mark the circumferential boundary of the branch opening, facilitating identification of the position of the stent branch opening in alignment with the branch blood vessel.

[0091] In other embodiments, as shown in Figures 13-15 , the branch stent 20 includes a connection section 24 and an extension section 25. The connection section 24 connects the extension section 25 and the main body stent 10. The outer diameter of the extension section 25 is larger than that of the connection section 24. The extension section 25 and the connection section 24 further include a transition section 27. The outer diameter of the transition section 27 gradually increases from the connection section 24 to the extension section 25. The branch stent 20 is provided with a half-restraint structure 26. During adjustment of the proximal end release of the main body stent 10, the branch stent 20 is in a half-restrained state. The diameter of the restrained branch stent is 40% to 75% of the diameter of the unrestrained branch stent. The branch stent 20 can move axially in the branch, thereby facilitating adjustment of the fitting position of the branch stent 20 and the proximal end side connection of the main body stent 10 with the blood vessel. When a branch small stent is needed, the half-restraint structure 26 can not be provided, and the outer diameter of the branch stent 20 is set to be smaller, facilitating axial adjustment of the position of the branch stent 20 after the sheath tube 32 is released. The outer diameter is set to be in the range of 6mm to 20mm, so that the released branch stent is not attached to the inner wall of the branch blood vessel. Finally, a branch small stent is released by the guide wire 90 to fit the inner wall of the branch blood vessel.

[0092] As shown in Figure 15 , the semi-binding structure 26 includes a binding line 26a arranged circumferentially around the branch wave ring 22, a plurality of line buckles 26c fixed to the branch wave ring 22 in the circumferential direction, and a limiting buckle 26b arranged at the end of the binding line 26a. Correspondingly, the delivery device 30 also includes a limiting rod 33. During loading, the limiting rod 33 passes through the limiting buckles 26b at both ends of the binding line 26a along the axial direction of the branch support 20, thereby semi-binding the branch support 20 and keeping the branch support 20 in a circumferential incomplete release state. The limiting rod 33 can be a metal guide wire 90 with good elastic memory and small surface roughness, such as a nickel-titanium wire, which meets the physical requirements and has good biocompatibility with the human body. A plurality of binding lines 26a are arranged at intervals along the axial direction of the branch support 20. In the natural state, the binding line 26a covers a circumferential angle of 180°-270° of the branch support 20 in the circumferential direction, so as to control the change range of the branch support 20 from the semi-release state to the complete release state within a reasonable range; the binding line 26a can be a flexible line with strong tensile resistance, such as a PTFE line or a polyester suture.

[0093] As shown in Figure 12 , the axial distance from the proximal end connection point of the branch support 20 to the proximal end of the main body covering film 13 is defined as L5, wherein L5 satisfies: 3mm≤L5≤16mm; when the proximal end surface of the first bare wave ring 11 is not perpendicular to the axial direction of the covering film stent 100, the proximal end surface is an inclined surface, and the first bare wave ring is sutured to the main body covering film. When the foldable part is folded, the distance from the proximal end of the main body stent to the proximal end connection point of the branch stent is less than L5. The overall length of the branch support 20 along the axial direction of the branch support is defined as L6, which satisfies: 3mm≤L6≤60mm; wherein L5 and L6 satisfy: L6>L5; the branch wave ring of the branch support can be arranged at intervals along the axial direction of the branch support, or can be a support wave ring structure formed by hooking and weaving. The branch wave ring only needs to meet the performance of the support wave ring, and its specific structure is not limited here. When the guide wire 90 is selected to enter the branch on the arch, the sheath core assembly 31 needs to pass through the branch support 20 from the distal end of the main body support 10, so as to send the branch support 20 along the guide wire 90 into the branch. L6>L5 is set, so that the foldable part of the first bare wave ring of the covering film stent is folded to the support part, the wave rod of the support part is opened, and together with the axial positioning part, it is compressed in the sheath tube to form a stent system. During the release process of the stent system, the branch support is exposed to the distal end of the sheath tube away from the operating handle before the proximal end of the main body support, so as to adjust the proximal end of the main body support 10 in the main cavity of the arch part, and prevent the proximal end of the main body support 10 from being released in the branch support 20 on the arch first.

[0094] In this embodiment, a first developing element 16 is provided at the position of the axial line T1 of the first side of the main body film 13 connected to the foldable part 111 and closest to the midpoint E of the first side 101 in the circumferential direction. This first developing element 16 is used to mark the proximal end of the main body support 10 after the foldable part 111 is folded. The first developing element 16 can be a developing filament sewn onto the main body film 13, and can be in the form of an 8 or an O shape. The coating support 100 also includes a second developing element 17, which is located near the proximal end of the foldable portion 111. It can be used to indicate the specific position of the end of the foldable portion 111 after it is folded and compressed inside the sheath 32 (when the sheath 32 passes this end position, the foldable portion 111 is released from the sheath 32). The second developing element 17 can be a developing wire wound on the proximal peak of the first waveform unit 1111; or the second developing element can be omitted from the proximal end of the foldable portion. The wire diameter of the first bare wave loop can be larger than the wire diameter of the positioning wave loop 14. This can also make the outline of the foldable portion clearly visible under contrast imaging, distinguishing it from the outline of the positioning wave loop, so that its position in the sheath in the folded state can be directly identified.

[0095] This embodiment also provides a support system, such as Figures 16-28 As shown, the stent system includes a delivery device 30 and a coated stent 100 as described above. The delivery device 30 includes a sheath core assembly 31 and a sheath tube 32. The sheath core assembly 31 also includes a guide head 311. The sheath core assembly 31 enters from the distal end of the main stent 10 and exits from the branch stent 20. The first bare wave coil 11 is partially folded and loaded entirely inside the sheath tube 32. A third imaging element 321 is provided at the proximal port of the sheath tube 32 to indicate the position of the sheath tube 32 relative to the coated stent 100 during the retraction process when the coated stent 100 is released.

[0096] The process of loading the above-mentioned covered stent 100 into the sheath 32 is as follows:

[0097] First, the sheath core assembly 31 is inserted into the distal end of the main support 10 and exits through the port of the branch support 20 on the side away from the main support 10. The second bare wave coil 21 of the branch support 20 is hooked onto the distal end of the sheath core assembly 31, forming a releasable hook connection between the sheath core assembly 31 and the second bare wave coil 21. Since the branch support 20 and the main support 10 are set at a certain angle in their naturally expanded state (the angle can range from 60° to 90°), when the sheath core assembly 31 exits from the side of the branch support 20 away from the main support 10, the branch support 20 bends towards the proximal end of the main support 10 and adheres to the proximal end of the main support 10. Figure 16 As shown;

[0098] Then, the distal end of the main stent 10 is gradually loaded into the sheath tube 32, and when loaded to the proximal end of the main stent 10, the sheath tube 32 is retracted to the distal end of the axially positionable portion, and then the foldable portion 111 of the first bare coil 11 is folded towards the distal end of the main stent 10 with the first connection point P as the fulcrum, and the foldable portion 111 is folded by 180° in the axial direction, and the third wave unit 1131 of the support portion 113 is opened by an external force, so that the included angle between the first wave rod 1131a and the second wave rod 1131b of the stent is increased (tends to 180°), and the axially positionable portion 112 is close to the second wave rod 1131b under radial compression, so that the axially positionable portion 112 is radially compressed in the sheath tube 32, as shown in Figures 17-18 ;

[0099] Finally, the first bare coil 11 which is partially folded and overall compressed is retracted into the sheath tube 32, and the sheath tube 32 continues to advance to retract the branch stent 20 into the sheath tube 32 until the distal end of the sheath tube 32 is retracted to the proximal end of the guide head 311, and the loading is completed to form a stent system, as shown in Figures 19-20 . As shown in Figure 20 , in the stent system, the free end 111a of the foldable portion 111 which is not connected with the covering does not interfere with the proximal end of the axially positionable portion 112 (i.e. close to each other but not in contact), or the free end of the foldable portion is pressed on the outside of the axially positionable portion, so that when the first bare coil is released from the sheath tube, the foldable portion 111 and the axially positionable portion 111 are released in turn, thereby avoiding that the axially positionable portion 112 is pressed on the outside of the foldable portion after folding in the stent system, resulting in instantaneous release of the first bare coil, causing the foldable portion to be attached to the large curve side of the blood vessel and the complete release of the first bare coil to be attached to the wall, resulting in the inability to adjust the position of the foldable portion attached to the large curve side of the blood vessel wall in the axial direction.

[0100] Taking the implantation of the branch stent 20 into the left subclavian branch artery 803 as an example, the process of implanting the above-mentioned loaded stent system into the human aortic arch 800 is as follows:

[0101] First, the guide wire 90 is selected into the left subclavian branch artery 803 to be implanted from the femoral artery to establish a delivery channel, as shown in Figure 21 , and then the branch stent 20 in the stent system is delivered to the left subclavian branch artery 803 along the guide wire 90, as shown in Figure 22 .

[0102] Then, as shown in Figures 23-24 , the position of the stent system is adjusted so that the first visualization member 16 does not enter the supra-aortic branch, and the sheath tube 32 is retracted to the third visualization member 321 close to the first visualization member 16, as shown in Figure 23As shown, the sheath 32 is then slowly retracted. Because there is a certain angle between the main stent 10 and the branch stent 20, during the process where the third imaging element 321 is located between the first imaging element 16 and the second imaging element 17, and as the third imaging element 321 moves away from the first imaging element 16 and closer to the second imaging element 17, the proximal end of the main stent 10 gradually moves away from the branch stent 20. During this process, the sheath 32 is slowly released, while the delivery device 30 is pushed forward. Due to the presence of the guidewire 90, the sheath core assembly 31 advances along the guidewire 90 towards the branch, and the exposed foldable portion 111 moves away from the branch stent 20 (and the portion near the large bend is the membrane section), until the membrane covering the main stent 10 exceeds the proximal inflection point of the left subclavian branch artery 803. Then, the sheath 32 can be retracted to gradually release the proximal end of the main stent 10. Figure 25 As shown, the foldable portion 111 in the main stent 10 is preferentially released, and the foldable portion 111 flips back to the proximal side of the opening of the left subclavian branch artery 803, tending to conform to the greater curvature side of the aortic arch 800; the sheath 32 continues to be gradually withdrawn, as... Figures 25-26 As shown, after the support portion 113 and the axial positioning portion 112 are released, they return to their natural state. During the first half of this process, the foldable portion 111 has already folded back 180° and tends to conform to the large curve of the aortic arch 800, while the support portion 113 has not yet been fully released. The first wave trough 1131c is in a deformed state (the β angle is increased compared to the first bare wave circle 11 in its natural state), giving the support portion 113 a restoring force towards the proximal end; and because the support portion 113 is compressed (the first wave...) The deformation of the first wave rod 1131a and the second wave rod 1131b (causing the α angle to approach 180°) causes the sheath 32 to retract, and the foldable part 111 to adhere to the large bend side of the aortic arch 800. There is a gradually approaching restoring force between the first wave rod 1131a and the second wave rod 1131b. At the same time, it can drive the axial positioning part 112 to move towards the proximal end and release. Therefore, while the axial positioning part 112 expands radially, it will also move towards the proximal end to adhere to the second side 102 of the aortic arch 800.

[0103] Finally, as Figure 27 As shown, after the proximal end of the main stent 10 is released, the sheath 32 is quickly withdrawn to release the entire main stent 10, thus isolating the tumor 810. Then, the second bare wave coil 21 is released through the post-release structure of the sheath-core assembly 31, thereby completely releasing the branch stent 20, as shown. Figure 28As shown; if the branch stent 20 includes a semi-binding structure 26, the limiting rod 33 can be retracted before the second bare wave coil 21 is released, thereby releasing the main body of the branch stent 20 so that it fits against the inner wall of the left subclavian branch artery 803; if branch reconstruction is required, a small branch stent can be released along the guidewire 90 to the left subclavian branch artery 803 and anchored to the branch stent 20 using the same guidewire 90; if branch reconstruction is not required, the delivery device 30 and guidewire 90 are withdrawn from the body.

[0104] Understandably, the guidewire 90 can also be selected into the brachiocephalic trunk branch artery 801 or the left common carotid artery 802, and the branch structures can be released into the brachiocephalic trunk branch artery 801 or the left common carotid artery 802.

[0105] Compared with the prior art, the covered stent 100 provided by the present invention does not require the placement of the main guidewire in the main lumen of the aortic arch. The guidewire 90 is directly selected into the supra-arch branch for overall stent release, and the anchoring part of the main stent 10 can be released smoothly to achieve anchoring of the proximal end of the main stent 10. Even if a branch stent is then connected, it can be achieved using the branch guidewire 90, which reduces the operation time and lowers the operation risk.

[0106] Example 2

[0107] Example 2 proposes another type of covered scaffold, such as Figures 29-32 As shown, the same or interchangeable features in the covered stent of Example 2 and the covered stent of Example 1 will not be described again here. The main difference is that in the covered stent of Example 2, such as... Figures 29-30 As shown, the foldable portion 511 includes a first waveform unit 5111, the axial positioning portion 512 includes a second waveform unit 5121, and the support portion 513 includes a first inclined rod 5130. The first inclined rod 5130 is located between the first waveform unit 5111 and the second waveform unit 5121. The first inclined rod 5130 can be a straight rod inclined relative to the axial direction or an arc-shaped rod inclined relative to the axial direction. In this embodiment, the first inclined rod 5130 is connected to the proximal end of the main body film. The included angle formed by the axial inclination of the first inclined rod 5130 is the same as the included angle formed by the plane where the proximal end oblique cut of the main body film is located relative to the axial direction, so that the first inclined rod 5130 is fixed as a whole to the proximal inner edge of the main body film.

[0108] In the embodiment, when the covered stent is compressed and sheathed, the first inclined rod 5130 and the axial positioning portion 512 are close to each other, and the foldable portion 511 is folded towards the distal end with the first connection point as a fulcrum to be close to the first inclined rod 5130, so as to compress the first bare wave ring in the sheath tube. The first inclined rod 5130 is arranged to facilitate adjusting the length occupied by the support portion in the axial direction when the support portion is expanded, so as to coordinate the folding of the foldable portion and the compression state of the first bare wave ring when the foldable portion is folded and the first bare wave ring is radially compressed in the sheath tube.

[0109] As shown in Figures 30-31 , the main body stent further comprises a positioning wave ring 54, and the positioning wave ring 54 comprises a second inclined rod 541. The first inclined rod 5130 and the second inclined rod 541 are connected by a steel sleeve 60 to fix the first bare wave ring and the fixed wave ring. In the embodiment, the first bare wave ring is a circumferential whole wave ring, and the positioning wave ring 54 is a half wave ring, and each of the two ends of the positioning wave ring 54 comprises a second inclined rod 541 to be fixed with the first bare wave ring. As shown in Figure 31 , the first bare wave ring is a circumferential whole wave ring, so that the recovery reliability of the first bare wave ring after deformation is high. In other embodiments, as shown in Figure 32 , the positioning wave ring 54 and the axial positioning portion 512 are a circumferential whole wave ring, and the foldable portion 511 and the support portion 513 form a half wave ring, and each of the two ends of the half wave ring comprises a first inclined rod 5130 to be fixed with the positioning wave ring 54. The positioning wave ring 54 and the axial positioning portion 512 are a circumferential whole wave ring, so that the proximal end of the main body stent has good overall support and uniform stress.

[0110] In other embodiments, as shown in Figure 32 , the support portion 513 can further comprise a third wave unit 5131, and the first inclined rod 5130 is connected with the third wave unit 5131. The first inclined rod 5130 and the third wave unit 5131 are located between the first wave unit 5111 and the second wave unit 5121, and the third wave unit 5131 is located between the first wave unit 5111 and the first inclined rod 5130. The support portion 513 comprises the third wave unit 5131 and the first inclined rod 5130, so that when the covered stent is compressed in the sheath tube, the length occupied by the support portion 513 in the axial direction when the support portion 513 is expanded is not limited by the wave height of the third wave unit 5131, and the covered stent is facilitated to be compressed in the sheath tube. When the support portion 513 is compressed in the axial direction, the first bare wave ring is released, and the recovery process is slow, which reduces the possibility that the foldable portion 511 and the axial positioning portion 512 suddenly recover to the original shape and damage the inner wall of the blood vessel.

[0111] In other embodiments, the first bare wave ring comprises eight wave units, and the arc length corresponding to the center angle of each of the two wave troughs of each wave unit in the eight wave units is substantially the same in the circumferential direction of the lumen of the main body stent, as shown in Figure 33As shown, it is similar to that in Example 1. Figures 1-3 and Figures 5-7 The difference in the first bare wave ring is that a support ring 5132 is provided at the crest of the support part 513. This support ring 5132 can be formed by wrapping an extra loop at the crest connection during the wave ring forming process, which can increase the restoring force of the support part 513 when it naturally expands back to its natural state.

[0112] In other implementations, such as Figures 34-35 As shown, the support portion 513 may include four (two on each side) third waveform units 5131 located in the middle, with two third waveform units 5131 on each side of the connecting line T. The specific number of waveform units included in the support portion is not limited here. When the support portion 513 includes a large number of waveform units, the arc length spanned by a single third waveform unit 5131 can be appropriately reduced so that the overall circumferential arc length spanned by the support portion 513 is appropriate. This is to facilitate radial compression of the foldable portion 511 together with the unfolded support portion 513 after folding. Among them, a support ring 5132 is provided at the valley connection between the two third waveform units 5131 on the same side. The support ring 5132 can increase the restoring force between the two connected first waveform units 5131 by wrapping an extra loop at the valley connection during the wave ring forming. In addition, support rings can also be provided at the peaks of the two third waveform units to increase the overall restoring force of the support part. The number of support rings is not limited, as long as they are set at the peaks or valleys of the first bare wave ring.

[0113] Example 3

[0114] Example 3 proposes another covered scaffold and scaffold system, such as Figures 36-42 As shown, the same or interchangeable features in the covered stent of Example 3 and the covered stent of Example 1 will not be described again here. The main difference is that in the covered stent of Example 3, such as... Figure 36As shown, the distal end of the first bare wave coil 61 is connected to the proximal end of the main body covering film 13, and the plane of the distal end of the first bare wave coil 61 is perpendicular to the axial direction of the main body support 10. The proximal end of the main body covering film 13 is generally flat-mouthed with a vertical axial direction, and a circumferentially unfolded portion 132 is provided at the proximal end of the main body covering film 13. The circumferentially unfolded portion 132 is provided in the circumferential direction corresponding to the support portion 613, so that the waveform unit of the support portion 613 is not restricted by the main body covering film 13, and can be unfolded in the circumferential direction. That is, the main body covering film 13 does not restrict the unfolding of the support portion 613, so that when the foldable portion 611 of the first bare wave coil 61 is folded to the support portion with the first connection point as the fulcrum, it is radially compressed together with the opened support portion 613, so that the proximal end of the main body covering film does not restrict the opening of the support portion in the circumferential direction, thereby allowing the foldable portion to be folded smoothly. The circumferentially unfolded portion 132 includes a notch recessed towards the distal end. In other embodiments, the circumferentially expanded portion may also have pleats within a V-shaped region, with the "V"-shaped opening facing the proximal end. It is understood that in other embodiments, the distal end of the first bare waveband may also be obliquely cut as in Embodiment 1, with the proximal end face of the main body coating having the same inclination as the distal end face of the first bare waveband, making it easier to expand in conjunction with the circumferentially expanded portion.

[0115] The expandable length of the circumferentially expandable portion 132 is greater than or equal to the expandable length of the support portion at its corresponding position. The expandable length of the circumferentially expandable portion refers to the maximum length that can be expanded on the plane containing the proximal end face of the main body film, with the distal end of the circumferentially expandable portion as a fulcrum and the two proximal ends moving away from each other. The expandable length of the support portion refers to the maximum length that can be expanded on the plane containing the proximal end face of the main body film, with the crest of a wave unit of the support portion as a fulcrum and the two troughs moving away from each other. As long as the expandable length of the circumferentially expandable portion 132 is greater than or equal to the expandable length of the support portion 613, the circumferentially expandable portion 132 does not restrict the expansion of the support portion 613. In this embodiment, as... Figures 36-37 As shown, the circumferentially expandable portion 132 is configured as a V-shaped notch recessed towards the distal end of the main support. The V-shaped notch includes a first endpoint 1321 and a second endpoint 1322 at the proximal end, and a third endpoint 1323 at the distal end. The expandable length of the circumferentially expandable portion 132 is the sum of the length of the line connecting the first endpoint 1321 and the third endpoint 1323 and the length of the line connecting the second endpoint 1322 and the third endpoint 1323. The support portion 613 includes a wave element, and the expandable length of the support portion is the sum of the lengths of the two wave rods (the sum of the lengths of the first wave rod 6131a and the second wave rod 6131b shown in the figure). In other embodiments, such as Figures 38-39As shown, the circumferential expansion part 132 is arranged as a U-shaped notch recessed towards the distal end of the main support, which includes a first end point 1321 and a second end point 1322 at the proximal end, and a third end point 1323 and a fourth end point 1324 at the distal end, wherein the line connecting the third end point 1323 and the fourth end point 1324 is parallel to the line connecting the first end point 1321 and the second end point 1322, and both are perpendicular to the axial direction (or when the covering film is a bevel cut, the line connecting the third end point and the fourth end point is parallel to the line connecting the first end point and the second end point, and is inclined relative to the axial direction). The expandable length of the circumferential expansion part 132 is the sum of the lengths of the lines connecting the first end point 1321 and the third end point 1323, the third end point 1323 and the fourth end point 1324, and the second end point 1322 and the fourth end point 1324. In other embodiments, the line connecting the third end point and the fourth end point can also be parallel to the line connecting the first end point and the second end point, which is not limited herein. The circumferential expansion part 132 further includes an axial buffer part 1325 to reduce the pulling of the main covering film 13 in the axial direction when the circumferential expansion part 132 is expanded. Taking the V-shaped notch as an example, when the circumferential expansion part 132 is expanded, the two wave rods (6131a, 6131b) of one wave unit of the support part 613 move away from each other, causing the support part to tend to flatten. The third end point 1323 gradually approaches the flattened support part in the axial direction, causing the third end point 1323 to gradually move away from the distal end of the main covering film 13, thereby pulling the main covering film in the axial direction where the third end point 1323 is located. Therefore, the higher the circumferential expansion part 132 in the axial direction, the greater the pulling of the corresponding part of the main covering film 13 in the axial direction when the circumferential expansion part 132 is expanded. The axial buffer part 1325 extending in the circumferential direction can reduce the pulling of the main covering film when the circumferential expansion part is expanded, thereby reducing the deformation of the main covering film 13. In the embodiment of the U-shaped notch, the line connecting the third end point 1323 and the fourth end point 1324 is the axial buffer part 1325. In the embodiment of the V-shaped notch, the corresponding part of the main covering film in the axial direction is deformed less by the circumferential expansion part 132, thereby reducing the influence of the expansion of the circumferential expansion part 132 on the deformation of the main covering film. In this embodiment, the axial buffer part 1325 is the inclined bottom or flat bottom of the U-shaped notch (the inclined bottom is as shown in Figures 40-42 and the flat bottom is as shown in Figures 38-39 ). In the embodiment of the U-shaped notch, the support part 613 includes one wave unit, and the expandable length of the support part is the sum of the lengths of the two wave rods (such as the sum of the lengths of the first wave rod 6131a and the second wave rod 6131b as shown).

[0116] The main support 10 further includes a positioning wave ring 64, which is arranged with wave rods along the edge of the circumferential expansion part 132, which is beneficial to the edge of the circumferential expansion part 132 to adhere to the wall when the main support is released.

[0117] The proximal end of the first bare coil 61 is provided with a bevel structure, as shown in the embodiment, the proximal end of the first side of the first bare coil 61 is axially beyond the proximal end of the second side, so that the proximal end of the first side of the first bare coil 61 is farther away from the distal end of the main body support 10 than the proximal end of the second side; or, the proximal end of the second side of the first bare coil is axially beyond the proximal end of the first side, which is not limited here, and the structure of the proximal end of the first bare coil is flat, which is easier to fold. Figure 36

[0118] In other embodiments, as shown in the embodiment, the distal end face of the first bare coil 61 and the proximal end face of the main body covering film can also be provided with a bevel cut as in Embodiment 1, in combination with the setting of the circumferential expansion part, which is conducive to the foldable part 611 of the first bare coil 61 being radially compressed in the sheath after being folded with the support part 613, and the line connecting the third end point 1323 and the fourth end point 1324 is not perpendicular to the axial direction, wherein the line connecting the third end point 1323 and the fourth end point 1324 can be parallel to the line connecting the first end point 1321 and the second end point 1322. That is, the axial buffer part is parallel to the distal end face of the first bare coil, and when the axial buffer part is a bevel bottom of a U-shaped notch, the bevel bottom is parallel to the distal end face of the first bare coil. Figures 40-42

[0119] In other embodiments, as shown in the embodiment, the proximal end of the main body covering film 13 can also extend to cover the first bare coil 61, and a covering film notch can be provided on the main body covering film 13 between the support part 613 and the positioning coil 64 as the circumferential expansion part 132, as long as the circumferential expansion part 132 is set so that the covering film does not limit the expansion of the support part. Figure 42

[0120] The technical features of the above-described embodiments can be combined in any way, and to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the description.

[0121] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.​​​

Claims

1. A covered stent, characterized in that, The covered support includes a main support and a branch support. The main support includes a first side and a second side. The branch support is located on the first side. The main support includes a first bare waveband, a main waveband, and a main cover. The main cover is disposed on the main waveband. The first bare waveband is connected to the proximal end of the main cover. The first bare waveband includes a foldable portion, a support portion, and an axial positioning portion along the circumferential direction. The foldable portion is close to the first side and can be folded to the support portion. The foldable portion can be folded back. The axial positioning portion is close to the second side. The support portion is connected between the foldable portion and the axial positioning portion. The distal end of the second side of the first bare waveband extends axially beyond the distal end of its first side. The proximal end of the main cover has a circumferentially unfolded portion, which corresponds to the support portion in the circumferential direction, so that the main cover does not restrict the unfolding of the support portion.

2. The covered stent according to claim 1, characterized in that, The circumferentially expanded portion includes a notch recessed towards the distal end.

3. The covered stent according to claim 2, characterized in that, The notch is V-shaped or U-shaped.

4. The covered stent according to claim 1, characterized in that, The deployable length of the circumferentially expandable portion is greater than or equal to the deployable length of the support portion at its corresponding position.

5. The covered stent according to claim 1, characterized in that, The circumferential unfolding section includes an axial buffer section to reduce the axial pulling on the main body film when the circumferential unfolding section unfolds.

6. The covered stent according to claim 5, characterized in that, The circumferentially expanded portion includes a U-shaped notch recessed towards the distal end, and the axially buffered portion is the sloping bottom or flat bottom of the U-shaped notch.

7. The covered stent according to claim 1, characterized in that, The near end of the main body coating is obliquely cut.

8. The coated stent according to claim 5, characterized in that, The circumferentially expanded portion includes a U-shaped notch recessed towards the distal end, and the axially buffered portion is the sloping bottom of the U-shaped notch, the sloping bottom being parallel to the distal end face of the first bare wave coil.

9. The covered stent according to claim 1, characterized in that, The foldable part includes a first waveform unit; the axial positioning part includes a second waveform unit; the support part includes a third waveform unit; the third waveform unit is connected to the first waveform unit and the second waveform unit respectively, and the wave height of the third waveform unit is less than the wave height of the first waveform unit, and the wave height of the third waveform unit is less than the wave height of the second waveform unit.

10. A support system, characterized in that, The stent system includes a delivery device and a film-coated stent as described in any one of claims 1-9. The delivery device includes a sheath core assembly and a sheath tube. The sheath core assembly enters from the distal end of the main stent and exits from the branch stent. The first bare wave coil portion is folded and loaded entirely within the sheath tube.

11. The support system according to claim 10, characterized in that, The conveying device further includes a guide head, defining the axial distance from the proximal end connection point of the branch support to the proximal end of the main body film as L5, and defining the overall length of the branch support along its axial direction as L6, wherein L5 and L6 satisfy: L6 > L5, and in the support system, the branch support is closer to the guide head in the axial direction than the proximal end of the main body support.

12. The support system according to claim 11, characterized in that, The free end of the foldable part does not interfere with the proximal end of the axial positioning part, or the free end of the foldable part is pressed against the outside of the axial positioning part.

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